tag:blogger.com,1999:blog-65203473346090739542024-03-14T05:20:11.891-04:00SciHistoryHistorical investigations of a curious engineerLaurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.comBlogger24125tag:blogger.com,1999:blog-6520347334609073954.post-50573467204628284832015-10-23T07:22:00.000-04:002015-10-30T12:20:52.491-04:00Avogadro's Number Part 1: A History of the Mole with Very Little about AvogadroHappy Mole Day! I thought that it would be appropriate to recognize the day with a post about Avogadro's Number and the associated Mole. Avogadro's Number, which denotes the number of objects in a mole (6.022*10<sup>23</sup>), has a certain fascination for people, particularly, in my experience, among chemistry students. There is even a website (and foundation) dedicated to <a href="http://www.moleday.org/">Mole Day</a> and the mole. While I have been trying to make these posts about people, to get to the bottom of Avogadro's number, one has to dig a lot deeper than Avogadro. He does, however, make a good starting place.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/3/3d/Avogadro_Amedeo.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://upload.wikimedia.org/wikipedia/commons/3/3d/Avogadro_Amedeo.jpg" height="200" width="144" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Amedeo Avogadro (1776-1856)</td></tr>
</tbody></table>
Lorenzo Romano Amedeo Carlo Avogadro of Quaregna and Cerreto (phew, that's long) was by training a lawyer. He became interested in math and physics around 1800 and started working with electricity and metallic salts. Despite his lack of formal training, he did end up with a post as the chair of theoretical physics at the University of Turin. One of his projects was determining the electronegativity of various elements. He is best known for, and has the mole name after him because of, his "molecular hypothesis", first suggested in an essay in 1811. He suggested that molecules in a gas are scattered such that the average distance is constant when the temperature and pressure are constant. That is, that at the same temperature and pressure, there are the same number of molecules in a set volume of one gas as of another gas. By using this hypothesis, he was able to calculate the molecular weight of gases by using their densities.This, however, put Avogadro in opposition to <a href="http://historyofsci.blogspot.com/2012/08/john-dalton-atoms-weather-and-vision.html">John Dalton</a> (1766-1844), who had rejected this idea (see page 555 onwards of <i><a href="http://archive.org/stream/newsystemofchemi01daltuoft#page/554/mode/2up">A New System of Chemistry</a></i>, 1810). This was in part because Dalton and others believed that all gases contained only one atom of an element--for instance, that a molecule of water was HO rather than H<sub>2</sub>O. Since Avogadro kept to himself and tended to cite himself, his hypothesis did not gain much credibility, though André-Marie Ampère (1775-1836) came to the same conclusion in 1814. This additional support doesn't seem to have helped any, so it was a while before his hypothesis was accepted.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Cannizzaro_Stanislao.jpg/393px-Cannizzaro_Stanislao.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Cannizzaro_Stanislao.jpg/393px-Cannizzaro_Stanislao.jpg" height="320" width="209" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Stanislao Cannizzaro (1826-1910)</td></tr>
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By the middle of the 19th century, scientists were still debating about the nature of atoms, molecules, and their divisibility, and to make matters worse, they were starting to write formulas, diagrams, and calculate masses without a standard system. They could not agree on notations and other conventions, such as how to write chemical formulas or what the standard weight for describing an atom would be. In order to deal with these problems, August Kekulé (1829-1896) organized what came to be known as the Karlsruhe Congress, which met in September 1860 in Karlsruhe, Germany. The hero of the day was Stanislao Cannizzaro, who had written an article in 1858 that was based on Avogadro's hypothesis. This paper was circulated at the conference, and in it Cannizzaro suggested that the weight of hydrogen be taken as 1.0. He also suggested that oxygen be assumed to be diatomic as a gas, such that the formula for water would be H<sub>2</sub>O and the mass is 16.0. Cannizzaro clearly stated a theory in which atoms, molecules, and multiple identical atoms in the same molecule are distinguished. His argument and explanation influenced Lothar Meyer and Dimitri Mendeleev to both accept Avogadro's hypothesis, and after the conference it gained a wider popularity.<br />
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Few scientists, however, were concerned with how many molecules were actually in that volume of gas. They were more concerned with the hypothesis itself and what that meant for being able to determine other properties of matter, such as how big atoms and molecules actually are. The next step in determining Avogadro's number takes us from Avogadro and Cannizzaro in Italy to Austria, where Johann Josef Loschmidt (1821-1895) was working.<br />
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-2LPq3MsUWvI/VeHi_TK5nQI/AAAAAAAAOfI/cjewCbOmKt0/s1600/Loschmidt.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img alt="https://commons.wikimedia.org/wiki/File:Johann_Josef_Loschmidt.jpg" border="0" height="320" src="http://3.bp.blogspot.com/-2LPq3MsUWvI/VeHi_TK5nQI/AAAAAAAAOfI/cjewCbOmKt0/s320/Loschmidt.jpg" title="" width="229" /></a></td></tr>
<tr><td class="tr-caption" style="font-size: 12.8000001907349px; text-align: center;">Johann Josef Loschmidt (1821-1895)<br />
(image from Wikimedia commons)</td></tr>
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Loschmidt wanted to find out what the actual size of a molecule of a gas was, and used current theories of gases to determine this. Rudolph Clausius had derived in 1859 the mean free path of molecules in a gas in terms of the cross-sectional area, and James Maxwell derived his own expression the following year. Loschmidt then calculated what fraction of the gas was occupied by the molecules themselves based on the mean free path and then assumed that when the gas is liquefied, the volume is only slightly larger than that of the molecules themselves. The problem then was the air had not been liquefied, so he used the work of Hermann Kopp to estimate the density of liquid air. He determined that the size of a nitrogen molecule was 9.69*10<sup>-10</sup> m, or about three times too big. But not bad. However, despite knowing how big molecules were, no one seemed particularly concerned about how many molecules were in a region of space. A following paper in 1865, ostensibly by Loschmidt, states that a cubic millimeter of gas contains 866 billion molecules, but that wasn't the point of the article.<br />
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Studies of gasses over the course of the rest of the century and into the 20th century would help to elucidate the question of how many molecules are in a given volume, but I will leave that for another day! Check back soon (or subscribe to the emails) for more information about the definition and calculation of Avogadro's number and where the name mole came from.<br />
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<hr />
<b>Original Papers in order of publication</b><br />
<div>
<ul>
<li>Amedeo Avogadro, "<a href="http://books.google.com/books?id=MxgTAAAAQAAJ&pg=PA58#v=onepage&q&f=false">D'une manière de déterminer les masses relatives des molécules élémentaires de corps, et les proportions selon lesquelles elles entrent dans ces combinaisons</a>", <i>Journal de Physique</i><b> 73</b>, (1811), 58-76. (Or in English: "<a href="http://web.lemoyne.edu/~giunta/AVOGADRO.HTML">Essay on a Manner of Determining the Relative Masses of the Elementary Molecules of Bodies, and the Proportions in Which They Enter into These Compounds</a>")</li>
<li>André-Marie Ampère, <i>Annales de chimie</i>, <b>90</b>, (1814), 43.</li>
<li>Hermann Kopp, "<a href="http://dx.doi.org/10.1002/jlac.18540920102">Ueber die specifischen Volume flüssiger Verbindungen</a>", <i>Justus Liebigs Annalen der Chemie</i> <b>92</b>, no. 1 (1854) 1-32. DOI: 10.1002/jlac.18540920102</li>
<li>Stanislao Cannizzaro, "<a href="http://www.minerva.unito.it/Storia/Cannizzaro/Sunto/slides/321.html">Sunto di un corso di Filosofia chimica, fatto nella Regia Università di Genova</a>", <i>Il Nuovo Cimento</i> <b>7</b>, (1858), 321-366. (Or in English: "<a href="http://books.google.com/books?hl=en&lr=&id=WTG4AAAAIAAJ&oi=fnd&pg=PA1&dq=sketch+of+a+course+of+chemical+philosophy&ots=DAkJPGnfNL&sig=FBxprNA_3sP1LvF8RuVjSwBptdc#v=onepage&q&f=false">Sketch of a Course of Chemical Philosophy Given in the Royal University of Genoa</a>")</li>
<li>Johann Loschmidt, "<a href="http://books.google.com/books?id=ppEAAAAAYAAJ&pg=PA395&hl=en#v=onepage&q&f=false">Zur Grösse der Luftmoleküle</a>", <i>Sitzungsberichte der kaiserlichen Akademie der Wissenschaften Wein</i><b> 52</b>, no. 2 (1865) 395-413. (English translation "On the Size of the Air Molecules" included in "<a href="http://dx.doi.org/10.1021/ed072p870.2">Loschmidt and the Discovery of the Small</a>") </li>
<li>Johann Loschmidt, <i>Z. Math. Phys.</i>, 1865, 10, 511-512. </li>
<li>Alexander Naumann, "<a href="http://dx.doi.org/10.1002/cber.186900201274">Das Avogadro'sche Gesetz abgeleitet aus der Grundvorstellung der mechanischen Gastheorie</a>", <i>Berichte der deutschen chemischen Gesellschaft</i> <b>2</b>, no. 1, (1869) 690-693. DOI: 10.1002/cber.186900201274 (Or in English: "<a href="http://books.google.com/books?id=aZuzm3GnhnIC&pg=PA317&lpg=PA317&dq=naumann+avogadro%27s+law&source=bl&ots=tIH5On65zA&sig=iH0Ih9R-lc9YEKc5zOfCFhO36SU&hl=en&sa=X&ei=Y75lUoeRO4W-2QXj0YHwDA&ved=0CCoQ6AEwAA#v=onepage&q&f=false">Avogadro's Law Deduced from the Fundamental Conception of the Mechanical Theory of Gases</a>", <i>Philosophical Magazine </i><b>39</b>, (1870) 317-320)</li>
</ul>
<div>
<b>References</b><br />
<div>
<ul>
<li>N. G. Coley, "<a href="http://dx.doi.org/10.1080/00033796400203064">The Physico-chemical studies of Amdeo Avogadro</a>", <i>Annals of Science</i> <b>20</b>, no. 3 (1964), 195-210. DOI: 10.1080/00033796400203064.</li>
<li>Ronald J. Duchovic and Joel A. Vilensky, "<a href="http://dx.doi.org/10.1021/ed084p944">Mustard Gas: Its Pre-World War I History</a>", <i>Journal of Chemical Education</i> <b>84</b>, no. 6 (June 2007), 944-948. DOI: 10.1021/ed084p944.</li>
<li>Jaime Wisniak, "<a href="http://dx.doi.org/10.1007/s00897000420a">Amedeo Avogadro: The Man, the Hypothesis, and the Number</a>", <i>The Chemical Educator</i> <b>5</b>, no. 5 (2000), 263-268. DOI: 10.1007/s00897000420a.</li>
<li>L. Cerruti, "<a href="http://dx.doi.org/10.1088/0026-1394/31/3/001">The Mole, Amedeo Avogadro and Others</a>", <i>Metrologia</i> <b>31</b> (1994) 159-166. DOI: 10.1088/0026-1394/31/3/001.</li>
<li>Alfred Bader and Leonard Parker, "<a href="http://dx.doi.org/10.1063/1.1366067">Joseph Loschmidt, physicist and chemist</a>", <i>Physics Today </i><b>53</b>, no. 3 (2001) 45-50. DOI: 10.1063/1.1366067</li>
<li>William W. Porterfield and Walter Kruse, "<a href="http://dx.doi.org/10.1021/ed072p870.2">Loschmidt and the Discovery of the Small</a>", <i>Journal of Chemical Education </i><b>72</b>, no. 10 (October 1995) 870-875. DOI: 10.1021/ed072p870.2</li>
</ul>
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Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com1Turin, Italy45.0708515 7.684340444.981139500000005 7.5264119 45.1605635 7.8422689tag:blogger.com,1999:blog-6520347334609073954.post-79288136664511714222014-10-04T19:24:00.000-04:002015-03-16T10:18:17.980-04:00Friedrich Bessel and the Stars<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-7rAOzbBuoX0/VDBQj8ynY-I/AAAAAAAAOGw/fdMSK_ya91U/s1600/Bessel.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://1.bp.blogspot.com/-7rAOzbBuoX0/VDBQj8ynY-I/AAAAAAAAOGw/fdMSK_ya91U/s1600/Bessel.jpg" height="200" width="164" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Friedrich Bessel (1784-1846)<br />
<span style="font-size: xx-small;">from Wikimedia Commons</span></td></tr>
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This post was going to be about math, but, as usual, these scientists surprise me! The subject of this week's post is Friedrich Bessel, and if you have ever taken a course on differential equations, you have probably heard his name in reference to Bessel functions. Unlike most of the scientists featured here, Bessel appears to have had no higher education after being apprenticed at the age of 14 or 15 to work in an import-export firm. In spite of that, he made significant contributions to the fields of mathematics and astronomy. During his apprenticeship, he self-taught many things, including navigation, astronomy, and foreign languages. In 1804 he wrote a paper on Halley's comet based on observations that had been made in the 1607 and showed it to Wilhelm Olbers, a noted German astronomer, who had it published. He was appointed in 1810 to be the director of the Konigsberg Observatory (which wasn't completed until 1813). He was also given an honorary doctorate, which was important for his position as a professor!<br />
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Bessel was the first to measure the distance of a star by parallax. This is the same phenomenon that you can see if you hold you finger up relative to something in the background and watch the position of your finger change as you look at it with each eye. If you know the distance between your eyes and the angle of the shift, you can calculate the distance of the object.The only catch is that as the object gets farther away, the angle of the shift gets smaller and smaller, but scientists hoped that a shift could be observed as the Earth moves around the sun. Bessel was particularly interested because he considered his duty as an astronomer to explain why the celestial bodies moved as they did.<br />
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Tycho Brahe tried in the late 1500s, but was not able to observe parallax. Robert Hooke tried again in the 1600s and claimed to have measured the distance to Gamma Draconis, but no one believed him. He was also wrong: he calculated that it was only 0.1 light years away, when it is actually around 154. James Bradley also tried to measure this distance, but was also unable to, although as a result of his measurements he discovered the aberration of starlight--that you need to account for the movement of the earth and the speed of light in a telescope. William Herschel (who later discovered Uranus) also set about measuring stellar parallax, and tried to find a combination of a close and far star so that he could measure the slight changes in position. Instead, he discovered actual pairs of stars, which are no good since they are about the same distance.<br />
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Bessel, as the director of the new observatory in Konigsberg in Prussia, had the use of a telescope made by Joseph Fraunhofer, a maker of telescopes with a precision never seen before. Such an instrument was also in the possession of Struve, astronomer at the Dorpat Observatory in Estonia, and he and Bessel began a race. Struve published a value of the paralax of Vega, but with only 16 measurements. Bessel had been interested in the double star 61 Cygni for many years, having published a paper in 1812 on the subject, and proposed that by observing how they moved in relation to each other, the total mass of the two could be determined. Since it is one of the fastest moving stars in the sky, it was assumed to be one of the closest, and it was observable from his observatory for most of the year. Bessel presented his calculations in 1838, giving a distance of 10.3 light years, which is not too far from the current value of 11.4. Because of his careful measurements, the scientific community, including Struve, accepted his accomplishment as the first.<br />
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Bessel's careful measurements of the stars enabled him to make a new discovery as well. He observed that Sirius and Procyon, both bright stars, moved oddly, as though something was influencing them, and corroborated this with historic data as well. He posited that there must be other stars that had not been observed, and indeed, the companion star of Sirius was discovered in 1862 and was recognized as the double star that Bessel had predicted, while Procyon B was not discovered until 1896.<br />
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It was also his desire for precise astronomy that led to the Bessel functions, which are solutions to a particular differential equation. Special cases of the functions had been studied before by several Bernoullis, Euler, and Lagrange, among others, but Bessel is considered to have been the person to systematize the equations, and as such, they have been named after him. They appear often in cases involving circles and cylinders, and as such, Bessel found them useful in his studies of the stars, though exactly how I do not know. If it were not for this, people might have never heard his name, but I wonder which accomplishments he would most want to be known for? (And hopefully whatever it was isn't one of the ones that I left out of this short summary.)<br />
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<hr />
<b>Selected Works by Bessel</b><br />
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<ul>
<li>"Über den Doppelsterne Nro. 61 Cygni", Monatliche Correspondenz <b>1812</b>, <i>26</i>, 148-63.</li>
<li>"<a href="http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1838MNRAS...4..152B&amp;data_type=PDF_HIGH&amp;whole_paper=YES&amp;type=PRINTER&amp;filetype=.pdf">On the parallax of 61 Cygni</a>", <i>Monthly Notices of the Royal Astronomical Society </i><b>1838</b>, <i>4</i>, 152-161. The beginning is worth a read, as he discusses some of the difficulties that he encountered both with the measurements and the calculations associated with them.</li>
<li>"<a href="http://dx.doi.org/10.1002/asna.18390160502">Bestimmung der Entfernung des 61sten Sterns des Schwans</a>", <i>Astronomische Nachrichten</i> <b>1839</b>, <i>16</i>, 65-96. doi: 10.1002/asna.18390160502. German paper on the same topic.</li>
<li>"<a href="http://dx.doi.org/10.1093/mnras/6.11.136a">On the variations of the proper motions of Procyon and Sirius</a>" <i>Monthly Notices of the Royal Astronomical Society </i><b>1844</b>, <i>6</i>, 136-141. doi: 10.1093/mnras/6.11.136a. This is also a very readable article. Of particular note is the last paragraph, where he deals with the issue of positing the existence of something that can't (or hasn't) been seen.</li>
<li>"<a href="http://dx.doi.org/10.1002/asna.18450221002">Ueber Veränderlichkeit der eigenen Bewegungen der Fixsterne</a>", <i>Astronomische Nachrichten</i> <b>1845</b>, <i>22</i> (10), 145-160. doi: 10.1002/asna.18450221002. Again, a German article on the same topic.</li>
</ul>
<div>
<b>References</b></div>
</div>
<div>
<ul>
<li>James Bradley, "<a href="http://dx.doi.org/10.1098/rstl.1727.0064">A Letter from the Reverend Mr. James Bradley Savilian Professor of Astronomy at Oxford, and F. R. S. to Dr. Edmond Halley Astronom. Reg. &c. Giving an Account of New Discovered Motion of the Fix'd Stars</a>", <i>Philosophical Transactions</i> <b>1727</b>, <i>35</i>, 637-661. doi: 10.1098/rstl.1727.0064. Bradley's paper on the aberration of starlight, unfortunately relegated to the references because it is not by Bessel.</li>
<li>Walter Fricke, "<a href="http://dx.doi.org/10.1007/BF00660603">Friedrich Wilhelm Bessel (1784-1846)</a>", <i>Astrophysics and Space Science</i>, <b>1985</b>, <i>110</i> (1), 11-19. doi: 10.1007/BF00660603</li>
<li>Alan W. Hirshfeld, "<a href="http://go.galegroup.com/ps/i.do?id=GALE%7CA79896845&v=2.1&u=northwestern&it=r&p=AONE&sw=w&asid=8d3ebd83c958f22319c68c687f0bd2c1">The Race to Measure the Cosmos</a>", <i>Sky & Telescope </i><b>Nov. 2001</b>, p.38. A fuller and very useful description of the various attempts to measure stellar parallax.</li>
<li>Jay B. Holberg, "LeVerrier and the Discovery of Sirius B: there was more to the discovery of Sirius's white-dwarf companion, now becoming visible again, than is usually told", <i>Sky & Telescope </i><b>Feb. 2008</b>, p.30. </li>
<li>Alister Ling and Martin Ratcliffe, "<a href="http://go.galegroup.com/ps/i.do?id=GALE%7CA113951077&v=2.1&u=northwestern&it=r&p=AONE&sw=w&asid=5378dfe1934bb7bd86db04c3b65b4968">The deep sky: several glittering jewels dot the expansive Milky Way in Cygnus the Swan, but the most intriguing spectacle may be the tattered remnant of a star that blew itself apart</a>", <i>Astronomy</i> <b>Aug. 2003</b>, p.65.</li>
<li>Alister Ling and Martin Ratcliffe, "<a href="http://go.galegroup.com/ps/i.do?id=GALE%7CA114608377&v=2.1&u=northwestern&it=r&p=AONE&sw=w&asid=8e49dec173092fc7d9d2a63f80f2a6c9">The deep sky: comet Encke swoops south and west along the spine of the Milky Way this month, highlighting a number of interesting and beautiful deep-sky objects</a>", <i>Astronomy</i> <b>Nov. 2003</b>, p.61.</li>
<li>Raymond Shubinski, "<a href="http://go.galegroup.com/ps/i.do?id=GALE%7CA245805864&v=2.1&u=northwestern&it=r&p=AONE&sw=w&asid=989b2e97002d0a8440cccd84c3ed983a">How the equatorial mount changed astronomy: an innovative design that allowed telescopes to track the sky made it the star of the 19th century--and today</a>", <i>Astronomy</i> <b>Feb. 2011</b>, 58.</li>
<li>Todd K. Timberlake, "<a href="http://dx.doi.org/10.1119/1.4824942">Seeing Earth's Orbit in the Stars: Parallax and Aberration</a>", <i>The Physics Teacher </i><b>2013</b>, <i>51</i>, 478-481. doi: 10.1119/1.4824942. A good description of the concepts of parallax and aberration with pictures, diagrams, and Hooke and Bradley's data on Gamma Draconis.</li>
<li>G. N. Watson, <i>A Treatise on the Theory of Bessel Functions</i> (Cambridge: Cambridge University Press, 1996). First published 1922, gives a history of studies of Bessel functions at the beginning.</li>
<li>Mari Williams, "<a href="http://www.jstor.org/stable/4026624%20.">Beyond the Planets: Early Nineteenth-Century Studies of Double Stars</a>", <i>The British Journal for the History of Science </i><b>1984</b>, <i>17 </i>(3), 295-309. </li>
</ul>
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Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0tag:blogger.com,1999:blog-6520347334609073954.post-49048557026287095082014-08-23T13:31:00.001-04:002014-08-23T13:33:45.955-04:00Wilhelm Ostwald<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-ODXo8QZMz9I/U_jO7aHyo-I/AAAAAAAAOFg/0JXY98hm8XA/s1600/Wilhelm_Ostwald.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://4.bp.blogspot.com/-ODXo8QZMz9I/U_jO7aHyo-I/AAAAAAAAOFg/0JXY98hm8XA/s1600/Wilhelm_Ostwald.jpg" height="200" width="181" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Wilhelm Ostwald (1853-1932)<br />
