Help about time/interuniversal travel theories.

[Kain]

I'm making a sci-fi story, where a man travels with a time machine back to where the Solar System was still formed, but his presence there disturbed the movement of some particles because of his vessel's gravity, which somehow resulted to the Dinosaur extinction never happening with an asteroid (instead the asteroid crashed on the dark side of the Moon), but slower because of intense volcanic activity, giving time to dinosaurs to evolve into a civilization of bird like creatures. As time passes and he tries to undo the damage to the timeline, he discovers that his machine does not actually travel only in time, but also between different Universes, or timelines if you will, making an Interuniversal Machine, or Multiverse Machine or whatever.

But I try to make the story as realistic and informative about the newest theories as it possibly could be. My biggest problem is how the machine travels in time and in the Multiverse.

I thought of having the machine somehow follow "streams" of gravity, since gravity extends to more than 3 dimensions and it could interact with other Universes, but as far as I know it does not travel through time.

Then I thought of the oldest trick in the book, the Wormholes. The machine detects a wormhole it could travel through and it leads to the desirable point in time, and then increasing the wormhole's size enough for the machine to enter it. But as far as I know, wormholes are not supposed to connect different Universes.

So I'm at a loss. All I know about physics is from mostly outdated documentaries, so if I understood something wrong, you are free to correct me. But mostly I want your opinion of what method I could use that could fool the scientists who created the machine into thinking it's only a time machine, when it can actually travel also between different timelines, making it also an interuniversal machine.

And, while you're at it, there is something I don't understand about th whole concept. If someone travels to the past or to another Universe, there would be a number of information (meaning mass and energy) suddenly dissapearing from the Universe at the starting point, and a number of information suddenly appearing out of nowhere to the destination. I know from relativity that mass can turn into energy and vice versa, but as far as I know the total amount of information in our Universe cannot be changed, meaning that no mass or energy can actually exit the Universe.

I know about the Hawking Paradox, where Stephen Hawking had a theory that information can, indeed, disappear from the Universe when a Black Hole collapses and disappears, but if I'm not mistaken his theory was disproved by a friend/"opponent" of his, with whom he has made a bet about that a long time ago.

If someone could help me with this concept, it would be greatly appreciated. Also, if I'm wrong at something, you are free to correct me.

 

[sojourner]

Not sure about the first part, but as to the whole information issue, there is no problem. The information stays in the universe regardless of what point in the timeline you place it at.

 

[Kain]

I see. So the total of information applies in all dimensions, and not only the spacial ones, meaning that the total of information refers to the total of information that has always been in the Universe. But what if you actually travel to another Universe? Some say that mass and/or energy from that Universe will be transferred to ours to fill the gap you leave behind as you leave our Universe. But what do we actually know about that matter? What do the recent theories say about this? That's what I want to know. I know I'm tapping the boundaries of known science here, but I want to understand as much as I can about the subject.

 

[trekkiedane]

But I try to make the story as realistic and informative about the newest theories as it possibly could be. My biggest problem is how the machine travels in time and in the Multiverse.

If a yet undescribed force emanating from the sun can effect the rate of radioactive decay on Earth, why not let it also have an effect on this 'time machine' of yours? - Neutrinos interacting with the fantasy-part of the time machine is as good a contemporary SciFi-trick as warping space was back when.

I thought of having the machine somehow follow "streams" of gravity, since gravity extends to more than 3 dimensions and it could interact with other Universes, but as far as I know it does not travel through time.

If the universe -as we know it- is a vibrating plane existing alongside other ('parallel') universes in some inter-universal medium and they sometimes bump into each other, this point of contact between two universes could be where your guy moves from one to another.
Especially since time -again: as we know it- takes on a whole new meaning; one time in one universe-go to another universe and then take a different route back to the first one -but in a different position (x-y-z-and time)

ETA:
Some light reading:
Membrane (M-Theory)
Introduction to M-theory
The strange case of solar flares and radioactive elements

 

[YellowSubmarine]

Any theory on time travel, multiple universes or additional spatial dimensions isn't scientific, only speculative. I wouldn't care that much realism.

