MovieChat Forums > Flight of the Navigator (1986) Discussion > Time Travel

Time Travel

posted 17 years ago by PhrenicGermal
44 replies | jump to latest

So according to David's brain, a trip of 560 light years was made in about 2.2 hours. According to the film, this caused him to jump forward in time by about 8 years.

So I went to find my old physics textbooks and check this out.

Now in Einstein's universe, ignoring factors like the change in mass of the ship and so on, this simply isn't possible. There is an easy to calculate time dialation factor that can be used to compare how my clock moving at a high velocity compares to one that I will call stationary. Now 560 light years is about 4,908,855.15 light hours. So travelling the distance that requires light 4.9 million hours in 2.2 hours inplies that I am travelling at about 2,231,297.795 times the speed of light. If we try to put this ratio into the time dialation equation we get an imaginary number.

So I'm trying to work out exactly how this might work with a wormhole. I was almost under an impression that a wormhole would only allow time travel into the past, or that if a person were to return through a wormhole to where he began then he would have taken the amount of time to travel relative to earth that he observed on his wristwatch?

[–] fatpie42 13 years ago

They didn't mention a wormhole. And of course, it is the speed that causes time to slow down for them, not the distance.

Perhaps you need to make clearer what your issue is. Certainly, the figures are going to be a bit messed up because this is fiction. In real life, scientists have generally said that faster than light travel is impossible.

[–] holtor 13 years ago

Probably there is not much point in making such statements about a movie where the production team obviously had no clue about physics at all and could not possibly care less. But the speed of the ship has nothing to do with the theory of relativity at all. The movie claims that Phaelon is 560 light years away and that the round trip took 8 years earth time. Both this distance and this time are meant with respect to the reference frame of someone on earth. (Special) Relativity is about comparing time and space coordinates in two different reference frames, which has nothing to do with the problem at hand. Forgetting about acceleration and assuming for simplicity that the ship has constant velocity, you simply get 560/4=140 times the speed of light as the ship's speed. That basically is the definition of speed no matter what.

Now there currently is no physical theory making any statements whatsoever about speeds larger than the speed of light, and up to now all evidence points to such speeds being impossible. Thus there is no point in thinking too much about the 2.2 hours which supposedly passed in the reference frame of the kid.

It is a pity because the production team could have remedied the problem so easily by making Phaelon just 8 light years away. But OTOH it is blatantly clear that they did not care about such considerations.

[–] chouse1020 12 years ago

Now there currently is no physical theory making any statements whatsoever about speeds larger than the speed of light, and up to now all evidence points to such speeds being impossible

Too general of a statement... we haven't unified physics therefore to make general assumptions based on the small amount of physics that we have been able to understand doesn't make a lot of sense.

Sure, Einstein says in his formulae that he doesn't know how something within our spacetime could go faster than the speed of light, he also was not aware of all of the things we've discovered in particle accelerators since his death. And of course, even he may not have been able to unify physics personally - it is a big achievement after all.

Just because we don't know how to go faster than the speed of light does not in any way imply that it's impossible. That's very similar to those few Middle Age folks who refused to believe that the Earth was round, although it was a well understood fact by sailors and scientists (although many history books would assert that many people thought that to be the case).

[–] jaybabb 12 years ago

What the people posting in this thread are forgetting-is that this is A MOVIE! Let me say that again: THIS IS A MOVIE And a kids movie at that. Every thing you see in this movie is first put on paper called a script-then put on film using a varity of methods-whether it be special effects or what not. You can do anything you want in a movie-it does not have to be realistic or based on reality at all. Just let your imagination run wild.

So this whole thread is utterly pointless.

Conspiracy therories are cleverly thought out to evade the real truth

Jay

[–] 12 years ago

[deleted]

[–] Syxiepoo 10 years ago

I have just returned from an alternate future to let you all know that time travel is indeed possible. However, going back in time requires the traveller to be fully and tightly wrapped in cling-film to avoid causing any changes to the space-time continuum. Sadly, that renders the experience rather sterile. This rule does not apply to experienced, professional time-travellers such as myself.

Travelling into the future is a little different in that this particular constraint does not apply. However, you will not be allowed to take with you any weapons, explosives or liquids. Also, do remember that if you travel forward beyond the actual year of your death ... you will simply disappear, never to return. Clearly, this represents a risk, since you don't yet know when your death will occur.

Finally, for clarity, please see my strap-line below:

There is real life ... and then there are movies!