I start with the first sentence. A maddening answer, and, for my own sake, I wish I had a better one. But it’s the only way I know how: one sentence on top of the other, one foot in front of the other. In that way, writing does feel exploratory to me. I never start with a map in my head or even a destination. All I have is a sense that I’m heading in an interesting direction.

Then I had another thought: Physics disgusts me a little bit now, but I used to enjoy doing physics.  Why did I enjoy it?  I used to play with it.  I used to do whatever I felt like doing—it didn’t have to do with whether it was important for the development of nuclear physics, but whether it was interesting and amusing for me to play with.

I remember being present when a Jesuit priest in Rome asked Tennessee Williams, “How do you write a play?” and Tennessee said, “Well, I start with a sentence.” Well, I start with a sentence, and that’s how you write a book.

There’s a lot of different ways. Sometimes, I could write directly to a beat, so somebody could send me a beat, and the beat tells me what to say. If I’m recording a demo, I can lay down the framework and start mumbling out a melody. Sometimes, I could just be walking, stumbling drunk from a bar in Berlin, and then, a melody comes to me and I have to make a voice note. It could also be the poem format, where a concept will come to me, I’ll write it down in my notes, and then, I’ll apply the beat. It depends, but once it comes, I just have to record it, because I’ll forget. I was just going through my voice notes and deleting some of them because I have so many.

Tony was cautious. He suspected I’d wired the radio telescope up wrong. So we checked on another radio telescope on the site. The thing was pulsing nicely on mine but as we stood by the pen recorder of this other telescope, nothing happened. It was a horrible moment. And suddenly there it was, five minutes later because we had miscalculated when the telescope would see it. If we’d miscalculated by 25 minutes, we’d have all gone home and the story would be different.

I was really proud that it was my stars that had convinced the prize committee that there was good physics in astrophysics.

I was very, very thorough, making sure I really understood how that telescope worked, and that it was working properly. I was quite convinced that I wasn't clever enough to be in Cambridge and would be thrown out at some stage. My policy was to work as hard as I could so that I'd know I'd done my best. We now label this as impostor syndrome, but we didn't recognise, and certainly didn't name it, back then.

My contemporaries were more upset about the Nobel than I was not to be recognised. One of them labelled it the 'No-Bell' prize! But it was fine by me. There's no Nobel Prize in astronomy and I was really proud that it was my stars that had convinced the prize committee that there was good physics in astrophysics.

It looked like an agricultural frame, something you might grow peas up – a lot of wires and cables strung from posts over a space the size of 57 tennis courts. It was actually built to study radio emission from quasars. I built the prototype and then six of us took two years to build the real thing.

The next generation of telescopes will see millions of events per night with computers that sift through huge amounts of data. If we had had access to a computer, we would never have programmed it to look for something so unexpected. How do you pick up the things you don't know exist, the things you can't tell it to look for? My project was to study quasars, and then we accidentally stumble over these things called pulsars. They were totally unexpected, totally unknown – and it's been huge fun.