Will the Hadron Collider send the world into a black hole?

It’s mildly alarming when people with access to futuristic super-machines begin publicly musing about how they might shatter reality as we know it. It’s worse when they seem gleeful at the prospect.

Last week, Sergio Bertolucci, a research director working on the Large Hadron Collider, said that the giant particle accelerator could tear a “door” into another dimension when it’s started up in the near future.

“Out of this door might come something, or we might send something to it,” Bertolucci said, in all likelihood while rubbing his hands together and laughing menacingly.

Mike Lamont, another LHC mucketymuck, threw cold water on the theory. By way of explanation, he told online tech bible The Register that Bertolucci is a “theorist.” Dirty word in science, apparently.

Lamont suggested that anyone requiring a reality check should read Warped Passages by Harvard physicist Lisa Randall.

Naturally, we’ve been up all night since, watching and rewatching Stephen King’s The Mist. Three things: Where did I leave my tentacle cutter? Why does Thomas Jane keep getting work? And will I be atomically disassembled soon?

Eventually, we found our hyperventilating bag and took some encouraging breaths. Then we called Randall and asked, “Should I be preparing to bow down before my extra-dimensional overlords?”

Short answer: No. Long, long answer: Wellll

First, Randall spoke to us like an adult. That didn’t go too well.

Then she began to recalibrate her converso-intellectual speech barometer (Us: “Lower, please. Lower. Much, much lower.”)

The upshot is this. When the LHC kicks in, scientists hope that a small, extremely brief peak into the up-until-now theoretical extra-dimensional world is achieved.

How will they know if that’s happened?

“What you expect are (theoretical, extra-dimensional) Kaluza-Klein Particles, that effectively have momentum in other dimensions,” Randall said. “If you see these new particles, they would be an indication that these extra dimensions exist.”

Okay, particles. Not so scary. What else is in this extra dimension?

“At the very least, there would be gravity in the extra dimension.”

Gravity. Good. Now, just in case there is something lurking in there, could stuff pass from this dimension to the other, or vice versa?

“Yes, in principle … it’s possible that gravity could take matter out into another dimension.”

Um. Is that a problem?

“No. It wouldn’t happen that much.”

If we look into the extra dimension, what do we expect to see?

“People talk about higher dimensional black holes, which is, in principle, possible. But really what you expect to see are new gravitational interactions associated with the extra dimensions.”

Alright, great. But I’d like to back up juuuust a little. “Black holes”?

“In principle, if you had enough energy, you could make a higher dimensional black hole. But the fact of the matter is that the LHC won’t have enough energy.”

So, just to be perfectly clear, the world is not going to get hoovered through a minuscule crack in space-time in the next couple of weeks?

“That’s correct,” said Randall, in tones reserved for art history majors who’ve wandered into the physics lab. “The world will not disappear.”


Second chance for Large Hadron Collider to deliver universe’s secrets

*Hmm…will something stop it?*

At first glance, the piece of metal in Steve Myers’s hands could be taken for a harmonica or a pen. Only on closer inspection can you make out its true nature. Myers, director of accelerators at the Cern particle physics laboratory outside Geneva, is clutching a section of copper piping from which a flat electrical cable is protruding.

It looks unremarkable. Yet a piece of cable like this one was responsible last year for the world’s most expensive short-circuit. More than £30m-worth of damage was done to the Large Hadron Collider (LHC), the most advanced particle accelerator ever built, a few days after its ceremonial opening. It has taken Myers – and hundreds of other Cern scientists – more than a year to pinpoint the guilty piece of cable and repair the wreckage. “It was a very small piece, but it did immense damage,” he said. It remains to be seen whether Myers can fix Cern’s tattered technological reputation in the process – when his team restart their great machine in a few weeks. “I am not a nervous person,” said the 63-year-old Belfast-born engineer. “And that is probably just as well.”

