# Is there a flaw in this do-try-this-at-home time travel experiment? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [February 1, 2006, 7:32pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554 "2006-02-01T19:32:16Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\ **Post date:** [February 1, 2006, 7:32pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/1 "2006-02-01T19:32:16Z")
Like many people, I’m fascinated by anything to do with time travel. So how about this: I resolve, that if time travel is discovered in my lifetime, and I have access to it, I will travel back to (say) February 9, 2006, and tell my “present self” all about it. Now, if, a week from Friday, I see no sign of my “future self”, I’ll be able to conclude that at least one of the following must be true: [ol] [li]Time travel won’t be discovered in my lifetime.[/li][li]Some kind of “paradox prevention” check-and-balance will prevent me from carrying out the experiment.[/li][li]I’ll have forgotten about the experiment (though, I’ll probably still be reading the SDMB right up to my demise, using my holographic direct-to-neuron Firefox Version 30, and that may jog my memory).[/li][li]My “future self” doesn’t / will not (hi to Douglas Adams fans) think it’s a good idea to carry out the experiment.[/li][/ol] Not a huge, informative result for the experiment, but given how little we know about time travel even being possible, doesn’t it tell us _something_ interesting at least? I feel this is some form of [predestination paradox](http://en.wikipedia.org/wiki/Predestination_paradox) but again, that doesn’t mean it’s impossible, with what we currently know about time travel. ---
**Author:** ![Revenant\_Threshold](https://avatars.discourse-cdn.com/v4/letter/r/f1d935/32.png) [@Revenant\_Threshold](https://boards.straightdope.com/u/Revenant_Threshold)\ **Post date:** [February 1, 2006, 7:37pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/2 "2006-02-01T19:37:48Z")
[QUOTE=DarrenS] [ol] [li]Some kind of “paradox prevention” check-and-balance will prevent me from carrying out the experiment.[/ol] [/li] The prevention doesn’t have to be of the logical kind. If time travel is invented, how about a “time police” that stop us regular joes from jaunting back and informing our past selves of the future, chatting, and, say, giving the lottery numbers for the next few years. Makes sense that if a government/governmental sponsored team creates the means for time travel, there’d be a system set up to prevent it’s abuse - and if it’s a lone inventor who creates it, then the rest of us won’t know about it at all. Plus, there’s the problem of cost. Likely, any time travel machine would be (at least for the first few models) filled with expensive, high maintenance equipment that short of a few billion private citizens wouldn’t be able to afford - again, assuming that the government chooses to allow the plans into the public domain, which would be incredibly foolish. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 1, 2006, 7:38pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/3 "2006-02-01T19:38:48Z")
In the future you may be incarcerated, institutionalized or worse. 🙂 ---
**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\ **Post date:** [February 1, 2006, 7:42pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/4 "2006-02-01T19:42:40Z")
[QUOTE=Revenant Threshold] > [@DarrenS](#): > > [ol] > [li]Some kind of “paradox prevention” check-and-balance will prevent me from carrying out the experiment.[/ol] [/li] > The prevention doesn’t have to be of the logical kind. If time travel is invented, how about a “time police” that stop us regular joes from jaunting back and informing our past selves of the future, chatting, and, say, giving the lottery numbers for the next few years. You mean, like [this](http://www.imdb.com/title/tt0111438/) ? 😃 Anyway - that’s what I meant by “if I have access to it.” **carnivorousplant** - I’m still laughing at your comment. Very real, though - I could get run over by a bus tomorrow :eek: Perhaps that _is_ the flaw in this experiment - it doesn’t really tell us anything because the criteria for failure are so broad. ---
**Author:** ![Nature\_s\_Call](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nature_s_call/32/19006_2.png) [@Nature\_s\_Call](https://boards.straightdope.com/u/Nature_s_Call)\ **Post date:** [February 1, 2006, 7:45pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/5 "2006-02-01T19:45:50Z")
Okay, I hereby resolve the following: [ul] [li]If affordable time travel is invented in my lifetime I’ll come back to the time just before I click Submit and tell myself to that fact and it’s details into this post.[/li][li]If it is either not affordable or not yet available, I will create an investment account with instructions to by descendents to keep this thing going until it’s feasible. In fact, I will do this on my way home so as to avoid incarceration/debilitation, etc. from keeping this promise.[/li][li] \
[/li][/ul] I actually am pausing before clicking submit… [deep breath…] ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [February 1, 2006, 8:02pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/6 "2006-02-01T20:02:53Z")
> [@DarrenS](#): > > I feel this is some form of [predestination paradox](http://en.wikipedia.org/wiki/Predestination_paradox) but again, that doesn’t mean it’s impossible, with what we currently know about time travel. It’s also a variant on the [Fermi paradox](http://en.wikipedia.org/wiki/Fermi%27s_paradox), with time taking the place of space. ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [February 1, 2006, 8:44pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/7 "2006-02-01T20:44:43Z")
In the future you are dead before time travel comes about. You will wonder after friday, if you died young or time travel doesn’t exist. ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [February 1, 2006, 9:09pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/8 "2006-02-01T21:09:02Z")
> [@carnivorousplant](#): > > In the future you may be incarcerated, institutionalized or worse. 🙂 What do you mean in the future? Anyone who tries to develop time travel is already incarcerated by **THEM**. **THEY** didn’t get to rule the world by letting people develop technology that could put **THEM** out of business. ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [February 1, 2006, 9:15pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/9 "2006-02-01T21:15:39Z")
I **could** travel back in time to tell myself… But then I’d have to kill me. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 1, 2006, 9:20pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/10 "2006-02-01T21:20:03Z")
