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What is it ?
A question of everything
Experiments at Cern's new giant particle accelerator remind us just how far science has come in recent years
* Tim Radford
*
o Tim Radford
o guardian.co.uk,
o Thursday August 07 2008 00:08 BST
o Article history
Cern particle accelerator
Part of Cern's giant particle accelerator. Photograph: Reuters
Any day now, engineers at Cern's Large Hadron Collider, the giant particle accelerator 100 metres under the city of Geneva (and under a few villages in France as well), will press a button and begin to push a volley of subatomic matter to 0.999999991 times the speed of light and then smash it into another salvo of protons coming the other way at the same speed. The idea is to recreate the heat and dust that must have existed in the universe when it was about as big as a beach ball, in the first trillionth of a second of creation.
This stupendous match of science and engineering won't answer any questions in a trillionth of a second (the timetable for the experiment is about seven years and the machine may not get up to full tilt until 2009) so the rest of us have time to reflect on the astonishing speed of the great adventure.
Start with 1964, the year Harold Wilson became prime minister, the year BBC2 switched on, the year Nelson Mandela was sentenced to life imprisonment. In 1964, it was possible to ask the world's greatest scientists a straight question - did the universe start from nothing, or was it always there? - and get a blank stare.
It was a question that was as old as religion, as old as inquiry itself and there wasn't an answer. By 1965, two radio astronomers at Bell telephone laboratories had unintentionally checked a series of predictions by a set of maverick physicists - among them a Russian called George Gamow - and delivered an unequivocal response: yes, the universe began in a fireball some time in the last 20 billion years. In the course of the next 43 years - hardly half a lifetime, at present western European expectations - physicists revised the hot big bang theory over and over again but still kept coming up with the same big answer: yes, there had been a beginning to everything that we can detect, and so, logically, there could be a theory of everything.
The Large Hadron Collider experiment at Cern is however only one instance of the astonishing pace of science in the last 44 years. In 1964, biologists knew about DNA, and they certainly knew that the sequence of chemical bases in that enormous string of biological information must provide some sort of code (George Gamow was involved in that, too) but nobody knew how to use the information; nobody expected to be able to "read" the patterns of inheritance and nobody believed that this knowledge could have any practical application.
It is now more than a decade since a British scientist took the DNA from a dead sheep, injected it into the empty egg from a live ewe, and cloned Dolly, the sheep that shook the world. In 1964 there were certainly space missions, and communications satellites, but the idea of sustained space voyaging seemed like a dangerous fantasy. Within a decade, 12 men had walked on the moon, and there were spacecraft heading towards the farthest reaches of the solar system. Within four decades, a European lander was preparing to touch down on one of the moons of Saturn.
This extraordinary adventure in long-distance travel was matched by a set of astounding discoveries on the surface of planet Earth. In 1964, many geologists and geophysicists believed that the ocean floor would be older than the continents that rested on it – stands to reason, doesn't it? – and that it was pure co-incidence that the shape of west Africa looked like a piece of jigsaw cut to fit around the coast of Brazil. By 1965, a paper by two British geologists had begun a revolution in earth sciences that explained why there was copper on Cyprus, mountains in the Andes, coral in the Pennines, volcanoes in the Caribbean, why earthquakes simply had to happen, and why the some of the youngest rocks on the planet were ocean basalt.
These great adventures were accompanied at every stage by technological mastery at a speed far beyond any science fiction fantasy. In 1964, the computers that drove the space effort were huge, clumsy bits of kit with less calculating capacity than the average 2004 washing machine, and that depended on reel-to-reel tape recorders to store their data. In 1964, there were western European children whose lungs were scarred by tuberculosis, whose faces were pitted with smallpox, whose limbs were withered by polio. In 1964, there were still doctors who thought smoking might be good for you, who prescribed black pudding for anaemia and Guinness for a condition called "nerves" and who had no idea how or why aspirin worked.
And, to get back to where we started, in 1964 Cern certainly existed in Geneva, and certainly accelerated matter. But discoveries there were limited by the problems of detection on scales far smaller than an atom and at speeds far faster than anything other than light itself. In 1968, a French scientist called Georges Charpak devised the first modern particle detector and now Cern's latest machine is equipped with four massive detectors capable of automatically sifting data from particle collisions 600 million times every second.