The LHC had been inaugurated at 9.30am on 10 September 2008 to a barrage of global media attention. This was the God Machine that would unravel the secrets of the universe, it was claimed. Beams of protons, one of the key constituents of the atom’s nucleus, were successfully fired round the machine’s subterranean 18-mile circular tunnel under the Jura mountains outside Geneva.

Over the following weeks, it was predicted, scientists would recreate conditions that existed a trillionth of a second after the universe’s birth and start making sensational discoveries as they smashed beams of protons into each other.

Discoveries would include the God Particle, a tiny entity also called the Higgs Boson, which is believed to give objects – including people – their mass. In addition, dark matter, a mysterious, invisible form of matter that permeates the universe, would be uncovered, along with a host of other revolutionary discoveries.

“It was all looking so good,” said Myers. Then, at 11.45am on 19 September, things went spectacularly wrong. Faulty soldering in a small section of cable carrying power to the machine’s huge magnets caused sparks to arc across its wiring and send temperatures soaring inside a sector of the LHC tunnel.

A hole was punched in the protective pipe that surrounds the cable and released helium, cooled to minus 271C, into a section of the collider tunnel. Pressure valves failed to vent the gas and a shock wave ran though the tunnel.

“The LHC uses as much energy as an aircraft carrier at full speed,” said Myers. “When you release that energy suddenly, you do a lot of damage.”

Firemen sent into the blackened, stricken collider found that dozens of the massive magnets that control its proton beams had been battered out of position. Soot and metal powder, vaporised by the explosion, coated much of the delicate machinery. “It took us a long time to find out just how serious the accident was,” said Myers.

A 400-metre chunk of the £2.5bn device had been wrecked, it was discovered. Worse, when scientists traced the cause to a tiny piece of soldering, they realised that they would have to redesign major parts of the collider’s entire safety systems to prevent a repeat event. That has taken more than a year to achieve.

Now Cern scientists have begun firing protons round one small section of the collider as they prepare for its re-opening. Over the next few weeks, more and more bunches of protons will be put into the machine until, by Christmas, beams will be in full flight and can be collided.

The LHC will then start producing results – 13 years after work on its construction began.

“There was so much expectation that we were about to make great discoveries last year and then the accident occurred,” said Cern researcher Alison Lister. “Morale was very low when we found out just how bad it was. However, we should now be getting results by Christmas, and you couldn’t get a better present than that.”

When fully operational, the LHC will soak up 10 times more power than any other particle accelerator on Earth, consuming 120 megawatts of electricity – enough for an entire Swiss canton – to accelerate bunches of protons, kept in two beams, each less than a hair’s breadth in diameter, to speeds that will come “within a gnat’s whisker of the speed of light”, according to Myers.

One beam will circulate clockwise, the other anti-clockwise. Then, at four points along the collider’s tunnel, the beams will cross.

Bunches of protons – each containing 100bn particles – will slam into other oncoming bunches, triggering collisions that will fling barrages of sub-atomic detritus in all directions.

These explosive interactions will form the core of the great collider’s operations and will generate new types of particle, including the Higgs, that will pop fleetingly into existence before disintegrating into a trail of other sub-atomic entities. New physics will be uncovered with Nobel prizes following in their wake. And that is not all, say sceptics. They argue that miniature black holes will be created and one of these could eventually grow to swallow up the Earth. The LHC would then not only be the world’s biggest experiment – but its last. This fear has led protesters to make legal attempts to close down the LHC, one even making it to the European Court of Human Rights. All have failed, though one case – in Germany – has still to be resolved.

Even stranger is the claim by another group of physicists who say the production of Higgs bosons may be so abhorrent to nature that their creation would ripple backwards through time to stop the collider before it could make one, like a time traveller trying to halt his own birth.

“All Higgs machines shall have bad luck,” said Dr Holger Bech Neilson of the Niels Bohr Institute in Copenhagen. Thus the cable meltdown that afflicted the LHC was an inevitable effect of the laws of time, a notion that leaves most Cern scientists scratching their heads in bafflement.

