Question of the Week: The cost of time travel

Suppose we’ve solved the problems of time travel. On paper, at least.  The boffins have even put together a feasible design for an actual time machine.  Should we build it?

There is one catch though.  The estimated cost is £1,000 trillion and it would take over 10 years to put together.

It would be an international effort, with the cost shared between participant nations.

Should it be done? Aren’t there better things for the world to club together and spend £1,000 trillion on? Is there even that much money in the world? If a referendum were taken – what would you vote?  Are you pro- or anti-time?

  1. #1 by Pete on October 25, 2009 - 13:59

    Bring it on!!! But if Moores law is correct and computing power doubles every 18 months to 2 years then lets wait a bit and in two years the cost may have fallen to only £500 trillion and that is a serious bargain!! Althought if GB govenment are involved the cost will rise over the life of the project to £6 gazillion and it will take over 25 years after which we’ll find the software is not fit and we’ll have to start all over again, so if we do do it please put the Japanese in charge!

  2. #2 by mike on October 25, 2009 - 15:44

    Of course we should! The trillion dollars could be easily recouped by pulling a Biff Tannen in Back to the Future II: get a sports almanac from the future, travel back to the present, and bet on all the longshots!

  3. #3 by mike on October 25, 2009 - 15:46

    Sorry, £1,000 trillion. My point remains valid 🙂

  4. #4 by Cynicron on October 25, 2009 - 16:02

    Obviously, we should just resolve to come back to tomorrow from far in the future after we’ve built it and reduced the cost of building it and bring the machine back, or the zillion dollars (which in the future will only be worth $147.50 anyway, accounting for inflation).

    What, you’ve never seen “Bill and Ted’s Excellent Adventure”?

  5. #5 by PaulJ on October 25, 2009 - 17:17

    We should definitely do this. We could borrow the money, and then go back in time far enough to deposit one pound in a savings account….

  6. #6 by Stu on October 26, 2009 - 11:05

    Surely if time travel were possible we would have had a visit from some future person/group already.

  7. #7 by Andy on October 26, 2009 - 11:56

    The cost is irrelevant for all the reasons given above. Once we have it though, There’ll be trouble.

    You can be sure the vested interests of whichever countries funded it will cause fights and possibly wars to break out over its use. Those conflicts would probably be won by whoever has the machine. So they will dominate the world and time as well. Mwahaha.

    There’ll be battles with new weaponry on old fronts changing history as we go. This has all been joyfully imagined by all manner of sci fi books and films.

    Basically, the building of this machine would give the holding country a massive tactical advantage. They would become more of what they really are as a result.

    I think we should eat the drawings and never build it.

  8. #8 by Andy on October 26, 2009 - 11:58

    And despite Einstein and his fancy math, I still don’t think time travel can actually happen. Recalibrating time, yes. Travel no.

  9. #9 by bob dezon on October 26, 2009 - 18:40

    I don’t think you could physically travel through time, but I can see no reason why you cannot observe light from an earlier time. (astronomers do that now with starlight) Historical events may be observable, but I doubt they could be interacted with. If you could alter history, then you would have to deal with alternate realities, and thats a bit “Dr Who” for me. It could however, be a useful debate settling method. Did jeebus exist or not? You could watch it on BBCBC.

  10. #10 by Michael on October 27, 2009 - 21:21

    Sorry. Some comments ar invalid. I should have mentioned that you cannot travel back further in time than the point in the timeline when the time machine first becomes operational. So say that it comes ‘online’ on 13:26’53.08″ on 24th Feb 2020, that is the furthest back in time you will be able to travel. Sorry all you ‘Back to the Future’ fans. But it also throws up quite a few moral, ethical and philosophical points that no one has yet seemed to address. But let us hope that you do.

  11. #11 by Pete on October 27, 2009 - 23:33

    I think by then uk plc will be owned by the chinese anyway and after buildin one, within weeks they’ll be all over Ebay!!!

  12. #12 by Pete on October 27, 2009 - 23:40

    bob dezon :I can see no reason why you cannot observe light from an earlier time. (astronomers do that now with starlight) .

    Sorry Bob, but no – you’d have to fly away from earth at faster than light and thats not possible! Secondly you’d need a flippin big telescope – as it is Hubble is not big enough to see lunar landing site, so imagine how big a scope you’d need to see 2000 light years distance so as to make out jesus! And what if it was a cloudy day? Sorry! Yes, we do look at stars as they once were, but thats true even for our sun – you see it as it was 8 and a bit minutes ago. To really mess with ya head nothing you ever see is “now”, it’s ALL in the past!!

