[QUOTE=Scoooby;34079461]It seems we've already kind of made this concrete with our current understanding of the universe.
In the dimension we experience time, is completely linear. Only going forward, not backwards.[/QUOTE]
That's not true though
[QUOTE=JohnnyMo1;34080829]That's not true though[/QUOTE]
I'm just saying it doesn't appear possible in our dimension.
Perhaps if we were to expand to the 4th dimension or something. Then perhaps.
I understand time isn't actually linear. It just is for us in the third dimension.
Considering string theory is based on different timelines and possibilities occurring, then I guess you could say it is possible.
I don't think it's very likely that we will be able to travel back in time, but traveling forward in time at increased speeds might be.
[QUOTE=Scoooby;34081460]I'm just saying it doesn't appear possible in our dimension.
Perhaps if we were to expand to the 4th dimension or something. Then perhaps.
I understand time isn't actually linear. It just is for us in the third dimension.
Considering string theory is based on different timelines and possibilities occurring, then I guess you could say it is possible.[/QUOTE]
No, even outside of string theory it's possible.
[url]http://en.wikipedia.org/wiki/Closed_timelike_curve[/url]
As I see it, if you want to go back in time you'd need to reverse Entropy for the entire universe or something.
That would require a lot of energy.
Okay guys rate me all your dumbs.
Timetraveling back in time is probably possible.
But like some posts state, it would probably create a new universe if one would go back to time since
the dimension you came from should by logic(according to me) continue on without you and as you go back in time you form a new universe since it needs to continue with you.
Or you'll just vaporize.
[QUOTE=NETVERK;34082899]As I see it, if you want to go back in time you'd need to reverse Entropy for the entire universe or something.
That would require a lot of energy.
Okay guys rate me all your dumbs.[/QUOTE]
time isn't being written as we experience it, you can't "undo it"
[QUOTE=JohnnyMo1;34082447]No, even outside of string theory it's possible.
[url]http://en.wikipedia.org/wiki/Closed_timelike_curve[/url][/QUOTE]
Yeah true. For some reason I've been including string theory into everything.
It makes sense though.
"A closed timelike curve can be created if a series of such light cones are set up so as to loop back on themselves, so it would be possible for an object to move around this loop and return to the same place and time that it started. An object in such an orbit would repeatedly return to the same point in spacetime if it stays in free fall. Returning to the original spacetime location would be only one possibility; the object's future light cone would include spacetime points both forwards and backwards in time, and so it should be possible for the object to engage in time travel under these conditions."
I've always viewed time as entropy. As entropy can't be reversed, so can't time.
[QUOTE=Parja;34094867]I've always viewed time as entropy. As entropy can't be reversed, so can't time.[/QUOTE]
when did anyone talk about reversing time
With the knowledge I have now, definitely fiction.
[QUOTE=BananaFoam;33532356]Lets put this in a way that easy to understand.
If timetravel is ever invented, we would likely all be dead already.
I mean, what's there to stop some dickhead from going back and say, aiding the Nazis to win WWII? How about a barrier to keep them from coming and enacting a nuclear holocaust in the cold war?
Fanatics, militants, terrorist, and just assholes could and likely would have gotten their hands on this by now if it ever gets invented.
However, time-travel is achievable (and already has been achieved) through different means. If something is going really, really fucking fast then whatever that item is will not age as fast as the world around it. It would technically warp to the future, but visiting the past is impossible.
And that "already achievable" thing, guess what, astronauts go so fast when travelling in rockets that scientists have verified that they are a fraction of a second younger then if they had merely stayed on Earth. of course, it's not like that makes a difference, but it shows it's possible.[/QUOTE]
The person who did time travel and did X would only see what he caused, we wouldn't as our time wouldn't be affected.
It's like a different universe.
[QUOTE=SIRIUS;34100750]when did anyone talk about reversing time[/QUOTE]
When you go back in time you reverse it, unless you assume alternate realities.. in which it isn't reversed.
[QUOTE=DanishD;32725766]Time travel, into the future is possible (and has happened).
if you had an identical twin, who was the exact same age as you, and you went into orbit around the earth for a couple of years, due to the speed you travel at in orbit, he would be older than you when you got back.