<span style="font-size: xx-small;"><a href="http://commons.wikimedia.org/wiki/File:Wilhelm_Ostwald.jpg#mediaviewer/File:Wilhelm_Ostwald.jpg">Licensed under Public domain<br /> via Wikimedia Commons</a></span></td></tr>
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One of my favorite things about writing this blog is discovering the interesting interests that the scientists <br />
that I write about had, in addition to whatever work they are remembered for. So as I started to look for information on Wilhelm Ostwald, I was fascinated to discover that there were articles discussing his involvement with color and the Bauhaus (an art school in Germany in the 20s). Ostwald ripening, which is where I had heard his name before, seems
to be one of the more minor contributions that he made: Ostwald won the 1909
Nobel Prize in Chemistry primarily for his work with catalysis, wrote 45
books and about 1000 publications, and
is considered one of the founders of physical chemistry.<br />
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Ostwald was born in 1853 in Riga, Russia, and became a
professor at Riga Polytechnic in 1882. One of his duties was to expand the
laboratory, so he toured laboratories in Germany and had the opportunity to
meet many German scientists. One of the things that he did at Riga was writing
a two volume textbook. Another was translating Gibb’s work on chemical
thermodynamics into German, which enabled it to be more widely read in Europe
than the original English. He founded, with van’t Hoff, the first journal in
physical chemistry, <i>Zeitschrift für Physikalische Chemie</i>. It wasn’t the first journal
he founded—he later started <i>Annalen der
Naturphilosophie</i>. <o:p></o:p></div>
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In 1887 he then moved on to a position in Leipzig as the
chair of physical chemistry—the only chair in physical chemistry in Germany. That
same year he first recognized that catalysis was a kinetic process when he was
studying the oxidation of hydrogen iodide by bromic acid, leading to the idea
that a catalyst is something that modifies the rate of a reaction without being
changed its self. Later, he tried to apply this to the problem of nitrogen
fixation, but his method by catalysis with iron did not work. He did, however,
patent a process for making nitric acid out of ammonia using a platinum
catalyst in 1902, which is still the most commonly used process for making
nitric acid today.<o:p></o:p></div>
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<a href="http://historyofsci.blogspot.com/2012/04/svante-arrhenius.html">Svante Arrhenius</a> published a paper in 1887 on electrolytic dissociation,
the first in the field of electrochemistry. Ostwald had studied salt
decomposition in obtaining a degree, and returned to it, developing his
dilution law. He also wrote <i>Elektrochemie</i>
from 1893-1896, a text on the subject, in which he also included the history of
the developments and biographies of the scientists involved. He also formed an
electrochemical society in 1894. <o:p></o:p></div>
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After about 1900, Ostwald turned more of his attentions to
ideas of natural philosophy. In one of his works, <i>Grosse Männer</i>, he divided
scientists into two categories, classicists or romantics. There is actually a
very interesting article by Robert Deltete and David Thorsell that compares the
working styles of Josiah Gibbs and Wilhelm Ostwald as examples of
these two styles. Ostwald is the romantic, jumping from one idea to the next, making connections with many people and not being afraid of publishing work before it is finished. Gibbs, on the other hand, led a fairly reclusive life, taught few students, and did not publish his work on thermodynamics until it was completed to his satisfaction.<br />
<br />
Ostwald retired in 1906, but continued being involved in many
different projects, societies, and researches. One of these was Brücke (The Bridge),
an organization with the goal of organizing science to make it more
efficient. Ostwald had been interested in energy for quite some time, and was
actually one of the last well-renowned scientists to reject atomism. He favored
an energetic explanation, and as such, conserving energy in many forms was one
of his interests. He even named his retirement home, which he moved to in 1906,
Haus Energie.[1] Some of the things that the Bridge did were to promote Esperanto as a universal language for science, reducing the need for translations of works, and to standardize publication formats for scientific publications. Several other scientists of note were involved in the Bridge, including Svante Arrhenius, Ernest Solvay, Ernest Rutherford, and Henri Poincaré. Ostwald also became involved in the German Monistic Alliance, which also had as its aim the unification of science, but included the reorganization of society as well. Ostwald was involved in both until Brücke closed in 1914 due to lack of funding and the
difficulties of unifying science during the Great War.<br />
<br />
After World War I, Ostwald he turned his
attentions to color theory. He had been a painter since at least 1884, and now
turned his scientific energies to color and developing a color theory. One of
his most important contributions was giving value to the color grey. He even
opened a pigment factory from 1920-1923. Walter Gropius invited him to speak at
the Bauhaus and he even became a trustee. Ostwald considered his contributions
to color theory some of his greatest work and nominated himself for a Nobel
Prize for it (while, having won a Nobel Prize, he could nominate people, one
can’t nominate ones self).<o:p></o:p></div>
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Now I don’t know how many of you may be materials scientists
or others interested in Ostwald ripening, but I realize I haven’t mentioned it
since the first paragraph. It is because very few of the articles I read even
mentioned that work, and for a little while I was convinced that I had gotten
the wrong Ostwald. But it turns out that this is the right guy. Ostwald
ripening, which is a thermodynamic process observed in solutions, either solid
or liquid, where larger crystals grow and smaller crystals shrink, comes from his work in the late 1890s.<o:p></o:p></div>
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[1] The house has been preserved, and was recently purchased
by Gerda und Klaus Tschira Stiftung and it will serve as a location for
scientific meetings. (Ertl, 2009)<br />
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<hr />
<b>Selected Works by Ostwald</b><br />
<div>
<ul>
<li>"<a href="http://dx.doi.org/10.1021/ja02118a001">On Chemical Energy</a>", <i>The Journal of the American Chemical Society</i> <b>1893</b>, <i>15 </i>(8), 421-430. doi: 10.1021/ja02118a001</li>
<li>"<a href="http://dx.doi.org/10.1002/andp.18962940509">Zur Energetik</a>", <i>Annalen der Physik</i> <b>1896</b>, <i>294</i> (5), 154-167. doi: 10.1002/andp.18962940509</li>
<li><a href="http://www.google.com/patents/US858904">Process of Manufacturing Nitric Acid</a>, Patent no. 858,904, July 2, 1907.</li>
<li>"<a href="http://www.jstor.org/stable/27900060">The Modern Theory of Energetics</a>", <i>The Monist </i><b>1907</b>,<i> 17 </i>(4), 481-515.</li>
<li><i><a href="http://books.google.com/books?id=FmHPAAAAMAAJ">Grosse Männer: Studien zur Biologie des Genies</a></i>, Akademische Verlagsgesellschaft, Leipzig,<br />1911. (First published 1909).</li>
</ul>
<div>
<b>References</b><br />
<div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<ul>
<li><span style="font-family: inherit; text-indent: 36px;">Philip Ball and Mario Ruben, "<a href="http://dx.doi.org/10.1002/anie.200430086">Color Theory in Science and Art: Ostwald and the Bauhaus</a>", <i>Angewandte Chemie International Edition</i> <b>2004</b>, <i>43</i>, 4842-4846. doi: 10.1002/anie.200430086</span></li>
<li>Wilder D. Bancroft, "<a href="http://dx.doi.org/10.1021/ed010p539">Wilhelm Ostwald: The Great Protagonist, Part I</a>", <i>Journal of Chemical Education</i>, <b>1933</b>, <i>10</i> (9), 539-542. doi: 10.1021/ed010p539. This and the second part of the article are a great overview of what Ostwald did written by one of his students.</li>
<li>Wilder D. Bancroft, "<a href="http://dx.doi.org/10.1021/ed010p539">Wilhelm Ostwald: The Great Protagonist, Part </a><u>II</u>", <i>Journal of Chemical Education</i>, <b>1933</b>, <i>10</i> (10), 609-613. doi: 10.1021/ed010p609</li>
<li>Robert J. Deltete and David L. Thorsell, "<a href="http://dx.doi.org/10.1021/ed073p289">Josiah Willard Gibbs and Wilhelm Ostwald: A Contrast in Scientific Style</a>", <i>Journal of Chemical Education</i> <b>1996</b>, <i>73</i>, 289-295. doi: 10.1021/ed073p289</li>
<li><span style="font-family: inherit; text-indent: 36px;">Gerhard Ertl, "<a href="http://dx.doi.org/10.1002/anie.200901193">Wilhelm Ostwald: Founder of Physical Chemistry and Nobel Laureate 1909</a>", <i>Angewandte Chemie International Edition </i><b>2009</b>, <i>48</i>, 6600-6606. doi: 10.1002/anie.200901193</span></li>
<li>Eduard Farber, "<a href="http://dx.doi.org/10.1021/ed030p600">A Study in Scientific Genius: Wilhelm Ostwald's Hundredth Anniversary</a>", <i>Journal of Chemical Education</i> <b>1953</b>, <i>30 </i>(12), 600-604. doi: 10.1021/ed030p600</li>
<li>Thomas Hapke, "Wilhelm Ostwald, the "Brücke" (Bridge), and Connections to Other Bibliographic Activities at the Beginning of the Twentieth Century", Proceedings of the 1998 Conference on the History and Heritage of Science Information Systems, eds. Mary Ellen Bowden, Trudi Bellardo Hahn and Robert V. Williams. (American Society for Information Science, Medford, NJ, 1999), 139-147.</li>
<li>Niles R. Holt, "<a href="http://dx.doi.org/10.1017/S0007087400015399">Wilhelm Ostwald's 'The Bridge'</a>", <i>The British Journal for the History of Science</i> <b>1977</b>, <i>10</i>, 146-150. doi: 10.1017/S0007087400015399</li>
<li><span style="font-family: inherit; text-indent: 36px;">J. Van Houten, "<a href="http://dx.doi.org/10.1021/ed079p146">A Century of Chemical Dynamics traced through the Nobel Prizes: 1909: Wilhelm Ostwald</a>", <i>Journal of Chemical Education</i> <b>2002</b>, <i>79</i>, 146-1</span>48. doi: 10.1021/ed079p146</li>
<li><span style="font-family: inherit; text-indent: 36px;">Julia Kunze and Ulrich Stimming, "<a href="http://dx.doi.org/10.1002/anie.200903603">Electrochemical Versus Heat-Engine Energy Technology: A Tribute to Wilhelm Ostwald's Visionary Statements</a>", <i>Angewandte Chemie International Edition</i> <b>2009</b>, <i>48</i>, 9230-9237. doi: 10.1002/anie.200903603</span></li>
<li><span style="font-family: inherit; text-indent: 36px;">Wim L. Noorduin, Elias Vleig, Richard M. Kellogg, and Bernard Kaptein, "</span><a href="http://dx.doi.org/10.1002/anie.200905215" style="font-family: inherit; text-indent: 36px;">From Ostwald Ripening to Single Chirality</a><span style="font-family: inherit; text-indent: 36px;">", </span><i style="font-family: inherit; text-indent: 36px;">Angewandte Chemie International Edition</i><span style="font-family: inherit; text-indent: 36px;"> </span><b style="font-family: inherit; text-indent: 36px;">2009</b><span style="font-family: inherit; text-indent: 36px;">, </span><i style="font-family: inherit; text-indent: 36px;">48</i><span style="font-family: inherit; text-indent: 36px;">, 9600-9606. doi: 10.1002/anie.200905215 </span></li>
<li><span style="font-family: inherit; text-indent: 36px;">Regine Zoot, "</span><a href="http://dx.doi.org/10.1002/anie.200330059" style="font-family: inherit; text-indent: 36px;">Friedrich Wilhelm Ostwald (1853-1932), Now 150 Years Young...</a><span style="font-family: inherit; text-indent: 36px;">",</span><span style="font-family: inherit; text-indent: 36px;"> </span><i style="font-family: inherit; text-indent: 36px;">Angewandte Chemie International Edition</i><span style="font-family: inherit; text-indent: 36px;"> </span><b style="font-family: inherit; text-indent: 36px;">2003</b><span style="font-family: inherit; text-indent: 36px;">,</span><span style="font-family: inherit; text-indent: 36px;"> </span><i style="font-family: inherit; text-indent: 36px;">42</i><span style="font-family: inherit; text-indent: 36px;">, 3990-3995. doi: 10.1002/angie.200330059</span></li>
</ul>
</div>
</div>
</div>
Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0tag:blogger.com,1999:blog-6520347334609073954.post-19169231225020453072014-05-20T20:00:00.000-04:002014-05-20T20:00:26.595-04:00The Way the Atom Splits: Lise Meitner, fission, and weighty elements<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/7/76/Lise_Meitner12.jpg/640px-Lise_Meitner12.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/7/76/Lise_Meitner12.jpg/640px-Lise_Meitner12.jpg" height="320" width="205" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Lise Meitner (1878-1968)<br />(photo from <a href="http://commons.wikimedia.org/wiki/File:Lise_Meitner12.jpg#mediaviewer/File:Lise_Meitner12.jpg">Wikimedia Commons</a>)</td></tr>
</tbody></table>
So far, I’ve written about people whose names are memorialized in scientific equipment, equations, and units, but not yet in that most permanent place, an element name. And to rectify that omission, today’s subject is Lise Meitner, the eponym of element 109, meitnerium (Mt). <br /><br />Lise Meitner was born in Vienna in 1878 and although Protestant, had Jewish roots that will be important later. She attended school and after was tutored in mathematics and physics to enable her to pass the Matura exam, which was required before one could study in a university. She went to the University of Vienna, and enjoyed the lectures by, among others, Ludwig Boltzmann. Her thesis was on “Heat Conduction in Inhomogeneous Materials”, where she showed experimentally one of Maxwell’s formulas related to conduction. Here second paper was on Fresnel’s reflection formulae. Both of these had very little to do with the subjects of her later work.<br /><br />After Boltzmann’s death in 1906, Meitner began helping Stefan Meyer with his work in radioactivity, measuring alpha and beta radiation. Around the same time, Max Planck visited the University, and she decided that she wanted to go to Berlin for a few semesters to learn more about physics. So in 1907, Meitner went off to Berlin for what turned out to be much longer than a few semesters. She attended lectures, but also went to the head of the institute of experimental physics, Heinrich Rubens, to ask if she could work in his lab. He suggested instead that she work with Otto Hahn, who was looking for a physicist who knew something about radioactivity. This work led to two very fruitful collaborations. Meitner also served as Planck’s assistant from 1912-1915.<br /><br />Her first notable discovery was made around WWI. In 1913, Hahn and Meitner moved their lab from the University of Berlin to the Kaiser Wilhelm Institute für Chemie. This proved to be very useful for their studies of radioactivity, because the new lab was not contaminated by radiation, so they could do more sensitive experiments. One experiment that they were particularly interested in was looking for an element which produced actinium (element 89). Actinium’s place in the periodic table had been determined in 1913, and according to the displacement laws developed by Frederic Soddy and Kasimir Fajans, also in 1913, actinium could be produced by beta emission from radium or alpha emission by an unknown element 91. Fajans and Oswald Göhring discovered a new element when observing the beta-decay of Thorium-234. It had a very short half-life, and, claiming discoverer’s privilege, they named it brevium. It was a beta emitter, however, and could not produce actinium, though they were close--they had discovered element 91, just not the isotope that that would decay into actinium.<br /><br />Meitner and Hahn worked to improve the technique Fajans had developed to separate brevium, but still wanted to find an isotope that produced actinium. When WWI started, Hahn was conscripted to serve in the special gas warfare unit that was run by Fritz Haber. This, along with the fact that most of the lab assistants were also serving in the war, meant that Meitner did most of the lab work by herself for the next several years, though Hahn was able to come back a few times and consult. Meitner did go off from 1915-1916 to serve as a nurse in Austria, but chafed at all of the time she was not busy and went back to the lab. She worked on substances derived from pitchblende and monitored them alpha emissions to try to discover the isotope that would lead to actinium. She needed more pitchblende, which, during the war, proved difficult. After trying several times, she was finally able to obtain a sufficient amount to determine the half-life of the alpha emitter that she had found. She and Hahn submitted a paper in March of 1918 entitled “The Mother Substance of Actinium, a New Radioactive Element of Long Half-Life”. They called the element protoactinium, which was shortened in 1949 to protactinium. Although they were not the first to discover element 91, Fajans and Göhring agreed that brevium was a silly name for an element that had isotopes with such long half lives, and agreed to the name. Soddy had also been working on the problem, and published their results in June of 1918, but acknowledged themselves beaten, and everyone agreed to the name.<br /><br />Meitner obtained her own lab in 1917 as part of the department for radioactivity, and she and Hahn ceased their collaboration in 1920. From 1920-1934 she worked with alpha, beta, and gamma radiation and various nuclear processes. She used a Wilson cloud chamber and was the first to observe electron-positron pair formation by gamma radiation. Meitner followed work being done in other labs, and was intrigued by Enrico Fermi’s work in 1934 where he bombarded elements with neutrons and discovered that this could cause nuclear reactions. Irène Joliot-Curie bombarded uranium with atomic particles and found elements similar to lanthanum and barium, which was a very strange result considering their positions on the periodic table. Meitner was very interested, and so she and Hahn resumed working together to look into it. They also invited Fritz Strassmann, who was skilled in chemical analysis, to join the team in 1935. Hahn didn’t believe the results that Joliot-Curie obtained, but repeated the experiments and found the same thing. It was Meitner who convinced Hahn that the lanthanum and barium-like elements they observed were actually those elements and that what he had done was split the atomic nucleus itself.<br /><br />At the same time, Jews in Germany were beginning to feel the Nazi persecution, and although Meitner was Protestant, she had Jewish heritage. This was not a problem for a while, since Meitner was Austrian, not German. However, when Germany annexed Austria in 1938, everything changed. She requested permission to leave, but it was denied. Then began a chain of scientists all trying to help Meitner. Hahn and Paul Rosbaud arranged for her to leave Austria illegally. Peter Debye (in Berlin) contacted Dirk Coster (in Gronigen) who was able to obtain her entry into Holland and Coster, along with Adriaan Fokker, helped to get her from Berlin into Holland. She left July 13, 1938. From the Netherlands, Meitner went to Sweden with further help from Debye and Bohr. Niels Bohr had begun working around 1932 to find persecuted Jewish scientists positions in foreign institutions, and it was through his efforts that she was given a position at the Nobel Institute for Experimental Physics in Stockholm, although she complained about having a lack of equipment there.<br /><br />Meitner continued to advise the research on fission, but had to do it from afar. From December 1938 to early 1939 she worked with her nephew Otto Frisch to develop a theoretical interpretation of the fission that Hahn and Joliot-Curie had observed. Meitner and Frisch published the paper together, but because of the political situation, Hahn working in Germany did not want to publish the paper on fission with Meitner, and her name was left off. Hahn received the 1944 Nobel Prize for the discovery of fission, and Meitner was recognized as a collaborator in the presentation speech. Her paper with Frisch, however, had shown that fission could actually occur and that there was enough energy to split the atom, rather than just break off a piece, and that when it did split, it released huge amounts of energy.<br /><br />In 1943 she was offered a post with the British scientists going to Los Alamos and in 1947 Fritz Straßmann invited her to join him at the Kaiser-Wilhelm-Institut, but she refused both offers. She retired to Cambridge in 1960, joining Otto Frisch and other relatives there. In 1966 she, Hahn, and Straßmann shared the Enrico Fermi Award for the discovery of the fission of Uranium. Meitner died in 1968 and her tombstone bears the epitaph “A physicist who never lost her humanity.”<br /><br />Now, as I mentioned at first, Lise Meitner has an element named after her, but if you were paying attention, I haven't talked about its discovery. This would not come until 1982 when element 109 was discovered by a group in Darmstadt. Elements 104-109 were all discovered between 1964 and 1982, some of them by several labs, each of which named the elements, and meitnerium got caught up in these disputes, even though the discovery and name were not disputed. The groups at Lawrence Berkley and Dubna both claimed to have discovered elements 104, 106, and 107 first, which made distributing naming rights difficult. The United States proposed a list, but it gave preference to the claims of the scientists from Lawrence Berkley. In 1986, IUPAC and IUPAP set up the Transfermium Working Group to try to settle who discovered the elements first. This, of course, caused responses from the scientists involved, which were published in 1993. Then the Commission on Nomenclature of Inorganic Chemistry met in 1994 and chose delegates to discuss names for the elements 101-109, which were chosen from names submitted by the various labs involved in the disputes—Lawrence Berkeley, Joint Institute for Nuclear Research in Dubna, Russia, and Gesellschaft für Schwerionen Forschung in Darmstadt, Germany. The United States then complained that Seaborgium had been removed from consideration and the American Chemical Society Committee on Nomenclature rejected the recommendations of IUPAC. Finally, in 1997, IUPAC took the issue to the general assembly and proposed a new list, which was finally accepted and element 109 was officially meitnerium.