> [@Harmonious Discord](#): > > You will wonder after friday, if you died young or time travel doesn’t exist. I was trying to spare him. 🙂 There is another possibility; perhaps the “time police” prevent the birth of those who would take information to the past. If not prevent the birth, kill the person before they can take the information back. Given this thread they would have to track us all down and kill us. Which is silly, they ca ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [February 1, 2006, 9:23pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/11 "2006-02-01T21:23:11Z")
Maybe it’s just real expensive. I haven’t flown into space, and that was invented a long time ago. ---
**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\ **Post date:** [February 1, 2006, 9:29pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/12 "2006-02-01T21:29:45Z")
> [@Fear Itself](#): > > Maybe it’s just real expensive. I haven’t flown into space, and that was invented a long time ago. Excellent point. Space travel has been around for, what, 40 years or so? And it’s still out of reach of all except a handful of people on the planet. Not only that, but if you didn’t know about it, there’s no way you’d conclude space travel exists by simply looking around you. Of course, maybe there _are_ time tourists around us - I knew those people on Art Bell’s show were convincing 😉 ---
**Author:** ![daffyduck](https://avatars.discourse-cdn.com/v4/letter/d/ec9cab/32.png) [@daffyduck](https://boards.straightdope.com/u/daffyduck)\ **Post date:** [February 1, 2006, 10:16pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/13 "2006-02-01T22:16:44Z")
My biggest problem with the idea of time travel is that it depends on the idea that the past (and I suppose the future) actually “exist” in some fashion, while my experience of life is that I am ever in the now and everything else is just imagination (memory). Since this is GQ, are there any physics to suggest that the future and past exist in any form other than imagination? ---
**Author:** ![charizard](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/charizard/32/4166_2.png) [@charizard](https://boards.straightdope.com/u/charizard)\ **Post date:** [February 1, 2006, 10:41pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/14 "2006-02-01T22:41:02Z")
OK, i’ll bite. How about: 1. \*time \* travel is discovered within your lifetime, but by that time Earth has travelled eleventy-leven bajillion miles from the point it was at on that day, and \*space \* travel will not have gotten enough better by then to get you back. I figure it’s been a flaw in time-travel stories, when they assume that the time machine will also automatically zip you back to the exact spot in the universe where the Earth was at that time. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 1, 2006, 10:48pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/15 "2006-02-01T22:48:54Z")
Cheap, practical time travel doesn’t have to be invented in your lifetime. All that’s needed is that time travel in some form be invented in your lifetime, and that cheap, practical time travel is eventually invented. Because if anyone ever invents expensive time travel, the first thing he’s going to do with it is to go to the future to get plans for a better time machine. > [@](#): > > My biggest problem with the idea of time travel is that it depends on the idea that the past (and I suppose the future) actually “exist” in some fashion, while my experience of life is that I am ever in the now and everything else is just imagination (memory). Since this is GQ, are there any physics to suggest that the future and past exist in any form other than imagination? If you used a time machine, you’d still be perpetually existing in your own present. The progression of your present wouldn’t match anyone else’s, but then, it doesn’t now, either. ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [February 1, 2006, 10:52pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/16 "2006-02-01T22:52:11Z")
How about time travel does exsist and future you has already come back to see present you? He’s just not allowed to interfere or interact with you, just observe. So that old man in the coffee shop you saw this morning who gave you a glance wasn’t just some old guy. That was future you in disguise checking you out. ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [February 1, 2006, 11:17pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/17 "2006-02-01T23:17:17Z")
> [@DarrenS](#): > > I resolve, that if time travel is discovered in my lifetime, and I have access to it, I will travel back to (say) February 9, 2006, and tell my “present self” all about it. I can’t help but think of [Bill & Ted’s Excellent Adventure](http://us.imdb.com/title/tt0096928/). If you’re going to promise to travel back in time, don’t just do it to say “Hey past self, time travel is real!” - remind yourself to bring back a jet pack, a sports almanac, or a strategically placed set of keys. ---
**Author:** ![jsc1953](https://avatars.discourse-cdn.com/v4/letter/j/5daacb/32.png) [@jsc1953](https://boards.straightdope.com/u/jsc1953)\ **Post date:** [February 1, 2006, 11:18pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/18 "2006-02-01T23:18:41Z")
> [@charizard](#): > > I figure it’s been a flaw in time-travel stories, when they assume that the time machine will also automatically zip you back to the exact spot in the universe where the Earth was at that time. :eek: Trippy! I like it! ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [February 1, 2006, 11:21pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/19 "2006-02-01T23:21:41Z")
> [@Hampshire](#): > > So that old man in the coffee shop you saw this morning who gave you a glance wasn’t just some old guy. That was future you in disguise checking you out. Not much of a disguise. I already \*\*am \*\*that old guy. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 1, 2006, 11:26pm UTC](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554/20 "2006-02-01T23:26:03Z")
> [@charizard](#): > > I figure it’s been a flaw in time-travel stories, when they assume that the time machine will also automatically zip you back to the exact spot in the universe where the Earth was at that time. Well, the tachyon pulses remain in phase due to the, ah, neutrino radiation that, er, is paused while in time travel transit and can thus be recreated and phased induced upon arrival of the time traveler. [Next page](https://boards.straightdope.com/t/is-there-a-flaw-in-this-do-try-this-at-home-time-travel-experiment/342554.md?page=2)