Theories - Time Travel, Parallel Dimensions, Etc.

[Blobbenstein]

Thought experiment: take a box travelling close to c. Wouldn't the front of the box appear to be moving away from the observer faster than the back, due to a larger component of its velocity being that which is the moving away(from the observer) part relative to the observer.

A would appear to be moving away from the observer than B.

If you imagine a really big box whose back end was close to the observer, B would hardly be moving away from the observer, but A would be moving away at close to v(the speed of the box).

Maybe as a atom omitting a photon oscillates forwards and backwards, it appears to speed up and slow down.....Maybe that would cause the path of the photon to be at an angle, and the observer sees the object magnified?

I dunno, this is just an idea.

 

[Blobbenstein]

maybe I'm wrong, I started off assuming that time dilation caused magnification, because it does with gravity, but perhaps it doesn't with just speed...well length contraction obviously shows that......

 

[Blobbenstein]

How is a wave function affected by relativistic speeds?

 

[Blobbenstein]

One thing I just notice on the Wiki time-dilation page is the working out for the formula about time dilation relies on the assumption that the distance between the two mirror walls, on the moving object, appears the same for all observers.

http://en.wikipedia.org/wiki/Time_d...nce_of_time_dilation_due_to_relative_velocity

The distance between the two walls is L, and based on the assumption that L appears the same distance for all observers, L is used to link the two reference frames.

Is it ok for them to make that assumption?

.

 

[FortyTwo]

Okay this thread no longer makes sense to me.

 

[Digger]

I'm not actually that bright so the thread never made sense to me... but I love the mirror universe from the various Star Trek series.

 

[nog]

well I'm not really read up that much on wave functions, but could it be said that say x percent of the wave function would form a ball...Like the chance of finding a particle is 10% within volume Q, where Q is a sphere? Depending on whether the object was moving maybe.

It's been awhile since I've dealt with quantum mechanics (QM), but I didn't study much (if at all) about relativity and QM together. I think, in general the two theories don't work well together.

I'm not sure if there are any members here studying Physics.

eta: and at close to the speed of light Q would be a flattened ball, with the same volume.

If Q is an object and the object is moving, then the object is contracted along the direction of motion. This means the volume shrinks. If Q is a region of space, it is not affected by motion so it's not flattened.

I'm not sure how well wave functions work with Special Relativity, so I just don't know how to answer that question.

Since the wave functions described the probability of finding a particle (even a large object), according to QM, and the object is length contracted, I would have to assume the wave function describing a particle (or object) has to change with increasing velocity. However, I'm really not clear on what you're asking.

 

[nog]

Thought experiment: take a box travelling close to c. Wouldn't the front of the box appear to be moving away from the observer faster than the back, due to a larger component of its velocity being that which is the moving away(from the observer) part relative to the observer.

A would appear to be moving away from the observer than B.

If you imagine a really big box whose back end was close to the observer, B would hardly be moving away from the observer, but A would be moving away at close to v(the speed of the box).

If you're asking what I think you're asking, yes, A would appear to be moving faster away from the observer than B. This doesn't have any impacts about length contraction, but does affect the appearance of objects moving at close to c. Length contraction happens only along the direction of motion for the object moving regardless of the location of the person observing the situation. There used to be programs online (in the old days of the late 90s) where you could upload an object and see how it changes simply according to relativity and then see how it changes adding it that light takes a finite time to reach you. So it was possible to view sides of objects that normally wouldn't be visible (assuming you were at certain locations, relative to the object, observing the object.

Maybe as a atom omitting a photon oscillates forwards and backwards, it appears to speed up and slow down.....Maybe that would cause the path of the photon to be at an angle, and the observer sees the object magnified?

I dunno, this is just an idea.

I'm sorry, I don't understand the question. I can say that objects change shape based on how fast their going and you can see interesting things.

 

[nog]

maybe I'm wrong, I started off assuming that time dilation caused magnification, because it does with gravity, but perhaps it doesn't with just speed...well length contraction obviously shows that......

I don't think time dilation causes magnification.

Mass warps space-time which changes the paths of EM radiation (like light). So it can have magnifying effect, but this isn't because of time dilation in and of itself.

