'Perfect' Electron Roundness Bruises Supersymmetry
Did you own a toy race-car track as a child? Ever crash your model trains into one another just to see what happened? If you did, then congratulations, you already know some of the basic principles behind the Large Hadron Collider (LHC). Built by the European Organization for Nuclear Research (CERN), the 27-kilometer tunnel buried in the Swiss countryside exists to smash particle beams into each other at velocities approaching the speed of light. The idea is to use the resulting data to better understand the structure and origins of the universe. We're talking heavy questions and even heavier answers. Perhaps it's understandable that some critics, conspiracy theorists, crackpots and (alleged) time travelers might fear something more substantial than the Higgs boson particle. In this article, we'll run through some of the more popular misconceptions about the LHC and how little you have to fear about it causing the end of the world as we know it.
5. CERN Is Making an Antimatter Bomb
The Dan Brown detective novel (and movie adaptation) "Angels and Demons" centers on a plot to steal an antimatter bomb from CERN and blow up the Vatican with it. While the blockbuster delivered its share of action and intrigue, it fell short on facts. Two of the film's biggest mistakes revolved around antimatter's potential use as both an energy source and a weapon. Yes, when an antimatter particle comes in contact with normal matter, the two particles destroy each other and release energy. But CERN is quick to point out that the energy payoff simply isn't there. In fact, the transaction is so inefficient that scientists only get a tenth of a billionth of their invested energy back when an antimatter particle meets its matter counterpart. As for developing an antimatter bomb, the same principles apply. CERN points out that, at current production rates, it would take billions of years for the organization to produce enough antimatter to generate an explosion equal to an atomic blast.
4. Fun-sized Black Holes
Some concepts don't become tamer when you tack a "micro-" or a "mini-" prefix in front of them. For example, a mini-stroke is still an excellent reason to visit the hospital, and you'd certainly be ill advised to question the power of a minigun. So when CERN scientists mention that they might create microscopic black holes in the midst of their particle smashing, it's easy to understand some of the ensuing panic. Based on Einstein's theory of relativity, a few speculative theories lend a sheen of possibility to micro-black hole creation. The good news is that these theories also predict the micro-black holes would disintegrate immediately. If these black hole welterweights did hang around a little longer, it would take billions of years to consume the mass of a tiny grain of sand. That means no reducing the European countryside to a singularity and certainly no destroying the planet "Star Trek" style.
3. Attack of the Strangelets
Read enough space publications and your perception of the universe changes pretty fast. Once you get beyond the absurd vastness of the cosmos, you encounter such mind-rending notions as black holes, antimatter and dark matter. After you've swallowed the notion of a gigantic star collapsing into something smaller than a pinhead, it's easy to get bowled over by the idea of universe-destroying strangelets. Strange matter is presumed to be 10 million times denser than lead and was birthed during the Big Bang from the hearts of dense stars. The fear, which originated with the start-up of the Relativistic Heavy Ion Collider (RHIC) in 2000, is that the LHC will inadvertently produce strangelets -- tiny particles of strange matter -- and that these particles will swiftly convert surrounding normal matter into even more strange matter. It only takes a thousand-millionth of a second for the chain reaction to convert the entire planet. Strangelets, however, are purely speculative, and haven't surfaced in over eight years of RHIC operation. CERN says that the RHIC was far more likely to produce the theoretical matter than the LHC, so there's really no chance of it consuming the planet.
2. Time Travelers Hate It
In "Bill & Ted's Excellent Adventure," the titular slacker duo wields time travel with the logic of a 12-year-old. When Bill and Ted need a cell key to bust a few historical figures out of a modern California jail, they simply make a mental note for their future selves to travel back in time and plant the key where they can find it. While the 1989 buddy comedy is pretty much the antithesis of hard science fiction, its view of time-travel logic is shockingly similar to a 2009 theory regarding the LHC. Danish string theory pioneer Holger Bech Nielsen and Japanese physicist Masao Ninomiya, in a series of posted physics articles, laid out their theory that the Higgs boson particle is so abhorrent to nature that its future creation will send a ripple back through time to keep it from being made. Naturally, this theory summons images of T-800s, Jean-Claude Van Damme and Hermione Granger all galloping back through time to prevent future disasters, but not everyone is busy cracking jokes and reminiscing about time-travel movies. The two scientists aren't even talking about shadowy strangers from the future, but merely "something" looping back through the fourth dimension. Imagine a poorly designed bomb that, upon creation, destroys half the bomb factory. Now expand that example out from the confines of linear time.
