Inside the big-bang machine

The future of particle physics is being built below ground, in a setting that's more appropriate for construction hardhats than lab coats. To get to the caverns where the world's most powerful particle collider is taking shape, you have to take an industrial-issue elevator down just one floor. But that floor is a doozy: It's about 100 meters below ground, roughly as deep as a 30-story building is tall.

The machines under construction in the depths are just as gargantuan: It's hard for any picture to capture the immensity of the ATLAS experiment's seven-story-tall, electronics-laden cylinder. You have to be there to get the full effect. So that's where we went today, and we've created three video postcards just to say "wish you were here."

ATLAS is just one of the four major experimental edifices placed around the 17-mile (27-kilometer) ring on the French-Swiss border - an underground tunnel that will be the home of the Large Hadron Collider, or LHC. Scientists from around the world have converged on CERN's facilities here in hopes of finding the answers to decades-old questions about the subatomic world.

Those scientists will have to wait longer than they expected to look for those answers: Like most construction projects, the LHC hasn't kept pace with the laid-out schedule, due to a nasty magnet accident as well as other hitches. The revised schedule calls for operations to begin next spring rather than this fall.

As a result, the construction crews building ATLAS and the other science structures have a little more time to finish their work - and at each of the three sites we visited today, the crews were clanging away. You'll have to bear with the background noise and the shaky shutter as you click through these home movies, but they'll at least give you some sense of the project's scale.

The first video postcard features Silvia Schuh, a researcher on the ATLAS experiment team, showing off the current state of the 82-foot-high (25-meter-high), 151-foot-long (46-meter-long) detector. The middle of the giant cylinder is almost totally hidden by scaffolding, but you can see the wedge-shaped elements that are designed to identify the track of muons as they zoom away from the proton collisions at the heart of ATLAS.

ATLAS is one of the LHC's two general-purpose detectors, and is expected to point to the existence of the long-sought Higgs boson (which is thought to create the field that gives particles their mass) as well as other weird particles that may be responsible for mysterious dark matter.

In the second video clip, Roger Forty, deputy spokesperson for the LHCb experiment at CERN, points out some of the components on the business end of his team's apparatus: LHCb is aimed at answering questions about why matter is so predominant over antimatter in our universe.

And in the third clip, Jurgen Schukraft, CERN spokesperson for the ALICE experiment, points out how a beam of heavy ions will come from a section of the 17-mile-round accelerator tunnel and plow right into his team's detector.

ALICE is designed to create miniature big bangs, enabling researchers to study the conditions that existed just an instant after the universe was born. Scientists say they've have already created such a primordial brew, known as quark-gluon plasma, in a liquid state. Schukraft and his team want to see if quark-gluon plasma might exist as a gas at higher energies. The ALICE experiment is one of the prime reasons why the LHC is called a "big-bang machine."

We have a couple of additional stops on our Big Science Tour on Thursday - including a look at the last of the LHC's four major experiments, known as the Compact Muon Solenoid, or CMS. The CMS team has had its challenges, reportedly leading some wags to refer to the project as "See a Mess." But we don't expect to see a mess during our visit - instead, we'll see still more signs of science under construction.

Previously from the Big Science Tour:The science behind the tour ... Living in the Web's cradle.