Thursday, September 21, 2006

The Gentleman of Absolute Zero


Physicist Heike Kamerlingh Onnes, known as the "Gentleman of Absolute Zero," was born on this day in 1853 in Groningen, Netherlands.

After studying at Groningen and later with Gustav Kirchhoff, Kamerlingh Onnes taught at Leiden in 1882 and began his intense preoccupation with the behavior of matter at extremely low temperatures. At Leiden he established the Cryogenic Laboratory, which became the worldwide center of low temperature research using liquid-helium facilities of his own design, even setting up a school for glass-blowers to train them to make the special flasks he needed. In fact, in 1908 Kamerlingh Onnes was the first person to liquify helium (by bringing it to a temperature of 4.2 degrees above the absolute zero, the complete absence of heat).

In 1911, Kamerlingh Onnes discovered the phenomenon of superconductivity while studying how the electrical resistance of metals varied at very low temperatures. Initially, he believed that the resistance would increase as the temperature was lowered, reaching the maximum near absolute zero, but he was surprised to find that the resistance of certain metals actually decreases at a temperature close to absolute zero. Although he could not explain the phenomena using classical physics, he was aware of its significance: if superconductivity could be developed in materials at higher temperatures the result could be a powerful energy source. In 1957, John Bardeen and others proposed a theoretical explanation for superconductivity using quantum electrodynamics, and the scientific community has spent considerable resources in attempting to harness superconductivity as an energy source for levitating trains, and for medical and nuclear applications.

For liquifying helium, Kamerlingh Onnes won the Nobel Prize for Physics in 1913. He also demonstrated the effect of paramagnetic saturation -- the parallel positioning of elementary atomic magnets in a very high magnetic field at low temperatures -- proving the magnetic material theory of Paul Langevin. In addition to his theoretical work, Kamerlingh Onnes also worked on designs for the practical use of refrigeration for food storage and transport. He died on February 21, 1926 in Leiden, South Holland.

His near-obsession with low temperature work led him to have extraordinarily high expectations for his assistants, and many of them viewed him as a tyrant around the lab. At his funeral, his lab assistants were walking behind his hearse when the hearse driver began to speed up, causing several of them to break into a run to keep up with it. "The old devil," observed one of them, "even after he’s gone he makes us run."

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