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Introduction
Ordinary matter has negatively charged electrons circling a positively charged
nuclei. Anti-matter 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.
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.
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.1
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 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.
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 in an
annihilation of both. The two heavy particles meet in a flare of energy and
vanish, their mass converted to high-energy radiation wile their opposite
charges and baryon numbers cancel out. We can make antiprotons in the
laboratory by turning this process round, using a particle accelerator to
smash protons together at such enormous energies that the energy of collision
is more than twice the mass/energy of a proton. The resulting reaction is
written:
p + p
p + p + p
+ p
Two protons (p) become three protons plus an antiproton(p); the total baryon
number before is:
1 + 1 = 2
And after the collision it is:
1 + 1 + 1 - 1 = 2 Still two.
Anti-matter elements have the same properties as matter properties. For
example, two atoms of anti-hydrogen and one atom of anti-oxygen would become
anti-water.
The Article
The article chosen reflects on recent advancements in anti-matter research.
Scientists in Switzerland have begun experimenting with a LEAR device (low
energy anti-proton ring) which would slow the particle velocity by a billionth
of its original velocity. This is all done in an effort to slow the velocity
to such a speed where it can combine chemically with positrons to form
anti-hydrogen.
The author of the article, whose name was not included on the article, failed
to investigate other anti-matter research laboratories and their advancements.
The author focused on the CERN research laboratory in Geneva. 'The intriguing
thing about our work is that it flies in the face of all other current
developments in particle physics' .2
The article also focused on the intrigue into the discovering the anti-matter
secret, but did not mention much on the destruction and mayhem anti-matter
would cause if not treated with the utmost care and safety. Discovering anti-
matter could mean the end of the Earth as we know it, one mistake could mean
the end of the world and a release of high-energy gamma rays that could wipe
out the life on earth in mere minutes.
It was a quite interesting article, with a lot of information that could
affect the entire world. The article, however, did not focus on the benefits
or disadvantages of anti-matter nor did it mention the practical uses of
anti-matter. They are too expensive to use for powering rocket ships, and are
not safe for household or industrial use, so have no meaning to the general
public. It is merely a race to see who can make the first anti-matter element.
Conclusion
As research continues into the field of anti-matter there might be some very
interesting and practical uses of anti-matter in the society of the future.
Science Essays
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