SHE
is a detailed study of the motions of isolated drops of
superfluid helium in the weightlessness of orbit. The idea is to suspend a single drop of liquid
helium, in this micro-gravity environment, and study its
behavior free of gravity's tug.
In
the absence of gravity a liquid drop floats, so it can be
isolated and better studied. Since it doesn't touch any
of the surfaces of its container, which could alter its
behavior, the results of the experiment are less susceptible
to error. A weightless liquid drop can also be studied for
a very long time.
To
conduct SHE, helium is cooled into a liquid, and an individual
drop is released into a grapefruit-size test chamber. The
chamber finely controls the temperature and pressure the
drop is subjected to. The drop motions are then recorded
with high-speed video at 1,000 frames per second, through
a window in the chamber. A laser scattering instrument precisely
measures the deformation of the drop.
With
the information gathered by SHE, scientists will better
understand the fundamental behavior of drops, to see if
peculiarities exist what were never before observed. There
are several other factors will be studied, including:
- Dependence
of the shape of a drop, on its rotation rate.
- The
creation of vortices - mini whirlpools - in rotating drops.
- Measurement
of the damping of drop oscillations.
- Investigation
of the combining of drops.
SHE
is an example of fascinating fundamental physics using low
temperatures and micro-gravity environments.
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