THERE may not have been a beginning to the thing we understand as “the universe”. Before I explain what I mean, I should say: of course, this isn’t the story I expected to tell audiences when I was a child who wanted to be just like Stephen Hawking .

I was certain, in fact, that the job I was signing up for was the one where we figured out exactly what happened in the very beginning, to a level of detail that humanity has never before known. As a grown-up scientist, I have had the wonderful …