Time Travel

[spiritcrusher]

According to Eisntein , if time travel is really possible how does one explain the grandpa paradox ??


The GrandFather Paradox

If time travel is possible and supposedly i am able to go back in the past and if i manage to kill my grandfather , how is my presence explained in the present future !!!



<_<

[venom mama]

in deep meditaion buddist monks are able to travel the universe so they could probably pass through time as well. there is no physical form involved so there would be no way to interact with anything, so you couldn't kill your grandfather.

[jesupocaplypse]

because you didn't kill your grandfather in the past, you killed him in the present, in what 'seemed' like the past,... but was really the present... in the past, which is the future, which is the past which is..... ARggghHH :huh: Ouch, my basal ganglia and my parietal lobes..... :duh:

:wacko: :finished:

[sahyo]

hehhheheeheeeeee

:D

[a random hack]

the fact that you are still here, proves you didn't kill your grandfather before he passed on genes to you

[todd]

Time travel assumes that time is not continuous and linear or one-dimensional.

One simple model is the following:
It is easy if you imagine time as meander river.
you are part of it, but if you jump on the shore you can take a sortcut and jump back in where your grandpa is.
You are not in the same stream anymore so any changes to that stream will change the stream but will not affect your past.
If you kill your grandpa, you will not find yourself in the stream anymore but you still have your own same past.

Another model is the interactive one:
You cannot escape your time stream. So any change you make in the past will change your present, So if considering the previous example, you don't jump on the shore, but you're in adjacent stream to the main one, like taking advantage of an island, taking the shortcut and get ahead.
In this scenario. if you kill your grandpa, your existence will cease.

There are many other models but these are the most popular.

[jesupocaplypse]

:knockout:

[NeverMind]

i wanna go back in time and kill Adam and Eve so that humans would never get a chance to eff the world up! But then I wouldn't have been around to go back in time to kill them! But then they wouldn't have been killed! But then I WOULD be around to kill them! AAH! :cry:

[sonrisa]

to get back to the Grandfather Paradox- I would say that's where the Heisenberg Principle kicks in.....

ditto for the Adam & Eve paradox, for lack of a better term. :)

[rich]

Do any of us realize that no matter where we are, or whoever looks at us, our images travel at the speed of light?

Just wondering about that.

[sonrisa]

good observation Richie :)

[NeverMind]

If I went back and got Eve pregnant I could be the father of the entire human race! I'm SO gonna do that. You will be a spoiled, fickle, violent bunch, but you will all be mine! I bet Eve was really hot... :unsure:

[sonrisa]

and what makes you so sure Eve wasn't some big hairy neanderthal broad?

And what if you get her pregnant with Abel?

[NeverMind]

maybe im into neanderthals. maybe i like big hairy manly women.
no i dont
that would be wack.

no we wouldnt have abel. and even if we did I'd be smart enough to give him a cooler name so he wouldnt get killed. Or kill his brother. Which ever one that was.

Plus, if she and Adam were neanderthals, so would Cain and Abel.
If Eve and I had a child, it wouldnt be so neanderthalic cuz I'm a homo sapien sapien!

[sonrisa]

provided that homo sapiens & homo neanderthalis were able to cross mate

[NeverMind]

We could at least TRY! :lol:

[sonrisa]

:D you can always try :D

[todd]

Do any of us realize that no matter where we are, or whoever looks at us, our images travel at the speed of light?

...in all directions too....
in deep meditaion buddist monks are able to travel the universe so they could probably pass through time as well
...in their imaginary universe, of course... we can all do it easily...no need to be a 'guru'..but this is about something we all accept as 'physical reality' and awareness.... not mine, not yours, not his but ...ours

[BingusVette]

Time travel is so simple, here let me show you a nice example of time travel. Look at your watch (please make a note of the time) now remember when? Okay glance back down at your watch again, you have move through time! Okay oldest joke going!

