[net.astro] StarDate: November 13 An Antimatter Universe

dipper@utastro.UUCP (Debbie Byrd) (11/13/84)

In our universe, there's both matter -- and antimatter.  More about it
-- right after this.

November 13  An Antimatter Universe

Antimatter sounds like a science fiction word, but it's not.  There
really is antimatter in the universe.  Antimatter is something that's
both like the ordinary matter around us in our world -- and not like
it.

Like ordinary matter, antimatter is made up of atoms.  But these atoms
are different from the ordinary kind, because the particles that
compose them are opposite those composing ordinary matter.  For
example, sub-atomic particles in antimatter have an opposite electric
charge than the same particles in matter.

Antimatter was first theorized in 1928, by a physicist whose equations
forced him to believe that nature is symmetrical.  The equations were
right.  Antimatter was found, just four years later, by scientists who
were studying cosmic rays.  Cosmic rays continuously bombard our
atmosphere from outer space -- and when they do, the bombardment
CREATES some antimatter.

But, due to a strange circumstance of nature, this antimatter in our
atmosphere doesn't stick around very long.  Matter and antimatter are
so incompatible that when they meet, they mutually annihilate one
another.  If our eyes were properly tuned, we'd see continuous showers
of gamma ray flashes that occur when matter meets antimatter.

In our part of the universe, there's lots more matter than antimatter.
But a few scientists have speculated that other parts of the universe
may contain mostly antimatter -- or that another whole antimatter
universe may exists side by side with ours.


Script by Deborah Byrd.

(c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin