We've brought it up before, but let's loop back around the cul-de-sac. I'm in San Francisco casting Silicon Valley types, and inevitably I encounter a theoretical physicist dressed as Rosie the Robot who claims she discovered that theÂ speed of light is slowing down.
Sound familiar? Sorry, Rosie, but it's a loophole physicians (and creationists) have been massaging for years.
In 1999, Dr. JoÃ£o Magueijo published a paper proposing that Einstein's relativity might be less fixed and more like the nature of light itself (perhaps ~ vs. =). Putting his theory to test, University of New Wales physicist Dr. John Webb and PhD student Michael Murphy measured the fine structure constant (i.e. fingerprints from gas cloud electrons) of light arrived from 12 billion year-old quasars.
When the constant was smaller than it should have been, the only possible reasons were that either the electrons' electric charge had increased or that the speed of light had slowed. Since it was unfeasible that the electron's charge would rise (a la the 2nd law of thermodynamics--energy only flows from hot to cold spots), they concluded there were forces at work retarding the speed of light--an entirely quantum conundrum.
Of course, NASA has a kick-back:
If the particles were moving slower than the accepted speed of lightÂ — 186,000 miles (300,000 kilometers) per second — they wouldn't have enough energy to annihilate each other.