ALMOST precisely 50 years in the past, once I was a PhD pupil, I wrote an article on this journal concerning the mounting proof for black holes, areas of house through which gravity is so robust that mild can by no means escape. At the moment, there isn’t a longer any doubt about their existence. We all know they kind from collapsing stars and that supermassive ones sit on the centres of galaxies. Now we have even taken an image of two of them. However in my article I additionally talked about a extra speculative risk: that smaller black holes might need fashioned within the early universe, shortly after the massive bang.
I used to be engaged on this concept underneath the supervision of Stephen Hawking, who had began to consider such a risk only a few years earlier. Our work collectively set the trajectory of my profession, a lot of which has been devoted to learning what we now name primordial black holes. We nonetheless don’t know in the event that they fashioned, however there are good causes to suppose they could have. A few of them may nonetheless be round at present and, excitingly, they might be the reply to an entire vary of cosmological conundrums.
Lately, nonetheless, I’ve turn out to be curious about an much more unique risk: that some black holes might be older than the universe itself. It’s a wild thought, however not inconceivable. And new analysis means that we would sooner or later be capable of positively establish them, a breakthrough that might seriously change our understanding of cosmology.
Most cosmologists would declare that each one the matter and power that permeates our universe at present got here into existence in …
