If you've ever looked at a model of the atom, you'd probably guess that electrons are spherical. But these elementary particles are actually slightly egg-shaped...and proving that could mean trouble for one particular model of subatomic physics.
Supersymmetry holds that all the subatomic particles we know have counterparts that are almost exactly the same, only much, much heavier. But the Large Hadron Collider hasn't found any supersymmetric particles yet, and they're running out of places to hide. Will we have to come up with a new model for subatomics?