 

[Christopher]

I see. So the total of information applies in all dimensions, and not only the spacial ones, meaning that the total of information refers to the total of information that has always been in the Universe. But what if you actually travel to another Universe? Some say that mass and/or energy from that Universe will be transferred to ours to fill the gap you leave behind as you leave our Universe. But what do we actually know about that matter? What do the recent theories say about this? That's what I want to know. I know I'm tapping the boundaries of known science here, but I want to understand as much as I can about the subject.

Any two spacetime domains that are connected and interacting must be treated as components of the same total system or "universe," even if that "universe" encompasses multiple quantum timelines, spacetime continua, or whatever. So the conservation laws apply to the total system and all the parts of it that are interacting.

It's common sense, really. All a conservation law says is that you can't get something from nothing, or have something spontaneously vanish into nothing. If a system is closed, then the amount of mass/energy in it is a constant. However, if that system becomes open, if it is connected to some other system, then it has a means of gaining or losing mass and energy. A conservation law applies to a closed system, not an open one. Those two or more connected systems can exchange mass, energy, or information. But in the larger, closed system encompassing those connected systems, the total mass/energy/information must still remain constant.

(And let's be clear on the difference between a timeline and a universe. Despite sloppy usage in fiction, a reality where the Sol system and Earth exist but history has unfolded differently is not a separate universe, just a separate timeline, a separate quantum state of our universe. Technically, it's an independent measurement history. A different universe would be literally that, a physically distinct continuum in a physically different place, with its own separate galaxies, stars, planets, species, etc. -- if it even had the same laws of physics at all.)

Any theory on time travel, multiple universes or additional spatial dimensions isn't scientific, only speculative. I wouldn't care that much realism.

That's not remotely true. There's actually quite a lot of theoretical physics on all those subjects. General Relativity provides for the theoretical possibility of closed timelike curves, i.e. time travel, a possibility that arises directly and rigorously from its equations. The Everett relative state formulation of quantum mechanics leads with mathematical rigor to the premise that the universe may contain multiple independent histories. And the concept of additional spatial dimensions has been basic to many unified physics theories from Kaluza-Klein theory to M-theory. Just because something isn't proven to exist doesn't mean it hasn't been theorized about in considerable detail. Science isn't just about what we already know to exist. The whole point of science is to go beyond the limits of existing knowledge and develop testable predictions and extrapolations into the unknown.

Heck, I just finished writing a novel that's all about time travel (Star Trek: DTI: Watching the Clock), and I researched a ton of scientific theory and learned a lot about the universe in the process.

 

[Kain]

Thanks everyone, the last posts were extremely informative. Also, thanks for correcting me about different timelines being different Universes. It also never crossed my mind that two Universes that came in contact once with such a machine will stay connected because of a constant exchange of mass/energy and become part of the same system.

My intent on the development of the story is that mankind creates a time machine, a time traveller goes back to the creation of the Solar system, his gravity produces a timeline where there is a civilization of birds on Earth, instead of humans. He is crash-landing so the machine gets mostly destroyed, but uses the memory banks and a computer made from the surviving parts of the machine to give new technology to the birds, so that they remake the time machine and he returns to the past to undo, somehow, the change that produced this timeline. The birds understand his motives, and fear that if he succeeds their timeline will cease to exist, so they imprison him and continue developing their technology rapidly, until they indeed remake the time machine. He escapes and steals it, but he is at a dillema, of whether it would be right to destroy another timeline to protect his own, until he discovers that his time machine can also travel between existing timelines, and not only in time, so both timelines could exist simultaneously, and the existence of one does not mean the disappearance of the other. So he decides to start exploring the different civilisations that exist in more and more distant and different timelines, reaching even timelines where the laws of physics are different because of slightly different development of the Universe shortly after the Big Bang.

I want my comic (I forgot to mention it will be a comic) to be as scientifically correct and informative as a comic with such a storyline could possibly be.

