Kamerlingh Onnes, Heike
Kamerlingh Onnes, Heike
(b. Groningen, Netherlands, 21 September 1853; d. Leiden, Netherlands, 21 February 1926)
physics.
Kamerlingh Onnes was the son of a well-known manufacturer in Groningen. After attending secondary school, he was admitted in 1870 to the University of Groningen, where he studied physics and mathematics. In November 1871 he passed the intermediate examination for the bachelor’s degree, whereupon he spent some time at Heidelberg. There he studied for three semesters with Bunsen and Kirshhoff, a tenure that was made possible by the Seminarpreis. Earlier he had won two other competition prizes, the gold medal of the University of Utrecht and the silver medal of the University of Groningen, both for research on the chemical bond. In April 1873 he returned to Groningen to complete his studies under R. A. Mees. In June 1876 he passed his doctoral examination, and on 10 July 1879 he defended his dissertation, entitled “Nieuwe bewijzen voor de aswenteling van de aarde” (“New Proofs for the Axial Rotation of the Earth”), a subject which, stimulated by Kirchhoff, he had started to study at Heidelberg. On the basis of this dissertation, in which he showed that he was also an excellent mathematician, he was awarded the doctorate magna cum laude.
In 1878 Kamerlingh Onnes was appointed assistant to Johannes Bosscha, who was then the director of the Polytechnic School (later the Technical University) at Delft. In 1880–1881 and 1881–1882 he lectured there for Snijders and Bosscha. During this time he was in close contact with van der Waals, who was then professor of physics in Amsterdam, and thus he became acquainted with problems related to the molecular theory of matter. An indication of this is found in his article “Théorie générale de l’état fluide” (1884).
In 1882 P. L. Rijke, professor of physics at Leiden, retired and kamerlingh Onnes was appointed his successor at the age of twenty-nine. He held this professorship, which included the directorship of the physics laboratory, for forty-two years.
The period in which Kamerlingh Onnes worked can be characterized as transitional for physics. The increasing importance of experimental physics is demonstrated by his appointment to the first chair of experimental physics in the Netherlands. Before then experimental and theoretical physics were not separated. On the other hand, the mechanistic image of physics was gradually being abandoned under the influence of Maxwell’s theory of electromagnetism; physicists were also gradually coming to believe that matter is not a continuum but has a corpuscular nature. When Kamerlingh Onnes came to Leiden most physicists still adhered to the idea of continuity, but Boltzmann and van der Waals in particular were promoting the corpuscular theory.
In his inaugural address at Leiden (11 November 1882), “The Significance of Quantitative Research in Physics,” Kamerlingh Onnes stated: “In my opinion it is necessary that in the experimental study of physics the striving for quantitative research, which means for the tracing of measure relations in the phenomena, must be in the foreground. I should like to write ‘Door meten tot weten’ [‘Through measuring to knowing’] as a motto above each physics laboratory.” This motto was a declaration of principle to which he always remained loyal.
In conducting his research and developing the necessary facilities Kamerlingh Onnes showed an enormous capacity for work, the more admirable because he was in very delicate health. His strong will and the great devotion and care of his wife, Elisabeth, enabled him to achieve what he did.
When Kamerlingh Onnes received his appointment at Leiden, he made it his purpose to give experimental support to van der Waals’s theory of the behavior of gases and especially to the “law of corresponding states.” This theory is based on the hypothesis that a gas consists of molecules circulating and exerting forces on each other. The law of corresponding states, which van der Waals had derived from his equation of state but which had a wider validity than for this form of the equation alone, says that all gases behave in exactly the same way and obey the same equation of state, when the units in which pressure, volume, and temperature are measured are adapted to the gas under specific consideration.
