Travels to the edge of time!


As many of you may know, the ATLAS detector (and for that matter CMS) is physically huge. It weighs about 7000 tons, and measures approximately 46 meters in length and 25 meters in diameter. It is literally the size of a small ship, one packed with sensitive silicon sensors, sophisticated electronics, and powerful on-board computers. Take a tour of the ATLAS detector for more details.

When we collide 4 TeV proton beams at the LHC, we re-create conditions that existed about 10-12 second after the big bang (of course, a lot of the interesting stuff had already happened in the first 10-37 second). In contrast, the Hubble space telescope can only see as far back as about one or two billion years after the big bang and the WMAP experiment which studies the Cosmic Microwave background observes the Universe about 300,000 years after the big bang! See the accompanying cartoon for a timeline of the Universe.

A brief history of time

All the heavy particles that we are trying to observe in these proton collisions, e.g., the Higgs boson, Supersymmetric partners to the usual particles, etc., existed freely in the aftermath of the big bang. One interesting phenomena that we may have observed is a new state of matter, called the Quark Gluon Plasma, which only exists at very high densities and temperatures. There was indirect evidence for it in the past, and recent results have put it on a firmer footing (e.g., see this result from ATLAS. You can also check out the website for ALICE, another experiment at CERN, which was specifically built to probe this state of matter).

Although, these collisions will be taking place in the laboratory, one can picture the good ship ATLAS travelling back to the beginning of time, and sending information about what is going on there!


Vivek Jain Vivek Jain is a Scientist at Indiana University, Bloomington. His current interests range from understanding various aspects of tracking to R-parity violating Supersymmetry. More information about his interests can be found at