New data from Europe's may signal the end of one of the most popular theories in physics, superstring theory. If the conclusions are true, scientists would need a new leading candidate for the "theory of everything."

The LHC actually hasn't debunked superstring theory directly. The theory maintains that everything in the universe is actually made up of extremely small vibrating strings. The strings, if they exist, would need to be much smaller than even the smallest particles that are known, and it's impossible for current science to probe such tiny scales.

However, the theory requires some effects on a scale that can be measured, one of those effects being "supersymmetry," which predicts that all normal particles actually have supersymmetric cousins, called sparticles, that are slightly different; the supersymmetric analog of the electron, for example, would be a selectron. Many scientists have supported supersymmetry because, in addition to being an essential element of superstring theory (it's the "super" part), it neatly explains how electromagnetism and nuclear forces are united, and it provides an answer to dark matter. But now evidence suggests it just might be fiction.

The LHC was studying the decay of "strange beauty" particles, called B-mesons, looking for evidence of supersymmetric particles. Last year, experiments at the Tevatron at saw that the decay of certain mesons was different from their antimatter versions, which scientists suspected may have been due to supersymmetry. The LHC was able to examine the process in more detail, however, and found no evidence of any sparticles whatsoever.

That result could mean a couple of things. It could mean that the simplest version of supersymmetry is wrong. There are more complicated versions of the theory that still allow for the existence of sparticles, but don't necessarily require the B-mesons' decay to show the influence of them.

It could also, of course, mean that supersymmetry is bunk. To date, no experiment has shown evidence that sparticles exist. That could be because they simply don't, and they're just wishful thinking on the part of theoretical physicists. That, in turn, would throw a wrench into the works of superstring theory (and its larger cousin, M-theory), a popular "theory of everything" that unites quantum physics with Einstein's theory of relativity, a task that has so far eluded experimental physics.

Experiments will continue, of course, but this could be the beginning of the end for superstring theory. There's no shortage of alternative grand theories for mixing quantum mechanics and relativity, however, and superstring theory's downfall could lead to many new theories being proposed. The next few years could be an exciting time to be a theoretical physicist.