Time Travel

[Tako]

what if the universe is a sphere of some sort? whit all the plnets etc on the outside on top of the sphere.

when you got through the sphere (I mean not around on the top but throughthe middel) you are faster on the other side then when you would travel around itsoutside.

Thus creating time'travel  you are there before the other at an other time then when you woiuld use conventional drive.

sort of like the wormhole pricipe mentioned before

I find this dificult to explain some help would be usefull, but I think I'm on to something

something like going through a tunnel in a mountain or going over the mountaiin fastes way would be to go through an at some level of vieuw you would travel in time as to the other who would go over the mountain

[TMA_1]

hey edric, this may sound stupid since I only know a little bit about this stuff, but is entropy related only to the dimension of time? In other words since movement of any kind is a paradigm of time-space, then is the slow decay of matter to simple forms of energy directly relating to time?

Also thanks nema, forgot about the idea of relativity. So that when I am moving at those speeds it isnt me who I see is affected but others around me. Does this then mean that when something is moved near or at the speed of light that it is almost a forced quickening of entropy, the conversion of matter into energy by speeding matter up? I know this sounds rediculous but I figure I can ask such a question as long as I am learning something.hehe

Also I was wondering if certain kinds of subatomic particles can be moved faster than the speed of light. I have heard that tachyons can theoretically do this. If so, is this because these kinds of particles are less dense than photons themselves and have different laws attached to them? If so has this ever been figured into the equasions?

[Edric O]

ah i see... sorta like if you take a deck of index cards and draw a cartoon frame by frame.. and then flip thru them really fast... it gives the illusion of movement. Interesting.

Exactly! That's a very good analogy. Of course, if there is only one deck of cards, then the Universe is deterministic (the future is pre-determined). But there could be an infinity of different decks of cards, which are all being flipped through, and our "present time" moves from deck to deck depending on the actions we choose to take.

There is a certain problem with ships that go fast enough - we'd have to find some material impervious to getting hit by dust and rock particles in space (exponentially more harmful as the ship approaches the speed of light). So, speed is not the only limitation, durability of the ship's material is as well.

Of course. Ideally, there would be some way for the ship to mop up the space in front of it as it moves.

You're onto something fantastic with your scenario. Kind of reminds me of Pitch Black (passengers are aboard a spaceship with their own motives for being there [e.g. a couple people were on a religious quest to Helios Prime; a couple were hitching a ride to collect a bounty on a criminal aboard] crashland on a planet and discover incredible things on the planet).

Well, I might develop that scenario into a full story some day... :)

hey edric, this may sound stupid since I only know a little bit about this stuff, but is entropy related only to the dimension of time? In other words since movement of any kind is a paradigm of time-space, then is the slow decay of matter to simple forms of energy directly relating to time?

You should read "A Brief History of Time" by Stephen Hawking. It's nothing short of fascinating. I'm not sure exactly what you mean here, though... The increase of entropy is indeed a special property of time and not space, at least from our point of view. But, of course, from our point of view, time has many properties that space does not have (and vice versa).

Also I was wondering if certain kinds of subatomic particles can be moved faster than the speed of light. I have heard that tachyons can theoretically do this. If so, is this because these kinds of particles are less dense than photons themselves and have different laws attached to them? If so has this ever been figured into the equasions?

Tachyons are hypothetical particles; they are supposed to be the "mirror image" of normal particles with regard to the speed of light. In other words, while normal particles ("tardyons") cannot go faster than light, tachyons cannot go slower than light. I don't know any more about them, though. I need to stress the fact that they are only hypothetical, though, and have never been actually observed.

[stefanhendriks]

some stupid question from a noob on this subject:

If time is related to gravity. How will time be in outer space? Since the test described on the wiki page says: "in the plane, the atom clock runs eventually slower then the clock on the ground".

But that means its a plane, attached by earth gravity. How would this be when the same plane would be somewhere in the middle of no-where in outer-space where no gravity is applied...

[Davidu]

Wouldn't each object generate it's own time? Time that can be compared with the time generated by other objects.

