Jocelyn Bell Burnell: The mystery of gravitational waves

In this edition of Titans of Science, Chris Smith sits down with Jocelyn Bell Burnell, the astrophysicist who's work detecting cosmic radio waves helped discover the existence of pulsars...

Chris - How on Earth did you go forward from this? Because there's sort of one way to start a career is to build up gently. Another is to put a huge rocket under it, <laugh> and explode from the beginning. Was it not difficult then having done this and seeing this dramatic beginning to your career to then carry it on at that sort of pace?

Jocelyn - It was made very difficult by my getting married. I got engaged to be married between discovering pulsar two and three I think it was. And we got married between my submitting my PhD thesis and having the viva so the examiners didn't know what surname to use <laugh>. And I married somebody who worked in local government and the way we operated it was he'd have a job and I'd get a job at a nearby astronomy place and then say after a bit, it's time I moved. And I could see my world falling apart. And he'd start looking at job adverts and he'd say, if I go to Timbuktu or somewhere is there anything astronomical anywhere near that where you might get a job? And that's the way we operated it. He'd go for the job if he got the job, I'd then write a begging letter to the nearest astronomy place. And so I left radio astronomy and went to work in gamma ray astronomy, which is the other end of the spectrum. Not many gamma rays around. And then we moved again and I migrated to X-ray astronomy and then we moved again and I migrated to millimetre and infrared astronomy. Absolutely crazy career. I don't think it even deserves the word career.

Chris - And you've seen enormous changes over your career from where we had to build primitive vineyard-like telescopes to see things like this through to what the James Webb is now enabling us to do, to literally see through the atmospheres of planets that aren't even in this solar system. And it is extraordinary, isn't it, the way that this has advanced?

Jocelyn - I think one of the most extraordinary things is us discovering many extra solar planets, planets around other stars. Stars that may be like the Sun, or maybe not like the Sun, but there seem to be a lot of planets around there with all kinds of configurations, patterns for these planets around these other suns. It's a new area of astrophysics that's absolutely booming at the moment. And I suspect it's still raising more questions than answers. It's that young a subject.

Chris - Speaking of which, do you think that little green men do exist for real? Given the statistics we now have and what you just said about the numbers of these exoplanets planets that are outside our own solar system around other stars, given the scale of the universe and the scale of those numbers, do you think it's an inevitability that there's a Jocelyn and a Chris somewhere else having a radio interview?

Jocelyn - I don't know what life looks like. I don't know whether it's intelligent or less intelligent than us at this stage, but I would be surprised if we were the only life in the universe, that's for sure.

Chris - And what would you really love the answer to? With the time you have left in research in your life and your career and space science, what question leaps out at you thinking if I could have the answer to that tomorrow, I'd be a happy woman.

Jocelyn - There's a new branch of astronomy that I've been watching, developing all my career. It's called gravitational wave astronomy. It's nothing to do with radio waves or light waves or infrared or ultraviolet or x-rays or any of those. It's to do with the way for instance, Earth going around the Sun alters the gravitational field of the Sun. You can think of an object like the Earth as actually denting the gravitational field. And then as it moves around the Sun, it makes a kind of groove that fills up and opens up as the Earth goes round. And those kinds of changes in a gravitational field can produce what we call gravitational radiation. And it was a field I was watching develop from quite early days. The signals are very weak. It's very, very hard to do, but we are now doing it and it's fantastic to have a whole new spectrum delivering information for us. So I'm watching things coming in from that with real interest because that's the latest window opening.