Quasars are the supermassive black holes at the centres of early galaxies. Scientists have unlocked their secrets to use them as ‘clocks’ to measure time near the beginning of the universe.
A fundamental prediction of relativistic cosmologies is that, owing to the expansion of space, observations of the distant cosmos should be time dilated and appear to run slower than events in the local universe. While observations of cosmological supernovae unambiguously show the expected redshift-dependent time dilation, this has not been the case for other distant sources. source (the Nature article)
1·1 year ago