Kamerlingh Onnes was greatly interested in this theory, for he had concluded that the conformity in the behavior of gases could be found in “the stationary mechanical similarity of the substances,” as he stated in his Nobel address. He was “mightily attracted” by the idea of carrying out precise measurements in order to verify the results of this theory. For this purpose he would have to consider the behavior of gases with simple molecules having low condensation temperatures. Moreover, since it would be important to have a large range of temperatures at his disposal, it was desirable to use the lowest temperatures possible. Just five years earlier (December 1877) Cailletet and Pictet, using different, methods, had liquefied air for the first time and so opened this new temperature region. It was necessary for Kamerlingh Onnes first to build an apparatus for the liquefaction of air in large quantities. Here the advantage of his method became evident. He did his work with great accuracy and perseverance, systematically, and with attention to all details, thus obtaining important results and advancing far ahead of all other researchers in this field. In 1892 his apparatus for the “cascade method” (using liquid methyl chloride and ethylene) for the liquefaction of oxygen and air was ready . (Boiling points of oxygen and air of normal composition are –183°C. and –193°C., respectively.) In the meantime much information was obtained about the behavior of pure gases and binary gas mixtures, a study that could be extended, after 1892, to lower temperatures.
The research of Kamerlingh Onnes and his collaborators followed two lines, one related to van der Waals’s theories (equation of state, viscosity, capillarity), and the other to the theoretical work of Lorentz (magnetorotation of the plane of polarization, Kerr effect, Hall effect). In a volume commemorating Kamerlingh Onnes’ forty years as a professor Lorentz referred to an earlier book (1904), similarly in his honor:
Many a physicist would be glad if, at the end of his career, he could look back at researches of the quantity and importance of those which are described in that book. But in the following years all this proved to be only an overture to a higher flight in which results and points of view were reached of which originally even the most daring imagination had not been able to dream.
This “higher flight” became possible by the liquefaction of hydrogen and helium, which have boiling points of –252.7°C. and –268.9°C. (20.4 K. and 4.2 K.). In February 1906 the hydrogen liquefier was ready, and on 10 July 1908 helium was first liquefied. Construction of the helium liquefier was facilitated by knowledge of the law of corresponding states. With this liquefaction a vast new temperature region was opened for research—a field in which, until his retirement in 1923. Kamerlingh Onnes remained absolute monarch.
It was evident that the simple van der Waals law, ,where p, T, and V are pressure, temperature, and volume and R, a, and b are constants, could not represent the results of the measurements quantitatively. Therefore Kamerlingh Onnes set up the experimental law where A (= RT for one mole), B, C, . . ., which he called the virial coefficients, depand on the temperature. For this dependance he wrote with similar expressions for C, D, F, and F. In this way he had twenty-five coefficients to describe the measured values. This did not lead to a better formulation of the law of corresponding states, but the second virial coefficient B and sometimes C as well are commonly used to represent deviations from the ideal gas law.
The study of the resistance of metals was Kamerlingh Onnes’ second major field. Originally accepting the idea expressed in 1902 by Kelvin, he expected that with decreasing temperature the resistance, after reaching a minimum value, would become infinite as electrons condensed on the metal atoms. Later, when this proved to contradict experimental results, he supposed that the resistance, caused by Planck vibrators which lose their energy at low temperatures, would become zero. This proved to be true although, for certain metals, in a way different from that he expected. In order to diminish the influence of impurities, very pure mercury resistors were prepared. To Kamerlingh Onnes’ great surprise the resistance showed a discontinuous decrease to zero. Discovered in 1911, this phenomenon, which he called superconductivity (later superconductivity), was found for various metals having different temperatures. J. Bardeen, J. N. Cooper, and J. R. Schrieffer gave a theoretical explanation of this phenomenon in 1957.
Kamerlingh Onnes had originally hoped that this property would allow him to establish strong magnetic fields without cooling difficulties; but he soon found that the superconductive state disappears in a magnetic field of a temperature-dependent value, never very high in the cases he studied. Also, a current sent through a superconducting wire destroys the superconductive state by its own magnetic field. Only today, after the discovery of alloys that can support strong the possible to take advantage of superconductivity for cheap production of very intense magnetic fields.
In 1913 Kamerlingh Onnes received the Nobel Prize in physics “for researches on the properties of matter at low temperatures, which researches have among others also led to the liquefaction of helium.” He received honors from the Dutch and foreign governments and was a member of many academies and societies. An especial honor was his election to membership in the Royal Academy of Sciences in Amsterdam before he was thirty.
