The Higgs Boson

Those who do a little reading in modern physics will probably be aware that one of the grand hopes behind the construction of the Large Hadron Collider (below), a huge atom smasher near Geneva, Switzerland, was that it would be able to accelerate particles to such high energies that the Higgs boson, sometimes called the "God particle", would be revealed.

The Large Hadron Collider

The Higgs is predicted by string theory, and if the Higgs isn't found it would be devastating to those physicists who have invested the last four decades of their lives in trying to demonstrate that string theory is correct. Moreover, since string theory is the fundamental support for other theories like the multiverse, parallel universes, and extra dimensions, these ideas, too, might be rendered less tenable should the Higgs not appear in the LHC experiments.

Here's a good video on the role that the Higgs plays in contemporary subatomic physics:

Recently, the news coming out of Geneva has been disappointing to those who hoped to find the Higgs. Tests that should have confirmed its existence haven't. According to an article in Wired if it's not found by 2013 scientists will have to reassess their models of how the universe works.