The past year has been an important one for Physics. Over the last few months the LHC has steadily gathered data and, just before the year's close, there was the announcement that it may have found evidence of the elusive Higgs boson. This announcement dominated science headlines for several days, even though the evidence was far from conclusive. Interestingly, however, there has been little, if any, mention of the things the LHC has not discovered. This may seem a rather odd point because, surely, discovering something ought to be far more important than not discovering something? So why do I feel otherwise?
Over the past forty years many of the major theories developed in particle physics, including SuperString theory, have been based on a hypothesis known as SuperSymmetry. SuperSymmetry is, mathematically speaking, a beautiful theory which, if true, could tie together many concepts concerning particles, forces and the nature of space and time. There is, however, no evidence that the theory is correct. The theory does, though, make a number of testable predictions, some of which should have come to light in results from the LHC. Naturally, the fact that no evidence has emerged has concerned some - so much so that many are now tweaking the theory in order to make it fit the evidence - or rather, lack of evidence.
I would love there to be evidence of SuperSymmetry but, under the circumstances, am inclined to say that, all things considered equal, the simplest theory is most likely to be the correct one, and the simplest theory on this case, given the lack of evidence, is that SuperSymmetry is wrong.
So perhaps it is time to abandon this theory and look elsewhere for an answer to questions of particle physics? However, many Physicists have too much tied up on this to give up so easily: After all, if the theory of SuerSymmetry is wrong, then so must any theory that incorporates it, including SuperStrings. Imagine if you had devoted your entire career to researching a theory just to see it evaporate before your eyes - wouldn't you do what you could to save it?
Personally I believe that many Physicists have committed the folly of believing that they could discover an ultimate theory of everything and have venture too far along untrodden paths. There has, to my mind, been no significant advancements in theoretical particle physics in the last forty years. Perhaps we should go back to the basics again and look at incrementally improving our models once more rather than lunging blindly towards some final theory? Whatever happens, there is still a huge gulf in our understanding that needs filling - one which may well exist for many generations to come.