Bob Maywood: I’ll trust you on that one then! Now, as most of our listeners know, our sun is also a star. Is it a typical star? Are there many types?
Katherine Collins: Plenty – so our sun is a G-class star, a yellow star, somewhere in the middle of the range in terms of size and brightness. It’s a baby next to the big ones though, you can get hypergiants which are hundreds of times larger than our sun and much more bright, and then you’ve got dwarf stars which are comparatively tiny and dull – red and brown dwarfs. Stars vary in size and luminosity as they age as well, with some eventually going supernova or exploding, others getting smaller and smaller and more and more dense until they end up compacted into something like a neutron star. Imagine something with the mass of our sun, but only a few miles across.
BM: That sounds pretty exotic! What other weird stuff gets your attention?
KC: The Universe is full of amazing things – it’s one of the reasons I love doing what I do. There’s a type of neutron star called a pulsar, which spins around like a lighthouse, so it’s like a blinking light out there in space. You can get binary star systems, when two stars orbit together, or stellar streams, or there’s even some scientists talking about stars that travel so fast they can escape the gravitational pull of galaxies, although we’re going to have to wait and see about that one. Then if you want to get really weird, you’ve got dark matter, strings and branes – and then you are into multiple universes and eleven-dimensional topology and the fun really starts.
BM: Mind-blowing stuff. I guess a field like astrophysics moves pretty fast – what do you think is going to happen in the future? What’s the next big discovery?
KC: I think if we knew that, then astrophysics would be a whole lot easier! There’s so many different angles to it at the moment, it’s hard to know where it’s all going. Personally, I’ve been always been involved in what’s called superstring theory. It’s pretty exciting, there’ve always been problems with quantum anomalies in the field, but there’s a new wave of research coming out that’s getting us past that. For a theoretical physicist, that’s incredibly exciting.
BM: Well, I don’t understand a word of that, but the idea we live in a universe made of string is just plain amazing. After this track, we’re going to move on to talk in more detail about some of those exciting ideas Dr Collins started talking about. So if you want to know your white dwarfs from your quasars, keep listening. And to get you into a cosmic frame of mind, our first track tonight is from the incomparable Pink Floyd – so lie back, close your eyes and get ready for a flight into the stars…