Experiments at the LHC continue to find no evidence of supersymmetry.

Modern physics is an uneasy blend of two revolutionary ideas from the twentieth century: general relativity and quantum mechanics. Like two competing nations, their laws work well within their own specific realms (relativity at large scales, quantum mechanics at very small ones) but those laws break down and become meaningless or even incomprehensible in the opposite domain. Between the two is a nebulous border region where strange, inexplicable things seem to occur.

Supersymmetry is a theory that attempts to bridge that gap. Experimental physics has confirmed the existence of a great many particles which make up the matter and energy we interact with every day. Many, such as photons and electrons, you may have heard of. Several, like muons and top quarks, are more obscure. By positing the existence of a set of massive, hard to observe partner for each of these particles, theoretical physicists had hoped that they untangled the thorny mess of conflict between relativity and quantum mechanics. As an added plus, it was hoped that experimental data would reveal these massive partner particles to be the source of the mysterious dark matter which pervades our universe.

Enter the Large Hadron Collider (LHC), the most powerful and expensive science experiment ever conceived. At 27 km in circumference, it is more of a man-made geographic feature than an edifice, and it contains detectors sensitive enough to detect the flickering of a candle from the moon. One of its main missions has been to evaluate the different models of supersymmetry. The data so far is not encouraging.

At the Lepton Photon Symposium in Mumbai, India, physicists from CERN, which operates the LHC, presented data which fails to find any evidence of supersymmetry. Although the findings do not rule out every version of the theory, there is a sense among physicists that a new theory may be needed to explain this data.

"It could be that this whole framework has some fundamental flaws and we have to start over again and figure out a new direction," said Dr Joseph Lykken of Fermilab, a competing detector in the United States with much less sensitivity and power. Dr. Lykken is a leading proponent of supersymmtry and organizer of a yearly conference for its advocates. "It's a beautiful idea. It explains dark matter, it explains the Higgs boson, it explains some aspects of cosmology; but that doesn't mean it's right.