Leo ESAKI
Chairman of Science and Technology Promotion Foundation, Ibaraki , Japan |
The Nobel Prize in Physics 1973
"for their experimental discoveries regarding tunneling phenomena in semiconductors and superconductors, respectively" |
19 June
|
The Challenge in Frontiers of Science and Technology |
|
Douglas D. OSHEROFF
Professor of Physics and Applied Physics, Department of Physics , Stanford University . |
The Nobel Prize in Physics 1996
"for their discovery of superfluidity in helium-3" |
9 July |
So, What Really Happens at Absolute Zero? |
It is a common myth that all motion just cease at absolute zero. This is indeed not the case, as several kinds of motion are required by quantum mechanics, which must be obeyed at all temperatures. The speaker will describe some of these kinds of motion and some of their (often unlikely) consequences, including the failure of liquid helium to solidify under its own vapor pressure even at absolute zero, why gases of Fermi particles (such as electrons) must have velocities approaching one percent of the velocity of light, even at absolute zero. This requirements that certain particles obey the Pauli Exclusion principle leads to the unlikely reality that at very low temperatures liquid 3He is more highly ordered than solid 3He, and it was a consequence of this fact that allowed the speaker to reach the very low temperature where liquid 3He becomes superfluid, within three thousandths of a degree of absolute zero.
Comments: This talk assumes that the audience has had a good course in high school chemistry and physics, so that they know what the Heisenberg Uncertainty Principle and the Pauli Exclusion Principle are. |
| The Discovery of Superfluid Helium Three As Seen Through the Eyes of a Graduate Student |
It was at the beginning of his fifth year of graduate study that Douglas Osheroff discovered evidence for the existence of two unexpected phase transitions in a mixture of liquid and solid Helium Three, both within three thousandths of a degree of absolute zero. The speaker will describe this event, and give his personal account of the excitement and confusion that ensured over the next seven months as he and his two professors sought to understand the origins of these transition and the nature of the ordered states. |
Walter Kohn
Professor, Department of Physics, University of California , Santa Barbara , USA |
The Nobel Prize in Chemistry
1998
"for his development of the density-functional theory" |
15 November
10:30 AM |
Science and Scientists in the Twentieth Century |
During the 20th century science completely transformed our understanding of the world in which we live. In the physical sciences, in the early years of the century, Einstein's Relativity Theory provided us with a radically new view of the nature of space-time ,and Bohr's and Heisenberg's concepts of complementarily and irreducible uncertainty transformed the earlier Newtonian picture of a causal and, in principle, completely predictable universe. In the middle of the century the discovery of the structure of DNA by Watson by Watson and Crick, and the subsequent elucidation of its dominant role in living systems, initiated a revolution of comparable scope in the biological sciences.
These scientific revolutions quickly engendered practical consequences ,which transformed the lives of members of the human race, for both good and bad. The new nuclear bombs, while, at the cost of 200,000 innocent lives, they brought to an end the unprecedented killing during World War II, also ushered in a new era in which all life could be threatened over areas of global dimensions, The transistor has revolutionized computing and communication, and also created unforeseen new possibilities for war and terrorism. The DNA revolution was accompanied by admirable progress in medicine, which, however, led to an unprecedented quadrupling of the human population between 1900 and 2000.
At the beginning of the present century we face wonderful new opportunities but also great new dangers, What can science and scientists contribute to help channel these possibilities in a positive, humane direction?
|