<br />
<div style="font-family: 'Courier New'; font-size: 12pt;">
<br /></div>
<hr />
<b>Selected Works by Meitner</b><br />
<div>
<ul>
<li>Lise Meitner, "<a href="http://dx.doi.org/10.1007/BF01326962">Über die Entstehung der ß-Strahl-Spektren radioaktiver Substanzen</a>" <i>Zeitschrift für Physik </i><b>9</b>, no. 1 (1922) 131-144. DOI: 10.1007/BF01326962</li>
<li>Lise Meitner and Wilhelm Orthmann, "<a href="http://dx.doi.org/10.1007/BF01339819">Über eine absolute Bestimmung der Energie der primären ß-Strahlen von Radium E</a>" <i>Zeitschrift für Physik</i><b> 60</b>, (1930) 143-155. DOI: 10.1007/BF01339819</li>
<li>Lise Meitner, Fritz Straßmann, and Otto Hahn, "<a href="http://dx.doi.org/10.1007/BF01340332">Künstliche Umwandlungsprozesse bei Bestrahlung des Thoriums mit Neutronen; Auftreten isomer Reihen durch Abspaltung von α-Strahlen</a>", <i>Zeitschrift für Physik </i><b>109</b>, (1938) 538-552. DOI: 10.1007/BF01340332<i> </i></li>
<li>Lise Meitner and O. R. Frisch, "<a href="http://dx.doi.org/10.1038/143239a0">Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction</a>" <i>Nature</i>, no. 3615 (Feb. 11, 1939) 239-240. DOI: 10.1038/143239a0</li>
<li>Lise Meitner and O. R. Frisch, "<a href="http://dx.doi.org/10.1038/143471a0">Products of the Fission of the Uranium Nucleus</a>" <i>Nature</i><b> 143</b>, (March 18, 1939) 471-472. DOI: 10.1038/143471a0</li>
<li>Lise Meitner, "<a href="http://dx.doi.org/10.1038/165561a0">Fission and Nuclear Shell Model</a>" <i>Nature</i> <b>165</b>, 561 (April 8, 1950), 561. DOI: 10.1038/165561a0</li>
</ul>
<div>
<b>References</b><b></b><br />
<b><br /></b>
<div>
<ul>
<li><span style="font-family: inherit;"><span style="text-indent: 36px;">Krafft, Fritz. “<a href="http://dx.doi.org/10.1002/anie.197808261">Lise Meitner: Her Life and Times—On the Centenary of the Great Scientist’s Birth</a>.” </span><span style="font-style: italic; text-indent: 36px;">Angewandte Chemie International Edition in English</span><span style="text-indent: 36px;"> <b>17</b>, no. 11 (1978): 826–842. doi:10.1002/anie.197808261. Full of translated letters to and from Meitner.</span></span></li>
<li><span style="text-indent: 36px;"><span style="font-family: inherit;">Sime, Ruth Lewin. “<a href="http://dx.doi.org/10.1021/ed063p653">The Discovery of Protactinium</a>.” <span style="font-style: italic;">Journal of Chemical Education</span> <b>63</b>, no. 8 (August 1, 1986): 653. doi:10.1021/ed063p653.</span></span></li>
<li><span style="text-indent: 36px;"><span style="font-family: inherit;">Sime, Ruth Lewin. “<a href="http://dx.doi.org/10.1002/anie.199109421">Lise Meitner and Fission: Fallout from the Discovery</a>.” <span style="font-style: italic;">Angewandte Chemie International Edition in English</span> <b>30</b>, no. 8 (1991): 942–953. doi:10.1002/anie.199109421.</span></span></li>
<li><span style="text-indent: 36px;"><span style="font-family: inherit;">Kean, Sam. <span style="font-style: italic;">The Disappearing Spoon and Other Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements</span>. New York: Back Bay Books, 2010.</span></span></li>
<li><span style="text-indent: 36px;"><span style="font-family: inherit;">Westgren, A, “Award Ceremony Speech for the 1944 Nobel Prize in Chemistry”, <a href="http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1944/press.html">http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1944/press.html</a></span></span></li>
<li><span style="text-indent: 36px;"><span style="font-family: inherit;">Rayner-Canham, Geoff, and Zheng Zheng. “<a href="http://dx.doi.org/10.1007/s10698-007-9042-1">Naming Elements after Scientists: An Account of a Controversy</a>.” <span style="font-style: italic;">Foundations of Chemistry</span> 10, no. 1 (April 1, 2008): 13–18. doi:10.1007/s10698-007-9042-1. </span></span></li>
<li><span style="text-indent: 36px;"><span style="font-family: inherit;"><span style="font-size: small;">International Union of Pure and Applied Chemistry in conjunction with International Union of Pure and Applied Physics, “</span><a href="http://www.iupac.org/publications/pac/1993/pdf/6508x1815.pdf">Responses on the Report Discovery of the Transfermium Elements</a><span style="font-size: small;">”, </span><i>Pure & Appl. Chem</i><span style="font-size: small;">. </span><b>65</b>, no. 8 (1993): 1815-1824. </span></span></li>
</ul>
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Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0tag:blogger.com,1999:blog-6520347334609073954.post-25212885754150282272013-07-31T19:47:00.002-04:002013-07-31T19:47:37.887-04:00Lord Kelvin: Beyond Degrees<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/9/91/Hubert_von_Herkomer03.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/9/91/Hubert_von_Herkomer03.jpg" width="158" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">William Thomson, Baron <br />
Kelvin of Largs (1824-1907)<br />
Painted by Hubert von Herkomer</td></tr>
</tbody></table>
It has been a little while since I wrote on someone who gave his name to a unit, so up this week is the eponym of the Kelvin, William Thomson, who is more often referred to as Lord Kelvin, because, for the last years of his life, he was Baron Kelvin of Largs. He did not inherit the title, but was actually the first scientist to be elevated to the House of Lords, and spent most of his life as William Thomson, although he was knighted in 1866, becoming Sir William Thomson. In addition to being the first Baron Kelvin, he was also the last, as he had no heir to succeed to the title. In just a bit of reading about him, I found out that Thomson/Kelvin was interested in all sorts of things, far more than just thermodynamics. These other interests include telegraph signals, navigational aids, and the age of the earth. I have become quite caught up in his and others work on the telegraph, so I initially intended to write this only on his telegraph work, but I have become so excited about telegraphy that I decided to give it a post all of its own. So this post will focus on Kelvin's work except for telegraphy, but look forward next week (hopefully) to a post all about the telegraph, and perhaps another post on Thomson.<br />
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So that I can skip on his scientific and engineering work, I'll give only a brief summary of William Thomson's life. He was born in Belfast and moved to Glasgow as a child. He studied at the Universities of Glasgow and Cambridge (where he was on the rowing team). At the young age of 22 he took a professorship at the University of Glasgow and never left, despite other offers. He gave many lectures, including a series at Johns Hopkins University. He also owned a yacht, the <i>Lalla Rookh</i>, built for him in the late 1860s, and several of his inventions were for improving navigation. He published more than 661 papers/communications and took out 70 patents. After his death in 1907, he was buried in Westminster Abbey next to Isaac Newton.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-HqyG6K_7i1E/Ufb6ed2ZVXI/AAAAAAAANT8/ZclIu_gwiNc/s1600/Kelvin+Lalla+Rookh.PNG" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="267" src="http://3.bp.blogspot.com/-HqyG6K_7i1E/Ufb6ed2ZVXI/AAAAAAAANT8/ZclIu_gwiNc/s320/Kelvin+Lalla+Rookh.PNG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The <i>Lalla Rookh</i><br />
From <i>The Life of William Thomson</i> by Silvanus Thompson</td></tr>
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The <i>Lalla Rookh</i> was a yacht of 126 tons. Thomson was known to take it out for much of the time between the semesters at the University of Glasgow, and sailed around Scotland and even farther afield, such as Lisbon. He also used it to entertain. In 1871 he planned a cruise to the Hebrides and West Highlands with Hermann von Helmholtz, Thomas Huxley, John Tyndall and James Maxwell, though it seems only Helmholtz was actually able to make it. Having the ship inspired twenty five different patented inventions. One of these was a device for correcting compasses when the ship had a metal hull. Another was an improved sounding (depth finding) device, using a wire rather than a rope such that measurements could be taken at speed.<br />
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The purchase of the ship may also have lead to his increased interest in fluid mechanics, which occurred in 1867, and was one of the subjects he discussed with Helmholtz on their journey in 1871. But his interest in fluid mechanics had a little remembered result as well--the idea of vortex atoms. Remember, the structure of the atom was not known in the mid-19th century. A common standard for atomic weights was not determined until 1860, and Mendeleev published the first periodic table in 1869. Even then, people didn't know what made up an atom. J. J. Thomson discovered the electron in 1897, and Rutherford's famous experiment which proved the existence of an atomic nucleus was not until 1909, after Kelvin's death, so the question of the nature of the atom was wide open. William Thomson spent considerable time developing the idea of vortex atoms, based on the descriptions of fluid motion made by Helmholtz, who had expanded descriptions of fluid motion to include more irrotational motion. This theory suggested that atoms are vortexes (such as smoke rings) in the ether that makes up space. By around 1883, Thomson began to feel that his theory was not sufficient to explain matter, but he had gotten other scientists thinking about the idea and furthered the field of hydrodynamics.<br />
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There is certainly more to be said, and I had hoped to say it, but hopefully that whets your appetite and you will go looking for more information on your own. The references should be quite helpful. And perhaps I will return to Kelvin at some point to talk about absolute zero, electricity, and the age of the earth. But if I try to cover them now, this post will never be finished.<br />
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<hr />
<span class="MsoFootnoteReference"><b>Miscellaneous Works by Thomson</b></span><br />
<ul>
<li>"<a href="http://www.jstor.org/stable/111918">On the Measurement of Electric Resistance</a>", <i>Proceedings of the Royal Society of London</i> <b>11</b>, 313-328.</li>
<li>"<a href="http://www.google.com/patents/US209942?dq=thomson+mirror+galvanometer">Improvement in Reflecting-Galvanometers</a>", patent number 209942, issue date November 12, 1878.</li>
<li>"<a href="http://books.google.com/books?id=iqxIJ9zvlNoC&dq=%22On%20an%20Absolute%20Thermometric%20Scale%22%20philosophical%20magazine%20thomson&pg=RA1-PA313#v=onepage&q&f=false">On an Absolute Thermometric Scale</a>",<i> Philosophical Magazine and Journal of Science, </i><b>32</b> (January-June 1848) 313-317. In which Thomson suggests a temperature scale in which a degree change will provide the same amount of work regardless of the starting temperature.</li>
<li><i><a href="http://books.google.com/books?id=fxtWAAAAMAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">Mathematical and Physical Papers</a> </i>(London: Clay and Sons, 1890). A compilation of his papers from 1841 to 1890.</li>
<li><i><a href="http://books.google.com/books?id=l7sSAQAAMAAJ">Treatise on Natural Philosophy</a> </i>(with Peter Tait) (London: Clay and Sons, 1883)</li>
<li><i><a href="http://books.google.com/books?id=e0pBAAAAYAAJ">Elements of Natural Philosophy</a> </i>(with Peter Tait) (1872)</li>
</ul>
<b>References</b><br />
<ul><span class="MsoFootnoteReference">
<li>Gillian Cookson, "The Transatlantic Telegraph Cable", <i>History Today</i> <b>50</b>, no. 3 (March, 2000) 44-51. A discussion of the difficulties and personalities involved in laying the first transatlantic cable, including both the failure in 1858 and the success in 1866.</li>
<li>Robert H. Silliman, "<a href="http://www.jstor.org/stable/228151">William Thompson: Smoke Rings and Nineteenth-Century Atomism</a>", <i>Isis</i> <b>54</b>, no. 4 (Dec., 1963) 461-474. A detailed discussion of Kelvin's vortex theory of the atom and its place in 19th century scientific thought.</li>
<li>Matthew Trainer, "<a href="http://dx.doi.org/10.1016/j.wpi.2004.05.003">The Patents of William Thomson (Lord Kelvin)</a>", <i>World Patent Information</i> <b>26</b>, (2004) 311-317. </li>
<li>University of Glasgow Library, "<a href="http://special.lib.gla.ac.uk/exhibns/Kelvin/kelvinindex.html">William Thomson, Lord Kelvin 1824-1907</a>", online exhibition. Includes a wonderful collection of Thomson's correspondence with other illustrious scientists, including Joule and Maxwell.</li>
<li>Silvanus P. Thompson, <i><a href="http://openlibrary.org/books/OL7067330M/The_life_of_William_Thomson_baron_Kelvin_of_Largs">The Life of William Thomson, Baron Kelvin of Largs</a></i> (London, Macmillan, 1910). A great biography of Thomson (or I assume it to be, from having read parts of it), with many letters written by him.</li>
<li>Alex D. D. Craik, "<a href="http://dx.doi.org/10.1140/epjh/e2012-30004-y">Lord Kelvin on Fluid Mechanics</a>", <i>European Physical Journal H</i> <b>37</b>, (2012) 75-114. This appears to go in depth into Kelvin's papers and involves lots of equations.</li>
<li>Alexander Russell, "<a href="http://dx.doi.org/10.1049/jiee-1.1916.0085">The Eighth Kelvin Lecture</a>", <i>Journal of the Institution of Electrical Engineers</i> <b>55</b>, no. 261 (December, 1916) 1-17.</li>
<li>Hasok Chang and Sang Wook Yi, "<a href="http://dx.doi.org/10.1080/00033790410001712246">The Absolute and Its Measurement: William Thomson on Temperature</a>", <i>Annals of Science</i><b> 62</b>, no. 3 (2005) 281-308.</li>
</span></ul>
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</span>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com2tag:blogger.com,1999:blog-6520347334609073954.post-30973738340848422182013-06-27T18:45:00.000-04:002013-06-27T18:45:00.884-04:00Erudite Euler<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://upload.wikimedia.org/wikipedia/en/thumb/2/20/Leonhard_Euler.png/480px-Leonhard_Euler.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://upload.wikimedia.org/wikipedia/en/thumb/2/20/Leonhard_Euler.png/480px-Leonhard_Euler.png" width="160" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Leonhard Euler (1707-1783)</td></tr>
</tbody></table>
Up this week is Euler, the great mathematician. It is impossible for me to do him justice in this post, because of the shear volume of his work and my lack of knowledge about mathematics. If you would like to read more about him, please look at some of the articles in the references. These ones are particularly good.<br />
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I mostly know of Euler from two things-Euler's method, which was an approximation method I used in calculus, and Euler's formula, which could actually mean many things, but in this case I refer to his formula that relates exponential and trigonometric functions, <i>e<sup>ix</sup></i> = cos(<i>x</i>) + <i>i</i>sin(<i>x</i>), and is perhaps seen more commonly in less scientific circles in the particular form where <i>x</i> = π, where it simplifies to <i>e<sup>iπ</sup></i> = 1. These are both definitely important, and I used the latter in about every other homework that I did this year, but Euler considered many more applied problems than this small sample size would suggest.<br />
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Leonhard Euler was the son of a minister and originally intended to study theology. Fields of study were different in the 18th century, though, and at the conclusion of his master's degree he gave a lecture comparing the natural philosophy of Newton and Descartes. At the University of Basel he studied, among other things, mathematics under the tutelage of Johann Bernoulli, who encouraged him to study mathematics more pointedly and was of much help in later years as well. As a young man, Euler competed for the prize question of the Paris Academy of Sciences, a competition open to the greatest scientific minds in Europe, and came in second. Not bad. In later years, he came in first twelve times. He applied to a position in physics at the University of Basel and failed, but then was invited to the Academy of Sciences in St. Petersburg, where he was devoted mainly to mathematics. He stayed in St. Petersburg from 1727-1741. He was then invited to help found the Academy of Sciences in Berlin, Prussia. He did not get along well with Frederick II, though, and when rebuffed from the position of president of the Academy, returned to St. Petersburg in 1766 at the invitation of Catherine II, and stayed there until his death in 1783.</div>
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<div>
In setting down to consider the accomplishments of Euler, I found it interesting to note who had gone before. Nicholas Fuss, one of Euler's students, in his eulogy on Euler, said:</div>
<blockquote class="tr_bq">
At the time when Mr. Euler entered into mathematics, nothing could be more discouraging. A mediocre talent simply could not expect to make a name for it and it was best to choose another career or to distinguish one brilliantly. The memory of the recently deceased great men that had been part of the past century and the beginning of ours was still particularly fresh in our minds. Hardly had Newton and Leibniz altered the face of geometry when they died and we had not yet forgotten the important services that the discoveries of Huyghens, Bernoulli, Moivre, Tschirnhausen, Taylor, Fermat and so many other mathematicians had provided to all the branches of mathematics.</blockquote>
Euler clearly chose the second option: "to distinguish one brilliantly". Rather than consider that mathematics had been exhausted, as one might think, or even that certain areas had, he pursued many different avenues and pushed mathematics in many new and old directions.<br />
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He tackled the field of mechanics in two volumes, introducing to it integral and differential calculus. He was also very interested in sound, and had written a <a href="http://www.17centurymaths.com/contents/euler/e002tr.pdf">thesis</a> on it when applying for the position in Basel. But he returned to the subject in St. Petersburg, and extended his writings to include the emotions that sounds can evoke. There he also developed the Γ function (which gives factorials for positive integers, but can be applied to non- and negative integers as well), and the constant γ, called Euler's constant. He also developed the concept of the fuction, and the notation still used today of f(x). While writing on complex and novel mathematical ideas, Euler also wrote works on more basic subjects, like textbooks on arithematic for use in Russian schools, and <i>Théorie complete de la construction et de la manœuvre des vaisseaux</i>, a text for sailors on navigation. Other problems that he dealt with included optimal profiles for the teeth on gears, why disks (think pennies being spun) seem to spin faster as they fall down, the critical load for a rod to buckle, and the number of vertices, edges, and faces for polyhedra. In investigating these, he also often returned to a topic for many years after he first looked at it.<br />
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Something that undoubtedly helped his work was his prodigious memory. He was reported to be able to recite the entirety of Virgil's <i>Aeneid</i> (which, having read, I can assure you is no mean feat). It helps, of course, that he could read and write Latin. He was also very good at doing calculations in his head and remembering the results afterwards. This was vital to his work, especially in later years, since he lost the sight in one eye in 1735 and suffered from cataracts in the other, eventually losing his sight almost completely. That did not, however, stop his productivity, and he had his sons and others take dictation, or copy large letters from a slate.<br />
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For one with such remarkable skills, he also seems to have been quite humble and well liked, and passed up opportunities to quibble over who had discovered things first. He married twice and had 13 children, five of whom survived to adulthood. He had a fit of apoplexy while playing with one of his grandsons and drinking a cup of tea, and died a few hours later. Fuss spoke glowingly about him: how he dropped calculations for ordinary conversation, explained concepts at the level of the listener, did not hold <br />
<div class="separator" style="clear: both; text-align: center;">
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grudges, fought injustice where he saw it, and many other praiseworthy qualities. It has been exciting to see how a man could be at the top of his field, clearly pursuing topics that piqued his interest, and yet still be praised as a humane, relateable, Christian man.<br />
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<hr />
<b>References</b><br />
<div>
<ul>
<li>Marquis de Condorcet, "<a href="http://www.math.dartmouth.edu/~euler/historica/condorcet.html">Eulogy to Mr. Euler</a>", <i>History of the Royal Academy of Sciences</i>, 1783, Paris 1786, p. 37-68. A nice summary of Euler's life and work, free of equations and with some nice anecdotes.</li>
<li>Nicolas Fuss, "<a href="http://www-history.mcs.st-and.ac.uk/~history/Extras/Euler_Fuss_Eulogy.html">Eulogy of Leonhard Euler</a>", read at the Imperial Academy of Sciences of Saint Petersburg, October 23, 1783. Fuss was a student of Euler and a grandson-in-law. His eulogy is longer than Condorcet's, but more personal. If you are interested in what Euler was like as a person, skip to the end. Fuss paints a wonderful picture of a caring, Christian family man.</li>
<li>Walter Gautschi, "<a href="http://www.cs.purdue.edu/homes/wxg/EulerLect.pdf">Leonhard Euler: His Life, the Man, and His Works</a>", <i>SIAM Review</i><b> 50</b>, no. 1 (2008), 3-33. DOI: 10.1137/070702710. A relatively short summary of his life, providing both an outline of life events and some of his mathematical accomplishments. For a quick summary of some of his math, this is a good place to start, as this one actually includes some diagrams and equations.</li>
</ul>
</div>
Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com1tag:blogger.com,1999:blog-6520347334609073954.post-74684331223350505622013-06-20T12:49:00.004-04:002013-06-20T13:14:17.230-04:00The Elusive Wulff<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><img alt="Wulff construction" src="//upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Wulff_construction.svg/256px-Wulff_construction.svg.png" style="cursor: move; margin-left: auto; margin-right: auto;" width="256" /></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A Wulff plot (the surface energies are given in red)<br />
Drawing by Michael Schmid <br />
and used under the <a href="http://commons.wikimedia.org/wiki/Commons:GNU_Free_Documentation_License_1.2">GNU Free Documentation License</a> </td></tr>
</tbody></table>
I first ran into the name Wulff last year in my thermodynamics class. He gave his name to a method for constructing the shape that a single crystal will take based on the surface energies of different crystallographic directions. It is a clever construction, and that particular homework problem was probably my favorite of the whole year. So I decided to see what I could find out about Wulff, and I have found him very difficult to track down, so I put this post on the shelf. Then in winter quarter I ran into the name again in an x-ray diffraction class where we used Wulff nets, and I decided to track him down again. It proved no easier, but I did get farther! It does seem strange, though, for a man who's name is so often used, that there is so little information on him. He doesn't even have an English Wikipedia page! The first reason for confusion about Wulff is that he was Ukrainian, so there are different transliterations of his name, but worse than that, he went by two names! Georg Wulff was the name he used in German-language publications, and thus is the name that we are more familiar with, but his name in Russian (transliterated, of course) was Yuri Viktorovich. I did, at last, find a nice article on him in the <i>Complete Dictionary of Scientific Biography</i>, and some information in one of my x-ray diffraction textbooks.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-nbJrgf8LBWA/UYQ_HLa6PyI/AAAAAAAANJk/jNVIVOfoxhI/s1600/Wulff+image+from+1902+paper.PNG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="172" src="http://1.bp.blogspot.com/-nbJrgf8LBWA/UYQ_HLa6PyI/AAAAAAAANJk/jNVIVOfoxhI/s320/Wulff+image+from+1902+paper.PNG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Image of a projection from Wulff's 1902 paper</td></tr>
</tbody></table>
Georg Wulff was born in the Ukraine in 1863 and studied at Warsaw University. In 1907, or 1908, or 1911, he became a professor (or teacher) of crystallography at Moscow University. Nobody seems to be able to agree. What is important, I think, is that between defending his dissertation and his death, he taught in various capacities at universities in Russia and the U.S.S.R.<br />
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He published two important papers in 1901 and 1902 regarding crystal structures and stereographic projections. They are both in German, so I don't know exactly what they are getting at. Hammond says that Wulff proposed the Wulff net in 1909, but there seems to be an image of part of a Wulff net in his 1902 paper. His 1901 paper introduced the principles of the Wulff construction, which is a graphical method for determining the faces of a crystal that are expressed based on the surface energy of the different crystallographic directions. This idea built on Josiah Gibbs' proposal that materials want to minimize total surface energy. Wulff himself did not prove mathematically why his construction worked, but it was proved by Conyers Herring (1914-2009) in the 1950s.<br />
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<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-B61gBYjW2qQ/UYQ_Gw8F_gI/AAAAAAAANJs/iU1Xh4XOcpQ/s1600/Wulff+image+from+1901+paper.JPG" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="137" src="http://3.bp.blogspot.com/-B61gBYjW2qQ/UYQ_Gw8F_gI/AAAAAAAANJs/iU1Xh4XOcpQ/s200/Wulff+image+from+1901+paper.JPG" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Crystal diagram from Wulff's 1901 paper</td></tr>
</tbody></table>
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Wulff was also in communication with William Henry Bragg and his son, William Lawrence Bragg, English crystallographers. Wulff derived an equation for x-ray diffraction in 1913 that was equivalent to the one proposed the year before by the Braggs, and so some people at the time called what is now known as Braggs' Law the Bragg-Wulff Law. Wulff appears to have lost out on the name because he published second, and, more importantly, he did not follow up with as many advancements on the topic as the Braggs. After that, he appears not to have taken on any new areas of study and faded into obscurity, though not without leaving his name for students of thermodynamics and crystallography to stumble upon.<br />
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<b>Works</b><br />
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<ul>
<li>G. Wulff, "<a href="http://archive.org/stream/zeitschriftfrkr01unkngoog#page/n494/mode/2up">Zur Frage der Geschwindigkeit des Waschsthums und der Auflösung der Krystallflächen</a>," <i>Zeitschrift für Krystallographie und Mineralogie</i> <b>34</b> (1901) 449-530.</li>
<li>G. Wulff, "<a href="http://archive.org/stream/zeitschriftfurk00unkngoog#page/n17/mode/2up">Untersuchungen im Gebiete der optischen Eigenschaften isomorpher Krystalle</a>," <i>Zeitschrift für Krzstallographie und Mineralogie</i><b> 36 </b>(1902) 1-18.</li>
<li>G. Wulff, "<a href="http://babel.hathitrust.org/cgi/pt?id=mdp.39015021268936;view=1up;seq=263">Über die Kristallröntgenogramme</a>", <i>Physikalische Zeitschrift</i> <b>14 </b>(March 15, 1913), 217-220.</li>
<li><a href="http://www.nationalarchives.gov.uk/a2a/records.aspx?cat=116-whbragg_1&cid=2-18-40#2-18-40">Correspondence</a> with the Braggs, held at the National Archives in the UK.</li>
</ul>
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<b>References</b><br />
<a href="http://commons.wikimedia.org/wiki/File%3AWulff_construction.svg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;" title="By Michael Schmid (Drawing created myself) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons"></a><a href="http://commons.wikimedia.org/wiki/File%3AWulff_construction.svg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;" title="By Michael Schmid (Drawing created myself) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons"></a><br />
<ul>
<li>V. A. Frank-Kamenetsky, "<a href="http://www.encyclopedia.com/doc/1G2-2830904737.html">Wulff, Georg (Yuri Viktorovich)</a>." <i>Complete Dictionary of Scientific Biography</i>. 2008. Retrieved May 03, 2013 from Encyclopedia.com.</li>
<li>Christopher Hammond, <i><a href="http://books.google.com/books?id=czQcnBYt5R4C&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">The Basics of Crystallography and Diffraction</a>, </i>3rd edition. Oxford University Press, 2009.</li>
<li>John C. Haff, "<a href="http://www.minsocam.org/ammin/AM25/AM25_689.pdf">Use of the Wulff Net in Mineral Determination with the Universal Stage</a>", <i>American Minerologist</i> <b>24</b> (1940) 689-707. A nice description of how to use a Wulff net, with illustrations.</li>
<li>Conyers Herring, "<a href="http://materials.mcmaster.ca/faculty/malakhov/3T04/LectureNotes/1951%20Herring%20'Some%20Theorems%20on%20the%20Free%20Energies%20of%20Crystal%20Surfaces'.pdf">Some Theorems on the Free Energies of Crystal Surfaces</a>", <i>Physical Review</i><b> 82</b> (April 1, 1951), 87-93. This may be the paper that proves the Wulff construction, but the date differs from that on the Wikipedia page (1953). In this paper Herring mentions that others have proven that other methods give larger surface energies than Wulff, but does not say that any prior work has proven the Wulff construction, nor without more knowledge of the subject, can I say whether this proves it or not.</li>
</ul>
Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com1tag:blogger.com,1999:blog-6520347334609073954.post-70814320460306700612013-04-27T15:04:00.002-04:002013-04-28T16:55:47.443-04:00Alexander Borodin: Chemist Composer<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/c/c6/Alexander_Borodin.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/c/c6/Alexander_Borodin.jpg" width="133" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Alexander Borodin (1833-1887)</td></tr>
</tbody></table>
The topic of this post is at the suggestion of Melissa. Thanks for commenting! I enjoyed researching Borodin.<br />
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Alexander Borodin was a Russian composer and chemist. Those two seem to be very divergent, and in reading about him, it is interesting that I can find very little about if the two fields interacted in any practical way. In fact, his science appears to have gotten in the way of his composing. I had never heard of him, or at least thought I hadn't. It turns out I have heard some of his music. Here is an example, the Polovtsian Dances from the opera <i>Prince Igor</i>. I would suggest starting this and listening while continuing to read, though the ballet is quite good too.<br />
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Borodin was the illegitimate son of a Georgian prince, but he was born in Saint Petersburg and registered as the son of a serf. The prince did not forget him, though, and he was able to receive a good education. He was interested in both science and music, and wrote his first existing composition, a polka, at the age of 9. He attended the Medico-Surgical Military Academy in Saint Petersburg and started out as a doctor, though he became very interested in chemistry and studied with the chemist Nikolay Zinin, who apparently was a Russian chemist of note. Despite being at a medical school, Borodin was squeamish and therefore not well suited to being a doctor, so he continued his chemistry studies. Zinin is said (probably apocryphally) to have told him</div>
<blockquote class="tr_bq">
Mr. Borodin, it would be better if you gave less thought to writing songs. I have placed all my hopes in you, and want you to be my successor one day. You waste too much time thinking about music. A man cannot serve two masters." (Podlech, from another source)</blockquote>
Borodin did not give up "writing songs", but still managed to become Zinin's successor. After graduating in 1858, he traveled Europe for three years. He started in Heidelberg, working first with <a href="http://historyofsci.blogspot.com/2012/11/robert-bunsen-1811-1899-robert-bunsen.html">Robert Bunsen</a>, though he ended up staying longer with <a href="http://historyofsci.blogspot.com/2012/01/more-than-flask-emil-erlenmeyer.html">Emil Erlenmeyer</a> (and I've already written about them!). There he became friends with Dmitri Mendeleev (of the periodic table) and his future wife, the pianist Yekaterina Protopopova. He also attended the Karlsruhe Congress in 1860, an important milestone in understanding and standardizing atomic weights. He went with Yekaterina to Pisa and asked to work in the laboratory of de Luca and Tassinari (whom I had never heard of ). They had platinum retorts, which enabled him to work with corrosive substances. There he was able to make the first nucleophilic replacement of a halogen with fluorine, which was difficult because of the strength of fluorine bonds and fluorine's toxicity.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-MIDIniInRaQ/UXwgdLMZUGI/AAAAAAAANI8/DP3r0HUL3uc/s1600/Russian+Five.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img alt="http://a2.ec-images.myspacecdn.com/images02/124/2fe162eddc9e4dd18038c7c64500805d/l.jpg" border="0" height="186" src="http://4.bp.blogspot.com/-MIDIniInRaQ/UXwgdLMZUGI/AAAAAAAANI8/DP3r0HUL3uc/s320/Russian+Five.jpg" title="" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The Five. From left to right: singer, Mussorgsky, <br />
Rimsky-Korsakov, Vladimir Stasov, Balakirev, Cui, and Borodin</td></tr>
</tbody></table>
Upon his return to Saint Petersburg, he became a professor, and also a member of The Five. The Five was a group of Russian composers in Saint Petersburg who were self-trained amateurs but wanted to write music that was authentically Russian. The other composers in this group were Modest Mussorgsky, Nikolai Rimsky-Korsakov, Mily Balakirev, and César Cui. Not a shabby bunch to be hanging out with!<br />
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Borodin continued his research and composing. One of the interesting things that happened in the next decade was a sort of dispute with August Kekulé. Borodin had been studying aldehydes, but Kekulé began research into their condensation in the late 1860s. It seems rather confusing who did what, but Borodin seemed to think that Kekulé was impinging on his territory. However, Borodin wasn't publishing much, so it was hard to actually make a claim. Eventually, Borodin ceded and returned to his work on amides. One of his most significant contributions in this field was a simple device to measure the amount of urea in animal urine. I have no idea why people wanted to use that, but contemporaries seemed pretty excited. After 1875, he did not publish any full papers. Instead, he spent more time on training students and advocating for women's rights. He gave lectures and provided special instruction for the female students studying medicine.<br />
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One wonders how Borodin juggled composing with science, and I found a great quote that expresses his difficulties.<br />
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In winter I can only write music when I am so ill that I don't give lectures, don't go to the laboratory, yet all the same can work a little. For this reason my musical friends, contrary to universal custom, always wish me not health, but sickness. (Letter to Liubov' Ivanova Karmalina, June 1, 1876)</blockquote>
Though his total oeuvre is small, the quality of his work is generally acknowledged to be good. He wrote two symphonies, some chamber music compositions, songs, and much of an opera. He worked on <i>Prince Igor </i>from 1869 until his death in 1887. Rimsky-Korsakov was concerned about it getting finished, and offered to help with it as much as he could. In the end, though, Rimsky-Korsakov and Alexander Glazunov had to finish it after Borodin's death, which unfortunately occurred at a fancy dress party.<br />
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<b>References</b><br />
<ul>
<li>Michael D. Gordin, "The Weekday Chemist: The Training of Aleksandr Borodin", in <i>A Master of Science History</i>, ed. Jed Z. Buchwald (New York: Springer, 2012), 137-166.</li>
<li>Joachim Podlech, "'<a href="http://dx.doi.org/10.1002/anie.201002023">Try and Fall Sick...'--The Composer, Chemist, and Surgeon Aleksandr Borodin</a>", <i>Angewandte Chemie International Edition</i> <b>49</b>, 37 (2010), 6490-6495. DOI 10.1002/anie.201002023</li>
<li>Michale D. Gordin, "<a href="http://dx.doi.org/10.1021/ed083p561">Facing the Music: How Original Was Borodin's Chemistry?</a>", <i>Journal of Chemical Education</i><b> 83</b>, 4 (April 2006), 561-565. DOI 10.1021/ed083p561</li>
<li>Leopold May, "<a href="http://www.scs.illinois.edu/~mainzv/HIST/bulletin_open_access/v33-1/v33-1%20p35-43.pdf">The Lesser Known Chemist-Composers, Past and Present</a>", <i>Bulletin for the History of Chemistry </i><b>33, </b>1 (2008), 35-43.</li>
</ul>
Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com1tag:blogger.com,1999:blog-6520347334609073954.post-65718880343302654352012-11-23T16:19:00.001-05:002013-06-20T12:51:48.500-04:00The Bunsen Burner, Spectroscopy, and Geysers<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-Lu6rPgNJ2F0/UK-535kXgeI/AAAAAAAANHQ/xdYaEECWwCY/s1600/Robert_Bunsen.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://2.bp.blogspot.com/-Lu6rPgNJ2F0/UK-535kXgeI/AAAAAAAANHQ/xdYaEECWwCY/s200/Robert_Bunsen.jpg" width="156" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Robert Bunsen (1811-1899)</td></tr>
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Robert Bunsen deserves to be remembered for more than his "invention" of the Bunsen burner. He was a brilliant chemist, and did work in spectroscopy, blast furnaces, batteries, and even geology. One of the things that I like about writing this blog is seeing just how many pies these scientists managed to get their fingers in. They were curious, and made discoveries that, even if tangential to their regular work, are in many cases still remembered. See my last post on <a href="http://historyofsci.blogspot.com/2012/10/bohrs-dueling-discovery.html">Bohr</a> for one example. Probably Bunsen's most notable research out of the field of chemistry was his foray into geysers. In the 1840s, on a trip to Iceland to study the recently erupted volcano Mount Hekla. But he also became curious about the geyser there and did some measurements. He came up with a theory about how geysers work, and did a demonstration with a model geyser to show that his theory worked. That would have been a fun demonstration to see!<br />
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His early research was in organic chemistry, and he studied arsenic compounds and arsenic poisoning. He showed that iron oxide hydrate could be used as an antidote for arsenic poisoning, and also did extensive research into cacodyl compounds. While still a young chemist, he nearly died of arsenic poisoning and lost the use of one eye from an explosion of one of his arsenic-containing compounds. I have not found anyone to say why he discontinued his studies of cacodyl compounds, but I think it may have had to do with their obviously dangerous effects. The results of his work helped Edward Frankland and Friedrich Kekulé in their studies of chemical valency. Bunsen also studied blast furnaces, which were of great importance in the 1830s due to the huge amounts of iron being produced. He showed that over half of the fuel was lost, and worked with Lyon Playfair to improve the furnaces to be more efficient and to catch potentially useful byproducts. This work resulted in his only book, <i><a href="http://books.google.com/books?id=0RwWzUysftEC&printsec=frontcover#v=onepage&q&f=false">Gasometry: Comprising the Leading Physical and Chemical Properties of Gases</a></i>.<br />
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When Robert Bunsen became a professor at the University of Heidelberg in 1852, he took charge of a new laboratory building. The building was equipped with gas, and during construction, Bunsen made suggestions to the building's mechanic, Peter Desaga, regarding the burners to be used. There had been previous burners used, including one by Michael Faraday, but his was an improvement on these and enabled the flame to be hot, sootless, and non-luminous. A biographer wrote at his death that "The Bunsen burner is now in use everywhere from the kitchen to the research laboratory." (Crew, p. 302) Not sure how it was used in the kitchen, but there you have it.<br />
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<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-Bgy8TqNvzds/UK_npvc6guI/AAAAAAAANHg/ZziTBfbW3hg/s1600/bunsen+spec.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="150" src="http://1.bp.blogspot.com/-Bgy8TqNvzds/UK_npvc6guI/AAAAAAAANHg/ZziTBfbW3hg/s200/bunsen+spec.jpg" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Bunsen and Kirchhoff's spectrometer</td></tr>
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Though I could also write about his carbon-zinc battery that was much cheaper to make and longer lasting than the previous platinum covered plates, or his invention of the ice-calorimeter and the vapor calorimeter, I do want to talk about his spectroscopic work, which is perhaps most important, and led to the discovery of two new elements. Bunsen's work with spectroscopy was done in collaboration with Gustav Kirchhoff (Kirchhoff's Law, anyone?), whom he met in 1851. He had already been interested in light, such as the improvement of the gas burner and showing that an electric current could create light. Kirchhoff joined Bunsen at Heidelberg and they formed, so it seems, a great team. Bunsen's work with electrochemistry and batteries gave him the ability to separate metals, and the non-luminous burner that he had improved meant that he could use flame tests to see the different colors that metals gave off. Kirchhoff suggested that the colors of different metals that had similar colors might be able to be distinguished by looking at the spectra with a prism. They found that these spectra were unique to different elements. When they noted a new spectral blue line, Bunsen hypothesized that it was a new element and went on to distill 40 tonnes of water to isolate 50 grams of a chloro-platinic coumpound, from which he identified this new element, which he called cesium, Latin for deep blue, from the blue line in its spectrum. In 1861 he announced the discovery of rubidium, and thereafter others used his spectroscopic methods to discover and isolate thallium, indium, germanium, gallium, and scandium.<br />
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If you are not familiar with the principle of a flame test, or even if you are because it is always cool, the following video is a nice demonstration of the different colors that different metals are, and shows the spectral lines too.<br />
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I will conclude with a sad reminder to back up your data. Bunsen also studied the spectra of rare earth metals, and had just finished a large manuscript on the subject. He left the manuscript on a table near a glass of water, and when he came back, he found the manuscript burnt. It took him two years to replicate the data and apparatuses. So the equivalent of hard drive crashes are nothing new.<br />
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<b>Works by Bunsen</b><br />
<ul>
<li>Robert Bunsen, <a href="http://books.google.com/books?id=0RwWzUysftEC&source=gbs_navlinks_s" style="font-style: italic;">Gasometry</a><i>: Comprising the Leading Physical and Chemical Properties of Gases</i>. (London: Walton & Maberly, 1857).</li>
<li>Robert Bunsen and Leon Schischkoff, "<a href="http://books.google.com/books?id=HBQQSYssQpQC&dq=%22on%20the%20chemical%20theory%20of%20gunpowder%22%20bunsen&pg=PA489#v=onepage&q=%22on%20the%20chemical%20theory%20of%20gunpowder%22%20bunsen&f=false">On the Chemical Theory of Gunpowder</a>", <i>Philosophical Magazine</i>, supplement to vol. XV., (1858) 489-512.</li>
<li>Robert Bunsen and Henry Enfield Roscoe, "<a href="http://www.jstor.org/stable/10.2307/108623">Photo-Chemical Researches. Part I. Measurement of the Chemical Action of Light</a>", <i>Philosophical Transactions of the Royal Society of London</i> <b>147</b> (1857), 355-380.</li>
<li>Robert Bunsen and Henry Enfield Roscoe, "<a href="http://www.jstor.org/stable/10.2307/108792">Photo-Chemical Researches. Part V. On the Direct Measurement of the Chemical Action of Sunlight</a>", <i>Philosophical Transactions of the Royal Society of London</i> <b>153</b> (1863), 139-160.</li>
</ul>
<b>References</b><br />
<ul>
<li>Henry Roscoe, "<a href="http://pubs.rsc.org/en/content/articlepdf/1900/ct/ct9007700513">Bunsen Memorial Lecture</a>", <i>Journal of the Chemical Society, Transactions </i><b>77</b>, 513-554. DOI: 10.1039/CT9007700513. This is the best biography of Bunsen that I found, and it was written by one of his friends and collaborators.</li>
<li>Henry Crew, "<a href="http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1899ApJ....10..301C&amp;data_type=PDF_HIGH&amp;whole_paper=YES&amp;type=PRINTER&amp;filetype=.pdf">Robert Wilhelm Bunsen</a>", <i>The Astrophysical Journal </i><b>10</b>, 5 (December 1899), 301-305. DOI: 10.1086/140654.</li>
<li>Floyd Lavern Darro, <i><a href="http://books.google.com/books?ei=7dKvUPrLIPH22QXm8oDADA&id=FSMGAAAAMAAJ&dq">Masters of Science and Invention</a></i>, vol. 1. (Harcourt, 1923).</li>
<li>"<a href="http://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Bunsen,_Robert_Wilhelm_von">Bunsen, Robert Wilhelm von</a>", <i>Encyclopaedia Britannica</i>, vol. 4 (1911).</li>
<li>James Kingsland, "<a href="http://www.guardian.co.uk/science/blog/2011/mar/31/robert-bunsen-burner-inventor-chemist">Robert Bunsen did a whole lot more than invent the Bunsen burner</a>", <i>The Guardian</i>, Notes&Theories: Dispatches from the Science Desk blog, March 31, 2011.</li>