It is manned by 7,000 physicists and engineers, more than half of whom were not born in 1964 but who expect in the next seven years to be able to answer some of the biggest questions of all: about the advent not just of matter, but of matter's apparent birth-partners, space and time. They may not get the answers they hope for. They may get answers so puzzling it could take another four decades to understand them. Or they may simply find more questions. Whatever they find, or don't find, the adventure will have been worth it: just think of the journey, and the colossal scientific rewards of the last four decades, and marvel.
What questions does it wish to answer ?
AIMS OF THE LHC PROJECT
The Standard Model of how fundamental particles are made up and how physics works at incredibly small scales has been a remarkably useful model, but it fails to address some important questions. The LHC is the tool that will enable us to explore some of our unresolved questions, such as:
What is mass?
In the Standard Model, all particles acquire their masses by interacting with another particle, the Higgs Boson, named after Peter Higgs of Edinburgh University. It is the strength of this interaction that gives rise to what we know familiarly as mass. Experiments have yet to show whether this theory is correct, but we do know that there must be a mechanism to give particles their masses, and that the associated new physics must emerge at energies accessible at the LHC.
Is there supersymmetry?
Attempts to develop a "grand unified theory", in which the electroweak and the strong interactions are brought together within a single framework, suggest that a deep symmetry, known as "supersymmetry", will become manifest at the energies of the LHC. Supersymmetry links the matter particles (the quarks and leptons) with the force particles (the gauge bosons) and predicts that there are additional "superparticles" necessary to complete the symmetry. The superparticles should have masses within the range of the LHC, around ten times greater than the heaviest particles studied so far.
What is Dark Matter?
The discovery of supersymmetric particles could have important implications for cosmology. Measurements in astronomy suggest that more than 90% of the universe is in the form of "Dark Matter", so far revealed only through its gravitational attraction. The lightest supersymmetric particles could be stable, in which case large numbers of them, created in the early universe, could now have clustered into structures of Dark Matter on the scale of galaxies.
Where has all the antimatter gone?
In the very early moments after the Big Bang (the start of the universe), the universe should have contained equal amounts of matter and antimatter. When matter and antimatter particles meet, they annihilate each other. Yet, the universe we see around us is made up almost entirely of matter. We expect experiments at the LHC to cast light on the puzzle of how the matter we see in our universe survived this primordial mutual annihilation.
Our present understanding of the asymmetry between matter and antimatter is inextricably tied up with the existence of three generations of quarks and leptons, and the studies at the LHC will provide an important new window on this effect.
Why are there six quarks?
Although we know that there are three "generations" of quarks and leptons, we do not know why there are three, or why the one that forms the world about us is not enough. The answer to this question is probably linked to the answers to the other questions, and in particular to the ideas of supersymmetry and the resolution of the matter - antimatter problem. Collisions at the LHC will readily produce particles containing even the heaviest quarks and will allow us to study them and their interactions in unprecedented detail.
The energy region around 1 TeV promises to reveal new physics that will address these questions. Exploring this energy region is the goal for the LHC. The easiest way to reach 1 TeV is by colliding together proton beams, as protons are relatively easy to produce and to accelerate. However, protons are complex objects, containing quarks and gluons (carriers of the strong force) amongst which the energy is shared. So in order to reach energies in the region of 1 TeV, the LHC's primary role will be to collide proton beams with higher energies, around 7 TeV. The machine will consist of a ring of superconducting magnets, 27-km in circumference. The twin-aperture magnets constrain the orbits of two beams of protons, circulating in opposite directions, allowing each of them to be accelerated to 7 TeV and stored at that energy for periods of up to a day. The two beams cross at four points around the ring , where they can be brought into head-on collision at a centre of mass energy of 14 TeV. Detectors are placed at each of the four intersections.
How much did it cost ?
The cost of building the LHC will be £2.1 billion over 13 years, of which, the UK's contribution will be around 16%.
Who participated in it ?
The Large Hadron Collider (LHC)
The final stages in the construction of one of the largest scientific experiments in the history of science are taking place at CERN (The European Laboratory for Particle Physics) in Geneva. In a 27km tunnel, on average 100m below ground, between Lake Geneva and the Jura mountains, cutting edge science and engineering are coming together to address some of the most fundamental questions we have about the universe we live in.
