Ordinary matter has negatively charged electrons circling a positively
charged nuclei. has positively charged electrons - positrons -
orbiting a nuclei with a negative charge - anti-protons. Only anti-protons
and positrons are able to be produced at this time, but scientists in
Switzerland have begun a series of experiments which they believe will lead
to the creation of the first anti-matter element -- Anti- Hydrogen.
Early scientists often made two mistakes about anti-matter. Some
thought it had a negative mass, and would thus feel gravity as a push
rather than a pull. If this were so, the antiproton's negative mass/energy
would cancel the proton's when they met and nothing would remain; in
reality, two extremely high-energy gamma photons are produced. Today's
theories of the universe say that there is no such thing as a negative mass.
The second and more subtle mistake is the idea that anti-water would
only annihilate with ordinary water, and could safety be kept in (say) an
iron container. This is not so: it is the subatomic particles that react so
destructively, and their arrangement makes no difference.
Scientists at CERN in Geneva are working on a device called the LEAR
(low energy anti-proton ring) in an attempt to slow the velocity of the
anti-protons to a billionth of their normal speeds. The slowing of the
anti-protons and positrons, which normally travel at a velocity of that
near the speed of light, is neccesary so that they have a chance of meeting
and combining into anti-hydrogen.
The problems with research in the field of anti-matter is that when
the anti-matter elements touch matter elements they annihilate each other.
The total combined mass of both elements are released in a spectacular
blast of energy. Electrons and positrons come together and vanish into
high-energy gamma rays (plus a certain number of harmless neutrinos, which
pass through whole planets without effect). Hitting ordinary matter, 1 kg
of anti-matter explodes with the force of up to 43 million tons of TNT -
as though several thousand Hiroshima bombs were detonated at once.
So how can anti-matter be stored? Space seems the only place, both for
storage and for large-scale production. On Earth, gravity will sooner or
later pull any anti-matter into disastrous contact with matter. Anti-matter
has the opposite effect of gravity on it, the anti-matter is 'pushed away'
by the gravitational force due to its opposite nature to that of matter. A
way around the gravity problem appears at CERN, where fast moving anti-
protons can be held in a 'storage ring' around which they constantly move -
and kept away from the walls of the vacuum chamber - by magnetic fields.
However, this only works for charged particles, it does not work for anti-
neutrons, for example.
The Unanswerable Question
Though anti-matter can be manufactured, slowly, natural anti-matter
has never been found. In theory, we should expect equal amounts of matter
and anti-matter to be formed at the beginning of the universe - perhaps
some far off galaxies are the made of anti-matter that somehow became
separated from matter long ago. A problem with the theory is that cosmic
rays that reach Earth from far-off parts are often made up of protons or
even nuclei, never of anti-protons or antinuclei. There may be no natural
In that case, what happened to it? The most obvious answer is that,
as predicted by theory, all the matter and anti-matter underwent mutual
annihilation in ...