Kamerlingh Onnes was also concerned with the application of low temperatures in everyday matters such as food preservation, refrigerated transport, and the production of ice. In 1908, at the opening ceremonies of the first International Congress of Refrigeration in paris, he “formally proposed the creation of an international organization of refrigeration which would further the work of the congress.” He insisted that one of the commissions be devoted to scientific problems. In the Netherlands he stimulated the foundation of the Nederlandsche Vereeniging voor Koeltechniek, of which he was president until his death. Another organization for which Kamerlingh Onnes was responsible was the Vereening tot Bevordering van de Opleiding tot Instrumentmaker (1901). The workshops of his laboratory were organized as a school, the Leidsche Instrumentmakersschool. This establishment has been of great importance in training instrument makers, glassblowers, and glass polishers in the Netherlands.
BIBLIOGRAPHY
I. Original Works. Most of Kamerlingh Onnes’ writings can be found in the Proceedings of the Section of Sciences of the Royal Netherlands Academy of Sciences in Amsterdam and the Verhandelingen (later Verslagen) of the meetings of the Academy. Reprints of these works are in Communications from the Physical Laboratory at the University of Leiden. Review articles on most of his research can also be found in the Reports and Communications presented by the president of the First Commission of the International Institute of Refrigeration to the third and fourth International Congresses of Refrigeration.
Among his works are “Algemeene theorie der vloeistoffen,” in Verhandelingen der K. akademie van wetenschappen, 21 (1881), and the following writings that appeared in Communications from the Physical Laboratory at the University of Leiden: “On the Cryogenic Laboratory at Leiden and on the Production of Very Low Temperatures.” in Communication, 14 (1894), which gives a review of the work of the first twelve years, including the liquefaction of oxygen; “The Importance of Accurate Measurements at Very Low Temperatures.” in Communication, supp. 9 (1904), his address as rector magnificus of the University of Leiden on its 329th anniversary; “Die Zustandsgleichung,” in in Communication, supp. 23 (1912), repr. from Encyklopädie der mathematischen Wissenschaften, V, pt. 10 (1912), written with W. H. Keesom; “Untersuchungen über die Eigenschaften der Körper bei niedrigen Temperaturen, welche Untersuchungen unter asderen auch zur Herstellung von flüssigem Helium geführt habn,” in Communication, supp. 35 (1913), his Nobel adress; and “On the Lowest Temperature Yet Obtained,” in Communication, 159 (1922), a paper read at the joint meeting of the Faraday Society and the British Cold Storage and Ice Association, repr. from Transactions of the Faraday Society, 18 (1922).
The liquefaction of hydrogen is described in Communication, 94 (1906), and that of helium in Communication, 108 (1908). The empirical eauation of state is introduced and discussed in Communication, 74 (1901). The superconductivity of mercury is treated in Communication, 122B and 124C (1911).
II. Secondary Literature. In Memoriam Heike Kamerlingh Onnes (Ledien, 1926) contains many of the newspaper obituaries and addresses at scientific societies, a review of his work, and a sketch of his personality; most of these are in Dutch. A similar work is Ernst Choen, “Kamerlingh Onnes Memorial Lecture,” in journal of the Chemical Society (1927), p. 1193. see also Gedenkboek aangeboden aan H. Kamerlingh Onnes 10 Juli 1904 (Leiden, 1904), and Het Natuurkundig laboratorium der Rijksuniversiteit te Leiden in de jaren 1904-1922 (Leiden, 1922).
J. Van Den Handel
Heike Kamerlingh Onnes
Heike Kamerlingh Onnes
Heike Kamerlingh Onnes (1853-1926) won the Nobel Prize in physics for his work with liquefied helium.
Heike Kamerlingh Onnes was a Dutch experimental physicist distinguished for his work in the field of low-temperature physics. He was the first scientist to succeed in liquefying helium, a breakthrough which yielded a previously unattainable degree of cold. This accomplishment won him the 1913 Nobel Prize in physics, in addition to numerous other awards. He is also credited with the discovery of superconductivity—that is, the complete disappearance of electrical resistance in various metals at temperatures approaching absolute zero.
