Superfluids essays

Superfluids essays "As we shall see, it is generally believed that the phenomenon of superfluidity is directly connected with the fact that the atoms of helium-4 obey Bose statistics, and that the lambda-transition is due to the onset of the peculiar phenomenon called Bose condensation." (Leggett, 1989) This is the phenomenon wherein the bosons (a type of particle) making up a substance merge into the lowest energy level, into a shared quantum state. In general, it refers to the tendancy of bosons to occupy the same state. This state, formed when a gas undergoes Bose-Einstein condensation, is called a Bose-Einstein condensate. The distinguishing feature of Bose-Einstein condensates is that the many parts that make up the ordered system not only behave as a whole, they become whole. Their identities merge or overlap in such a way that they lose their individuality entirely. A good analogy would be the many voices of a choir, merging to become 'one voice' at certain levels of harmony. The phenomenon of superfluidity was discovered in 1937 by a Russian physicist, Peter Kapitza, and then studied independently in 1938 by John Frank Allen, a British physicist, and his coworkers. It wasnt until the 1970s however, that the useful properties of superfluids were discovered. Thanks to the work of David Lee, Douglas Osheroff and Robert Richardson at Cornell University, we have gained valuable information on the effects and uses of superfluids. These three scientists jointly received a Nobel Prize in Physics in 1996 for their discovery of superfluidity in helium-3. It took a while, however, before they actually figured out what this phase in helium was. Superfluidity in helium-3 first manifested itself as small anomalies in the melting curve of solid helium-3 (small structures in the curve of pressure vs. time). Normally, small deviations, like this one, are usually considered to be peculiarities of the equipment, but th...