COUNTRIES COLLABORATING IN THE LHC PROJECT
The LHC is an international endeavour with the UK being among over forty countries participating in the project. Countries collaborating in the LHC project are Armenia, Australia, Austria, Azerbaijan Republic, Belarus, Belgium, Brazil, Bulgaria, Canada, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, India, Israel, Italy, Japan, Korea, Morocco, Netherlands, Norway, Pakistan, Poland, Portugal, Romania, Russia, Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom, United States, Uzbekistan.
Why was there a controversy and there where lawsuit against doing the experiment due to fear of it causing the end of the world ?
Back in 1910, the media correctly reported a most unusual event: the Earth would soon encounter a celestial body in the heavens - and pass through the tail of Halley's Comet. The media also correctly stated that the tail contained poisonous gases. This soon sparked an episode of mass hysteria that suddenly gripped the public. Overnight, would-be prophets sprung up at street corners warning of doomsday. People were frantically buying gas masks and home-made remedies to ward off the poison gas. Wild rumours fed on each other, stirring up even more panic among the public.
But the media failed to report the full truth, that the tail of Halley's comet was rarer than the finest vacuum on Earth, and that all the debris and gas inside the tail could probably fit inside something like a suitcase. So when the Earth finally passed through the tail of the comet, nothing happened.
Now the media is correctly reporting that some physicists believe that the Large Hadron Collider might produce mini black holes in its collisions, and that black holes are in general so powerful that they can swallow up not just the Earth, but whole star systems. The media also correctly reported that physicists, when pressed, cannot completely dismiss the chance of being eaten alive by these mini black holes from the LHC.
This in turn has sparked some rather sensational headlines, leading up to a lawsuit filed in the US District Court in Hawaii in March, where seven people are asking for a court injunction to stop the experiments at the LHC, stating that the mini black holes it produces could grow by swallowing matter until they become large enough to swallow up the entire Earth. Although the equipment is based in Europe, and is hence outside the jurisdiction of US law, many of its large magnets and key components come from the US. The lawsuit could, theoretically, cripple the project.
These headlines may sell newspapers, but the media conveniently downplay, or even omit, giving the full picture. First of all, mother nature can produce subatomic particles of greater energy than the puny LHC in the form of cosmic rays. These high-energy particles, which are accelerated to astronomical energies by huge magnetic and electric fields in space, have been raining down on Earth for billions of years, plenty of time to swallow up the planet - yet we are still here to write about it.
Secondly, these mini black holes are not just small black holes; they are actually subatomic in size, comparable to electrons or protons. The entire energy created by these particles would not even light up a light bulb if the LHC were running for a hundred years. Although the subatomic particles produced by the LHC can have trillions of electron volts, the LHC is expected, at best, to create mini black holes at the rate of one per second, which is much too small to cause any appreciable danger to anyone.
In the same way that animals from the cat family come in all sizes, from ferocious lions to harmless domestic cats, black holes also come in all sizes, from the astronomically colossal to the totally insignificant.
Thirdly, these mini black holes are unstable, and quickly decay. Instead of gobbling up matter and becoming big enough to eat up the Earth, they go in the opposite direction, emitting radiation so that they eventually disappear into nothing, a process proposed by the renowned Cambridge physicist, Stephen Hawking. So these subatomic black holes naturally self-destruct.
Some critics have claimed that these mini black holes might get captured by the Earth's gravitational field, but they decay too quickly for them to be a danger to anyone.
Fourthly, when pressed by journalists to flatly declare that the worst case scenario cannot occur, physicists shy away, not because we think the event might occur, but because of a loophole in the quantum theory. Because of Werner Heisenberg's uncertainty principle, there is a tiny chance that anything will occur. There is a chance that firebreathing dragons will be produced by the LHC. But the probability of this event is so small, one can show that it will not happen in the lifetime of the universe.
In my opinion, if an event is so rare that it will probably not happen in the lifetime of the Universe, then we physicists should say to the media that it will not occur, period. We physicists have to be more media savvy, and not split hairs. The final nail in the scaremonger's coffin is that many of their fears against the LHC are identical to the ones used against the Relativistic Heavy Ion Collider in Brookhaven National Laboratory in New York State, a much smaller machine that has been running successfully for years without incident.