<li>"<a href="http://www.corrosion-doctors.org/Biographies/BunsenBio.htm">Robert Wilhelm Bunsen (1811-1899)</a>", Corrosion Doctors.</li>
</ul>
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<br />Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com2tag:blogger.com,1999:blog-6520347334609073954.post-36044463998384087532012-10-03T09:24:00.001-04:002012-10-04T10:01:04.856-04:00Bohr's Dueling Discovery<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/6/6d/Niels_Bohr.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/6/6d/Niels_Bohr.jpg" width="141" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Niels Bohr (1885-1962)</td></tr>
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Unfortunately this summer I wasn't able to finish as many posts as I had hoped, so rather than a full post today, here is a tidbit. As per the latest poll, up this week is Niels Bohr! But there is a lot to talk about, particularly with respect to the atom, so instead, I'll talk about something you probably didn't know. One of Niels Bohr's contribution to science derived from his love of western films. He noted that the bad guys always drew first, but the good guys always won, and wondered if it was actually the case that the person who drew second won more often. He went out and purchased some cap guns and "dueled" his friends to find out. Sure enough, always drawing second, he won. Recently, proving that Bohr didn't just have faster reflexes than his friends, Andrew Welchman at the University of Birmingham confirmed that the second person to draw is milliseconds faster to the trigger. So stick to your hobbies! You never know where they may lead.<br />
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<b>References</b><br />
<ul>
<li>Andrew Welchman, James Stanley, Malte Schomers, R. Chris Miall, Heinrich Bulthoff, "<a href="http://rspb.royalsocietypublishing.org/content/277/1688/1667">The Quick and the Dead: When Reaction Beats Intention</a>", <i>Proceedings of the Royal Society B: Biological Sciences </i><b>277</b>, 1688 (June 7, 2010), 1667-1674. doi: 10.1098/rspb.2009.2123</li>
<li>Tom Feilden, <a href="http://news.bbc.co.uk/today/hi/today/newsid_8493000/8493203.stm">The Gunfighter's Dilemma</a>, on "Today", produced by BBC 4 Radio, February 3, 2010.</li>
<li>Ian Sample, <a href="http://www.guardian.co.uk/science/2010/feb/03/good-guys-draw-faster-gunfights">Why the good guys always draw faster in gunfights – but not fast enough</a>, <i>The Guardian</i>, February 2, 2010.</li>
</ul>
Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com1tag:blogger.com,1999:blog-6520347334609073954.post-40318451901346059832012-08-10T18:57:00.000-04:002018-12-05T22:48:47.203-05:00John Dalton: Atoms, Weather, and Vision<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"> <tbody>
<tr> <td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/d/d4/John_Dalton_by_Charles_Turner.jpg/240px-John_Dalton_by_Charles_Turner.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/d/d4/John_Dalton_by_Charles_Turner.jpg/240px-John_Dalton_by_Charles_Turner.jpg" height="200" width="161" /></a></td></tr>
<tr> <td class="tr-caption" style="text-align: center;">John Dalton<br />
1766-1844</td></tr>
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Since one of my undergraduate degrees was in chemistry, I cannot believe that to this point I have only written one post that warranted the tag of "chemists." So this post is an attempt to remedy this. In looking at the lists of names that I have as potential subjects for blog posts, the first that jumped out at me were Henderson and Hasselbalch, famous for the equation for determining the pH of a buffer solution. But I try to mix up the time periods that I write about, which either means that you, my readers, do not get bored or that you get horribly confused. If it is the latter, I apologize. I would have guessed that the Henderson-Hasselbalch equation was developed in the nineteenth century, but it ws actually in the 20th century, which eliminates them from consideration at the present time. So instead, I have decided to write on John Dalton, of Dalton's Law of Partial Pressures, which you may (or may not) remember from high school chemistry. Dalton is also well known for his work in developing modern atomic theory. Whether or not you know much about either of these topics, it is easy enough to find information on his contributions in these areas. So I would like to focus in this post on two areas that receive less attention, his meteorological observations and studies on color blindness.<br />
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<tr><td style="text-align: center;"><a href="http://lh3.ggpht.com/-npNRqE2bpmU/UCWDYQyQC-I/AAAAAAAANGk/ZqZuH6oRytY/s1600-h/Dalton%252527s%252520System%252520of%252520Chemical%252520Philosophy%25255B6%25255D.jpg" style="margin-left: auto; margin-right: auto;"><img alt="Dalton's System of Chemical Philosophy" border="0" src="http://lh4.ggpht.com/-6rZqgBsMfl8/UCWDY5P_FTI/AAAAAAAANGs/KYorS0WUuKM/Dalton%252527s%252520System%252520of%252520Chemical%252520Philosophy_thumb%25255B2%25255D.jpg?imgmax=800" height="244" style="background-image: none; border: 0px; display: inline; padding-left: 0px; padding-right: 0px; padding-top: 0px;" title="Page from Dalton's <i>System of Chemical Philosophy</i>" width="138" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Dalton's atomic and <br />
molecular symbolism, from <i><br />A New System of Chemical Philosophy</i></td></tr>
</tbody></table>
Dalton’s interest in meteorology began while he was at school in Kendal, where he made the acquaintance of John Gough, who was nine years his senior. It was he who first suggested that Dalton keep a meteorological journal. Dalton made observations throughout his long life, including a measurement made the day before his death. His first book of observations, <i><a href="http://books.google.com/books?id=Ot8KAAAAIAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">Meteorological Observations and Essays</a>,</i> was published in 1793, with a second edition little changed from the first appearing in 1834. While some of the book is simply his observations, he also included descriptions of many of the techniques used in making observations of the weather in use at the time. He noted in the preface that “as the number of [barometers and thermometers] is increasing daily, many of them must fall into hands that are much unacquainted with their principles.” In addition to writing about barometers, thermometers, hygrometers, thunderstorms, snows, winds, and the Aurorae Boreales, he also included essays regarding these phenomenon, particularly Aurora Borealis and its connection with magnetism. It was his study of the atmosphere, a gas, that probably led to his interest in gases in general, which finally led him to his theories of atomic structure. He also attempted to come up with the structures of many molecules, but was not always right since he didn’t know how much each atom actually weighed. For instance, he thought that water was HO (one hydrogen atom and one oxygen atom) rather than H<sub>2</sub>O.<br />
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John Dalton also put much thought into color blindness, a condition that he suffered from. He gave a lecture at the Manchester Literary and Philosophical Society, of which he was a member, in 1794, describing the inconsistencies that he observed between how he saw color and how those around him saw colors. He wrote to a friend that “the flowers of most of the Cranesbills appear to me in the day almost exactly <em>sky blue</em>, whilst others call them <em>deep pink.</em>” (<em>The Worthies of Cumberland: John Dalton</em>, p. 101) He also noted that his brother and he agreed on the colors of things, which to modern ears suggests that it was genetic color blindness. Dalton suggested that the cause of the difference between his vision and others was that the fluid in his eye was tinted blue. As a true scientist, he suggested that his eyes should be dissected after his death to see if this was true. It was not, but the eyes were preserved by the Manchester Literary and Philosophical Society and recently the DNA was examined, showing that Dalton lacked one of the three photopigments in the eye. (If you wish to see the present state of his eyes and related images, I suggest you go to <a href="http://www.sciencephoto.com/set/803">http://www.sciencephoto.com/set/803</a>.) This theory of photopigments had been proposed by Thomas Young (1773-1829), one of Dalton’s contemporaries who established the wave theory of light, but even though Young’s view was more correct, color blindness has been historically called Daltonism. This just goes to show that you don’t have to be right to be remembered, you just have to be the first, or perhaps the clearest.<br />
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<b>Selected Works by Dalton</b><br />
<ul>
<li><a href="http://archive.org/details/newsystemofchemi01daltuoft" style="font-style: italic;">A New System of Chemical Philosophy</a>, vol. 1<i>.</i> (Manchester, Russell), 1808. </li>
<li><i><a href="http://books.google.com/books?id=Ot8KAAAAIAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">Meteorological Observations and Essays</a></i>, 2nd edition. (Manchester, Harrison and Crosfield) 1834. </li>
<li>“Extraordinary Facts Relating to the Vision of Colours: with Observations”. <em>Memoirs of the Literary and Philosophical Society of Manchester</em> <strong>5</strong> (1831) 28-45.</li>
</ul>
<b>References and further reading</b><br />
<ul>
<li>Kristine Krug, "<a href="http://news.bbc.co.uk/2/hi/science/nature/3178890.stm">Science celebrates 'father of nanotech'</a>", BBC News, October 10, 2003. </li>
<li>Robert Angus Smith, <em><a href="http://books.google.com/books?id=ZOsAAAAAYAAJ&printsec=frontcover#v=onepage&q&f=false" target="_blank">Memoir of John Dalton and History of the Atomic Theory up to his Time</a></em>. (Manchesterr, Sowler and Sons), 1856. </li>
<li>Henry Roscoe and Arthur Harden, <em><a href="http://books.google.com/books?id=0YwEAAAAYAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false" target="_blank">A New View of the Origins of Dalton’s Atomic Theory: A Contribution to Chemical History</a>. </em>(London, Macmillan and Co.), 1896. </li>
<li>John Millington, <em><a href="http://books.google.com/books?id=S0cDAAAAYAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false" target="_blank">John Dalton</a>. </em>(London, Dent & Co.), 1906. </li>
<li>D. M. Hunt, K. S. Dulai, J. K. Bowmaker, and J. D. Mollon, “<a href="http://www.sciencemag.org/content/267/5200/984" target="_blank">The Chemistry of John Dalton's Color Blindness</a>”. <em>Science</em> <strong>17</strong> (February 1995) 984-988. DOI: 10.1126/science.7863342. </li>
<li>Henry Lonsdale, <a href="http://books.google.com/books?id=xoMvAAAAMAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false" target="_blank"><em>The Worthies of Cumberland: John Dalton</em></a>. (London, Routledge and Sons), 1874. <em>This includes a selection of letters to and from Dalton about colorblindness.</em> </li>
<li>Thomas Young, “Bakerian Lecture: On the Theory of Light and Colours”. <em>Philosophical Transactions of the Royal Society of London</em> <strong>92 </strong>(November 12, 1801) 12-48. DOI: 10.1098/rstl.1802.0004.</li>
</ul>
Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com2tag:blogger.com,1999:blog-6520347334609073954.post-66640765411644495402012-07-15T17:28:00.002-04:002012-07-15T17:28:39.335-04:00Hans Geiger and the Geiger-Müller Counter<div style="text-align: right;">
</div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/1/17/Geiger,Hans_1928.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/1/17/Geiger,Hans_1928.jpg" width="160" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Hans Geiger (1882 - 1945)</td></tr>
</tbody></table>
The first SciHistory poll is responsible for the subject of this latest post, Hans Geiger. I will try to always have a poll open, so when you stop by, vote! And remember that you can always leave suggestion in the comments, even if it isn't at all relevant to the subject of the post. But on to more serious business. (And I do apologize. In rereading this post, it is kind of dull.)<br />
<br />
Hans Geiger was born in Germany and received his PhD from the University of Erlangen in 1906. After graduating, he went to England to work at the University of Manchester with Ernest Rutherford (1871-1937), who won the 1908 Nobel Prize in physics for his work with radioactive substances. One of the first projects that Geiger collaborated on in Rutherford's lab was the famous gold foil experiment, also called the Geiger-Marsden experiment (Marsden was an undergrad working with Geiger) or the Rutherford experiment. In this experiment, where helium nuclei (alpha particles) were fired at a thin sheet of gold, Rutherford hoped to better understand the actual composition of atoms. When some of the particles deflected at very high angles, a reasonable explanation was that rather than having the mass of an atom spread fairly evenly, there must be a highly concentrated nucleus to an atom. This experiment was vital to the modern understanding of the structure of the atom. <br />
<br />
Geiger continued to work with alpha-particles, developing the first detector for alpha particles in 1908. This consisted of a wire in a low pressure chamber with a voltage applied across the wire and the outside of the tube. The voltage is high enough that a current can almost, but not quite, flow through the gas. When an ionizing particle came into contact with the wire, it disturbs the system enough to complete the circuit, and the resulting completion can be detected by an audible click or by a pointer, depending on the type of counter. Design variables included the applied voltage, the pressure inside the chamber, and the length and diameter of the tube. Geiger continued to try to make more sensitive devices, and in 1913, after returning to Berlin to work at the German National Institute for Science and Technology, created a more sensitive device that used a needle that stuck into the middle of the detecting tube, rather than a wire connected at both ends. This version was able to detect both alpha and beta particles.<br />
<br />
Geiger served as an artillery officer during World War I, and when he returned to direct radiation research at the University of Kiel and the University of Tübingen, and later at Technische Hochschule in Berlin. It was while working with a post-doc, Walther Müller, at Kiel, that the next breakthrough in the Geiger counter occurred. Geiger wanted Müller to determine the precise effect of a positive ion on the counter, and in general to test different configurations, voltages, polarities, etc. It was as a result of this that Müller discovered a configuration that lead to an increase in sensitivity of about 100 times, which is why in many publications and discussions of Geiger counters, one finds them called Geiger-Müller counters. The increased sensitivity of this counter made them more useful for the detection of cosmic rays, which were a subject of much interest around that time. They could also be combined with cloud chambers to watch electrons moving individually.<br />
<br />
After this discovery, the sources that I have found don't talk about what Geiger did next much. He continued researching radiation in various forms, including cosmic rays and nuclear fission. He was involved in the German efforts to create a nuclear bomb, and died a few months after World War II ended. What I find most interesting about his story is that he, more than many of the other people that I have written about so far, worked in collaborations. The gold-foil experiment was done with Marsden, but the conclusions about the atom were Rutherford's. The improved Geiger counter was the work of a student. I think this way of doing research is much more what we are familiar with today, when papers can have ten co-authors and, especially as a graduate student, one's advisor's name is on everything. Clearly, Geiger made important contributions, but he was not working alone.<br />
<br />
<hr />
<b>Works by Geiger</b><br />
<ul>
<li><i><span style="font-style: normal;">Hans Geiger,</span> <a href="http://onlinelibrary.wiley.com/doi/10.1002/andp.19073270507/abstract" style="font-style: normal;">Strahlungs-, Temperatur- und Potentialmessungen in Entladungsröhren bei starken Strömen</a>, Annalen der Physik</i>, <b>327</b>, 5 (1907), 973-1007. doi: 10.1002/andp.19073270507.</li>
<li>Ernest Rutherford and Hans Geiger, <a href="http://rspa.royalsocietypublishing.org/content/81/546/162.full.pdf">The Charge and Nature of the Alpha-Particle</a>,
<i>Proceedings of the Royal Society of London A</i>, <b>81</b> (1908), 162-173. doi: 10.1098/rspa.1908.0066.</li>
<li>Hans Geiger, <a href="http://www.tandfonline.com/doi/abs/10.1080/14786440809463795">The Irregularities in Radiation from Radioactive Bodies</a>, <i>Philosophical Magazine Series 6</i>, <b>15</b>, 88 (1908), 539-547. doi:
10.1080/14786440809463795.</li>
<li>Hans Geiger, <a href="http://rspa.royalsocietypublishing.org/content/83/565/492.full.pdf">The Scattering of Alpha-Particles by Matter</a>, <i>Proceedings of the Royal Society of London A</i>, <b>83</b> (1910), 492-504. doi: 10.1098/rspa.1910.0038.
</li>
<li>Hans Geiger and Walther Müller, "<a href="http://www.springerlink.com/content/g1041020wtl54808/">Elektronenzahlrohr zur Messung schwachster Aktivitaten</a> (Electron counting tube for the measurement of the weakest radioactivities)". <i>Die Naturwissenschaften</i> (The Sciences) <b>16,</b> 31 (1928), 617-618. doi:
10.1007/BF01494093.</li>
</ul>
<div>
<b>References and Further Reading</b><br />
<ul>
<li>"<a href="http://www.britannica.com/EBchecked/topic/227810/Hans-Geiger">Hans Geiger</a>". <i>Encyclopædia Britannica Online</i>. Encyclopædia Britannica Inc., 2012. Accessed July 13, 2012.</li>
<li>Thaddeus Trenn, "The Geiger-Müller Counter of 1928", <i>Annals of Science</i> <b>43</b>, 2 (1986), 111-135.</li>
<li>"<a href="http://web.mit.edu/invent/iow/geiger.html">Geiger Counter</a>", Lemelson-MIT Inventor of the Week, February 2005.</li>
<li>M. Walter and A. W. Wolfendale, "Early history of cosmic particle physics", <i>The European Physical Journal H</i> (2012). doi:
10.1140/epjh/e2012-30020-1
</li>
<li>Paul Frame, "<a href="http://graphics.tx.ovid.com/ovftpdfs/FPDDNCJCEGFEJO00/fs046/ovft/live/gv025/00004032/00004032-200506000-00008.pdf">A history of radiation detection instrumentation</a>", <i>Health Physics</i> <b>88</b>, 6 (2005), 613-637.</li>
</ul>
</div>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0tag:blogger.com,1999:blog-6520347334609073954.post-11361144953661363802012-06-22T18:28:00.000-04:002012-06-22T18:28:00.533-04:00Arnold Sommerfeld: Father of Quantum Physicists<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/3/3e/Sommerfeld,Arnold_1935_Stuttgart.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/3/3e/Sommerfeld,Arnold_1935_Stuttgart.jpg" width="160" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Arnold Sommerfeld <br />
(1868-1951)</td></tr>
</tbody></table>
Arnold Sommerfeld is a man that I had not heard of until taking a course in solid state physics. And I apologize to those of you who may hear the name with dread, but despite creating the Sommerfeld Equation, he really is an interesting guy, so please stick with me. And I will only mention the Sommerfeld Equation one more time. While he appears to have been known in his own time as a great mathematician and physicist, he is even better known by the students that he advised. These include Werner Heisenberg, Wolfgang Pauli, Peter Debye, and Alfred Landé, among many others. And these are just the students considered to be his advisees by the mathematics genealogy project. Others famous men who studied with Sommerfeld include Linus Pauling, Léon Brillouin, and Rudolf Peierls. He also has the unfortunate honor of being the man between 1901 and 1950 to receive the most nominations for a Nobel Prize without actually winning one, receiving eighty-one nominations.<br />
<br />
Arnold Sommerfeld was born in 1868 in Germany, and studied mathematics and natural science at the University of Köningsberg, receiving his PhD in 1891. He was an assistant professor at the University of Göttingen in mathematics and in mineralogy, before becoming a professor of mathematics at the Mining Academy of Claustel and then a professor of mechanics at the Institute of Technology of Aachen. In 1906 he become the head of the Department of Theoretical Physics at the University of Munich, a position that had previously been held by Ludwig Boltzmann. The University of Munich was well known in the field of theoretical physics, so this was both a great honor and a wonderful opportunity for Sommerfeld to influence a new generation of physicists. He taught there from 1906 to 1935, when he retired. <br />
<br />
When he receive the post of chair of Theoretical Physics, Sommerfeld wanted to learn more about the field, since he himself was a mathematician, not a physicist. He asked Abraham Joffe, who had helped to discover x-rays, for help in understanding physics. He suggested that they meet every morning at a café to discuss experimental physics, and these discussions quickly included many more scholars eager to discuss new ideas. Apparently he was a great lecturer, and was able to explain the complexities of atomic structure and other confusing topics with great clarity.<br />
<br />
His research started out in the field of the propagation of radio waves, which now seems rather outdated, but at that time was of vital importance. The telephone had been developed in the late nineteenth century, but by 1900, most people conveyed important communications by telegraph. While telegraphs traveled by wires in many parts of the country, telegraphs to ships required radio waves, and the difficulties with sustaining a cable across the Atlantic meant that transatlantic communications would have to be by radio waves. The first wireless telegraph was patented in 1897 by Guglielmo Marconi (who shared the Nobel Prize in physics in 1909 for his work with wireless telegraphy), and the first transatlantic telegraphic communications via radio waves were accomplished in 1901. Sommerfeld's 1909 paper "The Propagation of Waves in Wireless Telegraphy" was thus of vital importance at the time, and has been oft cited.<br />
<br />
As well as working with radio waves, Sommerfeld also worked with x-rays, still a very new and mysterious phenomenon, and his student Max von Laue showed that x-rays are also an electromagnetic wave (and won a Nobel Prize for it). Sommerfeld went on to develop the relativistic quantum theory of the fine structure of the hydrogen spectrum. Quantum theory is difficult enough, but adding relativity is quite an accomplishment. I first met the name Sommerfeld when considering the electronic theory of metals, where he developed the Sommerfeld Equation as a method to approximate functions as a function of temperature. He is also famous for his work with atomic theory and atomic physics, in the end publishing a six volume series on the subject of theoretical physics and going on two lecture tours in the United States. Unfortunately, however, he met his death as a result of an automobile accident in 1951. As Linus Pauling wrote, "The hazard of a mechanized world has prevented his students from celebrating during his lifetime still further anniversaries of the birth of this great man."
