An engineer works on CERN's Large Hadron Collider in 2007
Sometime on Nov. 3, the supercooled magnets in sector 81 of the Large Hadron Collider (LHC), outside Geneva, began to dangerously overheat. Scientists rushed to diagnose the problem, since the particle accelerator has to maintain a temperature colder than deep space in order to work. The culprit? "A bit of baguette," says Mike Lamont of the control center of CERN, the European Organization for Nuclear Research, which built and maintains the LHC. Apparently, a passing bird may have dropped the chunk of bread on an electrical substation above the accelerator, causing a power cut. The baguette was removed, power to the cryogenic system was restored and within a few days the magnets returned to their supercool temperatures.
The LHC, a 17-mile underground ring designed to smash atoms together at high energies, was created in part to find proof of a hypothetical subatomic particle called the Higgs boson. According to current theory, the Higgs is responsible for imparting mass to all things in the universe. But ever since the British physicist Peter Higgs first postulated the existence of the particle in 1964, attempts to capture the particle have failed, and often for unexpected, seemingly inexplicable reasons.
In 1993, the multibillion-dollar United States Superconducting Supercollider, which was designed to search for the Higgs, was abruptly canceled by Congress. In 2000, scientists at a previous CERN accelerator, LEP, said they were on the verge of discovering the particle when, again, funding dried up. And now there's the LHC. Originally scheduled to start operating in 2006, it has been hit with a series of delays and setbacks, including a sudden explosion between two magnets nine days after the accelerator was first turned on, the arrest of one of its contributing physicists on suspicion of terrorist activity and, most recently, the aerial bread bombardment from a bird. (A CERN spokesman said power cuts such as the one caused by the errant baguette are common for a device that requires as much electricity as the nearby city of Geneva, and that physicists are confident they will begin circulating atoms by the end of the year).
In a series of audacious papers, Nielsen and Ninomiya have suggested that setbacks to the LHC occur because of "reverse chronological causation," which is to say, sabotage from the future. The papers suggest that the Higgs boson may be "abhorrent to nature" and the LHC's creation of the Higgs sometime in the future sends ripples backward through time to scupper its own creation. Each time scientists are on the verge of capturing the Higgs, the theory holds, the future intercedes. The theory as to why the universe rejects the creation of Higgs bosons is based on complex mathematics, but, Nielsen tells TIME, "you could explain it [simply] by saying that God, in inverted commas, or nature, hates the Higgs and tries to avoid them."
Many physicists say that Nielsen and Ninomiya's theory, while intellectually interesting, cannot be accurate because the event that the LHC is trying to recreate already happens in nature. Particle collisions of an energy equivalent to those planned in the LHC occur when high-energy cosmic rays collide with the earth's atmosphere. What's more, some scientists believe that the Tevatron accelerator at Fermi National Accelerator Laboratory (or Fermilab) near Chicago has already created Higgs bosons without incident; the Fermilab scientists are now refining data from their collisions to prove the Higgs' existence.
Nielsen counters that nature might allow a small number of Higgs to be produced by the Tevatron, but would prevent the production of the large number of particles the LHC is anticipated to produce. He also acknowledges that Higgs particles are probably produced in cosmic collisions, but says it's impossible to know whether nature has stopped a great deal of these collisions from happening. "It's possible that God avoids Higgs [particles] only when there are very many of them, but if there are a few, maybe He let's them go," he says.
Nielsen and Ninomiya's theory represents one side of an intellectual divide between particle physicists today. Contemporary physicists tend to fall into one of two camps: the theorists, who posit ideas about the origins and workings of the universe; and experimentalists, who design telescopes and particle accelerators to test these theories, or provide new data from which novel theories can emerge. Most experimentalists believe that the theorists, due to a lack of new data in recent years, have reached a roadblock — the Standard Model, which is the closest thing the theorists have to an evidence-backed "theory of everything," provides only an incomplete explanation of the universe. Until theorists get further data and evidence to move forward, the experimentalists believe, they end up simply making wild guesses — like those concerning time-traveling saboteurs — about how the universe works. "Nielsen and Ninomiya's theories are clearly crazy theories," says Dmitri Denisov, a physicist and Higgs-hunter at the DZero experiment at Fermilab. "In recent years theorists have been starving for experimental input and as a result, theories of second type are propagating widely. The majority of them have nothing to do with world we live in."
Nielsen concedes, "We have very little data, so theorists are going their own ways and making a lot of theories that may not be very plausible. We need guidance from experimentalists to make the theories more healthy."
"But," he adds, "in terms of our theory, we are submitting to a form of experiment. We are saying the LHC won't be allowed to produce a large number of Higgs. If it does, it would be very damaging to our theory."
Particle physics has a long history of zany theories that turned out to be true. Niels Bohr, the doyen of modern physicists, often told a story about a horseshoe he kept over his country home in Tisvilde, Denmark. When asked whether he really thought it would bring good luck, he replied, "Of course not, but I'm told it works even if you don't believe in it." In other words: if preposterous theories are mathematically sound and can be confirmed by observation, they are true, even if seemingly impossible to believe. To scientists in the early 20th century, for example, quantum mechanics may have seemed outrageous. "The concept that you could have a wave-particle duality — that an object could take on either wave-like properties or point-like properties, depending on how you observe it — takes a huge leap of imagination," says Roberto Roser, a scientist at Fermilab. "Sometimes outlandish papers turn out to be the laws of physics."
So what would Peter Higgs himself make of the intellectual controversy surrounding his eponymous particle? Speaking on behalf of his friend, Professor Richard Kenway, who holds Higgs' former position at the University of Edinburgh, says that the 78-year-old emeritus professor remains quietly confident that the LHC will discover the Higgs boson when it is eventually running at full strength. For his part, Kenway says the LHC's delays are to be expected given the size and intricacy of the $9 billion experiment. And he says if he ever needs further proof that the Higgs boson is not abhorrent to nature, he need only spend time with his friend and mentor. "If nature truly did not want us to discover the Higgs, a cosmic ray would have zapped the embryo that became Peter, preventing its development into a physicist," he says.
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