Hi, I'm Steve Jones, and, I'm going to talk a bit about astronomical research. Well, astronomy is the study of bodies in the sky. And they can be stars, or planets, but mostly astronomy talks about objects which are rather more distant than the nearer planets. And very often there are galaxies and so forth, very distant from us. And there are two basic areas of study. One is radio astronomy, and the second is optical astronomy normal, optical astronomy looking through telescopes. I mean, visible astronomy using visible light, will use conventional reflecting telescopes, and these are based on a large mirror, and the large mirror may be as big as five or six meters in diameter. The idea is to collect as much light as possible and focus it into a,a, a viewing lens. So, this is a reflecting telescope. So, you'll have a huge mirror, curved of course, because it has to focus light. The light will come in from a distance, and all of this light will focus through to an observation point here, and that is where you will observe what you can see in the distance. Now,these are very big, very expensive, and very difficult to use. And, what is more, you don't see what you think you see. You see the visible light, but of course, from out there in space, most of the light is not visible. Visible light is all electromagnetic radiation, and it starts with x-rays and it ends with radio waves with visible in the middle. So, you also have the whole science of radio astronomy, which is looking at the massive range of waves that come from space, which are not visible. Now, these radio astronomy telescopes, the radio telescopes, as we call 'em, tend to be huge great dishes, rather like this. And they tend to be on great big frames, so that they can be pointed in the sky. And from here, comes a detector. The radio waves come in, and are focused to a central point, exactly in the same way as an optical telescope. There is no difference, except that this is an optical reflector. This is a radio reflector. The radio telescope, very often, is just a plain aluminum dish, polished aluminum dish. The same with an optical telescope. So, there is very little difference in the way it actually detects the radiation. The radio telescope, however, tends to be much bigger. This could be fifty meters in diameter, whereas this is only five or six meters in diameter. So, astronomical research is based on looking at the sky. First of all, looking at it using visible radiation, visible light, normal light which you can see. And the second part is looking at the radio waves and x-rays which come from the same area, and then putting the two pieces of information together, to create ideas about how space works. So, that is, what is the basis of astronomical research.