<br />
<br />
<hr />
<b>Other works by Sommerfeld</b><br />
<ul>
<li>"Über die Ausbreitung der Wellen in der drahtlosen Telegraphie (The propagation of waves in wireless telegraphy)", <i>Ann. der Phys.</i>, <b>28</b> (March 1909), 665-736. (This is the same as volume 333. They renumbered them in 2010.) doi: 10.1002/andp.19093330402</li>
<li>"Über die Ausbreitung der Wellen in der drahtlosen Telegraphie (The propagation of waves in wireless telegraphy)", <i>Ann. der Phys.</i>, <b>81</b> (December 1926), 1135-1153. (Now volume 386) doi: 10.1002/andp.19263862516.</li>
</ul>
<br />
<b>References and further reading</b><br />
<ul>
<li>Elisabeth Crawford, "<a href="http://physicsworld.com/cws/article/print/2001/nov/05/nobel-population-1901-to-50-anatomy-of-a-scientific-elite">Nobel population 1901-50: anatomy of a scientific elite</a>", Nov 5, 2001, <i>Physics World.</i></li>
<li>Suman Seth, "<a href="http://onlinelibrary.wiley.com/doi/10.1002/bewi.200801339/abstract">Mystik and Technik</a>: Arnold Sommerfeld and Early-Weimar Quantum Theory", <i>Berichte zur Wissenschaftsgeschichte</i> <b>31</b>, 4 (2008) 331-352.</li>
<li>Linus Pauling, "<a href="http://www.jstor.org/stable/1679525">Arnold Somerfeld: 1868-1951</a>", <i>Science</i> <b>114</b>, 2963 (Oct. 12, 1951) 383-384.</li>
<li>"<a href="http://dx.doi.org/10.1063/1.1710387">Professor Arnold Sommerfeld</a>", <i>Journal of Applied Physics</i> <b>9</b>, 12 (Dec. 1, 1938) 754-755.</li>
<li>Steven Schot, "<a href="http://www.sciencedirect.com/science/article/pii/031508609290004U">Eighty years of Sommerfeld's radiation condition</a>", <i>Historia Mathematica</i> <b>19</b>, 4 (Nov. 1992) 385-401.</li>
<li>John. J. Fahie, <a href="http://openlibrary.org/books/OL7201978M/A_history_of_wireless_telegraphy_1838-1899" style="font-style: italic;">A History of Wireless Telegraphy, 1838-1899</a>, Blackwood, Edinburgh, 1899.</li>
<li>"Arnold Sommerfeld", <i>Physics Today</i> <b>4</b>, 12 (1951) 21.</li>
<li>Joachim Pietzsch, "<a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1914/perspectives.html">The Nobel Prize in Physics 1914 - Perspectives</a>", Nobelprize.org</li>
</ul>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0tag:blogger.com,1999:blog-6520347334609073954.post-44599415838500226522012-04-15T21:59:00.001-04:002012-04-15T22:00:05.627-04:00Svante Arrhenius: A Man of Many Interests<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-euZzi3x6FZw/T3NXccJ3zmI/AAAAAAAAMog/tfKxRzSbfb4/s1600/Arrhenius_Svante.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://3.bp.blogspot.com/-euZzi3x6FZw/T3NXccJ3zmI/AAAAAAAAMog/tfKxRzSbfb4/s1600/Arrhenius_Svante.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Svante Arrhenius<br />
(1859 - 1927)</td></tr>
</tbody></table>
I'm sorry it's been awhile since my last post, but classwork caught up with me at last. I've been planning to write on Svante Arrhenius for two months now, when he came up in several homework assignments at the same time, and I expected this to be a simple post to write, since Arrhenius is best known, in my opinion, for his equation connecting the activation energy of a process and its kinetics. First, I found out that this was not the work for which he earned the Nobel Prize in Chemistry, and, more surprisingly, I discovered that he was also one of the first scientists to work out the effects of the greenhouse effect and he also postulated global warming resulting from human CO<sub>2</sub> production. So between classwork, research, and Arrhenius being a more complicated person to write on than I though, this post has taken a while. I will do my best to represent what Arrhenius actually wrote about global warming, but I can't read everything he wrote about the subject for this short post, so if you are curious, I would encourage you to look at some of his original writings, which are referenced and linked throughout.<br />
<br />
Arrhenius was born in Vik, Sweden, in 1859. His father was a land surveyor associated with the University of Uppsala, and the following year the family moved to Uppsala. Here Arrhenius studied at the cathedral school, showing aptitude in mathematics. He studied chemistry, physics, and mathematics at the University of Uppsala, but wanted a more rigorous physics education and went to Stockholm to study with Erik Edlund. His work there resulted in his thesis, "<a href="http://archive.org/details/recherchessurla00arrhgoog">Investigations on the galvanic conductivity of electrolytes</a>." This post's moral for graduate students is don't be discouraged if people think your ideas are wrong. When Arrhenius submitted this thesis to the University of Uppsala, some of the professors were doubtful of its merit. He proposed what is now universally accepted, that some chemical species dissociate in water into positive and negative ions, and that the degree of dissociation can depend on the concentration. Michael Faraday (1791-1867) had already proposed ionic species, but only in the presence of an electric current. In the end, his thesis was accepted. <br />
<br />
One of the main proponents of his ideas was Wilhelm Ostwald (1853-1932), with whom Arrhenius was able to work as a result of a travel grant from the Academy of Sciences in the late 1880s. He also worked with Ludwig Boltzmann (1844-1906), an Austrian physicist who was a proponent of the atom and a developer of statistical thermodynamics; Jacobus van 't Hoff (1852-1911), a Dutch chemist who studied, among other things, chemical kinetics and osmotic pressure; and Frederich Kohlsrauch (1840-1910), a German physicist also interested in the conductivity of electrolytic solutions. Arrhenius's theory of electrolytes helped to explain some abnormalities in osmotic pressure data that van 't Hoff had found, and his discussions with these men enabled him to elaborate on his theory of dissociation to explain increases from the expected boiling point elevations and freezing point depressions in some materials by species dissociation. These men were all instrumental in the formation of the modern field of physical chemistry. It was for this work, begun in his dissertation, that he won the Nobel Prize in Chemistry in 1903.<br />
<br />
As I mentioned before, Arrhenius also studied the greenhouse effect. The greenhouse effect, that the Earth's atmosphere can trap heat from the sun, had been proposed earlier by Joseph Fourier (1768-1830) in the 1820s. John Tyndall (1820-1893), proved that both water and carbon dioxide can act as what we now call greenhouse gasses. Arrhenius took their ideas and applied them to the question of whether the cycles of ice ages could be explained by changes in carbon dioxide in the air. He did the extensive calculations to show that if the amount of carbon dioxide in the air doubled, the temperature of the earth would increase by five to six degrees Celsius. He published these findings in the the Philosophical Magazine and Journal of Science under the title "<a href="http://www.globalwarmingart.com/images/1/18/Arrhenius.pdf">On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground</a>" in 1896. He had worked with his friend Arvid Högbom (1857-1940), a professor of geology at the University of Uppsala, who had considered carbon dioxide cycles over time. Arrhenius went further, and in his book <a href="http://archive.org/details/worldsinmakingev00arrhrich"><i>Worlds in the Making</i></a> (1908, p. 54), suggested that the burning of coal could be leading to an increase in carbon dioxide in the atmosphere, though much of it is absorbed into the oceans.<br />
<br />
Arrhenius lived for thirty more years and did many more things, including being the head of the Nobel Institute for Physical Chemistry. But, I've gone on for a bit about him already and hit some of the highlights, so I'm going to stop here. If you are still interested in Arrhenius, you might want to look up his writings on popular science (including <i>Worlds in the Making </i>and <i>Life of the Universe</i>); his work on hydroelectric power, the electrification of the Swedish railroads, and immunochemistry; and his successful efforts to obtain the release of scientists made prisoners of war during World War I. But to touch on those would mean more for you to read, and, more importantly, more for me to research, so I will leave Arrhenius with that. <br />
<br />
<hr />
<b>Other works by Arrhenius</b><br />
<br />
<ul>
<li><a href="http://books.google.com/books?id=M5U3AAAAMAAJ&printsec=frontcover#v=onepage&q&f=false" style="font-style: italic;">Textbook of Electrochemistry</a>, 1902</li>
<li><a href="http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1903/arrhenius-lecture.pdf">Nobel Lecture</a>: Development of the theory of electrolytic dissociation, 1903</li>
<li><i><a href="http://books.google.com/books?id=Cd08AAAAYAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">Theories of Chemistry</a></i>, lectures given at the University of California at Berkeley in 1904 on the history of chemistry</li>
<li><a href="http://books.google.com/books?id=Pyu6AAAAIAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false"><i>Immunochemistry: The Application of the Principles of Physical Chemistry to the Study of Biological Antibodies</i></a>, also lectures given at Berkeley in 1904</li>
<li><i>Life of the Universe, </i><a href="http://archive.org/details/lifeofuniverseas01arrhuoft">Vol. 1</a> and <a href="http://books.google.com/books?id=6gJJAAAAIAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">Vol. 2</a>, 1909</li>
<li><a href="http://books.google.com/books?id=w_EDb7HOQ9gC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false" style="font-style: italic;">Theory of Solutions</a>, lectures given at Yale University in 1911</li>
</ul>
<br />
<b>References and further reading</b><br />
<br />
<ul>
<li><a href="http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1903/arrhenius.html">The Nobel Prize in Chemistry 1903: Svante Arrhenius</a></li>
<li>Henning Rodhe, Robert Charlson, and Elizabeth Crawford, "<a href="http://www.jstor.org/stable/4314542" style="font-style: italic;">Svante Arrhenius and the Greenhouse Effect</a>", <i>Ambio</i> 26, no. 1, "Arrhenius and the Greenhouse Gases" (Feb., 1997), pp. 2-5.</li>
<li>Gustaf Arrhenius, Karin Kaldwell, and Svante Wold, <a href="http://www.iva.se/upload/Verksamhet/H%C3%B6gtidssammankomst/Minnesskrift%202008.pdf">Tribute to the Memory of Svante Arrhenius</a>, 2008</li>
<li>"<a href="http://www.aip.org/history/climate/co2.htm#N_5_">The Discovery of Global Warming</a>". Sorry about this one. I'm not sure who wrote it and what it's credentials are, which I try to avoid when writing these, but it seems sound and has a lot of references that are easy to follow up on. It appears to be by Spencer Weart, who wrote <i>The Discovery of Global Warming</i>, a book published in 2003 and 2008.</li>
<li><i>The Telegraph</i>, "<a href="http://www.telegraph.co.uk/earth/copenhagen-climate-change-confe/6729732/Copenhagen-climate-summit-gloomy-Swede-Svante-Arrhenius-saw-chill-wind-of-change.html">Copenhagen climate summit: gloomy Swede Svante Arrhenius saw chill wind of change</a>," December 4, 2009.</li>
</ul>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0tag:blogger.com,1999:blog-6520347334609073954.post-3339859090858204292012-02-17T20:28:00.000-05:002012-02-17T20:29:50.723-05:00Brook Taylor: Much More than a SeriesClasses and research have been keeping me busy, so this post will also be on someone I have been tackling in my homework this week. One of the main things that I have learned in graduate school thus far is that none of the equations we use are "correct." They are all approximations of one sort or another, whether because we can't solve the real equation or because we can't take into account all of the interactions. One of the most common tools for these approximations, when we have an equation but don't want to deal with it, is to use the Taylor expansion. I hadn't given it or him much thought until this week, but they just keep popping up, so Taylor is this week's subject.
<br />
<br />
Modern chemistry seems to have developed in the 19th century. That's when scientists finally agreed that atoms exist, and developed the modern concepts of energy and heat. Mathematics, however, seems to have had a heyday in the 18th century based on the number of mathematical operators, functions, rules, etc. that have been named after the mathematicians of that century. These include Laplace, Lagrange, L'Hopital, Maclaurin, Euler, Gauss, Fourier, Legendre, and, of course (or else this interlude would be rather pointless), Brook Taylor.
<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-3Zfhesklr8M/Tzh0oKp7wSI/AAAAAAAAMes/Nc221QCE_lA/s1600/Brook_Taylor.JPG" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://4.bp.blogspot.com/-3Zfhesklr8M/Tzh0oKp7wSI/AAAAAAAAMes/Nc221QCE_lA/s200/Brook_Taylor.JPG" width="177" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Brook Taylor<br />
(1685-1731)</td></tr>
</tbody></table>
In reading about Brook Taylor, I realized that, more than anyone I have discussed so far, I feel that I cannot do him justice. This stems from two main causes: my lack of understanding of the finer points of mathematics and its history, and the number of interesting things that I discovered about Taylor.
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Brook Taylor was an Englishman, born in 1685. He went to St. John's College at Cambridge and studied mathematics, which was apparently quite popular in those days. He began writing and publishing on mathematical subjects, but didn't publish soon enough after his discoveries to avoid trouble. In 1708 he developed a solution to the problem of the center of oscillation. I still haven't quite figured out what this is, but apparently it was a big deal. He didn't publish his discovery, however, until 1713: <a href="http://www.jstor.org/stable/103176">De Inventione Centri Oscillationis</a>.<sup>1</sup>
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Meanwhile, Johann Bernoulli had independently come to the same discovery, and argued about precidence with Taylor. In 1715 he published <a href="http://books.google.com/books?id=r-Gq9YyZYXYC&">Methodus Incrementorum Directa et Inversa</a>, which first introduced to the public what became known as Taylor's Theorem. The work was also the first discussion of what came to be known as the calculus of finite differences, for more information on which you will have to ask a mathematician. Taylor was not the first person to use the series, but he made the most general form of it. Specific instances had already been used by Edmond Halley, Isaac Newton, Johann Bernoulli, and Johann Kepler. The importance of the series was overlooked for many years, until it was pointed out by Joseph Lagrange in 1772. Other problems that he solved in this book involved oscillations of a string and a change of variables formula. He also write papers and letters on the subjects of magnetism, the movement of fluids, and logarithms. His writing, however, suffered from a brevity that lead to confusion about what he actually meant, which led to his being under appreciated for all of the contributions that he made to mathematics.<br />
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In 1715 Taylor also published a work on linear perspective, followed in 1719 by <a href="http://books.google.com/books?id=nalbAAAAQAAJ&">New Principles of Linear Perspective</a>, in both of which he used mathematics to explain linear perspective more generally than those before him had. Bernoulli, with whom Taylor had already had heated arguments, declared that the book was "abstruse to all," especially artists. Bernoulli's objections were so strong that Taylor wrote a reply in the <i>Philosophical Transactions</i>, <a href="http://www.jstor.org/stable/103347">Apologia D. Brook Taylor, J V D. & R S. Soc. contra V. C J. Bernoullium, Math. Prof. Basileae</a>. I think Bernoulli had a point, though, since Taylor's works on perspective contained no sketches, just written descriptions, and even when he wasn't writing about art, he had a tendency to be concise to the point of confusion.
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Taylor had been elected a member of the Royal Society in 1712, and had sat on the committee which adjudicated between Newton and Leibniz on the issue of which had invented calculus (they sided with Newton). After about 1715, Taylor began writing more philosophical papers, such as "On the Lawfulness of Eating Blood." His final paper in the <i>Philosophical Transactions </i>was "<a href="http://www.jstor.org/stable/103619">An Account of an Experiment, Made to Ascertain the Proportion of the Expansion of the Liquor in the Thermometer, with Regard to the Degrees of Heat</a>," published around 1721. He seems to have focused more on domestic matters and his health after that time, for in 1721 he also married. His father disapproved of his wife, which suggests that Taylor, for one, married for love. When she died in childbirth two years later, however, he and his father became reconciled. In 1729 (1725?) he married again, but she also died in childbirth. Taylor died just one year later.
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1. Most articles I found said that it wasn't until 1714 that he published it, but I think this is the article in question, and according to Jstor it was published in 1713. So that is what I'm going with.<br />
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References and further information<br />
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<a href="http://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Taylor,_Brook">Brook Taylor</a>, 1911 Encyclopedia Britanica<br />
<a href="http://www-history.mcs.st-andrews.ac.uk/Biographies/Taylor.html">Brook Taylor</a>, from someone at the University of St. Andrews<br />
<a href="http://en.wikisource.org/wiki/Taylor,_Brook_(DNB00)">Brook Taylor</a>, by Edward Irving Carlyle, <i>Dictionary of National Biography, 1885-1900</i>, vol. 55.<br />
<a href="http://books.google.com/books?id=m0cEAAAAYAAJ&pg=PR23&dq#v=onepage&q&f=false">Dr. Brook Taylor's Principles of Linear Perspective</a>, edited by Joseph Jopling, 1835.<br />
<i style="background-color: #e4f2e4; font-family: sans-serif; font-size: 13px; line-height: 19px; text-align: center;"></i>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com3tag:blogger.com,1999:blog-6520347334609073954.post-5023471255582444582012-02-02T08:32:00.000-05:002012-02-02T10:19:06.969-05:00Diesel and His Engine<div class="separator" style="clear: both; text-align: center;">
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-mW0yA90_uDI/TyDJnzZN4OI/AAAAAAAAMdo/kPX9Nz6i66Q/s1600/Diesel.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://4.bp.blogspot.com/-mW0yA90_uDI/TyDJnzZN4OI/AAAAAAAAMdo/kPX9Nz6i66Q/s320/Diesel.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Rudolf Diesel<br />
(1858-1913)</td></tr>
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<span style="font-family: Arial, Helvetica, sans-serif;">I've been hoping to find a scientist or engineer with an interesting story, and I think I found one. I was looking for information on how to synthesize monoglycerides, and discovered that the process is similar to making bio-diesel, which then begs the question (at least to me), what is diesel and why is it called that?</span>
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<span style="font-family: Arial, Helvetica, sans-serif;">Rudolf Diesel invented the diesel engine, and thus in a remarkable fit of (probably) proper attribution, has his name attached to it. He is an interesting character, because he wanted to improve the efficiency of engines and change the world, a vision that I think few engineers really believe in today.</span>
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<span style="font-family: Arial, Helvetica, sans-serif;">Diesel had a disjunct childhood. He was born in Paris to Bavarian parents in 1858, but was sent to school in England in 1870 as a result of the Franco-Prussian War. Less than a year later, he was sent to the Technical School in Augsburg, Germany. He graduated from the Techincal University in that city in 1880, and began working with Carl von Linde (1842-1934) in Munich. Von Linde had recently developed a method for refrigeration using ammonia and was therefore very interested in the studies of heat. In 1895, he even succeeded in liquefying air.<span class="MsoFootnoteReference"><span style="line-height: 115%;"><sup><a href="http://historyofsci.blogspot.com/2012/02/diesel-and-his-engine.html#f1">1</a></sup><a href="http://historyofsci.blogspot.com/2012/02/diesel-and-his-engine.html" name="f1b"></a></span></span></span>
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://www.google.com/patents?id=oV5wAAAAEBAJ&pg=PA2&img=1&zoom=4&hl=en&sig=ACfU3U3R9uklfK-iIsniFvcwD1PsYti_AA&ci=74%2C120%2C746%2C1171&edge=0" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><span style="font-family: Arial, Helvetica, sans-serif;"><img border="0" height="320" src="http://www.google.com/patents?id=oV5wAAAAEBAJ&pg=PA2&img=1&zoom=4&hl=en&sig=ACfU3U3R9uklfK-iIsniFvcwD1PsYti_AA&ci=74%2C120%2C746%2C1171&edge=0" width="203" /></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">Drawing from Diesel's apparatus for </span><br />
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">converting heat into work, </span><br />
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small;">US Pat. #542846</span></td></tr>
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Working with von Linde, Diesel was able to work on a problem that he had begun considering when an undergraduate. Steam engines were more efficient when large, so Diesel set out to develop an engine that would still be efficient when small. He was particularly interested in the ideal engine envisioned by Sadi Carnot (1796-1832) and descrived in 1824, called the Carnot cycle. At first, Diesel designed an engine similar to a steam engine that ran on ammonia, but, though the engine did work on a smaller scale than steam, he ran into problems like leakage. He then considered a case in which the combustion of the fuel took place in a cylinder of the engine, rather than in a boiler. Nikolaus Otto, a German engineer, had created the first marketed internal combustion engine in 1862, so this idea was not new. What made Diesel's engine different was that it did not need a spark to ignite the fuel, but used higher compression ratios than the existing internal-combustion engines, leading to self-ignition. It was this isothermal combustion that set the diesel engine apart.
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Diesel worked on models of the engine at the Augsburg-Nuremburg Engine Works with its financial backing and that of Krupp (a company that still exists today as ThyssenKrupp). One of the greatest challenges was creating chambers that could withstand the large pressures that Diesel required for combustion. After four years of testing and various accidents, Diesel and his manufacturing aides created a working prototype engine in 1897. The engines got off to a rocky start. Diesel tried to market his invention immediately, but there were still some kinks to work out. Several accidents making dents in Diesel's profits from the patents he had taken out (see the <a href="http://historyofsci.blogspot.com/2012/02/diesel-and-his-engine.html#list">list</a><a href="http://historyofsci.blogspot.com/2012/02/diesel-and-his-engine.html" name="listb"></a> in references for more information).
