Black Holes and the Large Hadron Collider, No Worries

BUFFALO, N.Y. -- No, the startup of the Large Hadron Collider this week won't create a massive black hole that will wipe out life on Earth as we know it, according to University at Buffalo assistant professor of physics Dejan Stojkovic.

Stojkovic ought to know, since he's an expert on black holes, general relativity and cosmology.

He recently created Black Max, a computational black-hole simulator, along with UB postdoctoral research fellow De Chang Dai and collaborators at Oxford University and Case Western Reserve University. Black Max was described most recently in "Black Max: A black-hole event generator with rotation, recoil, split branes, and brane tension" published in Phys. Rev. D 77:076007, 2008.

"It's a publicity stunt," he said recently of the lawsuit alleging that the startup of the world's most powerful particle accelerator could generate a black hole so large it would suck us all in.

Black holes are defined as regions in space that have such a strong gravitational pull that even light cannot escape them.

"According to the most reliable knowledge we have so far, all black holes that the LHC could possibly create would disappear extremely quickly, in a fraction of a second that you cannot even measure," said Stojkovic.

But, he said, the LHC startup, which he described as a "once-in-a-lifetime-event" for physicists, might, nonetheless, produce evidence of long-sought Higgs particles, certain kinds of quantum gravity effects, of which mini-black holes are certainly the most interesting, brand new particles and other, unprecedented physical phenomena.

On Sept. 10, billions of protons will make a first full circle around the 17-mile-long underground tunnel at the LHC, if all goes well, with the two particle beams smashing together at an energy of 14 trillion electron volts, an order of magnitude more powerful than the next most powerful accelerator at Fermilab in Chicago. (One trillion electron volts are equivalent to the energy provided by 1 trillion 1-volt batteries strung together.)

At four different points in this 17-mile underground tunnel, very brief particle collisions will occur; the resulting data will change what physicists know about the structure of matter and our understanding of the universe.

"Black Max, our black hole event generator, tells you what will result from some of the collisions that will occur at the LHC," he said. "It calculates the probability that a black hole will form at the LHC, the subsequent evolution and decay of such a black hole, and gives the particle outcome that we should look for in order to confirm or rule out the formation of a black hole.

"The latest and most comprehensive theoretical and numerical tools are embedded in Black Max."

Once proton-beam collisions begin at the LHC, probably next month, a very small black hole might form and then quickly disappear, he said.

"According to Black Max, the LHC will allow us for the first time to see products of black hole evaporation," said Stojkovic. "That's never been seen before. We weren't even close."

And while the structure of matter and the search for the Higgs boson may be the headline events at the LHC, Stojkovic noted that the new experiments have major implications for our understanding of cosmology.

"There is nothing more cosmological than black holes, they are very important but so difficult to study," he said. "The only way to study black holes is through the extensive Hawking radiation (named after Stephen Hawking) that small black holes produce. LHC is providing us with our only chance to produce a small black hole."

Experiments at the LHC might also provide evidence of other, new physics phenomena, he said.

"For example, what is dark matter, which is much more abundant than ordinary matter in our universe?" he asked. "It's the form of matter that has to interact with gravitational force, be stable, slow and has no charge. There is no such candidate in the standard model of particle physics. So even cosmology depends on what the LHC finds. And finally, if we are lucky, the LHC might shed some light on dark energy, a mysterious ingredient that drives accelerated expansion of our universe."