http://en.rian.ru/analysis/20080618/111107931.html
There will be no Armageddon
MOSCOW. (Yury Zaitsev for RIA Novosti) - A black hole will appear in mid-July
on the border between France and Switzerland, swallowing up first Europe and
then the entire planet. Such are the apocalyptic forecasts being made ahead of
the scheduled launching, in three weeks, of the Large Hadron Collider (LHC).
The ambitious research project, aimed at looking into superconductivity, high
energies and God or devil knows what else, is an international effort involving
several countries, including Russia. The report that the LHC will also produce
a black hole is the most talked about item.
Remarkably, the most powerful sources of radiation in the universe are not
those driven by thermonuclear reactions or annihilation processes. Much more
powerful are high-density objects called black holes and neutron stars. The
force of gravity around these bodies is tremendous, and accelerates any matter
caught by its pull to immense speeds. Matter impacting on the surface of a
neutron star does so at half the speed of light. The efficiency at which energy
is released from such impacts is more than ten times that of nuclear or
thermonuclear reactions.
The general theory of relativity says black holes appear when matter is
compressed into a more compact shape than that of a neutron star. As a result,
a black hole has a gravitational field so strong that neither a material body
nor any kind of radiation (including light) is able to escape its embrace. The
black holes are, therefore, impossible to see. They can only be identified
indirectly, by observing the matter they absorb from a neighboring visible
star, for example..
The gas flowing from such a star does not fall into the black hole at once.
First, it forms the so-called "accretion disk", where the matter rotates for a
long time. As it accelerates, it picks up a speed approaching that of light and
starts emitting super-high energy X-radiation, which can be measured by
instruments placed in space.
Will it be possible to reproduce these phenomena, as yet only theoretically
predicted, in the ground-based accelerator in the Alps?
The hadron collider straddling the French-Swiss border is a ring accelerator
designed to collide charged particles into each other at massive speeds. When
it is turned on more than a billion collisions per second will occur inside it.
The huge circumference of the collider ring (26.65 km) will allow the LHC to
whisk particles to speeds close to that of light and produce super-high energy
collisions.
The LHC is expected to generate collision energies of proton bunches (rather
than traveling in a continuous beam, particles in accelerators are generally
"bunched" together) as high as 7 teraelectronvolts (TeV). Electron-proton
bunches will collide with energies of up to 1.5 TeV, and bunches of heavy ions,
such as lead, with a total energy of over 1,250 TeV. This is nothing short of a
new phenomenon in physics, in particular the likely confirmation of a theory
that teraelectronic energies and corresponding gravitation give rise to black
holes.
Some theorists, however, and the public at large have started voicing fears
that when such processes are modeled there will be a danger of collider
experiments getting out of hand and giving rise to a chain reaction that could
destroy our planet. The most widely expressed fear is that microscopic black
holes may appear and capture the surrounding matter.
Some people take this threat extremely seriously. In March of this year a claim
was even filed with the Hawaii district court charging CERN (the European
Organization for Nuclear Research), which is building the accelerator, with an
attempt at Armageddon, and demanding a ban on the accelerator's launching.
Meanwhile, several years ago, it was discovered that black holes "evaporate"
with time - a crucial discovery for understanding their physics. Larger ones do
so only slowly, over billions of years, while smaller ones, practically
instantaneously, within 10-17 of a second. Naturally, they simply do not have
the time to absorb any sizeable amount of matter.
Some researchers also believe that black holes arise when space rays bombard,
at much higher energies, the Earth's atmosphere, the Moon and the surfaces of
other planets. We just cannot see them because the process is too short-lived.
Black holes are expected to appear (or be detected appearing) in the LHC every
second or so. As they evaporate they will leave a trail of radiation that will
be registered by the accelerator's monitoring devices. Such holes pose no
threat, even in theory. On the other hand, they should help improve our
understanding of the relationship between quantum mechanics and gravitation,
because evaporation of black holes is a quantum mechanical process.
It is estimated that it will take about 20 million CDs to record the data
produced by the collider and 70,000 mainframe computers to process it. But what
is important is not the volume of data but the findings physicists can draw
from it. The super-accelerator, by throwing light on the evolution of black
holes, will also recreate the conditions that obtained in the universe within
one-billionth of a second of the Big Bang. That, scientists hope, will help to
answer many questions about how our world began, questions usually still
discussed on a theoretical plane.
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