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Scientists Trying to Unveil the Secrets of the Origin of the Universe, to Simulate What Happened in the Millisecond After the Big Bang

AUSTRALIAN scientists are at the core of the largest and one of the most controversial science experiments in history - recreating conditions at the beginning of the universe.

The $8 billion, 27-kilometre circle of the Large Hadron Collider, built 100metres below ground on the border of Switzerland and France by CERN, the European Organisation for Nuclear Research, is due to come online in a few weeks.

Particles will be accelerated around the most powerful collider in the world until they reach close to the speed of light, then smash together inside a seven-storey high containment chamber known as ATLAS.

Scientists are trying to discover the secrets of the origin of the universe, to simulate what happened in the millisecond after the Big Bang, to work out how it led to the creation of stars, planets, organisms and humans.

But there are fears the incredible intensity of the collision could get out of control and create a black hole.

Some of the most extreme theories even suggest it could open a rift in time and space, or a door to another dimension.

This month two men sought a restraining order in a US court to stop the project, claiming there was at least a small chance of annihilation of the planet and perhaps the universe. CERN assured people the collider was safe and the challenge appears to have no legal jurisdiction.

Kevin Varvell, senior lecturer in physics at Sydney University, laughed at the suggestions of doom.

Dr Varvell has been part of a team from Sydney and Melbourne universities that contributed to building the particle detector at the inner heart of ATLAS to record the particles released under extreme conditions in the collision. "I have absolutely no concerns whatsoever about it not being safe," he said.

"There is speculation it could create a black hole, but it would be many mini black holes, many, many times smaller than a proton or neutron that are in the nucleus of an atom. It would exist only for a tiny, tiny fraction of a second before it breaks into a lot of other particles."

But he does concede there are likely to be many surprise results when the collider is operating.

"We expect to be making things which don't exist in our universe today, but which we think would have been around at the time of the Big Bang," he said.

The Holy Grail of the experiment is to detect a particle that exists only in theory - the Higgs particle. Named after the Scottish scientist Peter Higgs who theorised it must exist, it is a particle that existed for a tiny fraction of a second after the Big Bang and is responsible for all other particles having mass.

For that reason it's also been dubbed the God Particle, a term scientists such as Dr Varvell sniff at. "That's an expression I don't like," he said.

"In theory a Higgs could be created in the extreme conditions of the collision. But it will exist for only a fraction of a second and we will follow its traces in our detector."

Sydney University PhD student Jason Lee, 25, is thrilled to be at the CERN project in Switzerland tasked with tracking electrons. "Going down the shaft for the first time it feels space and time is warped and then the doors open up and you see this alien-looking technology.

"Up close, looking at the most complicated cutting-edge, custom-built machine, you get a sense of how far mankind has come and is now reaching closer to the Big Bang."

Another Australian scientist at CERN, Dr Aldo Saavedra, said it was like working on the 21st century version of the pyramids.

About Large Hadron Collider
The Large Hadron Collider (LHC) is a particle accelerator located at CERN, near Geneva, Switzerland. It lies in a tunnel under France and Switzerland.

It is currently in the final stages of construction, and commissioning, with some sections already being cooled down to their final operating temperature of ~2K. The first beams are due for injection mid June 2008 with the first collisions planned to take place 2 months later. The LHC will become the world's largest and highest-energy particle accelerator. The LHC is being funded and built in collaboration with over two thousand physicists from thirty-four countries as well as hundreds of universities and laboratories.

When activated, it is theorized that the collider will produce the elusive Higgs boson, the observation of which could confirm the predictions and "missing links" in the Standard Model of physics and could explain how other elementary particles acquire properties such as mass. The verification of the existence of the Higgs boson would be a significant step in the search for a Grand Unified Theory, which seeks to unify the three fundamental forces: electromagnetism, the strong nuclear force and the weak nuclear force. The Higgs boson may also help to explain why gravitation is so weak compared to the other three forces. In addition to the Higgs boson, other theorized novel particles that might be produced, and for which searches are planned, include strangelets, micro black holes, magnetic monopoles and supersymmetric particles.