Kamerlingh Onnes was born in Groningen, the Netherlands, on September 21, 1853. His father owned a tile factory, and both his parents were strict, imbuing Kamerlingh Onnes and his brothers with an understanding of the value of hard work and perseverance. He was initially educated at Groningen High School under J. M. van Bemmelan, and in 1870 he enrolled in the physics program at the University of Groningen. The following year he submitted an essay on vapor density and won first prize in a contest sponsored by the University of Utrecht. In October 1871, Kamerlingh Onnes transferred to the University of Heidelberg in Germany, where he was taught by the eminent German chemist Robert Wilhelm Bunsen . He was one of only two students allowed to work in the private laboratory of German physicist Gustav Robert Kirchhoff. In April 1873, he returned to the University of Groningen, where he spent the next five years studying for his doctorate.
In 1878, Kamerlingh Onnes moved to Delft Polytechnic where he became an assistant to the professor of physics there. In 1879 he travelled to Groningen to defend his thesis, entitled "New Proof of the Earth's Rotation." He was awarded his physics doctorate magna cum laude. At Delft Polytechnic, Kamerlingh Onnes composed a paper on the general theory of fluids from the perspective of kinetic theory. He soon realized though that such a general theory of the nature of fluids required accurate measurements of volume, pressure, and temperature over as wide a range of values as possible. To this end, he turned his attention to the problem of attaining and maintaining very low temperatures.
In 1882, at the age of twenty-nine, Kamerlingh Onnes accepted Holland's first chair in experimental physics at Leiden University. He also became the director of the laboratory there, where he was able to pursue his interest in low-temperature physics, also known as cryogenics. A dedicated experimentalist, Kamerlingh Onnes declared in his inaugural address: "I should like to write 'through measuring is knowing' as a motto above each physics laboratory." He would spend the rest of his career at Leiden. During the next forty-two years, he established it as the undisputed world headquarters of low-temperature research.
When Kamerlingh Onnes began his pioneering work, cryogenic physics was a relatively unknown science. Before him, the liquefaction of gases at very low temperatures was considered an end in itself, but Kamerlingh Onnes was interested in low-temperature physics in order to gather experimental evidence about the atomic nature of matter. When he set out to cool gases such as oxygen, hydrogen, and helium to extremely low temperatures, there were three means at his disposal. A cooling effect due to the rapid evaporation of a liquid had been discovered in 1877 by the Swiss physicist R. P. Pictet. That same year, the French physicist L. P. Cailletet had achieved low temperatures when he was able to cool oxygen by the application of intense pressure. The final method was based on the 1850 discovery by J. P. Joules and W. Thomson (Lord Kelvin) that when a gas under pressure is released through very small openings, its temperature is lowered by an amount that depends on the nature of the gas. In Munich in 1895, Carl Linde constructed an apparatus that made use of the so-called Joule-Thomson effect; gas was put under pressure and repeatedly forced into a coil of tubes that also acted as a heat exchanger. This was known as the regenerative process. The amount of liquid gas produced by all of these means was, however, negligible.
In trying to achieve very low temperatures, Kamerlingh Onnes employed a combination of Pictet's and Linde's methods. His first objective was to liquefy oxygen—the creation of a bath of liquid oxygen being necessary for the liquefaction of other gases, particularly hydrogen. Kamerlingh Onnes vaporized oxygen, then liquefied it, and then forced it under pressure into a closed, circulating system. The system was bathed in gases that had achieved progressively lower temperatures than the circulating oxygen. This methodology proved successful and Kamerlingh Onnes was able to produce about fourteen liters of liquid air an hour.
The production of liquid helium and liquid hydrogen proved more difficult than the production of liquid air. Kamerlingh Onnes theorized that if he could begin from a point of normal pressure and liquefy oxygen by the application of immense pressure, then it would be possible to liquefy hydrogen, starting with the temperature of liquid oxygen. In 1892, he was midway through this painstaking process when the Scottish chemist and physicist James Dewar succeeded in liquefying oxygen using a modified form of Pictet's cascade method. The process yielded about a pint of liquid oxygen.
One practical advantage of Dewar's achievement was that Kamerlingh Onnes now had a source of cold with which to attempt to liquefy helium. He believed that if he started out from the freezing point of hydrogen—the lowest temperature to which it was possible to cool it—he could thereby liquefy helium using Linde's regenerative process. Kamerlingh Onnes constructed a system with a jacket of liquid hydrogen; the liquid hydrogen evaporated, which cooled the helium, and then the helium was forced under pressure through a small aperture which cooled it further, liquefying some of it. He then compressed the helium in a refrigerator, where it passed through an elaborate circuit surrounded by circuits of liquid hydrogen, which were themselves surrounded by liquid air, which were in turn surrounded by a flask in which warmed alcohol circulated.
