On time travel

[Steakpirate]

What are your opinions on Time Travel?

 

I think that there may be room in the space time continuum for multiple layers (rather than that, each action creating a new universe bull-plop.)

 

What do I mean? That if you went back in time and stabbed yourself in the throat, you would still have been born and traveled through time to stab yourself in the throat, but that from that point on in your life (well rather, in the history of the world, as you are dead,) history would account for your death. I believe that the You who traveled back in time to do the initial throat-stabbing would still exist, but were you to return to your own time period, things would be vastly altered.

 

So long as you were not the original inventor of the time machine, or at least you remembered how to construct one, I think that you might then be able to travel back in time and stab yourself in the throat before he could stab the younger you in the throat. You would have both a traumatic childhood (that you wouldn't remember), and a bizarre experience that isn't true for anyone else.

 

Commence the poking of plot-holes.

[Steve E]

Sounds a bit like Everett's take on the Many-worlds interpretation of quantum physics. I prefer Kaku's take on hyper-temporal M-Theory. Similar but different.

 

American theoretical physicist (and string theory pioneer) Dr. Michio Kaku takes an 11-dimensional view of space-time. But lets simplify it to 5 dimensions, making our universe a great big 4-dimensional bubble expanding into the fifth dimension. On the surface of the bubble is all the (3-dimensional) matter and energy of the universe. The bubble started off as a point and then expanded in the (radial) temporal dimension. Which is to say, the measure of the radius of the bubble is the age of the universe.

 

So what does this have to do with time travel? Simple: there isn't just one bubble. There are tangential bubbles (where the membranes touch) and there are concentric bubbles (where they don't). The seed of our universe, according to some, is in a constant state of Big Banging. Whole universes, largely identical, separated only in the temporal dimension. (There is no rule that says the Big Bang happened only once. In a 5-dimensional universe it could be going on all the time.)

 

This is a Many-worlds set-up for time travel. You drill down into the past, into an alternate universe. The mass of our universe isn't there, it has moved on, forward in time/space. But a similar (perhaps identical) arrangement of matter exists there (maybe). This is more like hyper-dimensional space travel than time travel, but the result is the same except that there is no paradox. Anything you do in that other universe (even initiating the Grandfather Paradox) has no effect on your home universe.

 

So how do we do it? By knocking everything down another dimension we can use a geometric example. Bubbles become expanding circles. Traveling along the curve of a circle is traveling within your universe. Measure the length of the arc and the expansion of the circle during the arc's progress and you have a distance and a time—speed. Increase your speed to a point where you are moving faster than your circle is expanding and you form a cord. The center part of the cord is closer to the center of the circle than it's ends. In short, you've traveled back in time by moving in the right direction at a speed that exceeds the circle's expansion.

 

Take this with a pinch of salt. It's still pretty speculative, and to be fair, I've simplified it a lot. The math quickly gets daunting and then stupefying. But it's not the sort of detail fiction writers need to worry about. Hard sci-fi writer Larry Niven wrote about alternate universe time travel back in 1973 in his collection The Flight Of The Horse. There the protagonist used a time-traveling egg.

 

(I use the wristwatch version. Just €34.99 at Target in the 25th Century.)

-Thoth.

[Steakpirate]

Sounds a bit like Everett's take on the Many-worlds interpretation of quantum physics. I prefer Kaku's take on hyper-temporal M-Theory. Similar but different.

 

American theoretical physicist (and string theory pioneer) Dr. Michio Kaku takes an 11-dimensional view of space-time. But lets simplify it to 5 dimensions, making our universe a great big 4-dimensional bubble expanding into the fifth dimension. On the surface of the bubble is all the (3-dimensional) matter and energy of the universe. The bubble started off as a point and then expanded in the (radial) temporal dimension. Which is to say, the measure of the radius of the bubble is the age of the universe.

 

So what does this have to do with time travel? Simple: there isn't just one bubble. There are tangential bubbles (where the membranes touch) and there are concentric bubbles (where they don't). The seed of our universe, according to some, is in a constant state of Big Banging. Whole universes, largely identical, separated only in the temporal dimension. (There is no rule that says the Big Bang happened only once. In a 5-dimensional universe it could be going on all the time.)

