University of Virginia Library

Tungsten Spheres

Two high density tungsten
spheres of equal weight are fixed on
opposite sides of a turntable. A tiny
metal cylinder suspended by a
quartz fiber in an airtight, helium
filled chamber is placed in the
center of the turntable with the
cylinder's as at an acute angle to
the two tungsten spheres.

Each side of the cylinder is
attracted to the sphere closest to it
and it begins to rotate in an
attempt to close the angle between
it and the sphere. The turntable,
however, prevents the cylinder
from catching up to the sphere.

An optional tracking device
attached to the turntable activates a
motor which causes the table to
rotate as the cylinder begins to
move, keeping the angle between
the cylinder and the sphere constant.
As the cylinder keeps trying
to catch up to the sphere, the table,
which floats on a thing layer of air,
accelerates and within two hours is
making five revolutions per minute.