I can't really explain it better than that :/ other than this has happened to an astronaut, who was in orbit for a long time, and because of that, "travelled" a few seconds into the future.[/QUOTE]
Isn't this just slowing down time? By going into the future you've made all the actions/decisions pre-made that make you who you are or where you are etc. By slowing down time you're still consciously making these everyday decisions therefore I don't count this as time travel in my book. This is sorta like saying inception is time travel. Unless I'm getting this terribly wrong of course.
Time dilation isn't time travel Danish. The bending of SpaceTime has already been observed, but it's unrelated to actually traveling in the past.
Well, if you shot away from earth, faster than the speed of light, wouldn't you pass the light beams going to wherever you land, and then, provided we had a telescope that could see that far, look into the past? It isn't exactly time travel but...
Traveling in time forward is possible by going fast enough - you essentially "fast forward" time, like you would a movie.
Going back is impossible, as consider this:
I stand infront of a portal that goes back intime and unload a gun from its case. I then go around to the other side of the portal and shoot myself through the portal, since when the bullet hits me i will be back in time - standing infront of the portal.
What happens now?
For simple reasons it doesnt work.
[QUOTE=iwancoppa;34103391]Traveling in time forward is possible by going fast enough - you essentially "fast forward" time, like you would a movie.
Going back is impossible, as consider this:
I stand infront of a portal that goes back intime and unload a gun from its case. I then go around to the other side of the portal and shoot myself through the portal, since when the bullet hits me i will be back in time - standing infront of the portal.
What happens now?
For simple reasons it doesnt work.[/QUOTE]
All paradox arguments like this for the inability to go back in time rely on the existence of free will.
Nothing physical excludes backwards time travel.
[QUOTE=Bawbag;34101040]When you go back in time you reverse it, unless you assume alternate realities.. in which it isn't reversed.[/QUOTE]
That's how I'd look at it.
If time travel were feasible, I would assume that going back into time would lead to parallel universes and not the same previous ones we existed in.
It wouldn't make sense for us to reverse time, because what we've been learning from quantum mechanics is there's large support for multiple dimensions/universes.
I've been trying to understand QM. It's difficult considering I've only been able to understand so much of the mathematical concepts. Matrices make sense, vectors make sense. Scalars seem to focus more on the rotation/orientation. Tensors seem to show that a vector can be split into several more directions. Which adds on to the possibility of alternate dimensions beyond the visible dimension. Or perhaps I'm analyzing it too hard, (I think I heard that from somewhere). Tensors may just be nothing more but to be used to represent momentum fluxes.
[img]http://upload.wikimedia.org/wikipedia/commons/thumb/4/45/Components_stress_tensor.svg/300px-Components_stress_tensor.svg.png[/img]
(Reminds me of 3D modeling)
Spin and Angular momentum are hard concepts for me to grasp too (without ever taking an intro to physics class in highschool).
I'm understanding internal and external forces in relation to the conservation of angular momentum, but how that relates to QM and subatomic particles having spins, is where it gets a little hazy. :d
Vector's represent x,y coordinate properties (position in vector space). So I'm guessing scalars and tensors expand from there.
You're misunderstanding tensors but I don't see why you're having issue with them? I don't think they generally show up in introductory QM. They're much more related to relativity.
[QUOTE=iwancoppa;34103391]Traveling in time forward is possible by going fast enough - you essentially "fast forward" time, like you would a movie.
Going back is impossible, as consider this:
I stand infront of a portal that goes back intime and unload a gun from its case. I then go around to the other side of the portal and shoot myself through the portal, since when the bullet hits me i will be back in time - standing infront of the portal.
What happens now?
For simple reasons it doesnt work.[/QUOTE]
You can't simply go "forward" in time.
I guess by sleeping you are time travelling.
In theory, can't you can travel in a rocket going at the speed of light for a year and then come back to earth and while you would have aged 2 years everyone else on earth would have aged hundreds of years? Or at least you would have aged at a much slower pace than everyone else?
I saw something about this once on the show Through the Wormhole with Morgan Freeman.
[QUOTE=Lilyo;34122158]You can travel in a rocket going at the speed of light[/QUOTE]
Not so much
[QUOTE=iwancoppa;34103391]Traveling in time forward is possible by going fast enough - you essentially "fast forward" time, like you would a movie.
