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Subject: Slip strem leave room for time travel?

If you can go faster than the speed of light, Cant you bend space and time?

If this is true wouldent UNSC prepare to BAN all travel?

  • 12.07.2010 9:20 PM PDT

Message me if you want, I will try to get back as soon as possible.

See you on the forums and in the games.

This happens because they are basically going through another dimension. Physics in Slipspace are different than in the real world.

  • 12.07.2010 9:25 PM PDT
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Posted by: scar 444
If you can go faster than the speed of light, Cant you bend space and time?


While, I don't know about 'bending' space and time, but FTL and relativity do imply time travel. FTL, Relativity, Causality. Pick 2.

If you start at Earth, make a FTL jump to Epsilon Eridani, have lunch, accelerate away from Episilon Eridani, then make another jump back to earth, it is quite possible to arrive before you left. Although I use the word jump, it really doesn't matter how you travel FTL. Whether it's somehow just moving FTL, going through another dimension, warping space, teleporting, whatever, they can all lead to causality violation when combined with relativity.

Obviously you can avoid this if you throw out relativity.

Why this problem doesn't appear in Halo, I don't know. Most writers probably just don't realize it.(though there are a few exceptions. Stephen Baxter comes to mind)

  • 12.07.2010 9:45 PM PDT

I enjoy halo for it's story and when I am in the mood, its gameplay. Reach was significantly worse then I expected but was still a great game (minus the european hitscan fiasco). I am sitting on a two mile wide fence on the subject of halo 4. Most of the things I like a technical aspects though and not story or game play. Plus I am slightly mad they took my elites from MP.

@scar 444 yes its possible but then add the law of faster speed = slower passing of time and the fact that if a object from our universe fully entered another universe with a slight variance in the laws of physics the object would be destroyed, so I beleive slipspace actually works as the name suggests by folding a ship in a sphere of our space time and flying it through slipspace like a full body snow plow then exiting into our universe again this means that the passage of time inside the bubble remains the same as in our universe but also stops the vessel from going back in time as the buuble of 'warped' space (the space/time making the bubble) ages as the same rate as rest as our universe and essentialy re-joins with another bubble of the same space time, which is the parent universe

  • 12.08.2010 11:08 AM PDT


Posted by: opogjijijp
Posted by: scar 444
If you can go faster than the speed of light, Cant you bend space and time?


While, I don't know about 'bending' space and time, but FTL and relativity do imply time travel. FTL, Relativity, Causality. Pick 2.

If you start at Earth, make a FTL jump to Epsilon Eridani, have lunch, accelerate away from Episilon Eridani, then make another jump back to earth, it is quite possible to arrive before you left. Although I use the word jump, it really doesn't matter how you travel FTL. Whether it's somehow just moving FTL, going through another dimension, warping space, teleporting, whatever, they can all lead to causality violation when combined with relativity.

Obviously you can avoid this if you throw out relativity.

Why this problem doesn't appear in Halo, I don't know. Most writers probably just don't realize it.(though there are a few exceptions. Stephen Baxter comes to mind)


in slip-space you are not going faster then light; you are traveling at the same speed through a "shortcut", essentially a wormhole, through space.

This is described in Contac Harvest.

  • 12.08.2010 1:26 PM PDT

"Find where the liar hides, so that I may place my boot between his gums!" - Rtas 'Vadum

Posted by: opogjijijp
Could Slipspace not be regarded as the special frame of reference though?

  • 12.08.2010 2:22 PM PDT




in slip-space you are not going faster then light; you are traveling at the same speed through a "shortcut", essentially a wormhole, through space.

This is described in Contac Harvest.



THIS. except.
Slip space uses the same theory as Einstein-Rosen Bridge Wormholes.
You are not actually travelling faster than light. The idea is that you fold space like a sheet of paper and travel through a short cut inbetween. Its faster because it would take a beam of light more time to go around the fold; if you shot a beam of light or something at the speed of light it through the worm hole it would still get there first due to the universal speed limit. E=MC2

  • 12.08.2010 4:57 PM PDT

they aren't going faster than the speed of light, they are moving through a different dimension

  • 12.08.2010 5:21 PM PDT
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Posted by: ROBERTO jh

Posted by: opogjijijp
Posted by: scar 444
If you can go faster than the speed of light, Cant you bend space and time?


