Available online
Description
The programme uses a science fiction setting to illustrate the problem of distinguishing left from right. The result that it is possible to distinguish between them and that even more sophisticated... symmetries are broken in some elementary particle interactions are expressed as problems of communications with a being from another world.
The programme uses a science fiction setting to illustrate the problem of distinguishing left from right. The result that it is possible to distinguish between them and that even more sophisticated... symmetries are broken in some elementary particle interactions are expressed as problems of communications with a being from another world.
| Module code and title: | S354, Understanding space and time |
|---|---|
| Item code: | S354; 09 |
| First transmission date: | 27-06-1979 |
| Published: | 1979 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:13 |
| + Show more... | |
| Producer: | James Burge |
| Contributors: | David Broadhurst; Paul Clark |
| Publisher: | BBC Open University |
| Keyword(s): | Antimatter; Asymmetry; Cobalt; Communication; Mirror; Muons; Science fiction setting; Symmetries |
| Footage description: | Over shots of deep space, brief introductory commentary by Paul Clark. Over shots of radio telescopes, a spaceship against the stars, and of an alien space man inside, commentary by Clark points out how an alien can learn from us through radio contact. Clark points out also the difficulty of conveying the difference between left and right to an alien. David Broadhurst, standing next to a mirror, points out that the laws of gravity, electromagnetism and the strong nuclear force don't make any distinction between left and right. Broadhurst goes on to explain how, in 1956, through experiments involving decay of the isotope cobalt 60, it was discovered that the weak nuclear force did seem to differentiate left from right and so broke the principle of mirror invariance. Prof. Valentine Telegdi recalls the impact, on physicists, of this discovery. Over shots of the alien spaceship and the alien spaceman inside, commentary by Paul Clark explains how this discovery could be used to convey to the alien the difference between left and right. David Broadhurst and Valentine Telegdi tell of the suggestion made in 1957 that a new form of invariance actually survived cobalt decay. With the aid of models and animations, David Broadhurst explains that nature of antimatter which is at the heart of the new invariance suggested above. Broadhurst, with additional models and animations, explains the nature of the new invariance - CP invariance. Broadhurst goes on to explain how CP variance was verified with experiments on negative and positive muons. Finally Broadhurst discusses the slight flaw in CP variance which was discovered in 1964 during experlments on neutral K mesons. He explains how this experiment would allow the alien spaceman of the programme to tell left from right with no possibility of error. |
| Master spool number: | DOU3140 |
| Production number: | FOUS070N |
| Videofinder number: | 2040 |
| Available to public: | no |