Seriously if folks could move through time in the other direction don't we think there would be a shred of proof....its not religion right we don't have to take it on faith or do we? :unsure:

[MidnightSun]

i think its possible

[Thomas Knierim]

Irritatingly, time travel is a theoretical consequence of general relativity. The concept of time dilation (as in special relativity) is pretty straightforward and plausible. But, according to relativity, time travel requires spatial travel at extreme speeds. We can't stay in the same location. But, if space geometry (as in general relativity) is abstruse enough to form certain channels in spacetime and if physical objects can move through these channels unharmed, then timetravel is theoretically possible. These are two big "ifs". First, we haven't yet observed any such spacetime geometries and it is very questionable whether they exist at all. Second, if they should actually exist, then the physical conditions inside these channels are unlikely to allow physical compounds to be preserved. Finally, relativity and quantum theory cannot be both true, at least not with some modifications. So maybe it's all humbug.

That's the physics part. The common sense part is: we don't meet people from the past or future. So we can safely relegate time travel (for physical objects) to the world of fiction.

Cheers, Thomas

[scameter]

it's good seeing you again, Thomas. i don't see you on here much, or especially ever posting. it's good to be audience to your return, friend. :)

are you talking about wormholes, Thomas?

[MidnightSun]

Yes, its beyond us and we have to stay out of it coz we dont need that at all. Where are some things humans must not know.

[sonrisa]

or are you talking about time travel as in :D the Philadelphia Experiment? :D

[MidnightSun]

:lol: travel there by time and check out time travle machine :lol:

[BingusVette]

we seems to have skipped over the proof part...the theory is great...it establishes that under a very finite set of crazy circumstances...yeah the theory exists....we have multitudes of theories...some even expound on the existance of a divine being (can you imagine) but if it were true, if it were something we could prove.....wouldn't we know it... :nono:

[MidnightSun]

where is a true story about traveling by time. So ,i guess it was fishermans, were swimming in the boat and suddently saw somel with really old equip of diving ,who was searching for something. They came closer and asked who is this man. He told his name and last name and that he is searching for a ship survivors. Later they identified that guy with same name and last name. This guy dived somewhere in 1900 (inaccurate year but something like that) looking for survivors in that ship and that he never came to the surface...or maybe he did? in 21th century?

[zewc]

of course time travel is possible, we do it all the time...think back to yesterday, and viola, we have time travel. We can also travel to the distant future, and no, not by the same means, but with a space ship that can travel at speeds that approach the speed of light.

there has also been proof that time travel is possible quantum mechanically, though this may be of little relavence for us "big people".

[Thomas Knierim]

zewc: We can also travel to the distant future, and no, not by the same means, but with a space ship that can travel at speeds that approach the speed of light.

You probably allude to the "twin brothers" thought experiment, stated by Einstein, where one twin stays on Earth, and the other twin undertakes a space journey in a near-to-lightspeed vessel. When astronaut brother returns to Earth, his twin brother would have aged considerably more than himself. I am not sure if this really qualifies as genuine time travel. It is just the effect of relativistic time dilation. This means that both twins have travelled "normally" through time in their own reference frame, but their reference frames have different time lines. Well, in a sense it is time travel, since the space-travelling brother described a closed path in the space dimensions.

The obvious (practical) problem is the near-to-lightspeed vessel, the energies that are needed to accelerate this vessel, navigation, prevention of collisions, etc., all of which suggests that matter as we know it cannot travel at this speed.

Cheers, Thomas

[MidnightSun]

its true that time in space ships (not those humans are creating) year does slower.

[zewc]

In repsonse to Thomas, I guess I should have been more specific. The traveller in the space ship would be able to travel forward in EARTH's history, if he or she was to travel, say a 50 lightyear round-trip at 0.99c (or thereabouts) away from the earth and then back, he would return to earth thousands of years in EARTH's future, and not his or her own.

Mkay. :think:

Of course there are obvious technological difficulties NOW, but it remains as a thought experiment very viable.

[Jori]

I don't think time travel is possible. One cannot go back to the past because the past is already finished, gone, non-existent, destroyed. There is nothing to go back into. One cannot go into the future because it hasn't happened yet; it's non-existent. There is nothing to go forward into. The past and future referred to in time travel are both non-existent.

