Matt Visser: Horizon Documentary
HORIZON --- The Time Lords
On 2 December 1996 the British Broadcasting Corporation broadcast a documentary in the Horizon series called ``The Time Lords''. The BBC subsequently sold this documentary to the PBS NOVA series. It was re-titled ``Time Travel'' and re-broadcast in the USA on 12 October 1999.
This documentary is about the physics of wormholes and the limitations physics places on the possibility of time travel. It's a nice introduction to the subject for the general public. People interviewed for the program, in addition to myself, include: Stephen Hawking, Kip Thorne, John A. Wheeler, Carl Sagan, ...
My own contribution to the programme consists of about three minutes interview responses dispersed throughout the program: I mainly discuss the nature of exotic matter, the (large) quantities of exotic matter required to hold a wormhole open, the experimental situation, and some limitations on the consistency conjecture of Igor Novikov.
You can find a full transcript of the show by searching on the net:
To the BBC timelord web-page: http://www.bbc.co.uk/horizon/timelord.shtml
To the BBC horizon homepage: http://www.bbc.co.uk/horizon/
To the PBS time travel web-page: http://www.pbs.org/wgbh/nova/transcripts/2612time.html
To the PBS NOVA homepage: http://www.pbs.org/wgbh/nova/
Horizon - The Time Lords
The Time Lords reveals the practical details of time travel. For a start, a time machine already exists, and it looks remarkably similar to a 747. In a 25-year celebration of the first demonstration that the slowing of time is a human experience, HORIZON took the original experimenter and an atomic clock on a transatlantic crossing, to measure how far British Airways took them into the future. And we're not talking different time zones. We're talking real time travel, for everyone. Only a lack of cash for big enough engines stops us travelling years into the future.
The real problem for a time traveller has always been getting back, and Thorne's work showed that all you might need are "quantum wormholes" and some "exotic matter". Quantum Wormholes are all around us, deep in the wierd world of particle physics, but they are far too small to detect. As for Exotic Matter, there's another respectable Time Lord, Steve Lamoreaux, who makes it in his lab.
If you could travel back in time, all hell might break loose. You could slaughter your parents before you were born, but then you wouldn't exist, and thus wouldn't be able to do the dirty deed. But then they would survive, and you would be born after all, so....... The paradoxes opened up by time travel are so logically offensive that they alone have reassured many scientists that it will never be a serious possibility. But it seems that Nature has ways to protect herself from such confusions, while still allowing time travel to occur. And Igor Novikov, the Time Lord who cracked this one, believes that travel into the past will be possible in about 200 years.
Another broken taboo concerns sending messages faster than light. Breaking the light speed barrier is totally forbidden by Einstein, and all who believe in him, for moving beyond it would make time stand still. But that has not stopped a German Time Lord, physicist Gunter Nimtz, transmitting Mozart's 40th Symphony across his lab at 4.7 times the speed of light. Impossible, yes, but demonstrated on screen in HORIZON.
Judith Bunting's quirky film takes us to the boundaries of modern thought. The truth about time travel is wrapped up in the detail of how our Universe works and how it all began, and that's where Stephen Hawking comes in. Hawking does not want time travel to be possible and he has gone to the frontiers of physics in his attempts to show that it probably won't ever be possible.
But even he can't quite rule it out.
Book: Lorentzian Wormholes---from Einstein to Hawking
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