Hints of a breakdown of special relativity
The team from the MAGIC gamma-ray telescope has some tantalizing evidence that, in fact, special relativity is incorrect. They found indications that high-energy gamma rays travel slower through vacuum than low-energy rays. Here's the meat of the observation:
The team studied two gamma-ray flares in mid-2005 from the black hole at the heart of the galaxy Markarian 501. They compared gammas in two energy ranges, from 1.2 to 10 tera-electron-volts (TeV) and from 0.25 to 0.6 TeV. The first group arrived on Earth four minutes later than the second. One team member, physicist John Ellis of CERN, says: "The significance of the time lag is above 95%, and the magnitude of the effect is beyond the sensitivity of previous experiments."
Now, why exactly this would happen is way beyond my understanding. According to SciAm, it could be that there's some kind lensing that occurs due to fluctuations in the fabric of space-time that happens at higher energies. (It sounds almost like increasing air resistance with speed, perhaps that's a good metaphor the proposed effect?) This kind of effect can happen in theories of Quantum Gravity, and if this result is real, it could help constrain the possible "theory of everything".
However, it needs to be said that this is a big claim, and it could be totally wrong. There need to be thorough checks done on the work, and it would be nice if a separate lab confirmed the result. But if it stands, this could well be one of those turning points in modern physics. I can't wait to hear more, new physics is very exciting! (Or at least it is when it's possibly a real result.)