SIGNIFICANT EVENTS  FUTURE FLIGHT PROGRAM
03/16/01
BEST Experiment Team Finds First Evidence of Dynamic FiniteSize Scaling
The Boundary Effects at the Superfluid Transition (BEST) Experiment is a collaboration between the
University of California, Santa Barbara (PI Prof. Guenter Ahlers) and JPL (CoPI Feng Liu) to study the
effects of a solid boundary and the finite size of the system on critical thermal transport near the
superfluid transition of helium4. The theory of Dynamic FiniteSize Scaling predicts that a set of universal
scaling functions govern how the critical thermal transport varies with the size of confinement. The BEST team
studied the thermal conductivity (a dynamic variable of the fluid) of ^{4}He confined in highly uniform glass
capillary arrays with 0.5 micron and 1.0 micron diameters. The data provides the first experimental evidence
in support of the Dynamic Finite Size Scaling theory. BEST scientist Dr. Edgar Genio (UCSB) presented the
latest results at the American Physical Society's March, 2001 meeting in Seattle. A more rigorous
verification of the theory over a wide parameter range requires a microgravity environment free of gravity
smearing. BEST will conduct the microgravity measurement on the second mission of the Low Temperature
Microgravity Physics Facility on the International Space Station.