In fact, the real problem facing the LHC is simple. It is a vast device the size of London’s Circle Line but is engineered to a billionth of a metre accuracy. Ensuring that no flaws arise at scales and dimensions like these pushes engineering to its absolute limits.

Cern almost succeeded last year. Now it is convinced that it has got it right this time. “All I can say is that the LHC is a much safer, much better understood machine than it was a year ago,” said Myers.

Most physicists believe he is right. “If it works, we will have built the most complex machine in history,” said one. “If not, we will have assembled the world’s most expensive piece of modern art.”


Le futur sabote-t-il la recherche sur le boson de Higgs ?

Le LHC (Large Hadron Collider) le grand accélérateur de particules du CERN, près de Genève, serait-il victime d’une malédiction venue du futur? Cette monstrueuse machine dont la construction a nécessité 15 ans de travaux et coûté plus de 6 milliards d’euros est tombée en panne en novembre dernier, peu après sa mise en service. Elle est destinée à produire une mystérieuse particule, le boson de Higgs, qui n’aurait existé qu’au tout début du big-bang et qui est censée être à l’origine de la masse de la matière. Pour la recréer, les chercheurs ont donc conçu une expérience consistant à accélérer des protons dans un anneau souterrain avec une énergie proche de celle qui a régné pendant le premier trilionième de seconde de la naissance de l’univers.

Cette entreprise hors du commun a déjà inspiré toutes sortes d’élucubrations: peu avant qu’elle ne démarre, en septembre 2008, deux Américains prétendant qu’elle allait déclencher la formation d’un trou noir susceptible d’absorber la terre ont assigné le Cern devant un tribunal d’Hawaï en demandant l’arrêt des travaux -ils ont été déboutés. Cette fois, ce sont deux physiciens reconnus et respectés qui lancent une hypothèse pour le moins iconoclaste: selon Holger Nielsen, chercheur à l’institut Niels Bohr de Copenhague, et Masao Ninomiya, de l’institut de physique théorique de l’université de Kyoto, il serait possible qu’une mystérieuse contrainte venue du futur sabote le projet pour empêcher la découverte du fameux boson de higgs! Leur théorie ne date pas d’hier: ils l’ont exposé il y a plus d’un an dans deux papiers publiés dans des revues scientifiques et passés pratiquement inaperçus (1).

Cette influence maligne pourrait, selon eux expliquer pourquoi les Etats-Unis ont abandonné en 1993 un projet d’accélérateur similaire au LHC destiné à produire le boson, après que des milliards de dollars aient été investis. L’idée chère aux auteurs de science-fiction que le temps puisse être réversible et qu’il soit possible de voyager dans le passé n’est plus aujourd’hui considérée comme délirante par les physiciens, qui ne s’interdisent plus de cogiter sur des univers parallèles ou l’influence du futur sur le présent, dans la mesure où les lois universelles de la physique sont, pour nombre d’entre eux, réversibles. Il serait ainsi possible que l’univers limite fortement la probabilité de certaines découvertes en raison du danger que celles-ci représenteraient pour l’univers lui-même.

Pour en avoir le coeur net, Nielsen et Ninomya proposent que le Cern réalise un “test de chances” consistant à utiliser un générateur de nombres aléatoires équivalent à tirer des millions de cartes dans un jeu afin de savoir si certaines figures improbables apparaissent. Ce qui signifierait que les probabilités pour que le LHC fonctionne correctement sont très minces…


CERN shut down…

The cooling system for the Large Hadron Collider’s high-powered magnets that steer beams of particles around the tunnel malfunctioned earlier this week.

The European Organisation for Nuclear Research (Cern) replaced the equipment in the underground tunnel near Geneva, Switzerland, but the damage is worse than previously thought.

Cern spokesman James Gillies said: “There has been an incident in a test. One section of the machine will have to be repaired.

“In layman’s terms, the LHC is a great big fridge, and part of the power supply failed.”

