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Time Travel


Renate

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<< Not backward, not forward.

I find it unlikeley that we will ever have the technology to travel in time, and if we ever get the technology, I believe it will not be used, for fear of what som time pilot might do to mess with history. >>

 

 

 

Hmm .. Im not sure i agree here. Once there was a writer who told a story about a boat that traveled 20000 leagues under the sea. He also told as story about how two men traveld to the moon and back. What Jules Verne wrote in his days was commonly thought of as science fiction and completely impossible. Today we have thousands of submarines, and not only traveled to the moon, but also walked on it ... many times.

 

The future will take a long time to explore and what we technologically will be able to do MIGHT also include Time Travel. I think it is a possibility, regardless of our current status on the matter =)

 

As for "messing with history".... if you travel to 1960 and buy an icecream, then you already have done so =) ... Its a matter for the philosophers. Can one change history with time travel or not? Perhaps ... never heard any arguments that rules out either possibility

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As we seem to be in the philosophical corner here ... Recently saw the movie K-Pax ... which had its own view of this. "On K-pax we know that the universe will eventually collapse upon itself. It will then explode again and everything will be repeated exactly as it happened the time before. So get it right the first time, for you will be repeating both the good and the bad times an infinite number of times" (quoting from memory here .. so I may be off on a word or two =) ). Wierd way to envision how the universe works, but an intriguing idea after all =)

 

As everything has happened has happened .... will it be possible to alter it after the event has already occured. "Can you be your own grandfather?".

 

Ill not even START to think about that one =)

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The K-Pax idea that the Universe is constantly blowing up and contracting is not generally accepted by cosmologists today, although it has been one of the many interesting theories.

 

In the book "The Five Ages of the Universe" (Hypography review) the authors argue that the universe will last for so long that all the matter in it will be exhausted before the cosmos eventually disappears.

 

However, some interesting ideas arise within something called "anthropic" theory, which claims that the Universe we live in is the way it is because we are here to observe it. This might lead to an obvious question: perhaps our universe is indeed one universe in a long sequence of universes, and only one of a multitude of parallell universes, born out of each other...much like evolution, in fact. Perhaps universes evolve and improve as well?

 

But my point is basically that if in fact our universe should collapse and regenerate, it would not be the same universe - I think this is an important point.

 

As to how this applies to time travel I don't know...just my 2 cents.

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wagenius -

 

Stephen Hawking has a neat resolution to the problem of "if time travel is possible, why haven't we been visited by travellers from the future?".

 

His argument is that if you are able to create a time machine, it will never be able to travel further back in time than to the date on which it was created. He sees this as some sort of built-in cosmic defence mechanism to avoid the paradoxes which arise from time travel.

 

However, it does not resolve the grandfather paradox. To do this, he says there is a possibility that when you travel back in time, you actually enter a universe which is very similar to ours, but not exactly the same - at the moment you arrive in time, the universe splits into two in some quantum fashion and from there the two variants branch off in different paths. So if you accidentally kill your grandfather before your father is born, you only kill him in this "new" universe, not your old one. So you still exist, even though you have killed your grandfather - because there are (well, were) two of him and you can never get back to the original one. As for your identical twin in the parallell universe, well, tough luck.

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I have a question - do we live in the parallell universe or does my twin? Am my twin supposed to to excactly the same things as I am? If not, it wouldn't be parallell, and if - if my twin is killed it can no longer be parallell??? I find it too confusing to be belivable - no there can't be parallell universe.

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Well, in my exampleyour twin does not exist until you go back in time, at which point the entire universe splits in two and goes in different directions (albeit very similar). Your twin would of course NOT exist if you kill her grandfather before her father is born...

 

But the idea of a multitude of universes is not merely gobbledygook, it has received serious attention from many scientists. There is something called"many worlds" theory which argues that at every moment a decision has to be made on a quantum level (say, should this electron bounce this way or that), the universe actually splits and each copy takes the opposite direction, so that both things actually happen.