While, I don't know about 'bending' space and time, but FTL and relativity do imply time travel. FTL, Relativity, Causality. Pick 2.

If you start at Earth, make a FTL jump to Epsilon Eridani, have lunch, accelerate away from Episilon Eridani, then make another jump back to earth, it is quite possible to arrive before you left. Although I use the word jump, it really doesn't matter how you travel FTL. Whether it's somehow just moving FTL, going through another dimension, warping space, teleporting, whatever, they can all lead to causality violation when combined with relativity.

Obviously you can avoid this if you throw out relativity.

Why this problem doesn't appear in Halo, I don't know. Most writers probably just don't realize it.(though there are a few exceptions. Stephen Baxter comes to mind)


in slip-space you are not going faster then light; you are traveling at the same speed through a "shortcut", essentially a wormhole, through space.

This is described in Contac Harvest.


I'm aware, but but that still doesn't get around the problems with causality.

Posted by: anton1792
[quote]Posted by: opogjijijp

Could Slipspace not be regarded as the special frame of reference though?


It's quite possible, and would explain why we don't end up with any crazy casualty breaking situations. Except for that thing with the crystal in First Strike, but nobody is really sure what happened there....

Though it falls into the 'ditch relativity' solution.

[Edited on 12.08.2010 5:23 PM PST]

  • 12.08.2010 5:22 PM PDT

causality isn't affected, example

leave earth and reach alpha centauri in one second (that's a hell of a lot faster than light!)

return to earth in one second

congratulations! it is now two seconds later and you have not bumped into yourself once

  • 12.08.2010 5:27 PM PDT


Posted by: blak n bloo
causality isn't affected, example

leave earth and reach alpha centauri in one second (that's a hell of a lot faster than light!)

return to earth in one second

congratulations! it is now two seconds later and you have not bumped into yourself once

I suspect you aren't that familiar with special relativity.

Any time that classical information gets from one place to another faster than it could via normal movement in one reference frame, there exist reference frames for which that information travelled back in time.



It doesn't really matter, though. It's standard for sci-fi to handwave relativity away in some way or another. When God was about to make the universe, he decided to outsource the job to the Jell-O branch of Kraft, and it's easier to just forget about that when building fiction.

[Edited on 12.08.2010 5:35 PM PST]

  • 12.08.2010 5:33 PM PDT

what is Casuality?

  • 12.08.2010 5:38 PM PDT


Posted by: LoneRanger 521
what is Casuality?

It's "Causality", not "casualty". The latter describes temporary or permanent human losses, ie a military suffering 5 wounded and 3 KIA in a fight is said to have suffered 8 casualties (many people out there think it only describes KIA, but they're technically wrong).


Causality is the state of things where a cause takes place before its effect. FTL travel violates causality because, according to special relativity, FTL travel in one reference frame implies reverse time travel in some other frame, allowing causes to take place after effects.
Causality is not necessarily considered a physical law, but it is often treated as such because there are no known and useable ways to violate it.

[Edited on 12.08.2010 5:43 PM PST]

  • 12.08.2010 5:42 PM PDT


Posted by: Tupolev

Posted by: blak n bloo
causality isn't affected, example

leave earth and reach alpha centauri in one second (that's a hell of a lot faster than light!)

return to earth in one second

congratulations! it is now two seconds later and you have not bumped into yourself once

I suspect you aren't that familiar with special relativity.

Any time that classical information gets from one place to another faster than it could via normal movement in one reference frame, there exist reference frames for which that information travelled back in time.



It doesn't really matter, though. It's standard for sci-fi to handwave relativity away in some way or another. When God was about to make the universe, he decided to outsource the job to the Jell-O branch of Kraft, and it's easier to just forget about that when building fiction.


ah you're saying you would see yourself flying towards alpha centauri as you return?

I love physics :3

  • 12.08.2010 5:46 PM PDT

Ok, that sort of makes sense but not really.
According to the Mad Scientist Paradox theory, and Steven Hawking. Causes always, always, always happen before effect.