So who is to blame for the current concern about the LHC? The media and fearmongers are mainly to blame; but physicists are as well, because we have failed to adequately convey the purpose and the scope of the LHC to the public and the media. During the cold war, whenever physicists in the US wanted funds for a new particle accelerator, we would bypass the public and simply go to Congress and say one word, "Russia!" Congress would get scared, whip out a chequebook and say two words, "How much?"
This is not because these particle accelerators had any direct military value in the cold war. But Congress was worried that the US would lose its edge in a crucial area of high technology and wanted to compete with Russia's increasingly powerful particle accelerators. Well, now it is obvious that Russia is not building huge atom smashers anymore, and politicians are wary of funding them.
Now, we have to appeal directly to the public to support basic research. We physicists have to sing for our supper, just like all the other interest groups fighting for their share of the pie. As with Halley's Comet and now the LHC, history seems to be repeating itself, the first time as tragedy, the second as farce.
It is easy to forget that the US had begun building a much bigger particle accelerator in the 1990s, called the Superconducting Supercollider, which was cancelled by Congress in 1993. In the last days of hearings, one congressman asked an important question: "Will we find God with this machine? If so, I will vote for it." The poor physicist at the hearing was thrown by the question and failed to give a convincing answer, and the SSC was soon cancelled - the whole business of digging a hole for the SSC and filling it in cost $2bn of US taxpayers' money.
Since then, we physicists have replayed that scene over and over again in our minds. How should we have answered that question?
I don't know, but I would have said the following: "God. By whatever signs or symbols you ascribe to the deity. This machine, the supercollider, will take us as close as humanly possible to his or her greatest creation, genesis. This is a genesis machine, designed to study the greatest event in all history: the birth of the universe."
· Michio Kaku is professor of theoretical physics at the City University of New York. His latest book is Physics of the Impossible
Recommended sites : http://www.guardian.co.uk/science/cern
Sources.
http://www.vmine.net/scienceinparliament/LHC Briefing Document.pdf
http://www.guardian.co.uk/science/2008/jun/30/cern.particlephysics1
http://www.guardian.co.uk/education/...feed=education
And other ones i currently miss.
A question of everything
Experiments at Cern's new giant particle accelerator remind us just how far science has come in recent years
* Tim Radford
*
o Tim Radford
o guardian.co.uk,
o Thursday August 07 2008 00:08 BST
o Article history
Cern particle accelerator
Part of Cern's giant particle accelerator. Photograph: Reuters
Any day now, engineers at Cern's Large Hadron Collider, the giant particle accelerator 100 metres under the city of Geneva (and under a few villages in France as well), will press a button and begin to push a volley of subatomic matter to 0.999999991 times the speed of light and then smash it into another salvo of protons coming the other way at the same speed. The idea is to recreate the heat and dust that must have existed in the universe when it was about as big as a beach ball, in the first trillionth of a second of creation.
This stupendous match of science and engineering won't answer any questions in a trillionth of a second (the timetable for the experiment is about seven years and the machine may not get up to full tilt until 2009) so the rest of us have time to reflect on the astonishing speed of the great adventure.
Start with 1964, the year Harold Wilson became prime minister, the year BBC2 switched on, the year Nelson Mandela was sentenced to life imprisonment. In 1964, it was possible to ask the world's greatest scientists a straight question - did the universe start from nothing, or was it always there? - and get a blank stare.
It was a question that was as old as religion, as old as inquiry itself and there wasn't an answer. By 1965, two radio astronomers at Bell telephone laboratories had unintentionally checked a series of predictions by a set of maverick physicists - among them a Russian called George Gamow - and delivered an unequivocal response: yes, the universe began in a fireball some time in the last 20 billion years. In the course of the next 43 years - hardly half a lifetime, at present western European expectations - physicists revised the hot big bang theory over and over again but still kept coming up with the same big answer: yes, there had been a beginning to everything that we can detect, and so, logically, there could be a theory of everything.
The Large Hadron Collider experiment at Cern is however only one instance of the astonishing pace of science in the last 44 years. In 1964, biologists knew about DNA, and they certainly knew that the sequence of chemical bases in that enormous string of biological information must provide some sort of code (George Gamow was involved in that, too) but nobody knew how to use the information; nobody expected to be able to "read" the patterns of inheritance and nobody believed that this knowledge could have any practical application.