 

This is a Many-worlds set-up for time travel. You drill down into the past, into an alternate universe. The mass of our universe isn't there, it has moved on, forward in time/space. But a similar (perhaps identical) arrangement of matter exists there (maybe). This is more like hyper-dimensional space travel than time travel, but the result is the same except that there is no paradox. Anything you do in that other universe (even initiating the Grandfather Paradox) has no effect on your home universe.

 

So how do we do it? By knocking everything down another dimension we can use a geometric example. Bubbles become expanding circles. Traveling along the curve of a circle is traveling within your universe. Measure the length of the arc and the expansion of the circle during the arc's progress and you have a distance and a time—speed. Increase your speed to a point where you are moving faster than your circle is expanding and you form a cord. The center part of the cord is closer to the center of the circle than it's ends. In short, you've traveled back in time by moving in the right direction at a speed that exceeds the circle's expansion.

 

Take this with a pinch of salt. It's still pretty speculative, and to be fair, I've simplified it a lot. The math quickly gets daunting and then stupefying. But it's not the sort of detail fiction writers need to worry about. Hard sci-fi writer Larry Niven wrote about alternate universe time travel back in 1973 in his collection The Flight Of The Horse. There the protagonist used a time-traveling egg.

 

(I use the wristwatch version. Just €34.99 at Target in the 25th Century.)

-Thoth.

 

That's actually one of the most reasonable theories I've heard as far as being close to my general perception of things. It has a sad feeling to it sort of as, any way you look at it, it's not really your home and you're not going back. If you are it's to the exact point you left from, and how do you know it's still your world? Feels very planet of the apes. (Though I haven't actually seen it.

[Steve E]

It has a sad feeling to it sort of as, any way you look at it, it's not really your home and you're not going back.

Since you're drilling down to a smaller bubble, one with a smaller radius, it is, relative to you, in your past. True, it's not your home, and an alternate version of you would be there (unless it too went back in time), but it would be close enough, give or take quantum fluctuation effects. (So winning the lottery might be out of the question except in high probably games.)

 

If you are it's to the exact point you left from, and how do you know it's still your world?

Again, not the same point in time and probably not the same point in space (unless you've been traveling in circles). Remember, both alternate universe bubbles are expanding continuously. You can never return to the time you departed unless it's is in fact a different universe/bubble than the one you originally left.

 

Feels very planet of the apes. (Though I haven't actually seen it.

Wait. You've never seen Planet of the Apes or its numerous sequels? Shocking. But given your clean palette, consider reading the Pierre Boulle novel instead (La Planète des singes (1963)). The Xan Fielding translation is called Monkey Planet. Much more dystopian.

 

-Thoth.

[Steakpirate]

Since you're drilling down to a smaller bubble, one with a smaller radius, it is, relative to you, in your past. True, it's not your home, and an alternate version of you would be there (unless it too went back in time), but it would be close enough, give or take quantum fluctuation effects. (So winning the lottery might be out of the question except in high probably games.)

 

 

Again, not the same point in time and probably not the same point in space (unless you've been traveling in circles). Remember, both alternate universe bubbles are expanding continuously. You can never return to the time you departed unless it's is in fact a different universe/bubble than the one you originally left.

 

 

Wait. You've never seen Planet of the Apes or its numerous sequels? Shocking. But given your clean palette, consider reading the Pierre Boulle novel instead (La Planète des singes (1963)). The Xan Fielding translation is called Monkey Planet. Much more dystopian.

 

-Thoth.

 

I would say that depends on your method of transit. Everyone speculates on the nature of time, but not the method in which you would traverse it. Who's to say that a theoretical time machine could not move in a straight line, or in three dimensions to account for bubular drift?

[Steakpirate]

American theoretical physicist (and string theory pioneer) Dr. Michio Kaku takes an 11-dimensional view of space-time. But lets simplify it to 5 dimensions, making our universe a great big 4-dimensional bubble expanding into the fifth dimension. On the surface of the bubble is all the (3-dimensional) matter and energy of the universe. The bubble started off as a point and then expanded in the (radial) temporal dimension. Which is to say, the measure of the radius of the bubble is the age of the universe.

