Sign up ×  Given that antimatter galaxies are theoretically
possible, how would they be distinguishable from regular matter
galaxies?  That is, antimatter is equal in atomic weight and all
properties, except for the opposite reverse charge of the
particles, identical to regular matter. Hence a star composed of
antimatter hydrogen would fuse to anti-helium in an analogous
way to our own Sun, and it would emit light and radiation at the
same wavelengths as any regular matter star and would cause the
same gravitational forces for planetary systems to form as in
any other star system.  Hence, what would be a telltale sign if
you were observing a galaxy made up entirely of antimatter?
Also, is there any evidence for that half of all galaxies are
not made of antimatter -- while general theories currently
assume that there is an imbalance of matter over antimatter in
the universe, then what is the rationale for not assuming that
there is in fact an even balance between the two?
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