If the universe -as we know it- is a vibrating plane existing alongside other ('parallel') universes in some inter-universal medium and they sometimes bump into each other, this point of contact between two universes could be where your guy moves from one to another.
Especially since time -again: as we know it- takes on a whole new meaning; one time in one universe-go to another universe and then take a different route back to the first one -but in a different position (x-y-z-and time)

Would that not need you to travel back in time to the other Universe? I don't think I fully understand, but that gave me an idea. What if I make the machine travel, somehow, to all possible dimensions, both in space and time, but let the traveller discover later that by travelling in a direction of more that 3 dimensions can take him to another timeline? Or do I once more mistake a timeline for a Universe? I'm confused! That could work, somehow, because every change he makes in the timeline could just slightly change the multi-dimensional direction the machine is facing so that when he attempts to return, he will go to the timeline his change caused to exist.

Man, this is REALLY confusing. I will have to put a lot of work to this project to make it work. And I intend to. No wonder, though, since confusion is what you get when you try to reach the verge of known science and theories... It's worth the trouble, though.

 

[trekkiedane]

If the universe -as we know it- is a vibrating plane existing alongside other ('parallel') universes in some inter-universal medium and they sometimes bump into each other, this point of contact between two universes could be where your guy moves from one to another.
Especially since time -again: as we know it- takes on a whole new meaning; one time in one universe-go to another universe and then take a different route back to the first one -but in a different position (x-y-z-and time)

Would that not need you to travel back in time to the other Universe? I don't think I fully understand, but that gave me an idea. What if I make the machine travel, somehow, to all possible dimensions, both in space and time, but let the traveller discover later that by travelling in a direction of more that 3 dimensions can take him to another timeline? Or do I once more mistake a timeline for a Universe? I'm confused! That could work, somehow, because every change he makes in the timeline could just slightly change the multi-dimensional direction the machine is facing so that when he attempts to return, he will go to the timeline his change caused to exist.

What I was thinking (and I know nothing, whatsoever, of M-theory) was that if our entire 'universe' from the Big Bang to the Big Chill exists as a (mem)'brane' (I got it wrong in my previous post and called it a 'plane') and other 'universes' exist alongside it, any place (in time and space! (that's my point!)) in one brane would be able to contact any other place (also in time and space) in another brane... moving from the here and now in this brane into another is the tricky part, but once done it should be possible to move from that other brane to any place (in time and space) in this one. -Voila, a 'time machine'!

 

[Christopher]

Sounds like you're talking about something similar to what's discussed here:

http://www.analogsf.com/0610/altview.shtml

 

[trekkiedane]

Sounds like you're talking about something similar to what's discussed here:

http://www.analogsf.com/0610/altview.shtml

Yes, sounds remarkably like something like that. I find it even more remarkable that the secret life of the Nelutrino seems to be involved somehow...

The strange case of solar flares and radioactive elements

 

[YellowSubmarine]

That's not remotely true. There's actually quite a lot of theoretical physics on all those subjects. General Relativity provides for the theoretical possibility of closed timelike curves, i.e. time travel, a possibility that arises directly and rigorously from its equations.

If you have no empirical evidence backing those possibilities it's not science, just a funky application of several math equations. General Relativity might predict a lot of the world around us correctly, but that doesn't mean that it's complete, nor that every part of it applies to the physical world allowing you to extrapolate the results in all directions. There is still a part of it that's just math, not physics, and until someone makes an experiment to test it – it will remain this way.

 

[Kain]

That's not remotely true. There's actually quite a lot of theoretical physics on all those subjects. General Relativity provides for the theoretical possibility of closed timelike curves, i.e. time travel, a possibility that arises directly and rigorously from its equations.

If you have no empirical evidence backing those possibilities it's not science, just a funky application of several math equations. General Relativity might predict a lot of the world around us correctly, but that doesn't mean that it's complete, nor that every part of it applies to the physical world allowing you to extrapolate the results in all directions. There is still a part of it that's just math, not physics, and until someone makes an experiment to test it – it will remain this way.

Do we have to go there? I don't want this to become an "Evolution: Theory or fact" topic...

 

[Corwwyn]

Any theory on time travel, multiple universes or additional spatial dimensions isn't scientific, only speculative. I wouldn't care that much realism.