The collider is contained in a circular tunnel with a circumference of 27 kilometres (17 mi) at a depth ranging from 50 to 175 metres underground. The tunnel, constructed between 1983 and 1988, was formerly used to house the LEP, an electron-positron collider.

The 3.8 metre diameter, concrete-lined tunnel crosses the border between Switzerland and France at four points, although the majority of its length is inside France. The collider itself is located underground, with many surface buildings holding ancillary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants.

The collider tunnel contains two pipes enclosed within superconducting magnets cooled by liquid helium, each pipe containing a proton beam. The two beams travel in opposite directions around the ring. Additional magnets are used to direct the beams to four intersection points where interactions between them will take place. In total, over 1600 superconducting magnets are installed, with most weighing over 27 tonnes.

The protons will each have an energy of 7 TeV, giving a total collision energy of 14 TeV. It will take around 90 microseconds for an individual proton to travel once around the collider. Rather than continuous beams, the protons will be "bunched" together, into approximately 2,800 bunches, so that interactions between the two beams will take place at discrete intervals never shorter than 25 nanoseconds apart. When the collider is first commissioned, it will be operated with fewer bunches, to give a bunch crossing interval of 75 ns. The number of bunches will later be increased to give a final bunch crossing interval of 25 ns.

About ATLAS
ATLAS is one of the six particle detector experiments (ALICE, ATLAS, CMS, TOTEM, LHCb, and LHCf) currently being constructed at the Large Hadron Collider (LHC), a new particle accelerator at the European Organization for Nuclear Research (CERN) in Switzerland. When completed, ATLAS will be 46 metres long and 25 metres in diameter, and will weigh about 7,000 tonnes. The project involves roughly 2,000 scientists and engineers at 165 institutions in 35 countries. The construction was scheduled to be completed in June 2007, however is now stated to be April or mid-2008. The experiment is designed to observe phenomena that involve highly massive particles which were not observable using earlier lower-energy accelerators and might shed light on new theories of particle physics beyond the Standard Model.

The ATLAS collaboration, the group of physicists building the detector, was formed in 1992 when the proposed EAGLE (Experiment for Accurate Gamma, Lepton and Energy Measurements) and ASCOT (Apparatus with Super COnducting Toroids) collaborations merged their efforts into building a single, general-purpose particle detector for the Large Hadron Collider. The design was a combination of those two previous designs, as well as the detector research and development that had been done for the Superconducting Supercollider. The ATLAS experiment was proposed in its current form in 1994, and officially funded by the CERN member countries beginning in 1995. Additional countries, universities, and laboratories joined in subsequent years, and further institutions and physicists continue to join the collaboration even today. The work of construction began at individual institutions, with detector components shipped to CERN and assembled in the ATLAS experimental pit beginning in 2003.

ATLAS is designed as a general-purpose detector. When the proton beams produced by the Large Hadron Collider interact in the center of the detector, a variety of different particles with a broad range of energies may be produced. Rather than focusing on a particular physical process, ATLAS is designed to measure the broadest possible range of signals. This is intended to ensure that, whatever form any new physical processes or particles might take, ATLAS will be able to detect them and measure their properties. Experiments at earlier colliders, such as the Tevatron and Large Electron-Positron Collider, were designed based on a similar philosophy. However, the unique challenges of the Large Hadron Collider—its unprecedented energy and extremely high rate of collisions—require ATLAS to be larger and more complex than any detector ever built.

