  When a sizable, hard-sphere-like impurity is placed in a trapped
Bose-Einstein condensate, it will create a hole in the condensate wave
function. Since it costs more energy to drill a hole at the wave function's
maximum (near the trap center) than at its minimum (near the trap edge), the
impurity will be expelled from the condensate. This suggests that C-60
molecules freely falling through a condensate of atomic hydrogen may be
deflected by a radial acceleration comparable to g. The scattered fullerenes
would then form a characteristic banded density pattern outside of the trap.
The detection of these deflected molecules can be used to identify the onset of
Bose-Einstein condensation.
