[DivineNathicana]

Einstein said that instantaneous travel was impossible. Quantum physicists are saying that it is - for quantum particles. But I have a different question: Can we not say that macroscopic objects are ALREADY undergoing instantaneous travel? (I want to make it clear that I am NOT bashing either of the aforementioned.)

My reasoning is as follows: When an object (any object) moves (at all in general), it has to INSTANTANEOSLY move to SOMEWHERE: say from consecutive points A to B. If you push a ball down a hill, sure it doesn't go from the top of the hill to the bottom of the hill instantaneously. However, it must go SOMEWHERE instantaneously, be it a Planck's length distance, but still somewhere.

It should not take any time to get there because think about it: If it takes time to get there, that means that during the duration of this time, it was at a point BETWEEN A and B, to which then it must have traveled instantaneously and so on... There is a Planck's length limit to the distance an object can travel. Thus if it travels h-bar, it simply cannot be cought "in-between" hypothetical points A and B because there really is no "in-between", making its motion instantaneous.

- Alisa

[paultrr]

See: http://doc.cern.ch//archive/electro...xt-2004-109.pdf and http://doc.cern.ch//archive/electro...xt-2004-115.pdf and
http://doc.cern.ch//archive/electro...xt-2004-116.pdf and
http://doc.cern.ch//archive/electro...xt-2004-121.pdf for a general treatment using one VSL approach and for one possible solution to that question. If one takes some of the implications of QM and modern theory to heart then in essence at the Planck scale every object in this universe moves not only here, but, also through hyperspace itself. Since we generally tend to judge the expance of time for any given event based upon our measurement of C such movement through hyperspace would be for all intents done in zero time in relation to our observed frame of reference. However, its actual time in the frame of reference of hyperspace itself may involve some passage of time that is simply too fast for us to judge or even begin to measure. Sending Macro objects over a larger distance while theoretically possible actually would seem to involve a form of time travel into the future. As such, that type of path does not really beat light in our own frame. In fact, if the value of C is higher in hyperspace it really does not beat light in that frame of reference either.

One key here is playing with the local value of C for two different frames and comparing the results to each other. By usage of a frame with a higher value all one does is manage to travel into the future, not the past. As such, that path becomes little different from say making it somehow possible for a object here to move at C. By SR such an object would experience zero time in its own frame while for the earth hundreds or thousands of years might have passed.

[paultrr]

There are two types of superluminal effects found in theory.

1.) True tachyon like motion which involves beating light itself.(see Wormholes, Warp drive, etc). Even these can used altered local values for C. But the key difference is they really do establish a path over which an object could beat a light signal in our normal frame of reference.

2.) Altered local values of C where the frame in question still moves forward in time in relation to ours.(Those macroscopic spacetime shortcuts).

[gpdone]

Dear Divineone,

I cannot fault your logic for the following reasons:
*Based on the way we measure time the first tick cannot really exixt or be sensable until the smallist discrete particle of whatever things as we know them are made of has moved completly passed the starting point. In my opinion the only way that this can and probably will be challenged is mathmatically which bares no necessesary connection to reallity.

Lee

[DivineNathicana]

Paultrr, I wasn't really talking about altering the value of C so much as moving objects instantaneously. I mean, I see how they're related (discussions of movong macroscopic objects very fast often involve terminology such as ">C"), but I mean INSTANTANEOUSLY, which C is not.

- Alisa

[Tormod]

Originally Posted by DivineNathicana

Einstein said that instantaneous travel was impossible.

AFAIK Einstein's point was that it is impossible due to the limits on speed of information, ie c. So you cannot avoid c in this discussion.

Instantaneous travel boils down to semantics: what is an "instant". You might be interested in reading something about Goedels Continuum Hypothesis which tries to explain the relation between space, time, and distance:

The Continuum Hypothesis
http://www.ii.com/math/ch/

For something to move from the Sun to the Earth instantaneously, it would actually have to travel faster than light, which spends 8 minutes on the journey (at the speed of c, obviously). So instantaneous travel is the same as travelling back in time.

I think splitting the line of motion into points is needless - macroscopic objects most definitely do NOT move at planck scales. Even when you stand still every single cell in your body is moving somewhere (say you sway slightly back and forth or shiver) and the ground you are standing on is on a rotating globe in orbit around a star in orbit around a galaxy heading towards a galaxy cluster.