The ATLAS detector consists of a series of ever-larger concentric cylinders around the interaction point where the proton beams from the LHC collide. It can be divided into four major parts: the Inner Detector, the calorimeters, the muon spectrometer and the magnet systems. Each of these is in turn made of multiple layers. The detectors are complementary: the Inner Detector tracks particles precisely, the calorimeters measure the energy of easily stopped particles, and the muon system makes additional measurements of highly penetrating muons. The two magnet systems bend charged particles in the Inner Detector and the muon spectrometer, allowing their momenta to be measured.

The only established stable particles that cannot be detected directly are neutrinos; their presence is inferred by noticing a momentum imbalance among detected particles. For this to work, the detector must be "hermetic", and detect all non-neutrinos produced, with no blind spots. Maintaining detector performance in the high radiation areas immediately surrounding the proton beams is a significant engineering challenge.

About Big Bang
The Big Bang is a cosmological model of the universe that has become well supported by several independent observations. After Edwin Hubble discovered that galactic distances were generally proportional to their redshifts in 1929, this observation was taken to indicate that the universe is expanding. If the universe is seen to be expanding today, then it must have been smaller, denser, and hotter in the past. This idea has been considered in detail all the way back to extreme densities and temperatures, and the resulting conclusions have been found to conform very closely to what is observed.

Ironically, the term 'Big Bang' was first coined by Fred Hoyle in a derisory statement seeking to belittle the credibility of the theory that he did not believe to be true. However, the discovery of the cosmic microwave background in 1964 was taken as almost undeniable support for the Big Bang.

Analysis of the spectrum of light from distant galaxies reveals a shift towards longer wavelengths proportional to each galaxy's distance in a relationship described by Hubble's law, which is taken to indicate that the universe is undergoing a continuous expansion. Furthermore, the cosmic microwave background radiation discovered in 1964 provides strong evidence that due to the expansion, the universe has naturally cooled from an extremely hot, dense initial state. The discovery of the cosmic microwave background led to almost universal acceptance among physicists, astronomers, and astrophysicists that the Big Bang describes the evolution of the universe quite well, at least in its broad outline.

Further evidence supporting the Big Bang model comes from the relative proportion of light elements in the universe. The observed abundances of hydrogen and helium throughout the cosmos closely match the calculated predictions for the formation of these elements from nuclear processes in the rapidly expanding and cooling first minutes of the universe, as logically and quantitatively detailed according to Big Bang nucleosynthesis.

However, there are mysteries of the universe that are not explained by the Big Bang model alone. For example, a region of the universe 12 billion lightyears distant in one direction appears little different than a region 12 billion lightyears distant in the opposite direction. But since the universe is 'only' around 13.7 billion years old, it would appear these regions could never have been causally connected. How, then, can they be so similar? Alan Guth's 1981 theory of cosmic inflation, a short, sudden burst of extreme exponential expansion in the very early universe, provided an explanation for this horizon problem and several of the features unaccounted for by the original Big Bang model. The successor to Guth's original theory has found some circumstantial support, but it is not yet nearly as well supported as the Big Bang model.

The Big Bang theory developed from observations of the structure of the universe and from theoretical considerations. In 1912 Vesto Slipher measured the first Doppler shift of a "spiral nebula" (spiral nebula is the obsolete term for spiral galaxies), and soon discovered that almost all such nebulae were receding from Earth. He did not grasp the cosmological implications of this fact, and indeed at the time it was highly controversial whether or not these nebulae were "island universes" outside our Milky Way. Ten years later, Alexander Friedmann, a Russian cosmologist and mathematician, derived the Friedmann equations from Albert Einstein's equations of general relativity, showing that the universe might be expanding in contrast to the static universe model advocated by Einstein. In 1924, Edwin Hubble's measurement of the great distance to the nearest spiral nebulae showed that these systems were indeed other galaxies. Independently deriving Friedmann's equations in 1927, Georges Lemaître, a Belgian physicist and Roman Catholic priest, predicted that the recession of the nebulae was due to the expansion of the universe.

In figure, Massive ... The eight magnets on the ATLAS detector of the Large Hadron Collider will help measure the energy of new particles.