Contents
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. Until there is a
practical use, this is merely an attempt to prove which
research lab will be the first to manufacture the anti-
matter elements.
_______________________________
Swiss boldly poised to produce anti-matter – John Eades,
researcher at CERN
Swiss boldly poised to produce anti-matter – John Eades,
researcher at CERN