Instantaneous travel of macroscopic objects?

[paultrr]

It is completely continuous as far as the spread. The problem is found in the spread itself. At the Planck scale that spread is to infinity not only in the spread of its momentum as well as its position. By theory the particle exists as if it existed at every point in spacetime at the same time which rather is in contradiction to the normal locality of any event as defined under SR. It was over these same points that Einstein raised some of his first complaints about quantum theory somewhat leading to his famous, "Does God play dice) statement.

The original question here concerns is there instantious movement. By theory yes. But as you pointed out by measurement or at least what we can observe no as far as what we know about wavefunction collapse. I think it is safe to say that at macroscales our bodies are observed in one format or another constantly by someone or something. Planck scale effects for all intents do not exist at such scales. Now, does our very subatomic particles form such tricks is any bodies guess given we cannot measure such directly. In fact, the very act of measurement tends to collapse the wavefunction to begin with as Bo pointed out.

[DivineNathicana]

paultrr, why can't we consider Planck scales for macroscopic objects? Althouth we obviously cannot feel them directly, if they do exit, can't we say that we are constantly, on the fundamental level, moving through them? Why do conflicts arise when we take into consideration all measurements done for a macroscopic objects on microscopic scales as a sum? Shouldn't that theoretically be logical? Why can't it be applied to observable scales?

- Alisa

[Tormod]

Originally Posted by DivineNathicana

Why do conflicts arise when we take into consideration all measurements done for a macroscopic objects on microscopic scales as a sum? Shouldn't that theoretically be logical? Why can't it be applied to observable scales?

Just a small comment here: With "macroscopic" I mean anything that is larger than a hydrogen atom, deuterium, and other variations. Atoms and subatomic particles behave according to quantum mechanics (ie, the uncertainty principle, tunnelling, entanglement, energy quanta, plank length etc).

Macroscopic objects, ie anything that is a composite of the hydrogen atom and it's constituents, also behave according to qunatum mechanics but it very fast becomes less noticeable. A human body consists of so many particles that the body in itself will not ever experience instant tunnelling, say, or the effects of the weak and strong forces - even though the trillions of particles in our bodies do.

So while we use classical physics and relativity to explain the behaviour of macroscopic objects, we use quantum physics to explain the behaviour of the very small.

[Tormod]

Originally Posted by 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 is correct and my statement needs some explanation. The effects of instantaneous travel are interesting. If I should happen to be in an aircraft hovering above the surface of the sun at an angle where I can see the "back" of the sun yet still see the Earth, I can theoretically see a sunspot move into view to a point where it will be seen from the Earth.

Now, I travel instantaneously back to Earth with my spaceship's black hole field generator and look through my telescope when I arrive back on Earth. I will not see the sunspot move into view for another eight minutes. However, assuming I have an incredibly good telescope, I can also see my own spaceship hover above the surface of the Sun for those 8 minutes, and indeed also listen to signals I sent 8 minutes before I left the Sun.

So it will appear as if I have moved 8 minutes back in time. I could even say to someone that "I have seen a sunspot move into view, but you my friend will not be able to see it in another 8 minutes", and it will prove true in 8 minutes. I have thus moved faster from A (the surface of the Sun) to B (the surface of the Earth) than c and thus I have travelled faster than light. According to general relativity I have thus moved backwards in time (and thus also faster than information can travel, which is also c). Note that the spaceship has not travelled in time, only instantly relocated in space, so there are no relativistic problems with time dilation etc.

The above scenario is of course entirely hypothetical because as of yet we do not know of any way that instantaneous travel can occur.

[paultrr]

Yes, that was why I tried to contrast the two types of FTL motion. The one with the Instantious type motion actually could display notions of both types of movements. One in that case beats the light signal. By our perspective time keeping on earth its traveled backwards in time, yet, also, it never altered its own time frame to do so. Something almost akin to a short range warp drive also in that you move quicker than light, but you're still forward as far as time keeping goes. GR and QM both have all these funny little potential shortcuts by the math. The problem is figuring out if any of them actually are possible in the real world.

[DivineNathicana]

Tormod:

Hmm but is it correct to say that you traveled back in time? All that really happened is that those on Earth were not able to find out about your whereabouts due to the fact that you were now the “fastest moving reference frame”, and not c. Just because those back on Earth did not know about the sunspot did not stop it from being there, just as if the sun suddenly exploded, you would not say that just because we saw it only eight minutes later, it traveled back in time.

Your scenario only seems like time travel because you are actually introducing a speed above c, which is our basic (observed) speed limit. Do you see what I’m getting at here? It’s only “time travel” because you’re hypothetically traveling faster than the fastest speed, thus introducing a new “fastest speed” – instantaneous travel. If you accept this as your new speed limit, you can see that the situation can no longer be thought of “time travel”.

Anything ABOVE this speed, however, WOULD be considered time travel as it would be faster than instantaneous, which means literally arriving before you started out, and without any relativistic tricks.

