LHC Back Online

Scientists at CERN turned the Large Hadron Collider back on and injected protons into the particle stream on Friday, resuming operations for the first time in a year.

Last year, shortly after it became operational for the first time, the LHC experienced a failure in one of the containment magnets that keeps the particles within their track and going around in circles. Because of the tremendous forces required, these magnets are extremely powerful, and if they become misaligned by even a tiny amount, they can fail catastrophically, destroying themselves.

That's what happened last year, and resulted in repairs and replacement of the magnet. It took a while to complete the repairs because the LHC is kept at a brisk -271°C and had to be warmed up slowly, repaired, and cooled back down slowly, but the work is finally done and science is once again underway at the world's most powerful particle collider.

And, in case you hadn't noticed, it still hasn't destroyed the world.

LHC Won't Destroy the World

Good news! It seems that, when the Large Hadron Collider at CERN is turned on, it won't actually destroy the Earth. Of course, physicists were already sure of this, but now a new safety review conducted by CERN's governing council has confirmed the fact.

The main argument for why the high-energy reactions won't destroy the Earth is that they haven't so far. Since the Earth gets bombarded with highly-energetic cosmic rays all the time, they point out, the types of interactions that will happen within the controlled confines of the LHC have already happened 10³¹ times since the universe began. And none of those reactions destroyed the Earth. So since we're still here, these types of reactions aren't going to destroy the Earth. Pretty good logic from where I'm sitting, but it probably won't stop the conspiracy-theorists and doomsday prophets from continuing to predict the end of the world, and it almost definitely won't stop the lawsuit that is attempting to prevent CERN from activating the LHC.

At last, I can relax and stop worrying about the world ending. Until the next over-hyped doomsday scenario, at least.

A Test for String Theory?

Researchers at University of California, San Diego, Carnegie Mellon University, and University of Texas at Austin have developed what they believe will be a means of testing String Theory, the leading candidate for unifying the laws of physics into a single theory.

The process involves testing one of the three underlying mathematical assumptions used by String Theory, that there is a smoothness criteria for the scattering of high-energy particles after a collision. They propose to test this assumption by using the Large Hadron Collider to investigate the scattering of W bosons. If the W bosons do not scatter according to the predictions made by String Theory, physicists will know that there is a flaw in the theory.

“If the bounds are satisfied, we would still not know that string theory is correct,” said Jacques Distler, a professor of physics at The University of Texas at Austin.

One of the main criticisms of String Theory has been that it is largely untestable. And while this test is not a perfect test, it will allow researchers to test at least a part of the theory, and that's at least progress toward a better understanding of our universe.