Going back is impossible, as consider this:
I stand infront of a portal that goes back intime and unload a gun from its case. I then go around to the other side of the portal and shoot myself through the portal, since when the bullet hits me i will be back in time - standing infront of the portal.
What happens now?
For simple reasons it doesnt work.[/QUOTE]
A time paradox is no real argument against time travel.
There is no theory in physics explicitly forbidding time travel right now. In fact e.g. General Relativity is full of plenty of ways for time travel.
[editline]9th January 2012[/editline]
[QUOTE=Scoooby;34109703]That's how I'd look at it.
If time travel were feasible, I would assume that going back into time would lead to parallel universes and not the same previous ones we existed in.
It wouldn't make sense for us to reverse time, because what we've been learning from quantum mechanics is there's large support for multiple dimensions/universes.
I've been trying to understand QM. It's difficult considering I've only been able to understand so much of the mathematical concepts. Matrices make sense, vectors make sense. Scalars seem to focus more on the rotation/orientation. Tensors seem to show that a vector can be split into several more directions. Which adds on to the possibility of alternate dimensions beyond the visible dimension. Or perhaps I'm analyzing it too hard, (I think I heard that from somewhere). Tensors may just be nothing more but to be used to represent momentum fluxes.
[img]http://upload.wikimedia.org/wikipedia/commons/thumb/4/45/Components_stress_tensor.svg/300px-Components_stress_tensor.svg.png[/img]
(Reminds me of 3D modeling)
Spin and Angular momentum are hard concepts for me to grasp too (without ever taking an intro to physics class in highschool).
I'm understanding internal and external forces in relation to the conservation of angular momentum, but how that relates to QM and subatomic particles having spins, is where it gets a little hazy. :d
Vector's represent x,y coordinate properties (position in vector space). So I'm guessing scalars and tensors expand from there.[/QUOTE]
Multiverse theory is too popular in my opinion right now but a solution to avoid time paradoxes.
What I do not understand in your post is how you link "reverse time impossible" with quantum mechanics on one side and multiple dimensions on one side. You even set dimensions equal to multiple universes.
Also tensors are not that hard to grasp. They are the elements of an n-dimensional vector space spanned by several independant vector spaces (the mathematical "what are they"). For example, tensors of the rank 2 are nXn matrices.
Higher order tensors are often used to transform lower order tensors or a bunch of vectors into tensors of differen rank (0 = scalar, 1 = vector, 2 = matrix, etc etc). You apply a tensor of rank 3 onto two vectors and get one vector, which got transformed according to the tensor. This helps especially when you have a problem which depends from non-independant parameters.
Wouldn't time travel backwards mean that you'd have to re-align every atom in the universe to the exact state they were in that exact moment?
Time travel in the past is possible...
If a object is moving near the speed of light, it would be less affected by time as the world around him. If a object moves the exact speed of light the world around him would be paused, stopped...
If a object is moving faster than light the object would time travel backwards in time... If you travel back in time a new universe is created and if you kill your parents nothing will happen. It's because a new universe is created in multiverse.... Time travel solved.
BTW. Faster-than-light travel is possible...
EDIT: And no time traveler has traveled back in our time because what is the propabillity for 1 - 100 humans to show them in EXACTLY this universe in the multiverse?
[QUOTE=cartman300;34138899]BTW. Faster-than-light travel is possible...[/QUOTE]
Still not understood neutrino anomaly notwithstanding, no it isn't.
[QUOTE=JohnnyMo1;34139048]Still not understood neutrino anomaly notwithstanding, no it isn't.[/QUOTE]
Yes, it is.
Not if you're anything but a massless particle.
[editline]9th January 2012[/editline]
Actually not even then. Massless particles travel AT the speed of light, not above.
[editline]9th January 2012[/editline]
Unless you'd like to propose a radical change in our current understanding of physics?
[QUOTE=JohnnyMo1;34139863]Not if you're anything but a massless particle.
[editline]9th January 2012[/editline]
Actually not even then. Massless particles travel AT the speed of light, not above.
[editline]9th January 2012[/editline]
Unless you'd like to propose a radical change in our current understanding of physics?[/QUOTE]
No expert but......wormholes?
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