It is now more than a decade since a British scientist took the DNA from a dead sheep, injected it into the empty egg from a live ewe, and cloned Dolly, the sheep that shook the world. In 1964 there were certainly space missions, and communications satellites, but the idea of sustained space voyaging seemed like a dangerous fantasy. Within a decade, 12 men had walked on the moon, and there were spacecraft heading towards the farthest reaches of the solar system. Within four decades, a European lander was preparing to touch down on one of the moons of Saturn.
This extraordinary adventure in long-distance travel was matched by a set of astounding discoveries on the surface of planet Earth. In 1964, many geologists and geophysicists believed that the ocean floor would be older than the continents that rested on it – stands to reason, doesn't it? – and that it was pure co-incidence that the shape of west Africa looked like a piece of jigsaw cut to fit around the coast of Brazil. By 1965, a paper by two British geologists had begun a revolution in earth sciences that explained why there was copper on Cyprus, mountains in the Andes, coral in the Pennines, volcanoes in the Caribbean, why earthquakes simply had to happen, and why the some of the youngest rocks on the planet were ocean basalt.
These great adventures were accompanied at every stage by technological mastery at a speed far beyond any science fiction fantasy. In 1964, the computers that drove the space effort were huge, clumsy bits of kit with less calculating capacity than the average 2004 washing machine, and that depended on reel-to-reel tape recorders to store their data. In 1964, there were western European children whose lungs were scarred by tuberculosis, whose faces were pitted with smallpox, whose limbs were withered by polio. In 1964, there were still doctors who thought smoking might be good for you, who prescribed black pudding for anaemia and Guinness for a condition called "nerves" and who had no idea how or why aspirin worked.
And, to get back to where we started, in 1964 Cern certainly existed in Geneva, and certainly accelerated matter. But discoveries there were limited by the problems of detection on scales far smaller than an atom and at speeds far faster than anything other than light itself. In 1968, a French scientist called Georges Charpak devised the first modern particle detector and now Cern's latest machine is equipped with four massive detectors capable of automatically sifting data from particle collisions 600 million times every second.
It is manned by 7,000 physicists and engineers, more than half of whom were not born in 1964 but who expect in the next seven years to be able to answer some of the biggest questions of all: about the advent not just of matter, but of matter's apparent birth-partners, space and time. They may not get the answers they hope for. They may get answers so puzzling it could take another four decades to understand them. Or they may simply find more questions. Whatever they find, or don't find, the adventure will have been worth it: just think of the journey, and the colossal scientific rewards of the last four decades, and marvel.
What questions does it wish to answer ?
AIMS OF THE LHC PROJECT
The Standard Model of how fundamental particles are made up and how physics works at incredibly small scales has been a remarkably useful model, but it fails to address some important questions. The LHC is the tool that will enable us to explore some of our unresolved questions, such as:
What is mass?
In the Standard Model, all particles acquire their masses by interacting with another particle, the Higgs Boson, named after Peter Higgs of Edinburgh University. It is the strength of this interaction that gives rise to what we know familiarly as mass. Experiments have yet to show whether this theory is correct, but we do know that there must be a mechanism to give particles their masses, and that the associated new physics must emerge at energies accessible at the LHC.
Is there supersymmetry?
Attempts to develop a "grand unified theory", in which the electroweak and the strong interactions are brought together within a single framework, suggest that a deep symmetry, known as "supersymmetry", will become manifest at the energies of the LHC. Supersymmetry links the matter particles (the quarks and leptons) with the force particles (the gauge bosons) and predicts that there are additional "superparticles" necessary to complete the symmetry. The superparticles should have masses within the range of the LHC, around ten times greater than the heaviest particles studied so far.
What is Dark Matter?
The discovery of supersymmetric particles could have important implications for cosmology. Measurements in astronomy suggest that more than 90% of the universe is in the form of "Dark Matter", so far revealed only through its gravitational attraction. The lightest supersymmetric particles could be stable, in which case large numbers of them, created in the early universe, could now have clustered into structures of Dark Matter on the scale of galaxies.
Where has all the antimatter gone?
