Anti-Matter
Ordinary matter has negatively charged electrons circling a positively charged
nuclei. Anti-matter however 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. (Encarta 99) The Research

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. (Encarta 99) 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) they are attempting 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 near the speed
of light, is necessary 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 (along with 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. (Encarta 99) So how can
anti-matter be stored? Outer 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 slowly manufactured, 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 anti-matter anywhere. 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 the first seconds of
creation; but why there do we still have matter? It seems unlikely that more
matter than anti-matter should be formed. In this scenario, the matter would
have to exceed the anti-matter by one part in 1000 million. An alternative
theory is produced by the physicist M. Goldhaber in 1956, is that the universe
divided into two parts after its formation : the universe that we live in, and
an alternate universe of anti-matter that cannot be observed by us. (Encarta 99)

The Chemistry Though they have no charge, anti-neutrons differ from neutrons in
having opposite \'spin\' and \'baryon number\'. All heavy particles, like protons or
neutrons, are called baryons. A firm rule is that the total baryon number cannot
change, though this apparently fails inside black holes. A neutron (baryon
number +1) can become a proton (baryon number +1) and an electron (baryon number

0 since an electron is not a baryon but a light particle). The total electric
charge stays at zero and the total baryon number at +1. But a proton cannot
simply be annihilated. A proton and anti-proton (baryon number -1) can join
together