If a satellite in outer space detects bursts of cosmic light billions of light years away on Gerald Fishman's watch, he drops everything.
He will drive to the Marshall Space Flight Centre, Nasa's stakehold in Huntsville, Alabama, and look on the computer to see exactly where in the sky the burst of light, called a gamma-ray burst (GRB), occurred. The word goes out and astronomers point their telescopes at the location to see the optical light.
However, they must all move quickly. Although GRBs are the brightest events in the universe, a million times brighter than a supernova, the light dies very quickly. If the telescopes can't find the burst within the first few hours, it becomes difficult to observe. After a few days it is almost impossible to see.
Yet why do they matter? Fishman, who shared the US$1 million 2011 Shaw Prize in astronomy with Enrico Costa in Hong Kong, for their work on GRBs, sheds some light of his own.
What is the significance of GRBs?
The farther away something is, the older it is. It turns out that the light from galaxies where many GRBs are seen are from when the universe was only 10 per cent of its current age. [The best estimate for the age of the universe is about 13.7 billion years.] Light from the galaxies took 12 billion years to come to earth, so by studying the light from these galaxies, we can tell something about the types of stars and types of elements that existed in these galaxies when the universe was only one billion years old.