  • 12.08.2010 5:48 PM PDT


Posted by: blak n bloo

Posted by: Tupolev

Posted by: blak n bloo
causality isn't affected, example

leave earth and reach alpha centauri in one second (that's a hell of a lot faster than light!)

return to earth in one second

congratulations! it is now two seconds later and you have not bumped into yourself once

I suspect you aren't that familiar with special relativity.

Any time that classical information gets from one place to another faster than it could via normal movement in one reference frame, there exist reference frames for which that information travelled back in time.



It doesn't really matter, though. It's standard for sci-fi to handwave relativity away in some way or another. When God was about to make the universe, he decided to outsource the job to the Jell-O branch of Kraft, and it's easier to just forget about that when building fiction.


ah you're saying you would see yourself flying towards alpha centauri as you return?

I love physics :3


Which is why Wormholes are conveinient: they get you places quicker then light, and you also don't suffer from hyper-slow/reversed time.

[Edited on 12.08.2010 5:50 PM PST]

  • 12.08.2010 5:49 PM PDT
  • gamertag: opog
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It doesn't really matter, though. It's standard for sci-fi to handwave relativity away in some way or another.

Very true. Many don't even think about it, most of the rest just handwave it away.

Though it can be fun to try to justify it or come up with some way in which it makes sense.

  • 12.08.2010 5:57 PM PDT


Posted by: blak n bloo
ah you're saying you would see yourself flying towards alpha centauri as you return?

Suppose we have a frame of reference at the Earth. In this frame of reference, there is no problem.




However, in some frames of reference that happen to be moving quite snappily relative to the Earth, this stuff totally falls apart and breaks down.

For starters, if the frame is moving REALLY fast, the moment spent touching alpha centauri actually takes place before everything else along the journey.

It gets even weirder if the contracted frame's S-axis on Earth's spacetime diagram is parallel with the to-Centauri motion of the spacecraft. In THIS case, for the non-Earth frame of reference, everything the spacecraft does during the journey to Centauri happens simultaneously!


These are pretty simple examples of causality breakdowns. It gets a lot weirder when you get more involved.



Ok, that sort of makes sense but not really.
According to the Mad Scientist Paradox theory, and Steven Hawking. Causes always, always, always happen before effect.

Right, it doesn't make sense. That's exactly the point, and it's why many physicists suspect that FTL travel is impossible.

[Edited on 12.08.2010 6:19 PM PST]

  • 12.08.2010 6:07 PM PDT

I don't care. I really don't.

You're assuimng time is an existing law and movement, but it might just be a way humans pervieve and concieve the causes and effects of the third dimension rather than a dimension of its own, at which point time travel and people being in two places at once are renderd impossible in a third dimensional universe, which may be what our universe is.

But, everyone else is right, if time is a real dimension and not a way for the human mind to keep itself sane, then you could be in two places at once if using FTL within our dimension.
However, Slipspace was created to avoid this problem; the dimension is third dimensional, and has no time, which means there are no relativistic effects to those using it to move FTL, and they arrive after they left with no way to see themselves if they return to Slipspace and move back as they have already moved across and it is not possible to time travel without time.

That's as far as I know.

  • 12.08.2010 6:22 PM PDT

I don't care. I really don't.


Posted by: Tupolev

Right, it doesn't make sense. That's exactly the point, and it's why many physicists suspect that FTL travel is impossible.


Funny thing, those are probably the same physicists who are the ones that found out that we, at this moment in time, are moving FTL. Hahaha. I love it when scientists contradict themselves.

  • 12.08.2010 6:24 PM PDT


Posted by: Venator82
You're assuimng time is an existing law and movement, but it might just be a way humans pervieve and concieve the causes and effects of the third dimension rather than a dimension of its own, at which point time travel and people being in two places at once are renderd impossible in a third dimensional universe, which may be what our universe is.

But, everyone else is right, if time is a real dimension and not a way for the human mind to keep itself sane, then you could be in two places at once if using FTL within our dimension.

Care to rephrase that? I have no idea what any of it means.

