What a burst! A fresh attempt to see space-time foam with gamma ray bursts.

It�s an old story: Quantum fluctuations of space-time might change the travel-time of light. Light of higher frequencies would be a little faster than that of lower frequencies. Or slower, depending on the sign of an unknown constant. Either way, the spectral colors of light would run apart, or �disperse� as they say if they don�t want you to understand what they say.

Such quantum gravitational