 

[nog]

One thing I just notice on the Wiki time-dilation page is the working out for the formula about time dilation relies on the assumption that the distance between the two mirror walls, on the moving object, appears the same for all observers.

http://en.wikipedia.org/wiki/Time_d...nce_of_time_dilation_due_to_relative_velocity

The distance between the two walls is L, and based on the assumption that L appears the same distance for all observers, L is used to link the two reference frames.

Is it ok for them to make that assumption?

.

The short answer is yes. The long answer is that there's a derivation that doesn't rely on that assumption, but that's just a convenient example and useful to show that time must slow down with a corresponding length contraction as viewed from an outside observer.

In special relativity, there is only a contraction or change in length along the direction of motion. I'm not familiar with your level of math background, but perhaps the easiest answer is that if an object is moving along the x direction, the velocity will only change the value of the x position. The y and z values are perpendicular to the motion (velocity) and therefor remain constant (there is no mechanism that will change those values).

 

[Blobbenstein]

Yea, I guessed that that proof might not be the main proof.

I tried to work out the equation for contraction myself, but didn't end up with the right one.

Maybe a good way to try to understand it is for someone standing as the observer behind the box, the light path from A is longer so it gives a chance for the box to move forward, and so B appears closer to A when A, and B are seen at the same time.

ie that the light from A must pass through B(on the way back to the observer) at the same time as light leaves B, which gives B a chance to move forward, but maybe that isn't quite a relativistic way to think about it.

 

[FortyTwo]

I'm sorry, I don't understand the question. I can say that objects change shape based on how fast their going and you can see interesting things.

*they're

And now, I can be at peace with the fact that I don't understand half of what you people are talking about because I managed to find one grammatical error and rub it in your face, which is good enough for me.

 

[nog]

*they're

And now, I can be at peace with the fact that I don't understand half of what you people are talking about because I managed to find one grammatical error and rub it in your face, which is good enough for me.

I did type "they're", but it was going so fast it was length contracted and time dilated. That's why it ended up looking like a "their".

 

[FortyTwo]

I'm pretty sure I believe in the Self-Consistency Principle as far as time travel goes. I don't think wormholes are possible for more than a mere moment, and I think teleportation would probably kill you.

When I first made this thread I must not have been in my right mind, because I've now decided teleportation is entirely possible, by way of folding through the fourth dimension.

 

[nog]

When I first made this thread I must not have been in my right mind, because I've now decided teleportation is entirely possible, by way of folding through the fourth dimension.

If time dilation can be considered time travel, I think moving (via any mode, say walking, driving, flying, etc) to a location can be considered teleportation.

Speaking of the fourth dimension, isn't it commonly held that time is the fourth dimension? I'm just not sure what folding through that means.

 

[FortyTwo]

If time dilation can be considered time travel, I think moving (via any mode, say walking, driving, flying, etc) to a location can be considered teleportation.

Speaking of the fourth dimension, isn't it commonly held that time is the fourth dimension? I'm just not sure what folding through that means.

Well, that's one theory. There's another theory that bases itself off space rather than time and I tend to agree with that more.

If a one-dimensional region is a point, and a two-dimensional region is a grid, then the second dimension is made up of an infinite series of first-dimensional areas, on two axes. And an organism living in the second dimension would view things as one-dimensional. They would have no perception of depth aside from an object seemingly growing larger or smaller.

The third dimension is made up of an infinite series of two-dimensional areas. We, as 3D creatures, observe everything in two dimensions, inferring depth only from patterns of light that we recognize.

Imagine an ant on a piece of paper, crawling around. Think of what this looks like from the side, and you have a second-dimensional scenario, like a cross-section of sorts. Now imagine curling the piece of paper into a tube. The ant can go from one end to the other just by walking across the top. To a Flatlander, though, depth does not exist, so they would just see the ant walking to one end of the paper and reappearing on the other, as if by magic. We can observe the effects of this folding through the third dimension because it is second nature to us, but beings that see in one dimension would only see something they would consider teleportation.

The fourth dimension is, by extension, an infinite series of third-dimensional regions. We call this a Tesseract. If we could fold our dimension through the fourth dimension like that piece of paper we could get from one place to another in no time with no time delay or apparent effects on our universe.

Hypothetically.