That's not remotely true. There's actually quite a lot of theoretical physics on all those subjects. General Relativity provides for the theoretical possibility of closed timelike curves, i.e. time travel, a possibility that arises directly and rigorously from its equations.

You cannot have gone where you have not been.

 

[Christopher]

If you have no empirical evidence backing those possibilities it's not science, just a funky application of several math equations.

Have you ever looked up the word "science?" You clearly have no idea what it means.

Besides, your objection is irrelevant to this particular topic. You were claiming that if something is not completely proven, there's no point in bothering with realism. That's not true. There's a whole expansive genre called hard science fiction that's dedicated to exploring speculative scientific possibilities -- yes, including time travel and interuniversal travel -- in a way that is as realistic, as solidly grounded in known science, as possible. I've read it; I've written it; it exists. And if Kain wants to write a story about time travel that's rooted in hard science, then Kain is in excellent company and has every right to do it that way.

 

[YellowSubmarine]

Have you ever looked up the word "science?" You clearly have no idea what it means.

Science (from the Latin scientia, meaning "knowledge") is, in its broadest sense, any systematic knowledge that is capable of resulting in a correct prediction or reliable outcome.

In case of physics, this means that if you don't have testable predictions, you don't have any real science going on, just speculations and fancy math.

And, yes, it is relevant to the topic, because the GR equations don't say almost anything specific about time travel. If one needs real guidance, he would have to look into so-called theories that are completely speculative that are suggested above. So one might as well invent their own, or even adapt the time travel rules used in Star Trek. It's all the same.

The important thing is to devise rules, and then make certain that you follow them. But it's not that essential what the rules are because there isn't any set of rules supported by scientific evidence.

Yes, using established science when applying your rules is important. For example, if you have faster-than-light travel, GR dictates that in a battle with projectiles travelling faster than light (like in TOS “The Changeling”), you'd experience time travel paradoxes.

However, there is any science that you can use to resolve those paradoxes, and there isn't any science that explains how multiple universes interact with each other, so writing your own rules is better because you can make them fit the story.

 

[Christopher]

In case of physics, this means that if you don't have testable predictions, you don't have any real science going on, just speculations and fancy math.

There are testable predictions here, and some of them have been tested. It's not speculation; it's solid extrapolation FROM hard evidence to a broader theory that makes the predictions.

And, yes, it is relevant to the topic, because the GR equations don't say almost anything specific about time travel.

You're completely wrong about that. Frank Tipler demonstrated in 1974 how the equations of General Relativity predict closed timelike curves, and there's been extensive theoretical work on the topic ever since by Hawking, Thorne, Novikov, and other physicists. I'm talking, mind you, about papers I actually read during my research for the novel I just finished two days ago. So it's pretty ridiculous for you to tell me that they don't exist.

If one needs real guidance, he would have to look into so-called theories that are completely speculative that are suggested above. So one might as well invent their own, or even adapt the time travel rules used in Star Trek. It's all the same.

Kain, don't listen to this guy. He doesn't have a clue what he's talking about. There's a lot of real physics out there that you can use as inspiration for a hard-SF time travel tale.

The important thing is to devise rules, and then make certain that you follow them. But it's not that essential what the rules are because there isn't any set of rules supported by scientific evidence.

The first one and a half sentences of that are right. Of course, there's no requirement for a storyteller to use real science in a work of fiction. It's an option, a matter of stylistic preference. And yes, whatever rules you follow, the most important thing is to be consistent within the story.

But everything after "because" in that paragraph is totally wrong in at least three independent ways. One, there's a TON of real theoretical physics out there on the subject, as I know from my recent personal experience writing a time-travel novel that was as solidly grounded in real physics as I could make it. Two, it's tragically ignorant to assume that something is only scientific if it's been directly observed, since the whole POINT of science is to extrapolate beyond existing evidence. Third, it's even more ridiculous to claim that an author's freedom of choice in how to write a work of fiction is somehow dictated by the presence or absence of scientific evidence on a subject. There's a very wide range of approaches within science fiction, from the totally fanciful to the intensely scholarly and rigorous, and nobody has the right to tell any author which approach they should take.