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Diesel had a larger vision for his engine than just making it more efficient. He thought that his engine could transform society. Since his engines worked on a smaller scale than the steam engines, they could be used by small craftsmen and help to counteract that increase in the scale of manufacturing resulting from the industrial revolution. Diesel was part of a movement that believed that technology could save the world. Rather than having the workers rise up as Marxism called for, he believed that technology could better the lot of workers and narrow the class divide, so such a revolution would not be necessary. He did, however, believe in a form of communism in which workers would pool their resources for the greater common good. He presnted his ideas in a 1903 book entitled <a href="http://books.google.com/books?id=CYPXAAAAMAAJ&printsec=frontcover&dq=naturliche+wirtschaftliche+erlosung&hl=en&sa=X&ei=PaolT7z0J8SXgweFx72FCQ&ved=0CDIQ6AEwAA#v=onepage&q&f=false" style="line-height: 18px;"><i>Solidarismus: Natürliche wirtschaftliche Erlösung des Menschen</i></a><span style="line-height: 18px;"> (Solidarity: The Rational Economic Salvation of Mankind). </span>
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In 1912, questions about whether Diesel actually invented the diesel engine came to a head. Some people argued that credit needed to go to the factory assistants, rather than Diesel. When a history of the diesel engine was to be published, Diesel preempted whatever it might say about him by presenting a paper explaining his development of the engine at the German Society of Naval Architects. This might seem a strange place to give such a paper, but the main use of diesel engines at that point was in ships.
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The following year, Diesel was crossing the English channel and went overboard during the night. This incident led to much speculation about how he died, though the most likely explanation is that he committed suicide. The most interesting story that I came across was that he was killed by the German secret service to prevent him from betraying secrets about submarines to the British.
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<span class="MsoFootnoteReference"><span class="MsoFootnoteReference" style="font-family: Arial, Helvetica, sans-serif; line-height: 18px;"><span class="MsoFootnoteReference"><a href="http://historyofsci.blogspot.com/2012/02/diesel-and-his-engine.html" name="f1"></a>1. <a href="http://www.chemheritage.org/discover/chemistry-in-history/themes/early-chemistry-and-gases/linde.aspx">Carl von Linde</a> </span></span><a href="http://historyofsci.blogspot.com/2012/02/diesel-and-his-engine.html#f1b" style="font-family: Arial, Helvetica, sans-serif; line-height: 18px;">(back)</a></span>
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Holmgren, E. J., "<a href="http://www.nature.com/nature/journal/v181/n4611/pdf/181737a0.pdf">Rudolf Diesel, 1858-1913</a>" <i>Nature</i> <b>181</b>, no. 4611 (1958), 737-738.<br />
<span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="line-height: 115%;">Bryant, Lynwood, "<a href="http://www.jstor.org/stable/3103523">The Development of the Diesel Engine</a>" <i>Technology and Culture</i> <b>17</b>, no. 3 (Jul., 1976), 432-446.</span></span></span><br />
<span class="MsoFootnoteReference"><span style="line-height: 115%;"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="line-height: 115%;">Thomas, Donald Jr., "<a href="http://www.jstor.org/stable/3103371">Diesel, Father and Son: Social Philosophies of Technology</a>" <i>Technology and Culture </i><b>17</b>, no. 3 (Jul., 1978), 376-393.</span></span></span></span></span><br />
<span style="line-height: 18px;"></span><span class="MsoFootnoteReference"><span style="line-height: 115%;">
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<a href="http://historyofsci.blogspot.com/2012/02/diesel-and-his-engine.html" name="list"></a><b>List of Diesel's patents</b><a href="http://historyofsci.blogspot.com/2012/02/diesel-and-his-engine.html#listb"> (back)</a><br />
US Pat. #<a href="http://www.google.com/patents?hl=en&lr=&vid=USPAT542846&id=oV5wAAAAEBAJ&oi=fnd&dq=diesel&printsec=abstract#v=onepage&q&f=false">542846</a> Method of and Apparatus for Converting Heat into Work, filed August 26, 1892<br />
US Pat. #<a href="http://www.google.com/patents?id=vQVgAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false">608845</a> Internal-Combustion Engine, filed July 15, 1895<br />
US Pat. #<a href="http://www.google.com/patents?hl=en&lr=&vid=USPAT673160&id=FpFKAAAAEBAJ&oi=fnd&dq=diesel&printsec=abstract#v=onepage&q&f=false">673160</a><b> </b>Method of igniting and regulating combustion for internal-combustion engines, filed April 6, 1898<br />
US Pat. #<a href="http://www.google.com/patents?hl=en&lr=&vid=USPAT654140&id=hrlSAAAAEBAJ&oi=fnd&dq=diesel&printsec=abstract#v=onepage&q&f=false">654140</a> Apparatus for Regulating Fuel-Supply of Internal-Combustion Engines, filed September 10, 1898</span></span><br />
<span class="MsoFootnoteReference"><span style="line-height: 115%;">US Pat. #<a href="http://www.google.com/patents/US736944?printsec=abstract#v=onepage&q&f=false">736944</a> Internal-Combustion Engine, filed November 1, 1899</span></span><br />
<span class="MsoFootnoteReference"><span style="line-height: 18px;">US Pat. #</span><a href="http://www.google.com/patents?hl=en&lr=&vid=USPATRE11900&id=sOchAAAAEBAJ&oi=fnd&dq=diesel&printsec=abstract#v=onepage&q&f=false" style="line-height: 18px;">RE11900</a><span style="line-height: 18px;"> Internal-Combustion Engine, filed July 3, 1900</span></span><br />
<span class="MsoFootnoteReference"><span style="line-height: 115%;">US Pat. #<a href="http://www.google.com/patents?hl=en&lr=&vid=USPAT708029&id=VzhmAAAAEBAJ&oi=fnd&dq=diesel&printsec=abstract#v=onepage&q&f=false">708029</a> Internal-Combustion Engine, filed January 18, 1901</span></span><br />
<span class="MsoFootnoteReference"><span style="line-height: 115%;"><span style="font-size: small;">US Pat. #</span><a href="http://www.google.com/patents?hl=en&lr=&vid=USPAT873926&id=qslhAAAAEBAJ&oi=fnd&dq=diesel&printsec=abstract#v=onepage&q&f=false">873926</a> Longitudinally-Displaceable Car-Body for Motor-Vehicles, filed January 25, 1908</span></span><br />
<span style="font-family: 'Times New Roman', serif;"><span style="line-height: 18px;"><br /></span></span>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0tag:blogger.com,1999:blog-6520347334609073954.post-68088580751100621252012-01-27T18:32:00.000-05:002012-01-28T10:25:07.008-05:00Fick and Diffusion<div class="separator" style="clear: both; text-align: center;">
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-f5-EyfNFHaY/Txy-r5BU1DI/AAAAAAAAMb8/Xke4AJGoEhM/s1600/Adolph_Fick.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://4.bp.blogspot.com/-f5-EyfNFHaY/Txy-r5BU1DI/AAAAAAAAMb8/Xke4AJGoEhM/s200/Adolph_Fick.jpg" width="152" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Adolf Fick<br />
(1829-1901)</td></tr>
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I've been working on homework for a phase transformations class this week, and all of the problems have involved Fick's First and Second Laws of Diffusion, so he seemed to be a very obvious choice of subject this week. Adolf Fick actually began his studies as a mathematician and physicist, but switched to medicine and got his PhD in 1851. His thesis, rather than being on fluids as one might expect, was on astigmatism. He taught at Zurich and then at Würzburg until his retirement.<br />
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I haven't been able to find anything about Fick's personal life except that he had a son, but he was quite active in his scholarly life. He continued to apply the principles of physics and math to his study of medicine, and published works on how joints are articulated, where muscles get energy, how to measure blood pressure, how to measure how much carbon dioxide we exhale, and how we sense light and color.<br />
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I'd like to briefly introduce two of his inventions before returning again to diffusion. He designed the first tonometer, which measures intraocular pressure (in the eye). If you have ever been to an optometrist, they generally measure this now by puffing air into your eye. Fick's method involved direct contact. Using Fick's tonometer, one would press a plate against the eye and measure the force required to flatten the cornea to a specific diameter. Fick's particular contribution was developing a mathematical way to converting the surface area of the contact between the eye and a plate and the force exerted on that plate into a measure of the pressure within the eye. This relationship is often called the Imbert-Fick Law, since it was also discovered by Armand Imbert (1850-1922). The tonometer and Fick's studies of eyes led his nephew, also called Adolf Fick (1852-1937), to develop the first contact lenses in the late 1880s.<span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;"><sup><a href="http://historyofsci.blogspot.com/2012/01/fick-and-diffusion.html#f1">1</a></sup></span></span><br />
<span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;"></span></span><br />
Another of Fick's major contributions to medicine is known as Fick's principle or Fick's method. I had never heard of these before researching this post, but perhaps those of you with a background in medicine will be more familiar with them. Fick's principle provides a method for measuring cardiac output, or how much blood is being pumped by the heart. He assumed that the rate at which oxygen is consumed is proportional to the rate of blood flow and the rate of oxygen absorption by red blood cells. By comparing the amount of oxygen in the blood entering and exciting the lungs, the rate of oxygen absorption can be measured, and from this the rate of blood flow can be deduced as being the rate of oxygen absorption over the difference in oxygen. This principle can also be applied to blood flow through other organs, but as you can imagine, it is invasive and requires drawing and analyzing blood and oxygen consumption, but despite this, Fick's method is still referenced in literature today.<br />
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But back to diffusion. Fick began his studies of diffusion after noticing that Thomas Graham (1805-1869), though he studied diffusion of salts in water and gases, had not developed a fundamental law describing diffusion. Fick sought to rectify that. He did not start from scratch, however, but recognized that the diffusion of atoms would be similar to the diffusion of heat. Equations regarding heat transfer had been formulated in 1811 by Joseph Fourier (1768-1830). Fick pointed out that these equations had already been applied by Georg Ohm (1789 – 1854) to the diffusion of electricity in a conductor, so he set out to apply them now to the question of diffusion of liquids. He published his paper <a href="http://books.google.com/books?id=MVIwAAAAIAAJ&lpg=PR3&ots=fQeGiQVIma&dq=fick%20philosophical%20magazine%201855&pg=PA30#v=onepage&q&f=false">On Liquid Diffusion</a> in 1855 at the age of 26.<br />
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<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-LreYHh4bRRQ/TxzRBvmfIXI/AAAAAAAAMcE/243bLbvRAOE/s1600/Fick%2527s+Laws.JPG" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="93" src="http://2.bp.blogspot.com/-LreYHh4bRRQ/TxzRBvmfIXI/AAAAAAAAMcE/243bLbvRAOE/s200/Fick%2527s+Laws.JPG" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Top: Fick's equation<br />
Bottom: modern equation</td></tr>
</tbody></table>
Fick's second law is the first equation on the right. He concluded his paper by saying that "such an hypothesis may serve as the foundation of a subsequent theory of these very dark phaenomena."<a href="http://historyofsci.blogspot.com/2012/01/fick-and-diffusion.html#f2" style="font-family: 'Times New Roman', serif; font-size: 14px; line-height: 18px;"><sup>2</sup></a> On the whole, he was right. The form of the second law has not changed from his initial statement except to be extended into three dimensions and to allow for the diffusion coefficient to be <span style="font-family: inherit;">dependent on concentration. The similarity can be seen in the second equation, which is that found in my textbook today.</span><br /><br />
I will leave you with that, and go and finish my diffusion homework.</span><br />
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<span style="font-family: inherit;"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-size: inherit; line-height: 115%;"><a href="http://historyofsci.blogspot.com/2012/01/fick-and-diffusion.html" name="f1">[1]</a> Mark, </span></span></span><a href="http://www.nature.com/eye/journal/v26/n1/pdf/eye2011248a.pdf">Armand Imbert, Adolf Fick, and their tonometry law</a>, <i>Eye</i> (2012) 26, 13–16.
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<span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-family: inherit; font-size: inherit; line-height: 115%;"><a href="http://historyofsci.blogspot.com/2012/01/fick-and-diffusion.html" name="f2">[2]</a>
Fick, <a href="http://books.google.com/books?id=MVIwAAAAIAAJ&lpg=PR3&ots=fQeGiQVIma&dq=fick%20philosophical%20magazine%201855&pg=PA30#v=onepage&q&f=false">On Liquid Diffusion</a>, <i>Philosophical Magazine</i>, 10, no. 63, July 1855.</span></span></span>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0tag:blogger.com,1999:blog-6520347334609073954.post-60575256794046970052012-01-22T18:51:00.000-05:002012-01-22T22:58:24.646-05:00Schrödinger's CatWhile I try to write on people, this week I'll delve briefly into the subject of Schrödinger's Cat, which was raised by a comment on the introduction post (Thanks, Janet!). I regret that I haven't gotten to the bottom of why Schrödinger picked a cat, but hopefully I can make the subject a little bit clearer, without saying something wrong. I'm still trying to understand the nuances of quantum theory myself.<br />
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I usually try to have a picture to make the blog more interesting, but this time I'm going to start with a clip from the Big Bang Theory in which Sheldon explains the phenomenon of Schrödinger's Cat.<br />
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<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.youtube.com/embed/LFBrRKnJMq4?feature=player_embedded' frameborder='0'></iframe></div>
As Sheldon correctly states, Erwin Schrödinger (1887-1961) introduced his cat in a paper in 1935. This was nine years after he had formulated his famous equation outlining the wave formulation of quantum mechanics. (That will undoubtedly be covered in more detail in a later post). Below is the excerpt from the 1935 <a href="http://www.tu-harburg.de/rzt/rzt/it/QM/cat.html">paper</a> in which he describes the cat in the box, translated from the German.<br />
<blockquote class="tr_bq">
One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the following device (which must be secured against direct interference by the cat): in a Geiger counter there is a tiny bit of radioactive substance, <em>so</em> small, that <em>perhaps</em> in the course of the hour one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges and through a relay releases a hammer which shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives <em>if</em> meanwhile no atom has decayed. The psi-function of the entire system would express this by having in it the living and dead cat (pardon the expression) mixed or smeared out in equal parts.</blockquote>
Schrödinger introduced this thought experiment to show the "ridiculousness" of the concept of blurring and his discontent with the lack of determinism in quantum mechanics. These terms require some background knowledge of quantum mechanics.<br />
<br />
But first, what you may be wondering, even if quantum mechanics isn't your cup of tea, so why a cat? Did Schrödinger have a thing against cats, or did he have a pet cat so this was the first thing that came to mind? I have no idea. But I do know that the choice of a cat fits the parameters of the experiment very well. He needed an animal that would fit inside his hypothetical steel box, so elephants are out, but that would also be quiet while in there so as to not give away its state of being before the box was opened. I'm sure some would argue that a cat in a box would scratch, but just think how much noisier a bird or dog would be. And lastly, the animal needs to be killed by the poison and be obviously dead or alive in the end. The cat seems to fit all of these. Personally, I think a rabbit might have done better, but as I'm rather fond of them myself, I'm happy to let Schrödinger have his thought experiment cat.<br />
<br />
Now back to the details of the experiment. Quantum theory had introduced the idea that electrons and other particles can only be in certain states, but not ones in between. There is a modification to that, which is that particles can be in a situation called a superposition, where they are in two different states at the same time, though only one can be measured at a time. The <a href="http://en.wikipedia.org/wiki/Copenhagen_interpretation">Copenhagen interpretation</a> says that the wavefunction of the particle (or, using Schrödinger's words, the psi-function), gives the probabilities that, when measured, the electron will be in a certain state comprising the superposition. <br />
<br />
The nature of this superposition is what Schrödinger is addressing in this thought experiment. If the electron, or in this case the radioactive atom, is in two states at once, undecayed and decayed, the cat, whose life depends on the state of the atom, must also be in two states, corresponding to the two states of the atom. This is referred to as entanglement (another term with lots of implications). The idea that the cat is both alive and dead until we look in the box is obviously a problem, and shows Schrödinger's discontent with the probabilistic interpretation at the atomic scale.<br />
<br />
One issue with the cat is the question of an observer and how measurements affect the wavefunctions. When measurements are made of quantum systems, they always give a determinate answer-the electron is in one state or the other. This is called the collapse of the wavefunction. But if you sample an electron in the same state (though defining what is the same can be difficult), it will give different answers when you measure it multiple times. If it is in an equal superposition of states A and B, when you measure it numerous times (returning it to the same starting state each time), it will say it is in A half the time and in B the other half. When you ask the electron which state it is in by measuring it, you become an observer. So in the case of Schrödinger's cat, whose life is tied to the state of the nucleus, is the cat an observer of the nucleus such that it forces the nucleus to no longer be in a superposition? By this logic, though, if you are constantly measuring a radioactive element, will it ever decay?<br />
<br />
So after perhaps raising more questions than I gave answers, that is the general gist of the cat. I think one of the things that people often overlook is that this was a thought experiment proceeded by the phrase "one can even set up quite ridiculous cases..." Schrödinger was not saying that this is what actually happens to the cat by any means. He was using this to show that it he thought it was naive to think that electrons are smeared out over different states.<br />
<br />
Even though few people, and I would not even consider myself to be one of them, understand the full implications of what Schrödinger was trying to say, his cat has caught the public imagination. I here include several links to interesting more popular and humorous references to the cat.<br />
<a href="http://primastoria.com/story/viennese-meow">Viennese Meow</a>, a short story from the point of view of the cat<br />
<a href="http://www.straightdope.com/columns/read/113/the-story-of-schroedingers-cat-an-epic-poem">The story of Schroedinger's cat</a>, an epic poem<br />
<br />
And for those with a more scholarly bent, here are a couple of papers on the subject, from least to most scholarly.<br />
<a href="http://www.informationphilosopher.com/solutions/experiments/schrodingerscat/">Schrödinger's Cat</a>, a better description and certainly better illustrated<br />
<a href="http://www.technologyreview.com/blog/arxiv/24101/">How to Create Quantum Superpositions of Living Things</a><br />
<a href="http://web.archive.org/web/20061130173850/http://www.ensmp.fr/aflb/AFLB-311/aflb311m387.pdf">The death of Schrödinger’s cat and of consciousness based quantum wave-function collapse</a>, Carpenter and Anderson, Annales de la Fondation Louis de Broglie, Volume 31, no 1, 2006.Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com2tag:blogger.com,1999:blog-6520347334609073954.post-25599010568963816182012-01-06T10:19:00.002-05:002012-01-07T16:40:55.629-05:00Celsius and the Centigrade<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-_1ZjynL_gws/TwcNpW6RMVI/AAAAAAAAMWk/cHWuDwj19ik/s1600/Anders_Celsius.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://1.bp.blogspot.com/-_1ZjynL_gws/TwcNpW6RMVI/AAAAAAAAMWk/cHWuDwj19ik/s200/Anders_Celsius.jpg" width="150" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Anders Celsius<br />
(1701-1744)</td></tr>
</tbody></table>
There is quite a bit of confusion in the United States about what the temperature is. Today, for instance, I'd tell someone that it was forty-two degrees. But if I told that to one of my international friends, she would look at me funny and, perhaps, begin working on a conversion from Fahrenheit. Some true-blooded Americans also use the Celsius scale to give temperatures, as do most European countries. But that isn't the end of it. Some people, when asked which scale they just gave a temperature in, might say "centigrade," which just adds another term to the confusion. <br />
<br />
The first part of this confusion originated in the eighteenth century, when two men, Anders Celsius and Daniel Fahrenheit, both developed thermometers with different scales. Theirs were not the first, however. Galileo is usually credited with inventing the first thermometer, in 1592, but he did not develop a memorable scale to go with it. In the seventeenth century, liquid thermometers were developed and could be made quite accurately, but no standard scale had come into use. In the 1660s, Robert Hooke developed a thermometer scale that went from -7 to 13, and many other scientists also developed temperature scales.<br />
<br />
Anders Celsius was a Swedish astronomer. As a professor at the University of Uppsala, starting in 1730, he spent a lot of time making measurements. In 1730 he published a paper on a new method of determining the distance of the earth from the sun, and in 1736 he participating in an expedition to Lapland to measure the arc of a meridian. In conjunction with another expedition to Peru, this measurment confirmed Newton's theory that the earth bulges slightly in the middle. He also measured the brightness of stars by seeing how many layers of a thin film it took before the light disappeared. With the strength of these measurements behind him, he persuaded the University of Uppsala to let him build an observatory, which was completed in 1741. This was the same observatory that <a href="http://historyofsci.blogspot.com/2011/12/anders-jonas-angstrom-and-angstrom.html">Anders Ångström</a> would be in charge of over a hundred years later. <br />
<br />
None of those measurements would seem to necessitate having a thermometer, however, and this is in part because his job description as astronomer is different from what we think of today. Certainly measuring the distance of the earth from the sun falls under astronomy, but back in the eighteenth century, so did measuring distances like the arc of a meridian, the changes in the height of seawater, and more meteorological measurements, including temperature. Celsius developed his scale by setting the boiling point of water at 0 and the freezing point of water at 100. He called the units "centigrade", because the distance between those points is divided into one hundred equal steps. This was not radical, as that was the way most scales were created--by choosing two points and putting a certain number of degrees between them. Celsius took his study of temperature one step further. He was not content with just making a thermometer that worked in Uppsala, but wanted to better understand the nature of temperature and make sure that it was independent of location. By making measurement in many places, along with measuring the atmospheric pressure, he determined that the freezing point, but not the boiling point, was independent of pressure, though neither depends on latitude. He published a paper reporting his results entitled "Observations on two persistent degrees on a thermometer" in 1742. He died only two years later of tuberculosis.<br />
<br />