I mean "in space there's no time" it's quite far fetched because the clock on a space-ship still ticks... and time passes. The only difference is the SPEED of time. Sounds weird... Time passes faster or slower regarding a point of reference. Therefore time might have SPEED.

[stefanhendriks]

Thats not what i meant. I mean the theory that gravity and time is related so far that time can be slown done due gravity or somesort... which cannot work in outer space. So do many theories that apply on Earth btw. ;)

[Edric O]

Time is not related to gravity. Time is part of the continuum that makes up the Universe; gravity is one of the 4 fundamental interactions. You're probably thinking of the fact that gravity "folds" both space and time.

[Dude_Doc]

Mass is not dissapearing

But in a way it does. The matter that is sucked in will never get out, since obviously gravity is a bigger force than mass (since huge stars implode and become black holes). But I tend to think in the line of "if time stands still, is there then time?" (since time literally stops around the singularity of a black hole).

I'm not sure if this is necessarily the case. Indeed, there are hypotheses about the universe being entirely phase space and time having nothing to do with it - so there's no reason to require that chance be time-constrained.

But time is needed since chance needs it. Else, the universe is likely to have been created by some sort of reaction (twin-universes who "bounce" out and then towards each other, restarting the cycle, other theories etc).

then you find that the existence of the universe is inevitable - for there to be 'nothing', there has to be time for there to be nothing in.

Not necessarily. "Time" must also exist inside the black holes, and as we know it, time stops there. A black hole is literally "nothing" - no time, no space, zero.

Does time really exist or are we just using "time" as another name for "that which moves" or "that which works"?

In a way, I agree. But in order to measure this, one must also take into considerment the actions outside the box. The universe will one day end, or the box will eventually encounter an object or fly into the sun. The material of the object itself may decay after a while. If time is to "not exist", well, other objects must also be affected by that.

Sure, maybe the box is constructed in such a way that there really is no time inside, but let's say we place the box inside a black hole. There, time truly stands still, because the object can not be affected by anything - it can not fly into a star, or get crushed by a comet, decay - or even "be there" when the universe ends - since absolutely nothing can affect it if there is no time.

something like going through a tunnel in a mountain or going over the mountaiin fastes way would be to go through an at some level of vieuw you would travel in time as to the other who would go over the mountain

In a way, that can already be done. If you somehow "are" besides a very heavy "gravityfull" object, time will go slower for you, but if you increase speed, time will go faster. But all in all, time is still "created". It goes in different paces depending on where you are. Even if you went through a time-travelling device, you would only "wait" (although in a faster way than in queus, for example) while people in "normal time" would go at a faster pace.

Besides, you could never see a future that has not yet been created.  :)

But that means its a plane, attached by earth gravity. How would this be when the same plane would be somewhere in the middle of no-where in outer-space where no gravity is applied...

Actually, this has happened before: the space shuttles and rocket we sent into space. Time is moving faster there, but "not fast enough" so to speak. Like I said, time does go faster in space, but not as fast as some sort of time machine. I believe the same test has also been done by standing on a very high tower. To really reach a result, one needs a veichle that can travel around the speed of light.

[GUNWOUNDS]

TMA... the only way to travel faster than the speed of light is to put a negative number in the mass variable of Einstein's equation.

[Acriku]

Why is negative mass ethereal? No mass would be ethereal (i.e. intangible). Perhaps you're right to assign spirits to negative mass (a nonsensical term).

[GUNWOUNDS]

Why is negative mass ethereal? No mass would be ethereal (i.e. intangible). Perhaps you're right to assign spirits to negative mass (a nonsensical term).

correction..

[Acriku]

And since we cannot imagine a negative mass i just assigned it the term "metaphysical" which is obivously the realm of spirits and such.

You're right that no mass can in fact be tangible (to some degree). What you said above is what I was saying in the last part of my post; i.e. metaphysical is a nonsensical attribution, which is why it is appropriate to say negative mass (another nonsensical term) is metaphysical.

[nemafakei]

Presumably these ethereal things would be tachyons. And Edric, is that something you've made up? Tardions or (preferably) bradyons, please.

