Event
ChBE Seminar Series: Anneke Levelt Sengers
Tuesday, May 5, 2009
11:00 a.m.-12:15 p.m.
Room 2110, Chemical and Nuclear Engineering Bldg.
Professor Chunsheng Wang
cswang@umd.edu
A Gas That Sinks in a Liquid: The First Helium Experiment Published by Kamerlingh Onnes
Presented by Dr. Johanna (Anneke) Levelt Sengers
Scientist Emerita
Chemical Science and Technology Laboratory
National Institute of Standards and Technology
In 1908 the centenary of the liquefaction of helium was celebrated. The Leiden (Netherlands) physicist Heike Kamerlingh Onnes achieved the breakthrough that would revolutionize low temperature science. Kamerlingh Onnes obtained his very first sample of two liters of pure helium gas only in 1906. Near the end of 1906, Kamerlingh Onnes pressed some of his precious helium gas into a vial containing liquid hydrogen at its boiling point. He observed that at sufficient pressure the gas phase, as a bubble, sank to the bottom of the vial: the barotropic effect. My talk introduces a number of scientists of the Dutch School such as Van der Waals, Van Laar, Kamerlingh Onnes and Keesom, all trying to understand the phase behavior of this curious binary mixture. After a false start and some conflicts regarding priorities, they did succeed, be it not quantitatively. I will try to give an idea of the experimental facilities of the Leiden Laboratory a century ago, and hope to impress the audience with the advanced understanding of fluid mixture phase behavior achieved by the Dutch School from 1890 onwards.