1. Gateway to Hell
Black holes, antimatter explosions and even strangelets all originate from scientific fact and theory (albeit with a bit of imagination thrown in). Forget all that for the moment and consider the "Satan's Stargate" theory, proposed by Chris Constantine, better known on the Internet as YouTube user gorilla199. Constantine charges that the LHC exists "to disrupt a hole in the Van Allen belt that surrounds the Earth" and "to allow the return of the Annunaki from the planet Nibiru in order that they can come here, corrupt the rest of the Earth and do battle with God at Armageddon." There's also some stuff in there about freemasonry, cosmic rays and the Old Testament offspring of humans and fallen angels. According to BBC News, Constantine received a suspended sentence for DVD pirating after his defense attorney charged that Constantine suffered from a serious psychiatric condition. The Antichrist could not be reached for comment.
New measurements of the electron have confirmed, to the smallest precision attainable, that it has a perfect roundness. This may sounds nice for the little electron, but to one of the big physics theories beyond the standard model, it’s very bad news.
There currently are many efforts under way to search for physics “beyond” the standard model. The standard model predicts all known quantum interactions to a very high degree of accuracy. But, although being the vanguard for physics for many decades, the standard model does not account for mysterious dark matter and it does not encompass gravity.
One idea that theoretical physicists have pinned their hopes on is supersymmetry — the possible existence of “shadow particle” partners to regular subatomic particles. So, for example, every proton will have a more massive “shadow proton” (or “sproton”). Should these “sparticles” exist, perhaps they might explain the existence of dark matter that we know pervades the entire Universe, but have little idea what it is.
Alas, despite their best efforts in particle accelerators like the Large Hadron Collider (LHC), there is zero evidence of the existence of these sparticles. As if to underline this problem, it turns out that the recently-discovered Higgs boson is a “standard model Higgs” — the elusive particle is even predicted via standard model physics. Also, the LHC’s measurements of a rare Bs meson decay only confirmed standard model calculations and did not reveal anything exotic of a supersymmetrical nature.
Today, in research published in the journal Science Express, physicists have once again chipped away at supersymmetry not by smashing particles together at high speed, but by making the most precise measurement of the electron to date.
“We know the Standard Model does not encompass everything,” said physicist David DeMille, of Yale University, in a press release. “Like our LHC colleagues, we’re trying to see something in the lab that’s different from what the Standard Model predicts.”
DeMille works with John Doyle and Gerald Gabrielse of Harvard University on the ACME collaboration. ACME is hunting for exotic physics by seeking out the dipole moment of electrons and measuring their vital statistics. The standard model predicts that the electron has exactly zero dipole moment, meaning it is perfectly symmetrical. However, should supersymmetry exist, the dipole moment of the electron should be greater than zero, pushing the negatively-charged particle into a a more and more elongated shape. The presence of sparticles will squeeze the electron’s form away from being round.
As announced today, however, in measurements of the electron’s dipole moment that are 10 times more precise than any measurement that has come before it, the electron appears to be perfectly symmetrical, just as the standard model predicts.
When it comes to quantum physics, analogies are king. As described by DeMille: “You can picture the dipole moment as what would happen if you took a perfect sphere, shaved a thin layer off one hemisphere and laid it on top of the other side. The thicker the layer, the larger the dipole moment. Now imagine an electron blown up to the size of the earth. Our experiment would have been able to see a layer 10,000 times thinner than a human hair, moved from the southern to the northern hemisphere. But we didn’t see it, and that rules out some theories.”
And one of those theories — supersymmetry — just got bruised.
“It is amazing that some of these predicted supersymmetric particles would squeeze the electron into a kind of egg shape,” said Doyle. “Our experiment is telling us that this just doesn’t happen at our level of sensitivity.”
This is a fascinating study on the smallest of scales that should elegantly detect the influence of supersymmetrical particles on the electron’s structure. Alas, their influence has yet to be found — the standard model persists and supersymmetry goes back to the emergency room.