Wouldn't We Know...?
 

Wouldn't We Know If Time Travel Is Possible?

*I go back in time and says hey time travel is possible. We would know that it was because there would be a change... but we wouldnt really know the change would we?

Perhaps time travel is only possible in the range of times beginning when time travel is invented...

Time travel isn’t possible because time is a human concept. Time isn’t real, its just a measurement of movement of objects though space. If you want to move back in time then you would have to literally re-wind the movement of every bit of matter in the known universe. An impossible prospect.

You could go *"forward"* in "time" *slower*, but it's still going "forward". So you could basically time jump to the "future" (from your point of view), but once you're there you're there - no going back (yet).

And i dont mean one second per second.... For example it would "seem" like 30 seconds passed for you, but for others it would be, say, 37 seconds. So they would have aged 7 more seconds than you, and you would have jumped 7 seconds from your point of view.

could you not you also say that heighth, width and depth are merely human concepts? its entirely possible that there are things that exist in more/less/different dimensions than we do. if you allow that concession, then the manipulation of the dimension of time seems, at least, within the realm of possibility.

If the mind creates reality....arent memories a form of time travel.

got to agree with Mantus . . . . . . . . . . time is a relative concept and not an 'environment' through which one might 'travel'.

Obiex . . you are describing altered 'perceptions' of time rather than movement through time.

Irateplatypus . . . you are right . . height, width and depth are 'relative' concepts too . . . a fixed numerical scale used in an attempt to allow a meaningful comparison between different things . . but these 'things' arent 'things' as you suggest and do not therefore exist outside the thoughts in your head . . . . which leads us to conclude (by your own logic) that time travel IS possible . . but only in your mind! Books and movies are as close as we are going to get.

"After age 40 . . each year only has 6 months!"

Well said Tecoyah . . . . . . . . and a nice spiritual angle to that too!

. . .which leads me to wonder why the 'remembering' of something is often more pleasurable than the thing itself? We cant wait to get home from our holidays to look at the photographs and video we have taken . . . . . .

Nostalgia aint what it used to be . . . . .

Sorry folks . . I just remembered I could have used the 'edit' button rather than an annoying series of seperate posts.

No I don't think we would know....
I for one would not tell anyone is I discovered the means to pass through time..... to much knowledge and responsibility.

If the mind creates reality....I'm a billionaire living in a huge mansion populated with dozens of 18 year old cheerleaders.

Must be nice , irseg....could I borrow a couple.......

I think we will have time travel long before we have a means of going faster then light.
Who knows perhaps all these UFO sightings are just our future selves checking out the past.
That might explain why the farmer in Podunk Ohio gets abducted.
His distant relatives want to know what he was like.
Time travel may also be something that is tightly controlled.
Would you want just anybody to know everything that had happened in your past?

Well as unlikely as each seem, warp speed, IMO might be more likely to be first, but either way.

Thats an idea i've never thought of, very interesting and quite possible!

TimeCop?

Time travel is possible. You get older, don't you?

Wrong. To travel back in time, you'd just have to cover a distance in less time than light (in a vacuum) takes to cover the same distance.
Best way we've got of doing that at the moment is to figure out how to fall through a wormhole (they probably exist) without turning into spaghetti.

As for travelling forward in time...we're already doing that at a rate of one second per second. If you want to go faster than that, hop on the concorde. You'll pick up a very small fraction of a second on the rest of the world by the time you hit London.

TIO – I am not quite wrong. Time moving backwards once you breach the light speed barrier is a highly theoretical concept. Technically it’s not possible to do so in the first place.

The wormhole idea is once again very theoretical. Even if wormholes did exist, traveling though it would not necessarily enable time travel. Since the object going though a wormhole would still be traveling at sub-light speeds.

Mantus, I didn't say anything about moving faster than the speed of light. I said getting from one point to another faster than light can. You will never achieve superluminal speeds in your own frame of reference, but you will appear to have done so in another frame of reference. And you will, in every meaningful way, have travelled back in time. The mathematics and the geometry both support that conclusion. It's just that you need to be careful about your definition of 'now'.

Wormholes aren't all that theoretical. They (think they) made (a really, really small) one in a laboratory once a few years ago. Anyone got the link to that?

