The Moment

If you're reading this, the world didn't end last Wednesday morning--but then, no serious person thought it would. Two men with more of a cause than a clue, however, had sued to stop the Large Hadron Collider (LHC), a new particle accelerator near Geneva, from being switched on, arguing that it could lead to black holes or other scary things that could destroy the earth.

The weight of scientific evidence was overwhelmingly against the men, so the lawsuit didn't go ahead, and at 4:30 a.m. E.T. that day, the start-up of the LHC did. A beam of protons was sent whirling around a ring-shaped tunnel some 300 ft. underground and nearly 17 miles around, making the circuit in approximately 1/10,000 of a second.

The LHC represents the latest and easily most ambitious attempt to fathom such primal questions as how the universe began and what all matter--including us--is made of. When the device goes into collision mode later this fall, physicists will send two beams of protons through the tunnel, in opposite directions, causing about 600 million head-on crashes every second, each of which will create a minuscule fireball that briefly reproduces conditions that haven't been seen since a millionth of a millionth of a second after the Big Bang. And out of those fireballs will emerge ... well, nobody knows for sure, or no one would have spent $8 billion to build this contraption in the first place.

What physicists think they'll see is a long-sought particle called the Higgs boson. Quantum physicists have never really explained why protons, neutrons and all the things made out of them have mass, and they believe the elusive Higgs is what gives it to them. "If we didn't find the Higgs," says Lisa Randall, a Harvard theorist, "it would be shocking."

Beyond that, the LHC could discover a whole new class of particles predicted by a theory called supersymmetry. It could even uncover the existence of extra dimensions of space beyond the three we're familiar with. What it won't do--let's be clear--is destroy the planet.