In 1908, Kamerlingh Onnes finally succeeded in the long-elusive goal of liquefying helium. At first, he and his colleagues did not even notice what they had achieved: the liquid helium was colorless, and it was not until the circuit was almost full that they realized what had finally appeared before them. The accomplishment meant that a previously unattainable degree of cold was now at their disposal. Liquid helium was found to have a temperature of -268.8 degrees Celsius, only about four degrees above absolute zero—absolute zero being a hypothetical temperature characterized by a complete absence of heat and equivalent to about -273.15 degrees Celsius or -459.67 degrees Fahrenheit. Kamerlingh Onnes now set out to solidify the liquid helium in order to reach even lower temperatures, and in 1910, by boiling liquid helium under reduced pressure, he reached just over one degree above absolute zero.
Kamerlingh Onnes used these temperatures to extend the range of his research into the properties of substances at low temperatures, and the results of these investigations were published regularly in English as "Communications from the Physical Laboratory at Leiden." In 1911, Kamerlingh Onnes made yet another breakthrough when he discovered superconductivity, the complete disappearance of electrical resistance in various metals at temperatures approaching absolute zero. He also discovered that the superconductor effect can be negated without changing the temperature by the application of a magnetic field.
Kamerlingh Onnes and his team remained preoccupied with the challenge of crystallizing helium. Their experiments yielded some intriguing if baffling results. In 1911, they found that the density of liquid helium peaked at a temperature of 2.2 degrees Kelvin. When the various physical properties of liquid helium were measured, Kamerlingh Onnes discovered strange behavior in the helium in and around this temperature. Above 2.2 Kelvin it was violently agitated, but at or below this temperature it seemed to lose its dynamic qualities. Kamerlingh Onnes was unable to explain this phenomenon. This was because he was attempting to understand it in terms of the classical laws of physics, but the behavior of liquid helium at these temperatures, unbeknownst to him, obeys the laws of quantum mechanics. Kamerlingh Onnes simply did not have the tools at his disposal to account for his findings. In the end, he and his colleagues put them down to some fault in their methodology and published only "definite and reliable" values for temperatures above 2.2 Kelvin, the position of the inexplicable maximum of the density of liquid helium.
Although he had yet to achieve absolute zero, in 1913 Kamerlingh Onnes was awarded the Nobel Prize for physics for his investigations into the properties of matter at low temperatures leading to the discovery of liquid helium. By 1921, Kamerlingh Onnes came within a degree of reaching absolute zero, and for the next three years he relentlessly pursued his quest. In 1926, he came across further peculiarities in the behavior of helium at 2.2 degrees Kelvin. This time Kamerlingh Onnes did not dismiss his findings as due to technical faults but began to seriously consider the possibility that some kind of fundamental change in helium occurred at this temperature. Unfortunately, although he was on the right track, Kamerlingh Onnes did not live long enough to resolve the mystery. His successor at Leiden, W.H. Keesom, came to the conclusion that helium above and below 2.2 degrees Kelvin is in fact two separate liquids, differing in fundamental ways. Keesom also completed another aspect of Kamerlingh Onnes' work: he succeeded in obtaining solid helium by cooling the liquid to about -272 degrees Celsius under pressure.
Kamerlingh Onnes was widely recognized for his work in low-temperature physics, and he received a number of awards in addition to the Nobel Prize. In 1904, he received the first of many distinctions when he was created Chevalier of the Order of the Netherlands Lion. In that same year, which was the twenty-fifth anniversary of his doctorate, his students and colleagues at Leiden issued a Gedenkboek, a survey of the work carried out at the laboratory from 1882 to 1904. A second Gedenkboek was issued in 1922, commemorating Kamerlingh Onnes' forty-year tenure as professor of experimental physics at Leiden. In 1912, he was awarded the Royal Society of London's Rumford Medal, and four years later the society made him a foreign member. In 1923, he was elevated from Chevalier to Commander of the Netherlands Lion. Despite being known by his friends as "the gentleman of absolute zero," Kamerlingh Onnes died at Leiden on February 21, 1926, without ever having achieved it (German chemist Walther Nernst proved it was impossible to reach absolute zero in an experimental setting when he articulated the Third Law of Thermodynamics in 1905). That same year, he was posthumously elected a Corresponding Member of the Prussian Academy of Sciences in Berlin.
