Will firing up the accelerator bring about the end of the world? Not likely, but physicists are seeking clues on how the universe began

Talk about a public relations problem. Imagine spending years sinking vast quantities of money, time and ambition into an intricately complex project only to face accusations just before the project's debut that you might accidentally bring about the end of the world.

This, essentially, is the PR issue facing the Large Hadron Collider (LHC) as scientists on Wednesday plan to send the first beam of protons around the 27-kilometer (17-mile) long loop buried deep below ground not far from Geneva, Switzerland. Physicists say that the €6.4 billion ($9.2 billion) project—the lion's share of which came from European countries—may provide unique new insights into how our universe was formed, the existence of "dark matter" and even the possible reality of a number of new dimensions.

Critics, though, many of whom have found a powerful platform on the Internet, fear that by smashing protons against each other at 99.9999991 percent of the speed of light, scientists could create tiny black holes which could eventually grow to the point that they swallow up the Earth.

The European Organization for Nuclear Research—known by its French acronym CERN—has spent considerable energy discounting such fears. An international team of scientists published yet another assessment of the particle accelerator's safety over the weekend in the Journal of Physics G: Nuclear and Particle Physics—to go with a number of other safety evaluations conducted by the project.

"The LHC is safe, and any suggestion that it might present a risk is pure fiction," said Robert Aymar, who heads CERN.

Still, the project has been swamped by e-mails from those concerned that scientists may be biting off more than they can chew. Videos on YouTube show what it might look like were a black hole, starting below the ground outside of Geneva, to swallow up the Earth. Skeptics in the United States filed suit in a US District Court in Hawaii in an attempt to block the project. A similar effort was mounted by a German scientist who brought suit at the European Court of Human Rights—though the case was tossed out at the very end of August.

One Nobel prize-winning physicist associated with the project, Frank Wilczek from the Massachusetts Institute of Technology, has even received death threats connected with the start of the LHC. "I have received threats by both e-mail and by telephone," Wilczek told SPIEGEL ONLINE. "I'm trying not to let it bother me—with some success."

Even if scientists say they are confident that switching on the LHC won't bring the world to a sudden end, some of them are hoping to find evidence of dimensions in excess of the four we are currently aware of. Because the LHC is the most powerful and most precise particle accelerator ever built, many see it as the best opportunity yet to find proof for the veracity of "string theory."

String theory is a mathematical construct that many believe might explain away inconsistencies between Albert Einstein's General Theory of Relativity and quantum mechanics—a major focus in theoretical physics for much of the last century. The highly complex models used in string theory point to the possible existence of up to 11 dimensions and also make predictions about the existence of some as-yet unobserved sub-atomic particles. Should the LHC be able to find some of those particles, a much touted theory of physics would have its first kernel of proof.

But string theory is just one idea being investigated by the thousands of scientists from more than 80 countries who will be running, analyzing and evaluating the experiments at the Large Hadron Collider. Many also hope to find the elusive "Higgs boson," a theoretical particle named after the Scottish physicist Peter Higgs. He came up with a theory in 1964 to help explain what gives mass to matter, thus making the universe possible. Higgs pointed to a particle that has so far never been observed. By creating conditions similar to those that existed at the birth of our universe, the so-called "Big Bang," scientists hope to be able to find Higgs boson, also known as the "God Particle."