Also, my argument comes straight from the principles and mathematics of special relativity, the physical implications of which have been experimentally supported quite well over the past century.


However, Slipspace was created to avoid this problem; the dimension is third dimensional, and has no time, which means there are no relativistic effects to those using it to move FTL, and they arrive after they left with no way to see themselves if they return to Slipspace and move back as they have already moved across and it is not possible to time travel without time.

Teleportation and similar thingies would not allow handwaving of relativity. The effects don't happen simply because of the movement itself, but happen anyway based simply on the idea of an object being at specific positions at specific times in various frames of reference.

Funny thing, those are probably the same physicists who are the ones that found out that we, at this moment in time, are moving FTL. Hahaha. I love it when scientists contradict themselves.
What? That doesn't even mean anything.

  • 12.08.2010 6:33 PM PDT

Isnt FTL travel impossible due to the universal speed limit of Light? E =MC2.
Example. Say ur in a car traveling At the speed of light,.. you turn on your headlights... What happens? Same as Say ur on a train traveling at the speed of light you get up from your seat and start walking up the train. Are you walking faster than the speed of light?

  • 12.08.2010 6:43 PM PDT

I don't care. I really don't.


Posted by: Tupolev

Care to rephrase that? I have no idea what any of it means.


It means Time might not exist, although many physicists disagree with this notion, however they have no reason to back it up, and it seems they simply want time to exist because it can explain things more easily, and they take the lazy route.
If there is no time, then there is no time, then you cannot be in two places at once because only one of you exist and at any given time your singular self has to be somewhere and doing something, and cannot be doing something else as you are already somewhere and doing something.

Also, my argument comes straight from the principles and mathematics of special relativity, the physical implications of which have been experimentally supported quite well over the past century.

Yes, well we nowadays for some reason think we know almsot everything there is to know.
Funny, last time that happened, we "knew" the Earth was definately flat, and that theory was supported for much longer than the theories you are using for support. It is no different.

Teleportation and similar thingies would not allow handwaving of relativity. The effects don't happen simply because of the movement itself, but happen anyway based simply on the idea of an object being at specific positions at specific times in various frames of reference.

It is not teleportation. It is movement through a dimension that lacks time, and like I said above, without time if something exists it must be doing something and cannot be doing something else at the same time as there is no way for it to be in two places at once.
If time exists, then yes it can, but Slipspace has no such thing.

What? That doesn't even mean anything.

Our local Galactic Supercluster is moving at Faster Than Light speed due to the energy released from the Big Bang, and we are moving in different directions than other clusters, that is why at a certain point we will get no light from those clusters as we and the points of light are moving faster than the light can reach us, because although our movement relative to the movement around us, we are orbiting a star, orbiting a Galactic centre and orbiting other Galaxies, however everything we can see around us is moving at the same, Faster than Light speed.

If you want to argue physics, which I wasn't trying to do, then learn everything not a small, very advertised piece just because someone thought it up, it made sense and everyone liked it. People thought flat Earth made sense.

Isnt FTL travel impossible due to the universal speed limit of Light? E =MC2.
Example. Say ur in a car traveling At the speed of light,.. you turn on your headlights... What happens? Same as Say ur on a train traveling at the speed of light you get up from your seat and start walking up the train. Are you walking faster than the speed of light?


Ever heard of Cherenkov radiation? It's radiation given off by objects moving at FTL, and we detect it. Neutrinos? Sometimes they move FTL. Us? Yeah, we're moving FTL right now, just not relative to the objects and space directly around us.



[Edited on 12.08.2010 6:51 PM PST]

  • 12.08.2010 6:49 PM PDT

"Find where the liar hides, so that I may place my boot between his gums!" - Rtas 'Vadum

Posted by: opogjijijp
Posted by: anton1792
Posted by: opogjijijp
Could Slipspace not be regarded as the special frame of reference though?


It's quite possible, and would explain why we don't end up with any crazy casualty breaking situations. Except for that thing with the crystal in First Strike, but nobody is really sure what happened there....

Though it falls into the 'ditch relativity' solution.

Yeah, I guess it does.