In the very early moments after the Big Bang (the start of the universe), the universe should have contained equal amounts of matter and antimatter. When matter and antimatter particles meet, they annihilate each other. Yet, the universe we see around us is made up almost entirely of matter. We expect experiments at the LHC to cast light on the puzzle of how the matter we see in our universe survived this primordial mutual annihilation.
Our present understanding of the asymmetry between matter and antimatter is inextricably tied up with the existence of three generations of quarks and leptons, and the studies at the LHC will provide an important new window on this effect.
Why are there six quarks?
Although we know that there are three "generations" of quarks and leptons, we do not know why there are three, or why the one that forms the world about us is not enough. The answer to this question is probably linked to the answers to the other questions, and in particular to the ideas of supersymmetry and the resolution of the matter - antimatter problem. Collisions at the LHC will readily produce particles containing even the heaviest quarks and will allow us to study them and their interactions in unprecedented detail.
The energy region around 1 TeV promises to reveal new physics that will address these questions. Exploring this energy region is the goal for the LHC. The easiest way to reach 1 TeV is by colliding together proton beams, as protons are relatively easy to produce and to accelerate. However, protons are complex objects, containing quarks and gluons (carriers of the strong force) amongst which the energy is shared. So in order to reach energies in the region of 1 TeV, the LHC's primary role will be to collide proton beams with higher energies, around 7 TeV. The machine will consist of a ring of superconducting magnets, 27-km in circumference. The twin-aperture magnets constrain the orbits of two beams of protons, circulating in opposite directions, allowing each of them to be accelerated to 7 TeV and stored at that energy for periods of up to a day. The two beams cross at four points around the ring , where they can be brought into head-on collision at a centre of mass energy of 14 TeV. Detectors are placed at each of the four intersections.
How much did it cost ?
The cost of building the LHC will be £2.1 billion over 13 years, of which, the UK's contribution will be around 16%.
Who participated in it ?
The Large Hadron Collider (LHC)
The final stages in the construction of one of the largest scientific experiments in the history of science are taking place at CERN (The European Laboratory for Particle Physics) in Geneva. In a 27km tunnel, on average 100m below ground, between Lake Geneva and the Jura mountains, cutting edge science and engineering are coming together to address some of the most fundamental questions we have about the universe we live in.
COUNTRIES COLLABORATING IN THE LHC PROJECT
The LHC is an international endeavour with the UK being among over forty countries participating in the project. Countries collaborating in the LHC project are Armenia, Australia, Austria, Azerbaijan Republic, Belarus, Belgium, Brazil, Bulgaria, Canada, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, India, Israel, Italy, Japan, Korea, Morocco, Netherlands, Norway, Pakistan, Poland, Portugal, Romania, Russia, Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom, United States, Uzbekistan.
Why was there a controversy and there where lawsuit against doing the experiment due to fear of it causing the end of the world ?
Back in 1910, the media correctly reported a most unusual event: the Earth would soon encounter a celestial body in the heavens - and pass through the tail of Halley's Comet. The media also correctly stated that the tail contained poisonous gases. This soon sparked an episode of mass hysteria that suddenly gripped the public. Overnight, would-be prophets sprung up at street corners warning of doomsday. People were frantically buying gas masks and home-made remedies to ward off the poison gas. Wild rumours fed on each other, stirring up even more panic among the public.
But the media failed to report the full truth, that the tail of Halley's comet was rarer than the finest vacuum on Earth, and that all the debris and gas inside the tail could probably fit inside something like a suitcase. So when the Earth finally passed through the tail of the comet, nothing happened.
Now the media is correctly reporting that some physicists believe that the Large Hadron Collider might produce mini black holes in its collisions, and that black holes are in general so powerful that they can swallow up not just the Earth, but whole star systems. The media also correctly reported that physicists, when pressed, cannot completely dismiss the chance of being eaten alive by these mini black holes from the LHC.
This in turn has sparked some rather sensational headlines, leading up to a lawsuit filed in the US District Court in Hawaii in March, where seven people are asking for a court injunction to stop the experiments at the LHC, stating that the mini black holes it produces could grow by swallowing matter until they become large enough to swallow up the entire Earth. Although the equipment is based in Europe, and is hence outside the jurisdiction of US law, many of its large magnets and key components come from the US. The lawsuit could, theoretically, cripple the project.
