Summary
Melvyn Bragg and his guests discuss cosmic rays. In 1912 the physicist Victor Hess discovered that the Earth is under constant bombardment from radiation coming from outside our atmosphere. These so-called cosmic rays have been known to cause damage to satellites and electronic devices on Earth, but most are absorbed by our atmosphere. The study of cosmic rays and their effects has led to major breakthroughs in particle physics. But today physicists are still trying to establish where these highly energetic subatomic particles come from.
With:
Carolin Crawford Gresham Professor of Astronomy and a member of the Institute of Astronomy at the University of Cambridge
Alan Watson Emeritus Professor of Physics at the University of Leeds
Tim Greenshaw Professor of Physics at the University of Liverpool.
Producer: Thomas Morris.
Transcript
Click on a timestamp to play from that location
| 0:00.0 | Thanks for downloading the in-artime podcast. For more details about in-artime and for our terms of use |
| 0:05.4 | Please go to bbc.co.uk forward slash radio 4. I hope you enjoy the program |
| 0:12.5 | Hello one of the world's largest and most unusual astronomical observatories can be found on a vast empty plane in Western Argentina |
| 0:20.4 | The appear OJ Observatory covers an area larger than Luxembourg instead of telescopes |
| 0:26.4 | It uses 1,600 massive tanks of water to look at the heavens the scientists who work that aren't looking for light from the stars or even radio waves |
| 0:34.9 | Instead they're studying cosmic rays |
| 0:37.8 | First identified essentially your cosmic rays are subatomic particles which constantly bombard the earth from space |
| 0:43.9 | The discovery of high energy radiation coming from far beyond our solar system led to the emergence of particle physics as a new |
| 0:50.5 | scientific discipline today more scientists than ever are dedicated to the study of cosmic rays |
| 0:56.0 | But many questions remain answered including most importantly where they come from |
| 1:00.3 | With me to discuss cosmic rays are Carlin Crawford |
| 1:03.5 | Gresham professor of astronomy and the member of the Institute of Astronomy at the University of Cambridge |
| 1:08.7 | Alan Watson |
| 1:10.0 | Emeritus professor of physics at the University of Leeds and Tim Greenshaw professor of physics at the University of Liverpool |
| 1:15.9 | Carlin Crawford would you be in by giving us a slightly fuller explanation of what cosmic rays |
| 1:21.2 | Well to start with I think it's just reiterating what you said right at the beginning |
| 1:25.4 | Despite the name we're not talking about rays of light. We're talking about matter |
| 1:30.2 | Energetic particles that are impacting the top of the Earth's atmosphere |
| 1:33.6 | They're coming from all directions and outer space and some we even think are coming from outside our galaxy |
| 1:38.8 | And these are pieces of atoms and in some ways there are only direct samples of matter outside |
| 1:46.6 | The solar system coming towards us. They're electrically charged and they're traveling at huge speeds |
| 1:53.1 | sometimes close to the speed of light and |
... |
Please login to see the full transcript.
Disclaimer: The podcast and artwork embedded on this page are from BBC, and are the property of its owner and not affiliated with or endorsed by Tapesearch.
Generated transcripts are the property of BBC and are distributed freely under the Fair Use doctrine. Transcripts generated by Tapesearch are not guaranteed to be accurate.
Copyright © Tapesearch 2026.