Gamma-Ray Burst Time: A Cosmic Puzzle

Scientists have been wondering if gamma-ray bursts come from far-off parts of the universe. If they do, their light should take longer to reach us, making the bursts look stretched out in time. This is called time dilation. Researchers from the Compton Gamma Ray Observatory used data from their Burst and Transient Source Experiment to check for this effect. They compared bright and dim bursts to see if the dim ones were stretched in time. They found that the dim bursts were indeed stretched by about double the time of the bright ones over a wide range of time scales. To make sure their findings were accurate, they tested synthetic bursts that mimicked the bright bursts. The results suggested that these bursts come from very far away, possibly from a redshift of about $z \sim 1$. This supports previous ideas about the distance of these bursts based on their number and brightness.