[Sneakgab]

For all those who wonder how can their be no time/highly unusually space-time effects in space due to the absence of gravity (which apparently is tied to the curvature of space-time or something (not too knowledgeable)). One must remember that theoretically gravity is a long range force (may not be too knowledgeable, but most know that gravitational force is = to product of masses divided by sqaure of dist of two centres of obj's). Therefore, any object anywhere in space still experiences gravity. Of course, one might comment on the effect of no gravity (where mass = zero in space), but one must remember that such space even exists on Earth between particles. So this should explain the lack of highly unusual time effects in space and the like

[Umma Kynes]

I belive in time travel, I have devised a way to do it:

Black holes. As we know, black holes have infinite density and the ability to suck things in-- even light. With this knowledge, we'll get instering now-

Light; compacted; makes a laser, right? Black holes can crush anything. 2+2=4, people. With light being compressed beyond the physical plane, sub-atomic explosions would occur. These explosions would be crushed, resulting in an even more devestating explosion that the last. This would continue infinitely; thus resulting in unlimited physical power able to propel something beyond the physical plane.

Now here's the issue: if it worked, how would the said object stop? ??? :O

[Dude_Doc]

Light; compacted; makes a laser, right?

In a way (I don't know much about laser). But black holes has an unlimited capability.

Black holes can crush anything.

Even time...

This would continue infinitely; thus resulting in unlimited physical power able to propel something beyond the physical plane.

Well, can you control a black hole in order to do this? :)

[Umma Kynes]

Well, can you control a black hole in order to do this?

[DelugeD]

On adult swim

Futurama

he buys an old van  and under the passenger seat locates the time travel devise... water bong

[Umma Kynes]

I just had a briallant idea!

American Cyborg, you said black holes can crush time, right? Well, for something to be crushed, it needs to be compressed as well.

*ding ding*

Just put a spaceship near a black hole. Time would be compressed to the point a mere split second could be any amount of time. Why? Well, the time compression would last until one of two things happened:

1) You are dragged into the black hole.

2) Someone pulls you out of the time compression (aka, another ship).

Got it from the first episode of Gene Roddenbury's "Andromeada".;D

[Dude_Doc]

Just put a spaceship near a black hole. Time would be compressed to the point a mere split second could be any amount of time.

Actually, we are experiencing this "gravity-travel" already, by just being here. Everytime you fly in an aeroplane, time goes faster for you than it does for me. Hell, even standing at the top of a very high building is a difference, if only small.

2) Someone pulls you out of the time compression (aka, another ship).

Hmm... in order to get any special change in time, say one hundred years within an hour, you would have to be very close to the hole, if not too close. Remember that these suckers consume light as if air. Thus, a crew on a ship who wants to go into the future within a reasonable traveling time would ultimately be sucked in.... unless they find a force great enough to "go away" from the hole at the same time as being sucked towards it... or so I figured.

[Faetarius]

Commenting on the time dilation occuring as you enter a black hole. In theory this means that, as you approach a black hole, time slows down. Your rate of approach reduces accordingly, right up to the point that time, and your ship, stops. But as time is slowing for everything that means that you will be passing through many centuries, and, near the singularity, millions of centuries. So technically you're enjoying time-travel, with the side effects that A) You won't notice, and B) That you won't be alive to appreciate the results

[The Spac]

There is one problem in travelling to the future though, you arn't counted as a seperate observer, by just travelling to the future your potential future as if you existed in your world would be gone, the future where you didn't goto the future would be gone, so if you had any kids or grandkids they all wouldn't exist. While this doesn't seem like anything for 1 person.

If there are these spaceships that someone mentioned in an earlier post (I skimmed) where 100 or so peeps could goto the future at once could cause potentially massive disaster. If these people went 1000 years into the future and all their decendants no longer existed, then the time line would be massively altered.

EG. If Adolf Hitlers mother and father wanted to know what the future was like and travelled to the year 2005 and decided to bring up have child here instead of there, then world war two could possibly not have happend because hitler wouldn't have been born and could even go further into the futher where the cold war never happend and comunism still existed in russia.

This is the problem with travelling to the futher more then any other thing.