 

If the bubble is "Expanding" into that 5th dimension, what happens when our layer of the bubble is finally inside of that 5th dimension?

 

Do these bubbles have a structure, and would time travel affect the structural integrity of said bubbles?

 

So what does this have to do with time travel? Simple: there isn't just one bubble. There are tangential bubbles (where the membranes touch) and there are concentric bubbles (where they don't). The seed of our universe, according to some, is in a constant state of Big Banging. Whole universes, largely identical, separated only in the temporal dimension. (There is no rule that says the Big Bang happened only once. In a 5-dimensional universe it could be going on all the time.)

 

What would be the effect of the membranes touching, and what is to stop them from merging as they grow?

[Steve E]

If the bubble is "Expanding" into that 5th dimension, what happens when our layer of the bubble is finally inside of that 5th dimension?

As the bubble gets bigger the surface of the bubble (where we live) is moving forward in time (i.e., the surface is moving away from its center). Its center doesn't move at all (probably). It is always in the 5th dimension (as well as the 4th, 3rd, 2nd, and 1st), the same way a normal balloon remains in the 3rd, 2nd and 1st dimension as we blow it up and it gets bigger. So it doesn't "enter" the 5th dimension. It's already there.

 

Do these bubbles have a structure, and would time travel affect the structural integrity of said bubbles?

In terms of structure, the bubbles are bubble-shaped, in a multi-dimensional way. Beyond that, I can't really help you. It's not my theory and the math hurts my head.

 

What would be the effect of the membranes touching, and what is to stop them from merging as they grow?

The concentric bubble membranes all expand at the same speed (or so the theory goes) so they never touch. This "must" be true because if it were not then one universe would eventually sweep into and through all the others creating all kinds of havoc as stuff from one universe crashed into other stuff from another universe and then disappeared into the future. But Dr Kaku allows for multiple sets of non-concentric expanding bubbles as well, which is why we're working in 5 dimensions. It gives each set of bubbles ("M-branes" the physicists call them) a chance to be nudged in a direction (other than time) by the outermost bubble. Trust me, you wouldn't want to live in that particular universe, since where one bubble impinged on another you could travel between alternate universes in ordinary 3D space.

 

To be blunt, this whole M-brane thing is cutting edge and is still being hotly debated by brains way bigger than mine. Its implications (of multiple expanding 11 dimensional universes) haven't turned up any serious inconsistencies but none of this is yet canon (so to speak).

 

Such is the world of theoretical physics. H.G.Wells had it easy.

-Thoth.

[Steakpirate]

Hmm. I think I've got a handle on it now.

That still leaves the first part of my double-post.

 

I would say that depends on your method of transit. Everyone speculates on the nature of time, but not the method in which you would traverse it. Who's to say that a theoretical time machine could not move in a straight line, or in three dimensions to account for bubular drift?

 

If there is a membrane that would suggest that each universe is suspended inside of something, some sort of ethereal time-goo.

And in any-case, what if you could, rather than move yourself through the bubble, manipulate an individual layer and it's progress through said time-goop?

Would physically pushing it downwards and towards the previous layer of the universe alter time in the present universe?

 

And then there's the question of which layer of the bubble we'd be on, and that would suggest that time HAS to end, because there must be an edge to the bubble, unless we are arrogant enough to assume that we're on top. And if we were on top, would attempting to travel into the future shift us outside of the bubble?

 

 

This whole thing sort of reminds me of my solution to the Big Crunch.

[Steve E]

I would say that depends on your method of transit. Everyone speculates on the nature of time, but not the method in which you would traverse it. Who's to say that a theoretical time machine could not move in a straight line, or in three dimensions to account for bubular drift?

The bubble doesn't drift, it expands. That expansion is what we experience as time. It doesn't matter if the time machine "moves" in a straight line. The bubble of your universe continues to expand even if you're exploring another universe. You cannot return (in this theory) to the time you left since that time (represented by a distance from the surface of a bubble to its center) is no longer occupied by your original bubble. That "time" might be empty (containing no universe) or occupied by a different universe that has expanded into it. But you can return to your own universe, just a slightly future universe.