The main problem with these "workabouts" is that they tend to be born from the desire for FTL rather than on observations. Very few, if at all any, will actually be true in real life I suspect. In fiction though I can get used to it. It is obscure enough; I never even knew about it until recently.

  • 12.08.2010 7:07 PM PDT

I'm going to drop some things because this is just too bulky. Anyhow:

Posted by: Venator82
It means Time might not exist, although many physicists disagree with this notion, however they have no reason to back it up, and it seems they simply want time to exist because it can explain things more easily, and they take the lazy route.

My interest is piqued. What would a model of the universe that does away with the concept of time actually look like?

Funny, last time that happened, we "knew" the Earth was definately flat, and that theory was supported for much longer than the theories you are using for support. It is no different.
And the flat Earth theory was actually reasonable so long as you lived in a small region mapped on a very large sphere. In that sense, flat Earth theory has not been "disproven" so much as generalized, in the same sense that special relativity generalizes Newtonian mechanics to situations with nonnegligible relative velocities.

The other, larger issue with your example is that the moment a capable scientist came up with a plausible way to put the flat Earth theory to the test, way back thousands of years ago, it was shown to be false. Furthermore, SR became popular not because it was some cool thing but because competing theories such as ether theory began to look iffy and nonsensical in light of observations of the time; early SR theorists had to fight for it.

Teleportation and similar thingies would not allow handwaving of relativity. The effects don't happen simply because of the movement itself, but happen anyway based simply on the idea of an object being at specific positions at specific times in various frames of reference.

It is not teleportation. It is movement through a dimension that lacks time, and like I said above, without time if something exists it must be doing something and cannot be doing something else at the same time as there is no way for it to be in two places at once.
If time exists, then yes it can, but Slipspace has no such thing.

It doesn't really matter what slipspace has, though. If special relativity holds in real space under regular conditions, then the causality issue pops up. Again, my argument is not dependant on what happens to the spacecraft and what it experiences in the interem. If it is at Earth at t=0 and at Centauri at t=1 in Earth's frame of reference, then regardless of what happened between t=0 and t=1, there is a frame of reference such that the craft exists at Centauri prior to its launch, as long as SR holds in real space.

Our local Galactic Supercluster is moving at Faster Than Light speed due to the energy released from the Big Bang,
I was under the impression that we were moving FTL relative to far-off objects because of expansion of space itself, not because of the big bang's explosive energies. And also that that relative motion has no bearing on the casaulity breaking aspects of FTL travel according to SR in a localized sense.

Ever heard of Cherenkov radiation? It's radiation given off by objects moving at FTL, and we detect it.
This is a confusion of definitions. Cherenkov radiation is given off when objects move faster in a given medium than light waves travel in that medium. It has nothing to do with objects moving faster than c.

Neutrinos? Sometimes they move FTL.
Hmm. I've heard there's been some wonky research into those particles, but I'm not familiar with it. A quick google and wikipedia search only informed me that, supposedly, some neutrinos were measure moving at slightly over c, but not such that they were definitely moving at greater than c given confidence bounds.

Sounds interesting.






Other stuff:

Posted by: LoneRanger 521

Isnt FTL travel impossible due to the universal speed limit of Light? E =MC2.
Example. Say ur in a car traveling At the speed of light,.. you turn on your headlights... What happens?

Cars can't travel at c. Let's suppose for arguments sake that the car is travelling negligibly below c in some frame of reference. Then, from the car's frame of reference, the light will travel at c away from the car, like it would for a car at rest. In the frame of reference where the car is travelling at some speed just below c, then in this frame of reference the car will be travelling at just below c and light will be travelling at c.

Furthermore:
Same as Say ur on a train traveling at the speed of light you get up from your seat and start walking up the train. Are you walking faster than the speed of light?
Let's make a similar assumption, that in some reference from the train is travelling slightly below c. In the train's frame of reference, the person will be seen walking at some velocity v, just as if the train were at rest. In the frame of reference where the train is moving just barely below c, the train would be seen at almost c, and the person on the train would appear to be moving faster than the train but still below c (no matter how fast they were moving).

These phenomena occur because speed in SR is not directly additive.

  • 12.08.2010 8:20 PM PDT

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