But while we're on the topic, relativity does not prevent FTL travel. It merely prevents accelerating a massive body to the speed of light. It's causality that prevents FTL travel in a lot of situations, but there are ways around that.

Well, when time travel is invented there may be laws against changing anything like that... y'know? Wait... then why would we travel at all... wait... wait... oh no I've gone cross-eyed.

TimeCop?

Time Travel Laws would be an interesting concept, but somebody would surely find a way to break them.

If you've ever seen the new version of The Time Machine, it uses the idea that the past can only be changed in ways that won't affect the future in anyway to prevent the time traveler from eventually traveling back. Meaning that whatever motivates the time traveler can't be changed, cause he has to have a reason to travel back. It doesn't really make much sense if you think hard about it though. Of course, there could also be multiple dimensions/timelines, such that everytime you change the past, you create a breakaway point where 2 timelines seperate ala Back to the Future 2.

It all sounds to chaotic for me, so I personally don't think time travel backward is possible, although I definitely think future travel in many forms does and will exist. Also, it is interesting to note that movies never know what they're talking about, so why would they start knowing now? :)

Consider that there is no time, only movement.

When does this movement happen?

wrt TIO, the equations governing relativistic time-dilation tell us that the movement through time of an object moving through space at v>c is not in fact negative, but imaginary. Since time is on an imaginary axis relative to space, it should mean that you start going at a right-angle to time, or something like that, but not backwards.

The upshot of this is that travelling faster than light, although impossible, DOES NOT send you back in time.

For anyone who only has popular knowledge of relativity, but wants to understand it properly, try this link . People think it's for geniuses, but it's actually quite easy. QM, on the other hand...

If travel across our dimensions is possible, I think the odds are against us that we would recognize time travel as areality among us until we got there as a species. Time wouldn't be the only dimension folded over in such a freaky event!

The time dilation formula is not relevant to this. It also makes no sense whatsoever in curved spacetime, which is what wormholes and all that are all about.

Consider two events, A and B, separated such that light could not have traveled from one to the other. If you go through the math properly, you'll see that some observers would see A before B, while others would see B before A. Since the world seems to be causal we say that these two events could not affect each other, and certainly couldn't be the same object at different points along its trajectory.

As TIO said (much more briefly), this is why relativity doesn't allow FTL travel. Its a more general result than the mass increase effects, but requires the added assumption of causality. Its possible that strange topologies may exist that get around this (wormholes), but even the theoretical "evidence" is very iffy.

It's hard to tell...the way I interpret that is that you'll still manage to get out of the light cone of your initial position. Maybe not really time going backwards, but it's equivalent.

I see what you mean now. I wonder if it might take you through 'parallell universes' so to speak, just as moving along a third dimension from a plane would take you to parallell planes.

I wrote in a similar thread that I think time travel is a freakish warp of dimensions, which I will assume involves dimensions that we can't yet recognize. Folds in time likely affect more than just the dimension of time, and as such, we may today be among time travelers who know of our existence, while they remain "non-existent" to us, since we can't recognize more than the dimensions the human race has known for millenia.

I have a question about this aging idea. Why would someone age more than you? If everything is relative, then wouldn't your biological clock in a set time remain aging in the same amount of time if your point of reference was fixed?
(does my question make sense? haha)

Everything is always moving, so there is no natural divider between Movement 1 and Movement 2. A ball that lands on the ground bounces, then stops bouncing, is still vibrating from the bounce in geometrically smaller ripples. A rock on a mountain is on Earth which moves through space like most every other celestial object. Time is the arbitrary 24-hour divider of what is, on the cosmic scale, a constant ocean storm.

So time is continuous, not discrete. It's no big deal. You can say the same for space. It just happens that for purposes of practicality, we have approximate it to arbitrary discrete intervals, because if you gave someone a real number when they asked the time, they'd get pretty pissed off.

Man: "What time is it, buddy?"

Other man: "Uh, lets see, its 11:03 point 0885094587345982348762349....."

Man: "Zzzzz"

Plus by the time you'd started reading the time, it'd already be wrong. I don't see what implication human convention has for the possibility or otherwise of time travel. There is, of course a theory that if you look on a small enough scale, time is quantised, but that's another matter..

I came into this thread thinking one thing, and after reading this everything seems different :(
I'd have to go with this concept.