Quantum particles show strange behaviour, yes. But they are not observed to move faster than c (the hypothetical "tachyon" does this but is not yet observed - and Feynman's diagrams show that all particles move backwards in time - theoretically).

Since we do not completely understand what time is, arguments about this have a lot of fallacies. We know more about space than time so maybe we will find that isntant motion is possible. But as for today the only possible instant motion for macroscopic objects would be theoretical wormholes.

[paultrr]

Very true. In fact, the issue of wormholes comes up when one begins to discribe the quatum states itself. Some see the microscopic tunneling as being via wormholes. The problem there is the exotic energy requirement in the first place that tends at least at macroscopic scales to violate certain quantum energy conditions. Going down in scale one also encounters a wavefunction spread on anything one is trying to measure that makes it impossible to measure certain qualities exactly. Here time itself tends to break down.

When you consider a zero time frame itself there is not much of a difference between saying the object exists as if it was at C(with Lorentz time contraction to zero) and that its in an alternative frame where say C is infinite. Both result in a zero time experience. DSR(Double Special Relativity) somewhat hits upon this notion itself. Either way we cannot break time down small enough to actually measure events.

I also agree with the other statement made in a prior post concerning math. One can have mathamatical proofs that work out fine and have nothing to do with reality. Its the uncertanity principle that places our limits at present at understanding this. Untill we have a better grasp of what time exactly is we for the most part stuck with philosophical debate when it comes to this issue. Yes, multiverse type theory would tend to support there is movement there. But that same theory when combined with relativity also tends to show these paths are not the shortcut to everywhere some would like them to be. There is a vast difference between quantum information exchange and normal informational paths. While the first seems by EPR experiments to work in some kind of Instantaneous Frame from our perspective the second requires a more long term path. Also, even the first path requires the long path to actual measure anything.

[gpdone]

Tormod,

Please explain your logic here

For something to move from the Sun to the Earth instantaneously, it would actually have to travel faster than light, which spends 8 minutes on the journey (at the speed of c, obviously). So instantaneous travel is the same as travelling back in time.

I do not understand how the 'back in time' statement follows from the previous statement.

Lee

[paultrr]

There are two types of faster than light motion encountered in modern theory:

1.) True tachyon like motion that is backwards in time.

2.) Faster than light effects out of GR like wormholes, warp drives, etc. Their motion while providing a shortcut that allows faster travel are not really backwards in time. The arrow of time still is forward for these types of paths. From the perspective of a normal C frame they do tend to beat a photon. But they do so by the means of a shorter path.

He can correct me here. However, I assume he was refering to the first.

An interesting aspect in all this is found in something Hawking mentions in his books, "The Universe in a Nutshell". In that book Hawking mentions all those quantum wavefunction predictions and how ever set of them does contain FTL states. The normal assumption is these states are simply an artifact of the math involved. However, some of the more recent quantum based theory tends to assume these states possible exist in higher dimensions. Rather making the leap that perhaps the math has been telling us something all along. The problem here is that tachyon fields from what we can tell in our spacetime would tend to hyper inflate. Another words they would be unstable. So if any of these odd type of states are real one could also assume they must be simular to the second class mentioned above.

The real problem is none of these possible states have any direct way offered to measure them. A few of us who have looked at solutions like those Alcubierre once proposed have noted something of a signature such a field would have. That signature turns out to be simular to that of Hawking radiation in the form of very high blue shifted particles. A simular signature has always been known from theory for real tachyon particles if they could exist in our spacetime.

[Bo]

if i understand the original question correctly then i dont think we need space time curves, altering c or whatever (it is fun though ) The only thing we need is the quantum wave

the problem with the discontinuity on the planck scale only applies to a measurement of the particle. as soon as the particle is unperturbed, the wave function (describing the probability to find the particle anywhere) is spread out over space (due to the uncertainty effect). and it might move, or whatever, but the point is, it is completely continuous, onlyt when a measurement or interaction is made, the wave function collapses and feels the discontinuity of space.

i think i'm very tired and after writing the above down, i'm not completely sure anymore...

Bo