Hi Julia- These are really different forms of matter. Plasmas are gases
of electrically charged particles, with equal amounts of both positive
and negative charge. They behave a lot differently from ordinary gases
because the electrical forces between the particles are strong, all the
time. In a normal gas, the forces between the atoms or molecules are
usually very weak, except when they occasionally collide.
A Bose-Einstein condensate (such as superfluid liquid helium) forms
for reasons that only can be explained by quantum mechanics. There's a
specific lowest energy state for the particles- say helium atoms. When
the atoms become very cold, many of them go into that specific state.
The behavior is a lot different from that of an ordinary fluid, in
which there are plenty of different states for different particles.
Only certain types of particles, called bosons, can form
Bose-Einstein condensates. The other type of particle- Fermions- can
only have at most one particle in each state.
Plasmas tend to form at high temperature, since electrons then come
off atoms leaving charged ions. Bose condensates form at low
temperature, since at high temperatures more states are available to
the atoms.
Mike W.
(published on 10/22/2007)
