Signal detected from 'cosmic dawn'
Scientists say they have observed a signature on the sky from the very first stars to shine in the Universe. They did it with the aid of a small radio telescope in the Australian outback that was tuned to detect the earliest ever evidence for hydrogen. This hydrogen was in a state that could only be explained if it had been touched by the intense light of stars. The team puts the time of this interaction at a mere 180 million years after the Big Bang. Given that the cosmos is roughly 13.8 billion years old, it means the first stars lit up a full nine billion years before even our own Sun flickered into life. Dr Judd Bowman of Arizona State University, US, is the lead author on the scholarly paper describing the observation in the journal Nature.He told BBC News that the discovery's great s...