Physicists think they've spotted the ghosts of black holes from another universe
August 22, 2018 at 11:31 AM EDT
We are not living in the first universe. There were other universes, in other eons, before ours, a group of physicists has said. Like ours, these universes were full of black holes. And we can detect traces of those long-dead black holes in the cosmic microwave background (CMB) — the radioactive remnant of our universe's violent birth.