  13. #13 by AJ on October 28, 2009 - 02:59

    If I remember correctly, in his book, ‘The Fabric of Reality’, David Deutsch (Oxford University physics professor, quantum computing pioneer and a leading proponent of the many-worlds interpretation of quantum physics) says that time-travel to ‘the past’ is impossible in Einsteinian physics, and it would only be possible in the multiverse that the many-worlds interpretation of quantum physics proposes.

    He argues that it would involve returning to a different universe within the multiverse than the universe that the time-traveller began her journey from. If he’s right, I think it’s in all our interest to build the £1,000 trillion machine and try to find a universe where Derek Acorah says anything coherent. Although, I think even an infinite number of universes may not be a big enough sample size for that.

  14. #14 by Andy on October 28, 2009 - 10:36

    It does mess with your head a bit to think that everything observable is done so in the past. But it’s a “relative” (pun intended but probably confusing) thing. In most situations this discrepancy has no actual effect. But I don’t think this is what Einstein meant. Is it? He was talking about time actually slowing down as you move away from a gravitational force? Where’s a physics teacher when you need one?

  15. #15 by Marsh on October 28, 2009 - 10:43

    I believe the physics teacher is off abusing his punctuation and threatening vicars with crossbows…

    The best I understand the whole time slowing down thing is around the notion of the speed of light being a constant speed relative to your own speed – thus if you’re travelling 1mph, light is travelling the speed of light faster than you; if you’re travelling 100000mph, light is still doing the speed of light faster than you. If light speed is constant no matter what speed you’re doing, the only answer is that time itself is changing in those two situations. Something like that.

  16. #16 by Michael on October 28, 2009 - 14:27

    I’m Back!! The Doctor is in.
    There is only one constant in the universe in this case and that is the speed of light. No matter how fast you are traveling you are ALWAYS traveling at the speed of light through SPACE and TIME. If you are stationary to some coordinate system in spacetime you are still travelling at the speed of light. As you are stationary, you notice a spacesuited jogger sprinting past at 10 metres per second. You then see that he is travelling at the speed of light through space and time. The same speed you are going while apparently motionless. It is just that (as he is the one feeling a force) that his time velocity has slowed down w.r.t. your time velocity. His is 10 metres per second (m/s) slower than yours.
    You then notice a super fast alien spaceship going past at 200,000,000 m/s, yet it is still traveling at the speed of light through Space and Time. You notice (as it is also feeling a force) that its time velocity is now only 100,000,000 m/s while your velocity through time is 3 times as fast.
    So your speed through space + your speed through time = speed of light in spacetime.
    If you travel at 98% the speed of light your speed throughtime will only be 2% of the outside stationary observer. If they could see your wall clock in you space ship at that velocity it would be moving extremely slowly (t = t0/sqrt(1-(v^2/c^2). That is the Lorentz contraction for time dilation.
    YOU are always traveling at the Speed of Light trough Space and Time. Hope that helps in the understanding (it is NOT a direct linear relationship but this is a simple way of putting it)
    Now back to my target practice. You can tell I’m off today and NOT tidying up the kitchen as ordered.

  17. #17 by Mike on October 28, 2009 - 17:05

    Those suggesting that we deposit £1 in a savings account sometime in the past in order to save up enough money to pay for the project (Michael’s objections notwithstanding) haven’t thought it through!

    The interest earned in a savings account doesn’t appear magically. It comes from elsewhere in the banking system – such as the interest paid by other people on their overdrafts and mortgages. If you were to allow £1,000 trillion to accrue in interest then no-one else in the world would have any money – it would all be in your savings account.

  18. #18 by Michael on October 28, 2009 - 18:13

    This is the story line from Gore Vidal’s ‘Live from Golgotha’. Where they video Yesuah’s crucifixion for broadcast in this year’s Easter programming schedule. People travel through time via video conferencing and coerce the Romans and Sanhedrin into staging it. There is a drawback though. Yesuah doesn’t look right for TV. He is too Jewish looking and only 4’10” tall, balding and slightly obese.

  19. #19 by Carol Bellfield on October 29, 2009 - 14:25


    Just came across this site.

    Michael’s comment (no 17) makes perfect sense. I was always led to believe that time travel is impossible in a practical sense for no other reason, than if I was to travel back in time to shake hands with Adolf Hitler in 1938, at that time in 1938, I would have arrived from Adolf’s future.

    I believe the future only exists amidst an infinite number of potential possibilities. Therefore, at any given moment, future events at a given time cannot be predicted. Therefore as Adolf’s future is ‘there’ but not set for him (or doesn’t yet exist for him), there is no future from where a time traveller can originate.

(will not be published)