 

Of course there is no reason to assume we were the first Big Bang and, hence, the outer bubble.

 

I don't quite follow what you mean by the bubble having an "edge". All the bubbles (which we live on not in) are all expanding at the same time, one within the other. Just think of all the matter in the universe as the colorful slime on the surface of a soap bubble and you'll get the idea.

 

For further reading, may I suggest: Physics of the Impossible, Parallel Worlds, Introduction to Superstrings and M-Theory, or Hyperspace. All are pretty readable.

 

-Thoth

[Steakpirate]

The bubble doesn't drift, it expands. That expansion is what we experience as time. It doesn't matter if the time machine "moves" in a straight line. The bubble of your universe continues to expand even if you're exploring another universe. You cannot return (in this theory) to the time you left since that time (represented by a distance from the surface of a bubble to its center) is no longer occupied by your original bubble. That "time" might be empty (containing no universe) or occupied by a different universe that has expanded into it. But you can return to your own universe, just a slightly future universe.

 

Of course there is no reason to assume we were the first Big Bang and, hence, the outer bubble.

 

I don't quite follow what you mean by the bubble having an "edge". All the bubbles (which we live on not in) are all expanding at the same time, one within the other. Just think of all the matter in the universe as the colorful slime on the surface of a soap bubble and you'll get the idea.

 

For further reading, may I suggest: Physics of the Impossible, Parallel Worlds, Introduction to Superstrings and M-Theory, or Hyperspace. All are pretty readable.

 

-Thoth

 

So you're saying that this universe only exists in one point in time, and that as you travel in either direction far enough you meet another version of our universe, which without outside influence would accurately reflect our past or future. (Which is why you wouldn't be able to simply determine the rate at which your universe moves and return to the same point you left.)

Although if the event "seeding" these universes, as you put it, is not constant in every way imaginable for each burst, then traveling back in time could be much a difference as traveling to another time-bubble.

 

In that case, you'd have to do a lot of calculation beforehand if you want to end up in the right universe again.

(Perhaps by judging the distance of temporal markers that through the same mechanics of the time machine, maintain the universe's relative position at the time of their deployment, and calculate the rate at which the universe moves through time. But I digress)

 

And by the edge I meant the end of the bubble, outside of which, time would theoretically not exist.

 

I don't know how inter-bubular travel would be possible in a timeless environment, it might be as simple as throwing a spaceship out of a time bubble and having the momentum carry you to your destination in the alternate time-bubble,but certainly if our bubble is expanding into said absence of time, it is physically possible.

 

It would be interesting to know if gravity and the like are then bound to a universe by some means (and so you wouldn't be able to orbit a supermassive planet that no longer exists)

 

 

Oh, and one more thing... If this theory were true, than wouldn't traveling close to light speed, rather than slowing down the localized time in comparison to the rest of the universe, mean that you are traveling so fast that somehow time around you is manipulated, and you are caught up in either the next or previous universe?

 

If so, how would super-fast travel alter what layer of the bubble you are on? That requires the "substance" of time to permeate the universe in a near tangible form, in order for you to somehow become slowed down or tangled up in it (much as traveling right before you break the sound barrier). I guess that's why traveling at the speed of light would be in essence time travel.

 

It's wouldn't be that you can't travel faster than light, it's would be that doing so would cause you to travel through space faster than time itself moves. And as retarded as it sounds, wouldn't that mean that time travels at 300,000km/s/s? (And that light therefore travels instantaneously)

 

And in the case that time is in any way tangible means that manipulation of time in a localized field would be possible without motion, and time travel would work

 

I have to apologize though, sometimes I get caught up in things and theorize with information that I mis-analyze .

[Steve E]

So you're saying that this universe only exists in one point in time...

No. Its expansion moves the bubble's surface (which is our universe) outward in the temporal dimension. And I'm not the one saying it.

 

...and that as you travel in either direction far enough [in the temporal direction, which is orthogonal to our universe] you meet another version of our universe, which without outside influence would accurately reflect our past or future.

Yes. The underlying idea here is that one Big Bang is very much like another.

 

Which is why you wouldn't be able to simply determine the rate at which your universe moves and return to the same point you left.