 

[nog]

Well, I think time is typically held as the fourth dimension. I'm aware of other models, hypotheses, and conjectures (not theories ) that there are more spatial dimensions than just the 3 we're commonly aware of, but there is no evidence.

Interestingly, a lot of the ideas I've read about talk about more spatial dimensions, not temporal dimensions. I guess seeing as there are 3 spatial dimensions we can always use the analogies of 2 dimensional creatures vs 3-D creatures. With time though, it's not clear what having more temporal dimensions means.

I'd still like to see more understanding into what time and space actually mean.

So, I've wondered if time has 3 dimensions, but we're only aware of the t where it equals the square root of (tx^2 + ty^2 + tz^2).

 

[Blobbenstein]

time having more than one dimension means that you can be on time for an appointment however late you are.

 

[FortyTwo]

I don't think time exists though, aside from our own memories and our own plans for the future, so time being the fourth dimension doesn't make sense to me.

And yes it is an alternate theory, though I suppose "model" makes more sense in context.

The one you're thinking of states that the first dimension is only a point, the second dimension is a grid of points, the third dimension is a series of grids, the fourth dimension is every state that the series of grids has ever been in (i.e. the continuum of time), the fifth dimension is an infinite series of possible fourth-dimensional areas (parallel continuums with differences based on "our choices" though that is such a gross misunderstanding of the concept that it makes me cringe whenever it is used - personally, I think taking living things into special consideration is ridiculous and if we take our choices into account as affecting the outcome of a universe then we must also consider the movements and interactions of nonliving things and all of matter in general, which means that, if parallel universes do exist in this context, there is one for every single physically possible organization and outcome of the Universe, right down to the very quark of every bit of matter in existence as well as its interaction with the lesser-understood "antimatter" and "dark matter" [the classification of which is debatable as you have mentioned], but I digress), the sixth dimension contains all possible fifth-dimensional sets, and so on, until the tenth dimension, which is basically as far as we can go because it contains everything that ever is, was, could be, would be, will be, and wasn't.

I think this system is fun in theory, but only in theory because it has a serious flaw - for the fourth dimension it jumps from using space as an indicator to trying to tie time in, which doesn't make sense because time is just something we imagine in our heads. That's why I think the tesseract model of the fourth dimension makes more sense.

 

[nog]

I don't think time exists though, aside from our own memories and our own plans for the future, so time being the fourth dimension doesn't make sense to me.

Huh. I'm unable to see how time couldn't exist. I can see people not thinking it isn't like what we think it is, but... I'm just at a loss on that one.



And yes it is an alternate theory, though I suppose "model" makes more sense in context.

The one you're thinking of states that the first dimension is only a point, the second dimension is a grid of points, the third dimension is a series of grids, the fourth dimension is every state that the series of grids has ever been in (i.e. the continuum of time), the fifth dimension is an infinite series of possible fourth-dimensional area

I think you're wrong about the 5th Dimension.

http://en.wikipedia.org/wiki/The_5th_Dimension

(parallel continuums with differences based on "our choices" though that is such a gross misunderstanding of the concept that it makes me cringe whenever it is used - personally, I think taking living things into special consideration is ridiculous and if we take our choices into account as affecting the outcome of a universe then we must also consider the movements and interactions of nonliving things and all of matter in general, which means that, if parallel universes do exist in this context, there is one for every single physically possible organization and outcome of the Universe, right down to the very quark of every bit of matter in existence as well as its interaction with the lesser-understood "antimatter" and "dark matter" [the classification of which is debatable as you have mentioned], but I digress), the sixth dimension contains all possible fifth-dimensional sets, and so on, until the tenth dimension, which is basically as far as we can go because it contains everything that ever is, was, could be, would be, will be, and wasn't.

I think this system is fun in theory, but only in theory because it has a serious flaw - for the fourth dimension it jumps from using space as an indicator to trying to tie time in, which doesn't make sense because time is just something we imagine in our heads. That's why I think the tesseract model of the fourth dimension makes more sense.

I don't know what that means either. Do we have examples of 4 dimensional objects, such as a tesseract?

I think the idea of parallel universes makes for okay/mildly interesting sci-fi, but that's about it for me. Without some kind of evidence, I'm simply at a loss with that.