[WilliamMckeehan]

i agree it is not possible

[scameter]

Well i personally think it is possible. With the current scientific view of time as if on a graph and thus still present, and of parallel universes and wormholes, i think that if we were to go into a lightyear-long wormhole that we could possibly go into the past. And most definitely into the future, because the Earth doesn't travel at lightspeed, and thus if we did we would be going many, many, many years ahead of it into it's future. And i agree that the present is essentially gone before we canr ealise it, and thus "future" really doesn't exist, but from that view neither does time or much of anything else. Because everything is on our perspective, and if a scientist left Earth in a spaceship capable of lightspeed travel, went into lightspeed for about one hour, then came back, his entire world would be different. If they were flying spaceships in his time, they might be deatomizing as travel in the future, or any variation therewith. I think just about anything is possible with science, as long as we realise that logic is fallible, and that we should do it because we love it, and also that we are limited by our own perspective of this universe. :)

[Smurf]

hey everything is possible mate otherwise we wouldn't be here

[sonrisa]

just becuz we don't have the technological means or understanding to achieve something, doesn't mean that something ain't possible

[Smurf]

yup :P :)

[scameter]

Definitely. We never know what the future holds, but we must remember to live and be human, and try our best not to intrude on nature aggressively, but rather passively allow it to show it's self to us and allow us to do what it wants us to do. :)

[Smurf]

Yes i'm liking this Taoism, finally i have been able to put a name to the thing i strive so hard to achieve

btw the Tao of Pooh is an excellent book, i have been reccomending it to anyone i see!

[scameter]

:) I'm so proud to hear that my friend. Also after that one read it's sequal, "The Te of Piglet". And then also read Osho's "Tao" and Lao Tzu's "Tao Te Ching". They're all very good. But, honestly, i'm beginning to like Zen better. But, Taoism is in Zen, so really that's not true. Well, anyway, i'm glad you're liking it my friend. :)

[kskf]

Quite a lot of posts ues the term "time" in the same manner as the term "space" is used. Hence, since movement in space in all directions is possible, so is movement in time. However, in the first place, is there any prove that "time" has the "same" property as "space" (i.e. possible movement in all directions)?

The term "travel" is used in relation to occupying different locations in space, and that difference in location can be in any "direction" (in physical space we experience, possible directions in 3-dimentions) relative to the "original" location. When the term is to be used in relation to "time", is seems that the above discussions concentrate only on a 2-dimentional movement (i.e. either forward, in respect of which most would agree that we "can" travel in time, or backward, in respect of which the answers differ). How about movement "sideway"?

If the "possible" movements in time is only 1-directional, the use of the concept of "travel" when used in relation to time should be different from the concept of "travel" when used in relation to space - i.e. the term "travel" does not have the same meaning when used in the two disciplines. The discussion should then be to clarify the used of the terms and the underlying concepts behind them.

If the "possible" movements in time is 2-directional, the term "traval" still means different things when used in relation to time and space respectively, but the concepts behind the term in the two disciplines certainly share more similarities then where movements in time is only 1-directional.

What is "possible" causes differences in the precise concept of "travel" or "movement" and therefore the answer to the question "is time travel possible" depends on the precise meaning of the term "travel" and the treatment of the concept "time" relative to the treatment of the concept "space". It appears that noone has ever argued that "time" has exactly the same properties as "space". So, can the concept of "travel" usually used in "space" now usable in "time"?

[scameter]

But are time and space really one in the same? I know that current physicists think that space and time are the same in spacetime, but is that true? Thomas you'd probably like to comment here. :D

[kskf]

I was too hurry in writing my last post and therefore it is imprecise in many aspects. I make certain refinement / corrections below.

The term "travel" is used in relation to occupying different locations in space AT DIFFERENT TIME, and that difference in locations can be in any "direction" (in physical space we experience, possible directions in 3-dimentions) relative to the "original" location.

If the same concept is used in relation to time, it would mean occupying different time spot AT DIFFERENT TIME, which is either a tautology or a nonsense. I am in 2005 when I am in 2005 and in 2006 when I am in 2006 - this is tautology (i.e. moving forward in time is not "travel" in time unless "travel" has no real meaning). I am in 2005 when I am in 2005 and I am in 2000 (or 2017) when I am in 2006. This is nonsense (since it means there are TWO "I" which never happens when the term "travel" is used in space).

