[net.sf-lovers] Density of a vacuum

RG.CUTTER%MIT-OZ@MIT-MC.ARPA (01/15/84)

From:  Joseph D. Turner <RG.CUTTER%MIT-OZ@MIT-MC.ARPA>

Of course it would increase -- you're getting closer to a big source of
tons of little particles (That isn't what I really mean, I just can't
find the right words at the moment). In any event, space isn't "the
absence of anything" -- there are zillions of particles out there...
they're just very, very, v e r y, *v e r y* far apart...
                                            Joe

buck%NRL-CSS@sri-unix.UUCP (01/18/84)

From:  Joe Buck <buck@NRL-CSS>

At least two people have posted messages indicating their belief that
the concept of density of a vacuum is absurd. Since density is mass
over volume, a vacuum has a density of zero.

Actually the situation is more complex. Quantum field theory shows
that all vacuums have nonzero density, because particle pairs are
constantly being created and destroyed out of nothing.

Further discussions of vacuums should probably move to the physics list.