However, there is any science that you can use to resolve those paradoxes, and there isn't any science that explains how multiple universes interact with each other...

Again, wrong, wrong, wrong. The question of how alternate timelines would or would not interact is a fundamental part of Everett's "Many-World" equations. The possibility of non-linear quantum mechanics providing a mechanism for interaction between alternate timelines is discussed here: http://www.npl.washington.edu/AV/altvw48.html

And I know you're going to come back and say that it doesn't count if it hasn't been proven by "evidence," but even if you weren't wrong to dismiss that as unscientific, you'd be wrong to dismiss it as a valid basis for a story. Real or not, these theories exist, they're interesting to think about, and if a writer wants to base a story on them, there's no reason not to. That's why it's called science fiction. It's fiction that takes scientific concepts and theories and illustrates their ramifications.

 

[YellowSubmarine]

You're completely wrong about that. Frank Tipler demonstrated in 1974 how the equations of General Relativity predict closed timelike curves, and there's been extensive theoretical work on the topic ever since by Hawking, Thorne, Novikov, and other physicists.

OK, I stand corrected, at first I didn't realize that what you said wasn't as insignificant as it sounded, and I also wasn't specific enough with my posts, I was mostly referring to things M-theory and friends that have little basis in fact. I'd rather go for my own thing then, they are too complicated for the writer and for the reader.

 

[Kain]

I'm still working on this, and I have to say I'm really not sure of a way that inter-timeline and interuniversal travelling could actually be mistaken for time travel. I intend for a character at some point in the story to be lost in the timelines, and trying to find his way back to his, always missing and goind from one timeline to another.

I thought of some ideas, but I need the opinion of someone who knows more about science than I do.

One way I thought is that the machine could travel freely in all spacial dimensions, by using a fourth-dimensional (or five-dimensional or whatever) object to push the time machine out of the three-dimensional domain, freeing it from the dimensional restrictions.

Since time is also a dimension, the machine could also travel back and forth in it, instead of always forward at a specific speed like we do. For this to work imagine time as a vertical tube and us as a ball in it falling. Or as an one dimensional line and us as a point moving in it at a set speed. But since every possibility creates a new timeline, time forms a tree-like shape instead of an one-dimensional line, thus creating a second dimension of time. Unknown to the time traveller, the machine automatically follows the timeline produced by the changes the time traveller made to the past.

Another way I though is for the machine to somehow follow quants. Since quants could possibly travel to more than three spacial dimensions, the logic would be similar to the above.

Of course, there is also the usual solution of wormholes. The machine finds a wormhole leading to the time the pilot wants to go, inflate it, stabilise it for a short period of time for the machine to pass through it, and voila! But that would make it difficult for the character to be lost in the timelines, unless I could use a different technique for that side-story.

So if someone who knows more than me could point out if some of the above makes any bit of scientific sense, it would be really helpful.

 

[Corwwyn]

Unknown to the time traveller, the machine automatically follows the timeline produced by the changes the time traveller made to the past.

What do you consider to be "the past"? If "the past" refers to "that which has happened", then, how could the "time traveller" make changes to it?

 

[Kain]

Unknown to the time traveller, the machine automatically follows the timeline produced by the changes the time traveller made to the past.

What do you consider to be "the past"? If "the past" refers to "that which has happened", then, how could the "time traveller" make changes to it?

The machine travels in time to the birth of the Solar system.
The gravity of the machine (and its presence there whatsoever) changes the movement of some particles.
Right now, there are two timelines. The machine's timeline, where there were no changes, and the alternative timeline, where the changes the machine made at the birth of the Solar system take effect.
In fact, the alternative timeline branches from the machine's timeline at the moment of the machine's arrival to the birth of the Solar system.

So, since the machine entered the alternative timeline at the moment it arrived to the birth of the Solar system, when it tries to return to the present, it follows the timeline it's already in, which is the alternative timeline.


Also, what do you think of this theory?

Spoiler: Imagining the tenth dimension.

http://www.youtube.com/watch?v=JkxieS-6WuA
http://www.youtube.com/watch?v=ySBaYMESb8o&feature=channel