If the measurement is relative to another type of TIME, that really does "travel" in time mean? e.g. I am in 2005 when I am in, say, the third era; and I am in 2004 (or 2007) when I am in the fourth era. Here, "era" is independent of the normal time we are referring to (i.e. there is another dimenion independent of "time" so that "travel" will have some meaning). But what is this independent dimention?

In space, we may occupy the "same" location at different time, so in that sense we do not travel in space. Can we occupy the same time spot AT DIFFERENT TIME (or, say, in different "era")? "Travel" and "not travel" are logical twins as these two concepts occupy the whole logical space (NB not physical space) in relation to movements in space (at different time). If the twins do not exist in relation to time, we cannot say we "travel" in time since "travel" is already universal and occupy the whole logical space in relation to movements in time. "Travel" in time in that sense merely means "exist" in time, as the state of existence in time already implies "automatic travel" in time (in a forward direction).

When the reference frame is the earth, we may occupy the same location at different time. But at the same (period of) time, the earth moves aroud the sun and the solar system moves in the comos. So if the reference frame is some distant FIXED point in the universe, we DO travel in space at different time, but only involuntarily according to the movements of the earth and the solar system.

Can we change the "reference frame" in time so that we may, in one sense, "not travel" in time and in another sense "travel" in time?

The question whether time travel is possible may need to be moved from the "Science" section to the "Philosophy" section, since science should be used to answer only questions that has a clear meaning so that experiments, observations, data collection, model building and inductive or deductive analysis may be made. If the question itself is not clearly defined, how can science help?

[Thomas Knierim]

scameter: But are time and space really one in the same? I know that current physicists think that space and time are the same in spacetime, but is that true? Thomas you'd probably like to comment here.

It is not particularly meaningful to say that space and time are the same. What you refer to is probably the spacetime continuum, which is a mathematical abstraction, i.e. an amalgamation of space and time. Using the spacetime continuum model, you can theorize events as points in a four-dimensional space. These events have worldlines (histories) which define whether there are possible causal relationships or not. In General Relativity, spacetime has a topology which is described by Minkowski metrics. Spacetime models are useful for cosmological calculations and for looking at symmetries.

Cheers, Thomas

[scameter]

I see. So is spacetime physical or just a mathematical model? And, with new theories like string theory and the expansion theory(i think are the particular ones), isn't space like 11-dimensional?

[sonrisa]

according to some theories it is. What I don't like is that some of these scientists claim that these higher dimensions are wadded up into little balls. No imagination. That's why I like brane theory myself, which states that the dimensions are spread out like membranes over the bulk of the universe, like a membrane on cold soup. Our eyes can only see in 3 dimensions. Just bucuz we can't see more than 3 dimensions doesn't mean that higher dimensions don't exist or that things don't exist in them.

[scameter]

But they aren't saying that there's not more dimensions to existence. Actually, string theory i believe states that there are 11 to 13 dimensions, each of which having many odd things, such as microscopic black holes and macromolecule black matter, such as that, and even intangibles by us. They essentially say that there is much, much more to existence than we believe, which is why i detest the Theory of Everything propaganda. We could NEVER even hope to even possibly have that, mainly because we are in, not above, everything and thus cannot understand everything. But that is the glorious thing about it, that we will never possibly understand everything and thus can continue to hypothisize about existence and research it purely for enjoyment of discovery. :)

[WilliamMckeehan]

the only way to go into the future if there is any way is going FAST!

maybe?

[Smurf]

:lol: yeah in a big red dodge viper :D

[scameter]

Well honestly time travel would constitute a founded idea of what time is exactly, which we do not have. It could be many things. Some propose that it is linked to space in the spacetime continuum. And some too say that there is no past; it is merely a graphical plot of occurances that still exist now and will. And some even say that time dies once it is gone; that there is only a present. But, all this beside, we would need a concrete description of time before we could hope to travel along it. :)

[sahyo]

curvature

[scameter]

True, a curvature in spacetime would create a wormhole, which would then allow us to travel through both great lengths of space and time at will. If we could indeed predict their presence in the continuum. :)