No. The reason you can't return to the moment you left is because your universe is no longer in that moment. That is, all the matter of your universe has expanded past that point. Nothing is occupying it now. Or, perhaps, another universe has expanded into that position. Okay, here's the problem: ever since the invention of motion picture film people have gotten the idea that we (our very mass) exists at every point in time, like frames in a strip of photographic film. There is absolutely no scientific evidence or theory to support such an idea. All the evidence supports matter (i.e. particles) being three dimensional and moving through a forth (temporal) dimension. String Theory (the precursor to M-theory) expands the number of dimensions for matter but not into time.

 

Although if the event "seeding" these universes, as you put it, is not constant in every way imaginable for each burst, then traveling back in time could be much a difference as traveling to another time-bubble.

In this theory, traveling through time is traveling from your universe/bubble to another bigger or smaller (concentric) bubble. But yes, a Big Bang with different parameters would create a very different kind of universe. But (see above) it is assumed that every "seed" generates multiple identical Big Bangs. But lets face it; who knows? If the universes start substantially different then the difference between will be more than appearing to be the past or future.

 

In that case, you'd have to do a lot of calculation beforehand if you want to end up in the right universe again.

(Perhaps by judging the distance of temporal markers that through the same mechanics of the time machine, maintain the universe's relative position at the time of their deployment, and calculate the rate at which the universe moves through time. But I digress)

Sure. Why not.

 

And by the edge I meant the end of the bubble, outside of which, time would theoretically not exist.

And by "end of the bubble" I assume you mean it's surface. Beyond which is the still in a direction away from the center of the bubble so it is forward in time. Time here is a dimension and its existence is completely independent of any given bubble. However, if you mean the "space" between the outer surface of one bubble and the inner surface of the next bubble, there wouldn't be a universe (i.e., matter and energy) there but there would still be time.

 

I don't know how inter-bubular travel would be possible in a timeless environment...

Again. There would be time, and therefore motion. (I love that word, "bubular".) As to how it would actually be done? your guess is as good as mine but Einstein suggests time travel could be accomplished through speed or traveling through a wormhole (i.e., across an Einstein-Rosen Bridge).

 

It would be interesting to know if gravity and the like are then bound to a universe by some means (and so you wouldn't be able to orbit a supermassive planet that no longer exists).

This is just a guess but I'd think that without mass there would be no gravity, between bubbles. But (and here we go again) if gravity isn't due to the exchange of gravitons (possibly Higgs Bosons) and is a consequence of the shape of n-space, then maybe we'd find supergravity between bubbles. Then again, maybe not. We're flying blind here.

 

Oh, and one more thing... If this theory were true, than wouldn't traveling close to light speed, rather than slowing down the localized time in comparison to the rest of the universe, mean that you are traveling so fast that somehow time around you is manipulated, and you are caught up in either the next or previous universe?

Moving FTL could move you out of your bubble. Beyond that we're just guessing.

 

If so, how would super-fast travel alter what layer of the bubble you are on? That requires the "substance" of time to permeate the universe in a near tangible form, in order for you to somehow become slowed down or tangled up in it (much as traveling right before you break the sound barrier). I guess that's why traveling at the speed of light would be in essence time travel.

Okay. Again, in this theory (and most) time is a dimension and therefore has no "substance". It's just a measurement. A direction. The whole "permeating aether" thing has pretty much been dropped by modern physics. But who knows, maybe it's due for a comeback.

 

It's wouldn't be that you can't travel faster than light, it's would be that doing so would cause you to travel through space faster than time itself moves.

Can't move faster than light because you'd move in time. Interesting.

 

And as retarded as it sounds, wouldn't that mean that time travels at 300,000km/s/s? (And that light therefore travels instantaneously)

The speed of light might indeed be determined by the rate of bubble expansion. (And no.)

 

And in the case that time is in any way tangible means that manipulation of time in a localized field would be possible without motion, and time travel would work

Okay, now we've moved completely away from Einstein, Everett and Kaku and are exploring the Theories of Steakpirate. And why not.

 

I have to apologize though, sometimes I get caught up in things and theorize with information that I mis-analyze .

Noted. Apology completely accepted. I'm sure I've done the same myself.

-Thoth.