The faulty electrical connection between the two magnets led to a ton of liquid helium being leaked into the tunnel.

The magnets are chilled to as low as -271 degrees Celsius, which is close to absolute zero and colder than deep outer space.

Mr Gillies said the damaged section will have to be warmed up well above absolute zero so that repairs can be made.

He expects the atom smasher to remain switched off for at least two months.

The LHC, which started on September 10, took nearly 20 years to complete and at £4.4bn is one of the costliest and most complex scientific experiments ever attempted.

It aims to resolve some of the greatest questions surrounding fundamental matter, such as how particles acquire mass and how they were forged in the Big Bang that scientists believe created the universe 17 billion years ago.


Large Hadron Collider: First subatomic particle collision to happen next week

*Here we go, this will be when the real fun starts!!!*

The first collisions between subatomic particles will take place in the Large Hadron Collider next week, which will mark another milestone for the biggest experiment in history.

“If we get stable conditions, I am very optimistic things will go quite fast,” says Dr Lyn Evans, the coal miner’s son from Aberdare, South Wales, who is leader of the £4.4 billion particle accelerator, a project that involves around 10,000 scientists and engineers worldwide.

The LHC circulates particles in a 17 mile circumference underground tunnel straddling the French-Swiss border at The European Organization for Nuclear Research, near Geneva, Switzerland, known by the acronym Cern.

Although there was much ballyhoo last week about the first particles – protons – to whirl around the LHC at a shade under the speed of light, the real aim of the exercise is to bring counter rotating beams of particles into collision in the four “eyes” – detectors – of the machine to recreate conditions not seen since just after the birth of the universe.

This is the aspect of the experiment that has triggered all the angst and hand-wringing by doomsayers and Jeremiahs who fear that the collisions will mark the end of the world, as it tumbles into the gaping maw of a black hole.

These fears have been dismissed as nonsense by Dr Evans, along with scientists such as Prof Stephen Hawking, who say that the end of the world is not nigh.

The original plan was to take 31 days from the first proton beams circulating in the LHC to smashing protons for the first time.

“We were going along at a real good lick,” Dr Evans said of the days after particles first circulated.

But the cryogenics that keep the great machine cool – it is the biggest fridge on the planet – went down on Friday, as a result of thunderstorms disrupting the power supply.

“We have had problems with the electricity supply for various reasons and the cryogenics is recovering from that, so we will not have a beam again, probably until Thursday morning,” says Dr Evans.

The team now hopes to achieve collisions at between one fifth and one tenth of the full energy in a few days.

“We are very confident that we can go quite quickly. The experiments have asked us for some early collisions, at low energy. If we get stable conditions, we will get there next week.”

The collisions will take place in the two general purpose detectors of the giant machine, called Atlas and CMS, though Dr Evans adds the team will also attempt collisions in Alice, which will study a “liquid” form of matter, called a quark-gluon plasma, that formed shortly after the Big Bang, and an experiment called LHCb, which will investigate the fate of antimatter in the wake of the Big Bang.
Dr Lyn Evans in the control room of the Large Hadron Collider

“The main objective is to get to 5TeV” (that target energy per beam is equivalent to 10Tev collisions, while the LHC is designed to reach 14 TeV working full steam), said Dr Evans.

He says “I don’t know how long that will take,” though the schedule predicts that 14 TeV will be reached next year.

“We would not go to very high energy next, week, we are not that clever,” said “Evans the Atom”.

The LHC will be able to create fundamental particles that are too heavy to have been produced using existing particle colliders.

One of these could be the Higgs boson, named after the Edinburgh based physicist, which the LHC was built to find using the Atlas and the CMS detectors.

If discovered, the Higgs – jokingly called the “god particle” – would complete the Standard Model of particle physics by explaining how particles get their different masses.

The great machine may also catch a glimpse of a “supersymmetric” world, where a new myriad of heavy particles mirror those of the Standard Model, which may be responsible for a mysterious gravity source, called dark matter.

