Bob Maywood: So do you get to look at a lot of stars? How do you do that?
Katherine Collins: The actual looking at stars is only part of the picture. We’re also using more modern techniques like radio telescopy.
BM: What’s a radio telescope – it sounds very different to the normal kind our listeners may be used to?
KC: At root, they are actually very similar to a conventional radio. On your radio, you have an antenna, and it picks up radio signals. A radio telescope is really just the same, only it’s pointed out in space and it’s picking up radio waves from there. The sun, for example, emits a lot of radio waves, and so do other stars and lots of different types of objects. It’s a different kind of data, but it means we can find out about things that you can’t see using a conventional, optical telescope.
BM: So I guess we should ask the big questions – just how old is the Universe, and how do you go about figuring something like that out?
KC: Well, according to our current models, we’d put the age of the Universe at somewhere around 12 billion years old. The way we work it out is from the Big Bang – there’s a thing called Cosmic Background Radiation, which you can think of like an echo from the Big Bang. We’ve measured how much background radiation there is, and we can work backwards from that to the event. So the existence of this radiation is strong evidence that there was a Big Bang and also gives us clues as to when it happened. That’s a really good example of theoretical astrophysics – we can’t observe the Big Bang but we can build a theoretical model of it from the evidence we do have.
BM: And the Big Bang- can you explain that? Does that mean you’re looking for a place and time where everything kicked off?
KC: Time, yes – place, no. The Big Bang happened everywhere simultaneously. It’s hard to explain that without getting very technical.