Further Reading
Klein, Martin J., Paul Ehrenfest: The Making of a Theoretical Physicist, North-Holland Publishing Co., 1970.
Livanova, Anna Landau, A Great Physicist and Teacher, Pergamon Press, 1980. □
Heike Kamerlingh Onnes
Heike Kamerlingh Onnes
1853-1926
Dutch Experimental Physicist
Heike Kamerlingh Onnes is best known for his life-long investigations into the properties of matter at very low temperatures. The very first experimental physicist to liquefy helium in 1908, Kamerlingh Onnes went a step further in the field of cryogenics when, in 1911, he discovered what is called today superconductivity.
Born in Groningen, The Netherlands, in 1853, Kamerlingh Onnes entered the city's university at age 17. After receiving his "candidaats" degree (approx. B.Sc.) in 1871, he went to Heidelberg, Germany, as a student of Robert Wilhelm Bunsen (1811-1899) and Gustav Robert Kirchhoff (1824-1887) from October 1871 to April 1873. He then returned to Groningen to complete his studies, where he passed his "doctoraal" examination (approx. M.Sc.) in 1878; a year later he was awarded the doctorate magna cum laude. Kamerlingh Onnes's academic career began when he was appointed assistant at Delft Polytechnic School, a position he held until 1882 when, at the young age of 29, he became the new professor of physics at Leiden University. He would stay in Leiden for the next 42 years.
The first thing Kamerlingh Onnes did, as new professor of physics in Leiden, was to reorganize the physical laboratory in such a way that it would suit his own program of experimental physics. This he asserted right from the start in the motto taken from his inaugural address: "Door meten tot weten," or "Knowledge through measurement." Based on the solid ground of theory developed by two eminent Dutch contemporaries—Johannes Diderik van der Waals (1837-1923) and Hendrik Antoon Lorentz (1853-1928)—Kamerlingh Onnes undertook his low-temperature studies while simultaneously establishing one of the first cryogenic laboratories in the world. Years of effort culminated in the liquefaction of helium in 1908 (something that happens at the very low temperature of 4.2 Kelvin or -451.84°F). Leiden's laboratory, at the time, was justly nicknamed "the coldest spot on Earth." From then until his retirement in 1923, Kamerlingh Onnes would remain the undisputed monarch of low-temperature physics.
Just three years later, in 1911, while doing experiments with extremely cold mercury, he discovered an entirely new phenomenon, which he called supraconductivity (later superconductivity). Maintained at very low temperatures, some materials become superconductors, which means that, as Kamerlingh Onnes discovered, they display virtually no resistance to electric currents. Even though the experiment was easily reproduced afterwards, it took 46 years before three American physicists explained theoretically the underlying mechanism for superconductivity. Yet another very important phenomenon tied to very low temperature physics was the discovery of superfluidity. A superfluid is a liquid that, when cooled to no more than a few degrees above absolute zero (-459.4°F), lacks all inner friction.
When, in 1913, Kamerlingh Onnes received the Nobel Prize for physics "for his investigations on the properties of matter at low temperatures which led, inter alia, to the production of liquid helium," he opened up new vistas of experimental and theoretical researches. In fact, besides his own, seven other Nobel prizes (totaling 14 people) were awarded for work on low-temperature physics, the latest being in 1998. Superconductors are now widely used in hospitals in the form of magnetic resonance imaging (MRI) machines, and in the fields of high-energy physics and nuclear fusion. Furthermore, materials with superconductivity properties are investigated so that some day they can be used in levitating trains.
Kamerlingh Onnes is one of the most prominent scientists the Netherlands has ever produced. In Leiden today, the town's old university physics laboratory (also called the Kamerlingh Onnes Laboratory) is a tourist site, as is the Boerhaave Museum, which displays the thermos flask in which liquid helium was collected for the first time and the helium liquefier that made Kamerlingh Onnes's original experiment possible.
JEAN-FRANÇOIS GAUVIN