Quantum Lunch Location:
T-Division Conference Room, TA-3,
Building 123, Room 121
Quantum Institute: Visitor Schedule
The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121. For more information, contact Diego Dalvit, T-13.
Thursday, May 22, 2008
12:30 PM to 2 PM
Speaker: Yves Pomeau,
ENS Paris and CNLS Ulam Scholar
TOPIC: Quantum Braking
Motion at constant speed in vacuo cannot be detected. But there other kind of motion can be detected or against a background that is not Lorentz invariant. An example of the first statement is rotation: a spinning piece of matter (a dielectric) feels the existence of the non-rotating QED vacuum by a resistive torque. An interpretation of this torque is that zero-point fluctuations of the QED vacuum are scattered by the spinning dielectric and get some angular momentum. I'll show that this dynamical Casimir effect is within the limit of detectability. In superfluids, the ground state is of course not Galilean invariant and the scattering of the zero point fluctuations by the motion of an object is also a source of friction, even at vanishingly small velocities. In a closed geometry, however, this friction does not go forever and stops when enough normal fluid has been created. This is a kind of reversible friction, that should manifest itself by nonlinear effects in an Andronikashvili-like experiment.