Although based on much more speculative theories, the LHC may even find exotic entities such as mini black holes or evidence for additional dimensions.

HERE WE GO. Scientists Await Start-up Of Large Hadron Collider

*Certain or uncertain doom, who knows?*

ScienceDaily (Sep. 8, 2008) — The moment that James Pilcher has been waiting for since 1994 will arrive at 1:30 a.m. CDT on Wednesday, Sept. 10, when the world’s largest scientific instrument is scheduled to begin operation.

Pilcher is among six University of Chicago faculty members and more than a dozen research scientists and students, both graduate and undergraduate, who have contributed to the design and construction of the Large Hadron Collider at CERN, the particle physics laboratory in Geneva, Switzerland.

“This year, more than 11 of us will be in residence full-time at CERN, and the rest will be in Chicago,” said Pilcher, Professor in Physics. Along with Indiana University, the University of Chicago also houses a computing center that will support LHC data analysis for various Midwestern institutions.

Physicists at Chicago and elsewhere built the particle detector for the ATLAS (A Toroidal LHC ApparatuS) experiment at LHC, with the search for the Higgs boson and supersymmetry in mind. Theoretically speaking, the long-sought Higgs boson is the particle that endows all objects in the universe with mass. Evidence of supersymmetric particles, meanwhile, could provide an understanding of the dark matter, which makes up about a quarter of the mass of the universe.

Pilcher has been involved with ATLAS since 1994, first in its design, then in the search for funding, and finally in its construction and assembly. He served as chair of the experiment’s 150-institution collaboration board in 2000 and 2001.

“Now our team is working to get all parts of the detector working together and to be ready to analyze the first data this fall. It’s gratifying that we will finally be doing science soon after all these preliminaries,” Pilcher wrote via e-mail from Geneva.

LHC scientists and engineers injected the first protons into the accelerator during two weekend sessions in August. During these tests, the proton beam traveled around only part of the collider, which measures approximately 17 miles in circumference.

“On Sept. 10, the plan is to try and take both beams around the full machine,” Pilcher said. “Of course, after that, there is still a lot of work and tuning before physics can start.”

The preparations remind Mel Shochet, the Elaine M. and Samuel D. Kersten Jr. Distinguished Service Professor in Physics, of the early 1970s, before the accelerator was turned on at Fermi National Accelerator Laboratory. “There is enormous anticipation of finding phenomena never before seen,” said Shochet, a member of the ATLAS collaboration.

But the process involves more than pressing the “on” button and making instant discoveries. “Turning on, understanding and optimizing the performance of the accelerator and the detectors will take hard work and time. That effort will pay off in the years ahead as important scientific discoveries are made.”


Super-smasher targets massive mystery

MEYRIN, Switzerland – In the beginning was the big bang.

God may have been around before then — but as far as scientists are concerned, the big bang is as far back as they can go. And to get back there, they’re getting ready to blast subatomic particles so energetically that the extreme conditions of the freshly born universe will be re-created on Earth.

Will those “little big bangs” crack age-old scientific mysteries? Or, despite repeated assurances from the world’s top experts, will they create black holes that could gobble up the planet? After decades of preparation, scientists are finally switching on a machine that will separate the facts from what is plainly science fiction.

The machine is the $10 billion Large Hadron Collider, or LHC — the most powerful, most expensive particle-blaster ever invented. On Wednesday, Europe’s CERN particle-physics lab is due to start shooting beams of protons through the LHC’s 17-mile-round (27-kilometer-round) ring of tunnels beneath the French-Swiss border.

It will take months for the machine to reach full power. But eventually, those protons will be whipped up to 99.999999 percent of the speed of light, slamming together with the energy of two bullet trains colliding head-on. Underground detectors as big as cathedrals will track the subatomic wreckage on a time scale of billionths of a second. Billions of bits of data will be sent out every second for analysis.