If you were paying attention when I mentioned what the two points of his scale were, you will notice that his scale went backwards from what it does today--the boiling point of water is 0 and the freezing point is 100. The switched scale, as we know it today, was made popular by Carl Linnaeus, the Swedish botanist famous for originating the biological nomenclature used today. He made measurements of the conditions in which plants grow, and for him, the freezing point of water was vital, since many plants die below that temperature. In a paper published in 1745, only a year after Celsius's death, he used the same size of a degree and the same fixed points as Celsius, but placed 0 at the freezing point of water and 100 at the boiling point. The modern Celsius scale was born. Well, not quite.<br />
<br />
Celsius had called his scale the centigrade scale, and it continued to be called that for centuries. It was not until 1948 that the Ninth General Conference of Weights and Measures renamed degrees centigrade degrees Celsius, and caused even more confusion. So the next time someone says "degrees centigrade," they aren't wrong, per se, just outdated.<br />
<br />
<b>Sources and further information:</b><br />
<a href="http://www.imeko.org/publications/tc12-2004/PTC12-2004-PL-001.pdf"> Temperature Scales from the early days of thermometry to the 21 st century</a><br />
<a href="http://www.astro.uu.se/history/celsius_scale.html">History of the Celsius Temperature Scale</a><br />
<a href="http://www.astro.uu.se/history/Celsius_eng.html">Anders Celsius</a><br />
<a href="http://www.linnaeus.uu.se/online/life/6_32.html">Linnaeus' Thermometer</a>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com2Uppsala, Sweden59.8585638 17.638926757.8272028 12.5852157 61.889924799999996 22.6926377tag:blogger.com,1999:blog-6520347334609073954.post-6035078798386115602012-01-01T07:30:00.000-05:002012-01-02T13:12:41.383-05:00More than a Flask: Emil Erlenmeyer<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Duran_erlenmeyer_flask_narrow_neck_50ml.jpg/399px-Duran_erlenmeyer_flask_narrow_neck_50ml.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Duran_erlenmeyer_flask_narrow_neck_50ml.jpg/399px-Duran_erlenmeyer_flask_narrow_neck_50ml.jpg" width="133" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">An Erlenmeyer Flask<br />
<span style="font-size: xx-small;">(Photo by Lucasbosch and <br />used under the CC licence)</span></td></tr>
</tbody></table>
When learning one's way about the laboratory and it's equipment, it is easy to see how glasswares such as the volumetric flask and graduated cylinder got their names. The Erlenmeyer flask, however, is not at all descriptive, which perhaps stems from the fact that an easy name including a suggestion of its use or shape would be hard to come by. Maybe a swirling flask, or a narrow-neck flask? But whatever else it could be called, what has come down to us in the lab today is the name of the flask's inventor, Emil Erlenmeyer.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="clear: right; float: right; margin-bottom: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/0/09/Richard_August_Carl_Emil_Erlenmeyer-1.jpeg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/0/09/Richard_August_Carl_Emil_Erlenmeyer-1.jpeg" width="150" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Emil Erlenmeyer<br />
(1825-1909)</td></tr>
</tbody></table>
Erlenmeyer's full name was Richard August Carl Emil Erlenmeyer, so it is easy to see why he went with only Emil. He began his studies as a chemist, and then turned to pharmacy in the 1840's and became an apothecary. Recall, however, that this was hardly a time of sophisticated medicine. Florence Nightingale and her pleas for sanitation would not come until the next decade, and the effectiveness of the plethora of pills we have today was unheard of.<br />
<br />
He returned to chemistry, however, and began on an academic career in German universities, studying at the University of Geissen and then becoming a professor at the University of Heidelberg. I haven't been able to find a good story about how he created the Erlenmeyer flask, which he did in 1861, but since he was working in the lab experimenting with chemicals, it is easy to see why he did so. The shape has two main benefits: the shape, being wider at the bottom, makes it easier to swirl liquids without them splashing out, and the narrow neck reduces the amount of air exchange. He wasn't alone in working on improving laboratory equipment. Robert Bunsen, who had invented the Bunsen burner in the 1850s, was also a professor at the University of Heidelberg.<br />
<br />
After invention of his flask, he had many more years to enjoy the fruits of his labors and the greater ease that the flask gave him in performing his experiments. He published, according to a German website, at least twenty-seven articles, including several on cinnamic acid and other issues affecting organic chemistry.<a href="http://historyofsci.blogspot.com/2012/01/more-than-flask-emil-erlenmeyer.html#f1"><span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;"><sup>1</sup></span></span></a> Another notable organic chemist was also working at Heidelberg when Erlenmeyer was there, August Kekulé, who was the first to write the structure of benzene as alternating double bonds. The precise structure of molecules was a question that Erlenmeyer went on to study further.<br />
<br />
Erlenmeyer's most memorable contribution to organic chemistry, though not as good for his name recognition as the flask, is "Erlenmeyer's Rule." He developed this in the 1880s, by which point he was teaching at and retiring from the Munich Polytechnic School. When I took organic chemistry, I don't recall this principle being called Erlenmeyer's Rule, though a quick literature search revealed that the name is still used. Erlenmeyer's Rule says that if there is a hydroxyl group attached to a double bonded carbon, tautomerization will occur into the ketone or aldehyde form. I wish I had known it had a name in organic chemistry, because I tended to forget this when writing the result of a reaction, and it would have been much better to blame it on a rule!<br />
<br />
<a href="http://historyofsci.blogspot.com/2012/01/more-than-flask-emil-erlenmeyer.html" name="f1"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;">[1]</span></span></span></a> <a href="http://finden.nationallizenzen.de/Search/Results?lookfor=Emil+Erlenmeyer&type=AllFields&filter[]=author2Str%3A%22Erlenmeyer%2C+Emil.%22">DFG on Emil Erlenmeyer</a> And if you are in Germany, you can register and read them for yourself! I, however, do not speak German and am now wishing that I did.<br />
<div class="separator" style="clear: both; text-align: center;">
</div>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com2Munich, Germany48.1448353 11.558006747.9753153 11.2421497 48.314355299999995 11.8738637tag:blogger.com,1999:blog-6520347334609073954.post-6748761813765209862011-12-29T20:00:00.000-05:002011-12-29T20:00:04.379-05:00Liquids and Gases and Van der Waals<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/7/7c/Johannes_Diderik_van_der_Waals.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="http://upload.wikimedia.org/wikipedia/commons/7/7c/Johannes_Diderik_van_der_Waals.jpg" width="176" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Johannes Diderik van der Waals <br />
(1837-1923)</td></tr>
</tbody></table>
It seems strange to be including a Nobel Laureate in this blog that is supposed to be about lesser known scientists, but I decided to include Van der Waals because I, for one, didn't even realize that he had won a Nobel Prize for his work until I started writing this. Van der Waals won the 1910 Nobel Prize in Physics "for his work on the equation of state for gases and liquids." His name generally appears in general chemistry courses in two places related to those very topics: Van der Waals forces, the intermolecular forces that hold all molecules together, and the Van der Waals equation, which is a correction of the Ideal Gas Law which accounts for the size of and the intermolecular interactions between gas molecules. <br /><br />
Van der Waals was born in Leyden, the Netherlands, in 1837 and became a schoolteacher. He did not know Latin or Greek, and thus was prohibited from taking academic examinations and going to a university. How times have changed! He could still attended classes at Leyden University, however, and he earned teaching certificates in math and physics. When the laws requiring classical languages were changed, Van der Waals sat for examinations and in 1873 earned his doctorate at the age of 36 with a thesis entitled "<i>Over de Continuiteit van den Gas en Vloeistoftoestand</i>" (On the Continuity of the Gas and Liquid State). Four years later, he became the first professor of physics at the University of Amsterdam.<br /><br />
<span style="font-family: inherit;">Here, I think, it is important to realize what Van der Waals contribution actually was and what the other discoveries of his day were. Rudolf Clausius (1822-1888) had suggested that heat is a measure of motion only in 1850, and published his first work on entropy in 1865. His work also relied on the Maxwell-Boltzmann distribution, which was developed in the mid-19th century by James Clerk Maxwell (1831-1879) and Ludwig Boltzmann (1844-1906). Van der Waals tried to explain the phenomenon of a "critical temperature" for gases, and determined that it was due to the fact that atoms and molecules have a finite size and interact with each other, both facts that are ignored in the ideal gas law. After this, he developed the Law of Corresponding States, which provided the theoretical background for the experiments leading to the liquefaction of hydrogen and helium in 1898 and 1908 respectively.<br /><br />
Even with his later work, much of what Van der Waals is known for was in or came directly from his doctoral thesis. So to all of you graduate students out there, you may be working on Nobel Prize winning material!<br /><br />
<span style="font-family: inherit;">If you are interested in a better understanding of Van der Waals work, his Nobel Prize acceptance speech is a good summary of his work and also of his interactions with other scientists: <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1910/waals-lecture.pdf" style="font-family: inherit;">Van der Waals Nobel Lecture</a><span style="font-family: inherit;">.<br />
<br />
For more information about Van der Waals, I would highly recommend the resources provided on the Nobel Prize website, which has been the main source of information for this post: <a href="http://www.nobelprize.org/nobel_prizes/physics/laureates/1910/waals.html">J. D. van der Waals</a>.Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com1tag:blogger.com,1999:blog-6520347334609073954.post-36608314215306415622011-12-20T14:05:00.000-05:002011-12-20T14:12:13.234-05:00The Poisson Distribution<a href="http://1.bp.blogspot.com/-atxg9wZprfU/TvDP4D3rTHI/AAAAAAAAMVM/5ltn_bZEzpo/s1600/Poisson+Function.png" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="http://1.bp.blogspot.com/-atxg9wZprfU/TvDP4D3rTHI/AAAAAAAAMVM/5ltn_bZEzpo/s1600/Poisson+Function.png" /></a><span style="font-family: inherit; line-height: 115%;">The
Poisson distribution began life with unusual applications. It is a statistical
function that is used to determine how many events of low probability will occur
in a given time frame. It is useful because only the average number
of occurrences needs to be known. From this, one can calculate
the probability that the event will happen zero times in a given time interval,
or fifty times. λ is the expected number of occurrences in a
time frame, and the probability that there will be exactly
k occurrences of the phenomenon in a given time frame is given by the
function on the right.
<span style="line-height: 115%;"><span style="line-height: 115%;"></span></span><br />
</span><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-USX-xw2X6jc/TvDZ1KgHb9I/AAAAAAAAMVU/D1oxZJEw6Ls/s1600/Poisson+Distribution.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><span style="font-family: inherit;"><img border="0" height="200" src="http://3.bp.blogspot.com/-USX-xw2X6jc/TvDZ1KgHb9I/AAAAAAAAMVU/D1oxZJEw6Ls/s200/Poisson+Distribution.png" width="200" /></span></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-family: inherit;">Poisson Distribution for various values of λ</span></td></tr>
</tbody></table>
<span style="font-family: inherit; line-height: 115%;">
<span style="line-height: 115%;">
It's discoverer, Siméon-Denis Poisson (1781-1840), was a well-known
French mathematician who worked in electrostatics and celestial mechanics. He even got his name on the Eiffel Tower. He had studied mathematics at the École Polytechnique in Paris
starting in 1798 and became a professor there in 1802. He had studied
with the mathematicians Pierre-Simon Laplace (known for the Laplacian) and
Joseph-Louis Lagrange (of Lagrange multipliers), and was a professor at the same time as André-Marie Ampère, known for his work in electromagnetism. His treatise introducing
the Poisson distribution, however, bears the particularly unscientific title
of <i><a href="http://books.google.com/books?id=s3YAAAAAMAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">Research
on the Probability of Criminal and Civil Verdicts</a>.</i><a href="http://historyofsci.blogspot.com/2011/12/poisson-distribution.html#f1"><span class="MsoFootnoteReference"><span style="font-size: 12pt; line-height: 115%;"><sup>1</sup></span></span></a> It was
published in 1837, just three years before Poisson's death, and did not have a
great impact at the time.</span><br />
<span style="line-height: 115%;">
<br />His distribution was brought to greater prominence by Ladislaus Josephovich Bortkiewicz (1868-1931), a Polish statistician. In 1898 he published a book entitled, in English translation, <i><a href="http://books.google.com/books?id=o_k3AAAAMAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">The Law of Small Numbers</a></i>, in which he showed that the Poisson distribution held for events even when the probabilities varied. His examples were the number of men killed by horse kicks in the Prussian army over a 20 year period and the number of children who committed suicide in Prussia. His work brought the Poisson distribution to a wider audience, and it is often called the Law of Small Numbers today. As you can see, the Poisson distribution can be applied to many different situations, and some modern applications include the number of calls that a cell tower receives and the number of beds that an emergency room needs to have available.</span></span><br />
<span style="font-family: inherit; line-height: 115%;">
</span><br />
<div class="MsoNormal">
<span style="line-height: 115%;"><span style="font-family: inherit; line-height: 115%;"><a href="http://historyofsci.blogspot.com/2011/12/anders-jonas-angstrom-and-angstrom.html" name="f1"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-size: 12pt; line-height: 115%;">[1]</span></span></span></a> For a more detailed discussion of Poisson's work, see "<a href="http://www.jstor.org/stable/2284062">A Study of Poisson's Models for Jury Verdicts in Criminal and Civil Trials</a>" by Alan E. Gelfand and Herbert Solomon in the
<i>Journal of the American Statistical Association</i> , Vol. 68, No. 342 (Jun., 1973), pp. 271-278.
</span></span></div>
<span style="line-height: 115%;">
<span style="font-family: inherit; line-height: 115%;"><span style="font-family: inherit;">
</span></span></span>Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com1tag:blogger.com,1999:blog-6520347334609073954.post-78583322355789700432011-12-13T18:17:00.000-05:002011-12-13T18:17:01.005-05:00Introduction to SciHistoryNow that I've written my first post, I want to provide some explanation for this blog and also open up the discussion about what you, my readers, would like to see here. <br />
<br />
This blog stems from my curiosity about the people whose names are bandied about in science and math classes around the world attached to other things, like Raoult's Law, Schrodinger's Equation, the Boltzmann Constant, and the Bohr model of the atom. Teachers and professors rarely stop to explain who (and when) these people were, how they interrelate, and what led to the discoveries that have their names attached to them. The history of science is not a linear progression of ideas, but something full of arguments, dead ends, discussions, and eureka moments, and these discoveries were made by real people like you and me. <br />
<br />
I would like, in this blog, to focus on exploring the lives of the people whose names are familiar in science classes, but to whom most people couldn't even attach a first name. This means that I will not include, at least for now, people like Newton, Archimedes, and Einstein in favor of lesser known but equally mentioned of scientists, mathematicians, and natural philosophers like Hertz, Fourier, Arrhenius and Doppler.<br />
<br />
The biggest problem for me is how to organize SciHistory, and that is where I would like some input from you, my hopefully-to-be-faithful readers. I have had a bunch of ideas about how to start. For now, I am going randomly, but am trying to give variety in field of notoriety, type of discovery, and time period. (For instance, in picking a second person to write on, I thought of Rydberg, who has a constant, but discarded that since he, like Ångström, was Swedish and lived in the 19th century; he will have to wait.) Other ideas include<br />
<br />
<ul>
<li>Picking names off the Wikipedia <a href="http://en.wikipedia.org/wiki/List_of_craters_on_the_Moon">list of craters on the Moon</a> </li>
<li>Starting with units named after people and then moving on to constants and finally equations</li>
<li>Writing on whoever a professor mentions first after I finish a blog post</li>
<li>Reader suggestions</li>
</ul>
The first two still need some sort of algorithm unless I go alphabetically, and the third has the disadvantage of only working while I am taking classes. So the fourth is by far my favorite idea, but it will depend on you, dear readers. Let the suggestions begin!Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com1tag:blogger.com,1999:blog-6520347334609073954.post-80937571676870909772011-12-13T07:30:00.000-05:002011-12-29T21:22:21.239-05:00Anders Jonas Ångström and the ångström<div class="separator" style="clear: both; text-align: center;">
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<tr><td style="text-align: center;"><img border="0" height="200" src="http://www.angstrom.uu.se/img/andersstor.jpg" style="margin-left: auto; margin-right: auto;" width="140" /></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Anders Jonas Ångström<br />
(1814-1874)</td></tr>
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As any good chemist knows, an ångström is equal<rmal">
to 1x10<sup>-10</sup> meters
and is designated by the symbol Å, complete with the little circle on top. I’ve often wondered where the circle came
from,<a href="http://historyofsci.blogspot.com/2011/12/anders-jonas-angstrom-and-angstrom.html#f1"><span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;"><sup>1</sup></span></span></a>
but surprisingly until starting this blog had not wondered if the angstrom was
named after a person, especially since it does not follow the metric system
prefixes. Anders Jonas Ångström
was born in Sweden in 1814 and studied physics at the University of Upsala. He didn't leave except for brief sojourns to further science. He was interested in astronomical work, and
studied at the Stockholm Observatory before becoming the observer at the Upsala
Observatory. The Stockholm Academy of Sciences
gave him the job of analyzing the magnetic data obtained by the “Eugéne,” a ship which had
travelled around the world from 1851-1853.
In 1858 he became chair of the department of physics at Upsala
University (I told you he didn’t leave).</rmal"></div>
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Ångström is most known, when he is thought of at all, for his work
in optics which led him to be considered one of the founders of
spectroscopy. His work was primarily with things that gave off light, such as electric sparks. His greatest work was with the solar spectrum, and it is from this work that his fame as the
namesake of the ångström comes. By studying the wavelengths of light emitted by the sun using diffraction gratings, he determined in 1862 that the sun’s atmosphere contained hydrogen. In 1868 he published a book containing a map of the entire visible solar spectrum,
consisting of 1000 lines: <a href="http://www.archive.org/details/recherchessurle00nggoog"><i>Recherches sur le spectre solaire</i></a>.
Others doing similar work used arbitrary units, but Ångström
used units of ten-billionths of a meter, or at least he thought he did. He discovered that the meter from which he
measured the gratings was too short, and thus all of his calculations were off.<a href="http://historyofsci.blogspot.com/2011/12/anders-jonas-angstrom-and-angstrom.html#f2"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;"><sup>2</sup></span></span></span></a> He began the work to correct it, but died in 1874, before it was finished, leaving his assistant Thalén to finish the job.
A contemporary said that his “work [was] characterized by such accuracy
and completeness as to render it worthy of the highest admiration, to be
regarded as a pattern to all investigators.”<a href="http://historyofsci.blogspot.com/2011/12/anders-jonas-angstrom-and-angstrom.html#f3"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;"><sup>3</sup></span></span></span></a> Although others had attempted to make such
maps, Ångström’s
was the most complete and accurate, and so those who came after him used
his units to describe future measurements, calling them at first Ångström units and then ångströms.</div>
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Ångströms, however, are not the best units for describing visible light, since they result in numbers in the thousands, such as 6534. The wavelengths Ångström described are commonly now referred to in nanometers, so the values are only in the hundreds. Chemists, however, have a great affinity for
the ångström,
since it is the perfect unit for describing the length of chemical bonds, which
are on the order of an ångström. So, although the angstrom is no longer used in the field in which it
originated and has been relegated to the status of a “non-SI unit,” it still
finds its uses in chemistry although Ångström and his work have been long
forgotten.<br />
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<a href="http://2.bp.blogspot.com/-qjVFf8Hj3R8/TubdN_R_0kI/AAAAAAAAMVA/xZV6URGwKU0/s1600/Angstrom+Spectrum.png" imageanchor="1"><img border="0" height="216" src="http://2.bp.blogspot.com/-qjVFf8Hj3R8/TubdN_R_0kI/AAAAAAAAMVA/xZV6URGwKU0/s400/Angstrom+Spectrum.png" width="400" /></a></div>
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<a href="http://historyofsci.blogspot.com/2011/12/anders-jonas-angstrom-and-angstrom.html" name="f1"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;">[1]</span></span></span></a> Upon further investigation, the ring
is not a diacritical mark, but an integral part of the letter in Sweden.<o:p></o:p></div>
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<a href="http://historyofsci.blogspot.com/2011/12/anders-jonas-angstrom-and-angstrom.html" name="f2"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;">[2]</span></span></span></a> Some idea of the complication
of the creation and recalculation of this map can be gathered by looking at the
exercises in Robert
Alexander Houstoun's <a href="http://books.google.com/books?printsec=frontcover&id=jw_QAAAAMAAJ#v=onepage&q&f=false"><i>A Treatise on Light</i></a>, p. 254. </div>
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<a href="http://historyofsci.blogspot.com/2011/12/anders-jonas-angstrom-and-angstrom.html" name="f3"><span class="MsoFootnoteReference"><span class="MsoFootnoteReference"><span style="font-family: 'Times New Roman', serif; font-size: 12pt; line-height: 115%;">[3]</span></span></span></a> Heinrich
Schellen, <a href="http://books.google.com/books?id=Zva2mCXRIaEC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false"><i>Spectrum analysis in its application to terrestrial substances,
and the physical constitution of the heavenly bodies</i></a> (Longmans, 1872), p.
237. The figure is also from this book.
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As a reward for reading the footnotes, here is a link to an argument that Ångström had with a fellow physicist in the <i>Philosophical Magazine</i>: <a href="http://books.google.com/books?id=caJdQfAKHtMC&dq=research%20on%20the%20solar%20spectrum%20angstrom&pg=PA76#v=onepage&q&f=false>">"Observations on Certain Lines of the Solar Spectrum"</a>. Note that the fellow who argues against Ångström, Pierre Janssen, doesn't have a unit named after him, but they both gave their names to (separate) lunar craters, and only Janssen has a crater on Mars.</div>
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<br />Laurenhttp://www.blogger.com/profile/04790150221308781176noreply@blogger.com0