- Alisa

[sanctus]

I see the problem in completely other perspective: the macroscopic objects do actually move from point A to B instantanously, what we forget there is that a point is a mathematical object without any dimension, so when a macroscopic object moves from A to B it doesn't actually move in space-time so there is no contradiction with einstein.
We all now how reality is different, we can't take a point, but we have to take an interval (supposing continuity of space-time) and an interval has dimension and therefore A and B are actually separated in space-time and therefore instantanous travel is not possible.
Mathematically i see an intervall as the limit to infinite of consecuting points Ci, translating this to what I wrote above, it means that even if travelling from Ci to Cj (j=i+1) is istantaneous the limit to infinite (tehrefore an interval) hasn't to be istantaneous.

This reasonig follows from the mathematically property that if C=limCi and Ci < A we have C<=A.

[Tormod]

Originally Posted by DivineNathicana

Tormod:

Hmm but is it correct to say that you traveled back in time?

Notice I wrote that I would appear to have traveled back in time, because we could still look through the telescope and see my spaceship being close to the sun for another 8 minutes (until it vanishes). For all practial reasons I have travelled back in time with the only exception that I appear on Earth _after_ I relocate from the Sun, not before. Travelling at the speed of c would take me 8 minutes (plus of course the time it takes to accelerate and decelerate).

All that really happened is that those on Earth were not able to find out about your whereabouts due to the fact that you were now the “fastest moving reference frame”, and not c.

No, they know where I am all the time. If they were looking at my ship through the telescope they would know I am close to the Sun. Also, my radio signals would inform them that I would come back in 8 minutes (if I chose to say so). Then in the next instant I'd be right next to them. So they would see me as being in a spaceship hovering above the sun even as they were talking to me in the same room.

And here is the time travel part: After 8 minutes of talking to me, they see my ship vanish from the Sun. Thus I appear to leave the Sun 8 minutes after I arrived at the Earth.

I am not (in) the fastest moving reference frame at all, since I did not move through space-time (like sanctus pointed out).

Just because those back on Earth did not know about the sunspot did not stop it from being there, just as if the sun suddenly exploded, you would not say that just because we saw it only eight minutes later, it traveled back in time.

No, but I would be able to tell them when it was due to appear because I had observed it myself just seconds before, millions of kilometers away. So the information has moved faster through the wormhole than the light itself has moved from the Sun to the Earth.

I think you fail to see my point that we are talking about two things:

1) I move from A to B faster than light, thus violating the speed limits in the universe

2) ...However, I am using a trick (skipping the space dimension) so my timeline is ticking away at a normal rate relative to the Earth. No time dilation, no movement in space.

Your scenario only seems like time travel because you are actually introducing a speed above c, which is our basic (observed) speed limit. Do you see what I’m getting at here? It’s only “time travel” because you’re hypothetically traveling faster than the fastest speed, thus introducing a new “fastest speed” – instantaneous travel. If you accept this as your new speed limit, you can see that the situation can no longer be thought of “time travel”.

As far as I can see this is simply a rephrasing of what I wrote in my post.

Anything ABOVE this speed, however, WOULD be considered time travel as it would be faster than instantaneous, which means literally arriving before you started out, and without any relativistic tricks.

Yes. But it would also mean that you would need to travel in space, which I do not do in my example (I simply relocate).

Remember the discussion you started was about whether macroscopic can move instantaneously in time. My example shows a hypothetical situation in which this happens, and I then ask whether it is the same as time travel, which it is not - it requires a wormhole, which I was then asked to clarify (which I hope I have done).

I still question your opening statement that Einstein wrote that objects can move instantaneously in time. I have never seen this be written anywhere. I wonder if you are confusing "movement" in this case with "wave diffusion" - Newton believed gravity was instantanous over infinite distances, wheres Einstein proved that this was not true.

However, I am of course only happy to be corrected here.

[paultrr]

I'll attempt two answers at once here.

1.) Its an observational apperant version of time travel without actually going into the past as far as the craft is concerned. The craft at some point in its history saw an event. It then jumped to earth in zero time. So we have T+0 at this point for the craft. Those on earth watch the sun and the craft. At some point the craft vanishes from around the sun and appears instantly at the earth. Again we have T+0 on our clocks. The craft discribes an event at the sun. Eight minutes later that event is witnessed on earth. So we now have T+0+8 for the earth and the craft also. But the craft left the sun before the earth saw this event and yet, it left right after the event there. So for the earth's frame of reference the craft seems to have traveled back before the event. But the difference is found in the time it took for that event to be viewed on earth.

2.) The Planck scale is not a zero itself. It would not be a singularity at all of zero dimensions by any present accepted version of quantum theory including Loop Quantum Field Theory. Yet, the odd microscopic effets mentioned earlier by theory begin at that scale, not at an actual zero point.

[gpdone]

Thank you Tormod. You put it very well. Paultrr restated it correctly as far as I can tell with one goof;

'At some point the craft vanishes from around the sun and appears instantly at the earth.'

Literally this is incorrect. The craft would appear first at the earth and THEN vanish from around the sun eight minutes later.

In all cases, as far as I am concerned, only apparent time travel has occured.

Lee