As big as the numbers surrounding the LHC are, the mysteries it was built to address are bigger:
What was the newborn universe made of?
What causes things to have mass?
Why is most of that mass hidden?
Where did all the antimatter go?
Is our entire universe a mere sliver of all that is?

“The LHC is the most powerful microscope that’s ever been built,” said John Ellis, a theoretical physicist here at CERN. “It will be able to explore the inner structure of matter on a scale that is 10 times smaller than anyone’s been able to do before.”

Ellis said the LHC also serves as “the most powerful telescope ever built,” even though it looks inward rather than outward.

“We know that the way elementary particles interacted with each other controlled the very early universe,” he explained. “So with the LHC we are able to, in some sense, re-create the conditions that existed in the universe when it was just a fraction of a second old — the sort of thing that the optical telescopes just can’t see.”

What’s the point?
Past experiments in particle physics have yielded scores of practical spin-offs, ranging from new medical therapies to high-tech industrial materials — and even the World Wide Web, which you’re using to read this report. But the potential for spin-offs isn’t why more than 10,000 researchers around the world are looking forward so anxiously to the LHC.

“People ever since the ancient Greeks – and probably a long time before that – have wanted to understand how matter is made up, how it behaves, where the universe comes from,” said Ellis, surrounded in his office by stacks of research papers. “And so we are responding to that continuing human urge.”

The quest is not without controversy: Scientists say there’s a chance that the LHC could create microscopic black holes, a phenomenon never before observed on Earth. They hasten to add that the tiny singularities will instantly pop out of existence, but that hasn’t stopped critics from trying to block the collider’s startup. Two of the critics have filed suit in federal court in Hawaii, seeking the suspension of LHC operations until more studies are done.

Responding to the critics, CERN has issued a series of reports explaining why the LHC will pose no threat. Ellis was one of the report’s authors. “If the LHC were to make microscopic black holes, it would be tremendously exciting — and no danger,” he said.

The 62-year-old London native has spent more than half his life at CERN, delving into topics ranging from dark matter to the theory of everything. Once the LHC is up and running, he expects to find out whether the theories he and other physicists have developed over all those years lead to solid evidence — or lead to a scientific dead end.

“Theoretically, that would be the most interesting possibility, because it would really mean that we had to tear up our notebooks of the last 45 years and start more or less from scratch,” Ellis said.

The God Particle
The theory described in all those notebooks is known as the Standard Model, which ranks among the scientific world’s most successful theories. The Standard Model lays out a menagerie of subatomic particles and their interactions — and provides the basis for inventions ranging from television sets to microwave ovens to nuclear bombs.

Only one elementary particle predicted by the Standard Model has not yet been detected: the Higgs boson, which is thought to interact with other particles to give them mass. Without the Higgs, the big bang might have been an insubstantial flash in the pan — all energy, and no mass. Or so the theory goes.

The elusive Higgs boson looms so large as a gap in the Standard Model that Nobel-winning physicist Leon Lederman wrote a book about it called “The God Particle.” (He joked that he wanted to call it the “Goddamn Particle,” but his editor wouldn’t let him.)

“This is in some sense the holy grail of particle physics, to find this missing link in the Standard Model,” Ellis said. “So that’s one thing that we’re really looking forward to with the LHC. In fact, back when we persuaded the politicians to stump up the money to build the thing, that’s probably what we told them.”

Not even the LHC will be able to spot the Higgs boson directly. Instead, physicists will have to infer its existence through an analysis of the other particles that should be created when it decays. It’s not an easy task, but Ellis believes the evidence should turn up within a year or two of the machine’s startup.

Even that won’t mark the end of the quest. Ellis compared the Higgs boson to a doorway that should lead beyond the Standard Model.

“I don’t think that the Higgs door, if you like, is just closing off the room, and there is nothing beyond,” he said. “I believe there’s going to be a lot more physics beyond. What it’s going to be, I don’t know. Maybe it’s supersymmetry. Maybe space has additional dimensions. Maybe it’s something that we haven’t thought of yet. I certainly hope it’s something we haven’t thought of yet. It would be great to come across a real surprise.”

