|"...they say [Hollywood] that there's 'no sound in space'…which isn't entirely true, but there's no sound that we could hear in space..."|
|Dr Carolin Crawford|
Dr Carolin Crawford, and Professor Andy Fabian based at The Institute of Astronomy, Cambridge, took folk on a tour of the Universe through the medium of sound as part of The Cambridge Science Festival. We caught up with Dr Carolin Crawford who has a Research Fellowship from the Royal Society and works at the Institute of Astronomy in the University of Cambridge and is also a Fellow of Emmanuel College to find out what it was all about…
|Chandra Ripple Image of Perseus |
"Well this was just a fun idea that we had. Astronomy's a very visual subject - one of the reasons I myself got into astronomy was because it is very beautiful - but we thought we'd explore another aspect to astronomy that's not normally considered and that was the idea of Sounds in the Universe. People don't usually think of sound as anything to do with astronomy, in fact we're always told that there are 'no sounds in space' which isn't exactly true. We just thought that this is an unusual way of giving a tour of the Universe.
|X-ray Image of Perseus with gas |
"We used sound in lots of ways - we be played lots of real sounds from space that had been speeded up a lot. We demonstrated how sounds can illustrate an astro-physical phenomenon better when you can hear it. For example, one of the things that we talked about were spinning neutron stars called pulsars that rotate very fast. These are objects which are very massive and very small - they're not quite black holes but it's a similar idea, you've got something which has, for example, got the mass of the sun - now, the sun is about a million KM across - imagine squashing that down into about 10 KM, something the size of London. Some of these neutron stars rotate very quickly, and emit beams of radiation at their surface that sweep round like the beams from a lighthouse. When one of these beams crosses the earth, you get like a flickering radio signal - if we now change that radio signal into an sound that people can hear it gives a very different dimension into our perception of the pulsar spinning.
"Sound needs a medium to carry it so you require something like a gas, with little particles that can bounce off each other. Sound waves move by alternately compressing and then pulling apart these particles …so as long as you've got some particles you can transmit soundwaves. People often say that you can't hear sound in space because it's a vacuum - that's not actually true because a lot of space is not a vacuum - it's true, you can't hear sound within a vacuum, but there's still a lot of gas in space...
Want to hear some of the sounds? Click on the links at the top right hand...
1Chandra Ripple Image of Perseus
The Chandra data show the ripples in the hot gas that fills the Perseus cluster. The features were discovered by using a special image-processing technique to bring out subtle changes in brightness. These ripples are sound waves thought to have been generated by cavities blown out by jets from a supermassive black hole (bright white spot) at the center of the Perseus cluster.
(Taken from Chandra X-Ray Observatory).
2Chandra X-ray Image of Perseus, Temperature Map
A Chandra X-ray image of the hot gas in the Perseus cluster. The color shows the temperature of the X-ray emitting gas, with red showing the lower temperatures, green showing intermediate temperatures and blue showing the hottest temperatures. The hottest gas comes from faint X-ray emission in the outer parts of the cluster, so the blue regions are hard to see in the image. At the center of the image is a supermassive black hole (bright white spot) in Perseus A, the huge galaxy in the middle of the Perseus cluster. Extending away from the central supermassive black hole are two vast, bubble-shaped cavities in the cluster gas. These cavities, which were created by explosive events from the black hole, are not really empty, but are filled with high-energy particles and magnetic fields. They push the hot gas aside, creating sound waves that sweep across hundreds of thousands of light years.
(Taken from the Chandra X-Ray Observatory).