Re: Missing Mass (was Re: Big Bang: How widely accepted?)

Richard A. Schumacher (
7 Sep 1995 19:47:12 -0500

Keep in mind that there at least four lines of evidence for
missing mass:

1. The rotation curves of most galaxies don't fit the amount
of mass we can see in them, assuming that gravity acts at
large distances the way it does in the Solar system.

2. Some mix of hot and cold dark (unseen) matter is required
to get galaxies to form and clump together as we see them
now in the time since the big bang.

3. Some amount of non-baryonic matter (i.e, stuff not made of
protons, neutrons and electrons like you and me) is required
in the big bang to get the ratios of simple elements observed
inside stars (hydrogen, helium, lithium, beryllium, boron).

4. The known density of the universe is too small by a factor
of ten or so to eventually halt the expansion of the universe.
Such an "unbounded" universe makes the theories uglier, or so
say the theorists.

All of these might be the same stuff, or none of them might be.
So another question is, "which missing mass do you mean?"