But Ellis and his colleagues at CERN have two nagging concerns in the back of their minds: What if somebody else finds the magic door first? Or what if they spent all these billions of dollars and there’s no Higgs particle at all?

A competitive twist
Fifteen years ago, when Leon Lederman wrote “The God Particle,” he thought the Higgs boson would be found in the Superconducting Super Collider, a project that was just getting started in Texas. That machine would have been four times as powerful as the LHC — but when the costs started running far beyond the initial estimates, Congress killed the program.

Over the decade that followed, U.S. scientists weren’t just waiting for the LHC to be built: The focus shifted to the Tevatron collider at Fermilab in Illinois, which theorists figured might have just enough punch to pick up the Higgs’ trail.

Last year, researchers at Fermilab passed the word that they had found some interesting data — readings that hinted at the presence of the Higgs but weren’t yet solid enough to publish. That added a competitive twist to the grail quest.

“The longer we wait, the higher the probability that Fermilab discovers something that we wouldn’t mind discovering ourselves here,” Jos Engelen, CERN’s chief scientific officer and deputy director general, said last year.

Beyond the God Particle
What if physicists don’t find the God Particle they are expecting to see? Ellis acknowledged that was a possibility. “This might be a little bit difficult to explain to our politicians, that here they gave us 10 billion of whatever, your favorite currency unit, and we didn’t find the Higgs boson,” he said.

But Ellis has faith that even then, there’d be something to discover — maybe something even weirder and more wonderful than the Higgs boson.

“Probably the most likely option then might be extra dimensions,” Ellis said. “And there are some ideas where if you have some additional dimensions of space, you could somehow do the job that the Higgs does in the Standard Model.”

For years, string theorists have noted that their equations come out better if they assume that the universe has nine or 10 spatial dimensions instead of the three we can perceive. The LHC could provide the first evidence of those extra dimensions: Some theorists say the collisions could produce anomalously heavy particles, suggesting that part of their momentum was going into the extradimensional realm. Harvard physicist Lisa Randall estimates that the LHC could nail down the evidence for extra dimensions in five years.

Other theorists have focused on the idea that every subatomic particle should have an as-yet-undetected “supersymmetric” partner that mirrors many of the characteristics of the particles we know, but is dramatically different in other respects. The partners would have greater masses and a different spin, for example.

To date, no actual evidence of supersymmetry has been found. But if supersymmetric particles don’t exist, then a lot of the theories that look beyond the Standard Model would have to be thrown out.

If supersymmetric particles do exist, they could account for a large part of the universe’s dark matter. That’s the 90 percent of all matter that scientists can detect only by its gravitational effect — a puzzle that has bedeviled astronomers for decades. “There are good reasons to think that these dark matter particles, if they exist, will be observable in the LHC,” Ellis said.

Exploring the big-bang frontier
One of the LHC’s detectors, known as ALICE, is devoted to studying the stuff that the universe was made of less than a billionth of a second after the big bang. Earlier experiments have hinted that the stuff was a super-hot liquid consisting of subatomic particles known as quarks and gluons.

For one month out of every year, the LHC will switch from smashing protons to smashing heavy lead ions, in an effort to re-create that quark-gluon soup and let ALICE analyze the recipe.

Yet another detector, LHCb, will study the tracks of particles containing specific types of quarks and antiquarks. The Standard Model predicts that equal amounts of matter and antimatter should have been produced in the big bang — but today, we see hardly any antimatter in nature. That’s a good thing, because matter and antimatter annihilate each other when they come in contact, leaving pure energy behind.

LHCb will follow up on earlier experiments that suggest matter won out over antimatter because they somehow decay in different ways.

And then there are the wild cards in the deck: Could the LHC really create black holes or exotic forms of matter? What about all these claims that the world is in peril?