[This article is a summary of another article from SciAm Feb 08. The photos are also taken from there. Please let me know if any copy right law prohibits this!]

For a decade or more, particle physicists have been eagerly awaiting a chance to explore that domain, sometimes called the terascale because of the energy range involved: a trillion electron volts, or 1 TeV.

The machine that will take us to the terascale—the ring-shaped Large Hadron Collider (LHC) at CERN—is now nearing completion. The LHC is scheduled to begin operation in May 2008. 

You could think of it as the biggest, most powerful microscope in the history of science. Which is coming to revolutionize our understanding of the particle physics!

The machine is designed to produce beams with 40 times the intensity, or luminosity, of the Tevatron’s beams. When it is fully loaded and at maximum energy, all the circulating particles will carry energy roughly equal to the kinetic energy of about 900 cars traveling at 100 kilometers per hour, or enough to heat the water for nearly 2,000 liters of coffee!

Nearly 100 million  channels of data streaming from each of its two largest detectors would fill 100,000 CDs every second, enough to produce a stack to the moon in six months. So instead of attempting to record it all, the experiments will have what are called trigger and data acquisition systems, which act like vast spam filters, immediately discarding almost all the information and sending the data from only the most promising looking 100 events each second to the LHC’s central computing system at CERN, the European laboratory for particle physics and the collider’s home, for archiving and later analysis.

Now, it’s time to ask about the task that this giant collider is going to do.

The current Standard Model of particle physics begins to unravel when probed much beyond the range of current particle accelerators. So no matter what the Large Hadron collider finds, it is going to take physics into new territory.[Chris Quigg writes]

In this new world, we expect to learn what distinguishes two of the forces of nature—electromagnetism and the weak interactions—with broad implications for our conception of the everyday world. We will gain a new understanding of simple and profound questions: Why are there atoms? What makes stable structures possible?

The search for the Higgs particle is a pivotal step, but only the first step. Beyond it lie phenomena that may clarify why gravity is so much weaker than the other forces of nature and that could reveal what the unknown dark matter that fills the universe is. Even deeper lies the prospect of insights into the different forms of matter, the unity of outwardly distinct particle categories and the nature of spacetime.

But there are five goals for the LHC

REDISCOVER THE STANDARD MODEL
The first goal of the collider is not to probe the new but to confirm the old. The machine will produce familiar particles in prodigious numbers (several top quarks per second, for example) and scrutinize them with increasing refinement. Not only does this test the machine and its instruments, it sets precise benchmarks for determining whether new phenomena are indeed new.

DETERMINE WHAT BREAKS THE ELECTROWEAK SYMMETRY
The collider will seek the Higgs boson (or what stands in its place) and determine its properties. Does the Higgs provide mass not only to the W and Z particles but also to the quarks and leptons?

SEARCH FOR NEW FORCES OF NATURE
New force particles would decay into known particles such as electrons and their antimatter counterparts, positrons. Such forces would indicate new symmetries of nature and might guide physicists toward a unified understanding of all the interactions.

PRODUCE DARK MATTER CANDIDATES
By observing neutral, stable particles created in high-energy collisions, the collider could help solve one of astronomy’s greatest puzzles and test researchers’ understanding of the history of the universe.

ABOVE ALL, EXPLORE!
The collider will examine its immense new domain for evidence of hidden spacetime dimensions, new strong interactions, supersymmetry and the totally unexpected. Physicists will have to be attentive to connections among today’s great questions and alert to new questions the collider will open up.

And these are quite a lot! They are about to revolutionize our understanding of particle physics!