So what I'm saying is by travelling to the future is impossible, you would more likely be travelling to a parralell universe or a splintered one. Not sure the exact term. By travelling to the future you have changed the future. :)

[stefanhendriks]

I don't think time can change in that way, since by the 'time' you 'could figure that out'. It already happened.

So in short, everything is a simple cause-effect game. Even if you travel forward in time, others will not notice. Not even notice a timeline change. Perhaps, hitler was implanted by humans in far future to speed up a world-war, so in the end we might have world peace...?

You can never tell! :)

[Dude_Doc]

But you must also take into consideration what time really is. As far as I have understood it, there are two types. The first, is the one we have thought and discussed about in this topic: everything affects everything else. If I go back in time I cause a paradox where I can't go back, and so on, etc.

But then there are a so-called "informative time", where everything is information, and basically, everything is possible. Time here is like a movie, or rather, a film. If you stick a hole in the first frame, this wouldn't affect the rest of the movie, unless you stick a hole on every other frame. Exactly how things would turn out here can be debated, and would probably be something in the form of parallell universes...

[Sneakgab]

Some people are already ''in'' the future. Thanks to time dilation, their are many people already travelling through time at neglibly different speeds, and yet this does not cause a catastrophe. For example, when somebody slows time (hypothetical) for the universe relative to himself, one will notice that he will suddenly seem to react more quickly to everyone but that he will be ''slowed'' down. This is illustrated in the twins paradox where a twin travelling at near to light speed speeds comes back much younger than his identical twin. For him only 20 years have passed, but for his twin, perhaps 60 years have passed as a result of time dilation. So for the one experiencing the effect it seems time is normal and that everyone else in the universe is aging and experiencing things three times more quickly, while for everyone else in the universe it seems that the one experiencing the time effect is aging and experiencing three times more slowly. However, to both of these observers (Near light-speed traveller and the rest of the universe), it seems that their time is the ''normal'' time and besides the slowing down/speeding up of reactions and aging and the like everything is ''normal''. This is because time and the speed one is travelling through time is like speed and position, and only meaning because it's relativity. Relative to the rest of the universe, the near light speed traveler is travelling into the future, but relative to perhaps an even quicker traveler, it will seem like that that light speed traveler is having time slowed down for him.

On the note of blackholes and infite  explosions and such: Thanks to E = mc2 (only vaguely sure of effects here), it does not matter even if you have infinite energy. Since c2 is a constant, only m can change to ensure the equation balances out when E is increased. At lower values of E, one can increase E a lot with a hardly even noticeable change in m, because c2 is such a huge value that if m is 1 and E whatever, then increase m by 0.1 will it make E = 0.1c2, resulting an increase in a huge amount of energy (10 times who knows what to the power of who knows what:D) just due to multiplying such a large number by an additional 0.1. However, at larger amounts of energy, we find that the mass eventually starts increasing significantly as the mass starts nearing c2. Therefore, it is said that even if one has infite energy, he will never reach light speed as infinite energy = infite mass due to this equation and obviously force (produced by energy transfer, kinetic or otherwise) = massxaccelaration. With f and m infinite, a = infite divided by infinite which can be said to = 1 I suppose, or also ''who knows what''(I suppose that energy transfer probably cannot transfer an  infinite amount of energy instantly, so actually this probably never takes place, thusly preventing such a problem), though neither value is light speed.

However, using negative mass and 0 mass objects, one can see how time travel becomes possible. The only problem is that unsurprisingly I have not heard of any evidence to support the existence of such negative mass particles (Since they would probably be intangible and probably very difficult to detect). There do exist shorter and perhaps lighters wavelengths of light though, which perhaps has an alteration on speed. I've forgotten most of what I've learnt about wavelengths though, since as I said earlier I'm not to knowleadgeable about this stuff yet.

However, if one can go faster than light, I don't seem why time travel into the past would be impossible. Everything is relative, so travelling back in time should not be very different to travelling forward through time. To the person travelling back in time, it would seem like time speed is normal. Only by comparing it to the universe that is perhaps ''reverse reacting'' around him, would he see the relative difference.