These headlines may sell newspapers, but the media conveniently downplay, or even omit, giving the full picture. First of all, mother nature can produce subatomic particles of greater energy than the puny LHC in the form of cosmic rays. These high-energy particles, which are accelerated to astronomical energies by huge magnetic and electric fields in space, have been raining down on Earth for billions of years, plenty of time to swallow up the planet - yet we are still here to write about it.
Secondly, these mini black holes are not just small black holes; they are actually subatomic in size, comparable to electrons or protons. The entire energy created by these particles would not even light up a light bulb if the LHC were running for a hundred years. Although the subatomic particles produced by the LHC can have trillions of electron volts, the LHC is expected, at best, to create mini black holes at the rate of one per second, which is much too small to cause any appreciable danger to anyone.
In the same way that animals from the cat family come in all sizes, from ferocious lions to harmless domestic cats, black holes also come in all sizes, from the astronomically colossal to the totally insignificant.
Thirdly, these mini black holes are unstable, and quickly decay. Instead of gobbling up matter and becoming big enough to eat up the Earth, they go in the opposite direction, emitting radiation so that they eventually disappear into nothing, a process proposed by the renowned Cambridge physicist, Stephen Hawking. So these subatomic black holes naturally self-destruct.
Some critics have claimed that these mini black holes might get captured by the Earth's gravitational field, but they decay too quickly for them to be a danger to anyone.
Fourthly, when pressed by journalists to flatly declare that the worst case scenario cannot occur, physicists shy away, not because we think the event might occur, but because of a loophole in the quantum theory. Because of Werner Heisenberg's uncertainty principle, there is a tiny chance that anything will occur. There is a chance that firebreathing dragons will be produced by the LHC. But the probability of this event is so small, one can show that it will not happen in the lifetime of the universe.
In my opinion, if an event is so rare that it will probably not happen in the lifetime of the Universe, then we physicists should say to the media that it will not occur, period. We physicists have to be more media savvy, and not split hairs. The final nail in the scaremonger's coffin is that many of their fears against the LHC are identical to the ones used against the Relativistic Heavy Ion Collider in Brookhaven National Laboratory in New York State, a much smaller machine that has been running successfully for years without incident.
So who is to blame for the current concern about the LHC? The media and fearmongers are mainly to blame; but physicists are as well, because we have failed to adequately convey the purpose and the scope of the LHC to the public and the media. During the cold war, whenever physicists in the US wanted funds for a new particle accelerator, we would bypass the public and simply go to Congress and say one word, "Russia!" Congress would get scared, whip out a chequebook and say two words, "How much?"
This is not because these particle accelerators had any direct military value in the cold war. But Congress was worried that the US would lose its edge in a crucial area of high technology and wanted to compete with Russia's increasingly powerful particle accelerators. Well, now it is obvious that Russia is not building huge atom smashers anymore, and politicians are wary of funding them.
Now, we have to appeal directly to the public to support basic research. We physicists have to sing for our supper, just like all the other interest groups fighting for their share of the pie. As with Halley's Comet and now the LHC, history seems to be repeating itself, the first time as tragedy, the second as farce.
It is easy to forget that the US had begun building a much bigger particle accelerator in the 1990s, called the Superconducting Supercollider, which was cancelled by Congress in 1993. In the last days of hearings, one congressman asked an important question: "Will we find God with this machine? If so, I will vote for it." The poor physicist at the hearing was thrown by the question and failed to give a convincing answer, and the SSC was soon cancelled - the whole business of digging a hole for the SSC and filling it in cost $2bn of US taxpayers' money.
Since then, we physicists have replayed that scene over and over again in our minds. How should we have answered that question?
I don't know, but I would have said the following: "God. By whatever signs or symbols you ascribe to the deity. This machine, the supercollider, will take us as close as humanly possible to his or her greatest creation, genesis. This is a genesis machine, designed to study the greatest event in all history: the birth of the universe."
· Michio Kaku is professor of theoretical physics at the City University of New York. His latest book is Physics of the Impossible
Recommended sites : http://www.guardian.co.uk/science/cern
Sources.
http://www.vmine.net/scienceinparliament/LHC Briefing Document.pdf
http://www.guardian.co.uk/science/2008/jun/30/cern.particlephysics1
http://www.guardian.co.uk/education/...feed=education
And other ones i currently miss.