 

I didn't say it's credible, though.

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  • 3 weeks later...

Hello.

 

I'm new here and I hope I can add a little information.

 

Their are a lot of theories on ways to solve the grandfather paradox and others like it.

 

One is that whenever you go back in time you will do whatever you did already. That is, the act of going back in time did something which already occured, you can't kill your own grandfather no matter how hard you try because that would prevent you from being born and going back in time. It is just a law of nature. I know I am not explaining this very well but I'll try again later.

 

Another idea is the parallel universe thing. Someone already mentioned that universes split up when a quantume decision must take place. This theory has support in that you can't know the speed and position of a particle at the quantum level. The reason for this is that when you go to take a reading the universe splits into many where you looked at the position and got all posibilities and one where you looked at the speed and got all posiblities. Remember, quantum physics is ruled by probabilities.

 

Well, I hope this helped clear things up.

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  • 2 weeks later...

Hey, I'm new here too. Looks like the forum is underpopulated right now but it has potential.

 

I agree with Anonymous on the many-worlds quantum interpretation.

 

There's a set of multiple-universe conjectures on the table, too--the difference is that these universes don't arise from quantum uncertainty and may be absolutely unlike ours. For example, in the book The Bigger Bang James Lidsey mentions that other universes may be spawned by black hole singularities--essentially, such a baby universe would create a new big bang and new universe separate from ours and possibly with different physical constants. Some might recollapse almost immediately, others might contain no matter, etc.

 

Another conjecture, I think originated by the Soviet cosmologist Andrei Linde, posits that the inflationary epoch of the universe is actually eternal and our universe, along with a potentially infinite number of others, is a bubble of spacetime in which the 'false vacuum' state has decayed into normal vacuum. Because the false vacuum uber-universe is expanding exponentially, even though these bubble-universes are expanding also they never meet and coalesce.

 

Still another proposal is that the false vacuum varied across finite domains, with differing physical constants in the domains. I haven't read too much on 'chaotic inflationary theory' but it seems to involve inhomogenous inflation in finite domains of the expanding universe. Some regions would expand immensely, and others might remain subatomic. In this view our visible universe might be a small part of a much larger domain that expanded rapidly, but somewhere far far away there may be other domains with other physical constants.

 

Er, this really doesn't have much to do with time travel, I guess. Sorry about that.

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  • 1 year later...

I didnt believe in time travel until i did research on the HAARP project. Now i believe time travel to be possible through the use of wave lengths. The entire galaxy gives off a wavelength somewhere between 400-450 megahertz, so does the human dna strand. Does this mean our exsistence is just a wave length?

 

There is a theory that if you converge multiple high energy extremly long frequency waves in one area you can open a hole to another space time. There are rumurs that the HAARP project accidentialy opened up a hole in time back to 100 million b. c. by doing exactly this.

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Well i am new here and i just saw that at one of the home page posts stated (that you mit reach a star if you can travel faster then the speed of light). Well as far as i know science has showen/hypothesize that there is only one thing that can move faster then the speed of light and they are tachyons. But tachyons only move backwords in time not forwards.

 

The only way science has shown that tachyons exist is that if we put a partical on one side of a room and BANG its on the other side we believe that tachyons hit it on there way back in time.

I know this throws the whole time travel theme off of my post but movies and books have given people the idea that faster then light travel is posable and it is IF u want to go back in time!!

 

Hope u get some ideas from this or give me some information i may have missed.

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I was just looking around and i saw a ad for the Time Travel Institute and i saw a buntch of facts that i agree with like!

 

Logic would suggest that if time travel were ever to exist, then it already does. If time travel is possible, then the methods required will eventually be devised. Maybe it will take another 10 thousand years to discover the secrets of time travel, but if it's possible, then it's inevitable. Which suggests that time travellers are already visiting us... and visiting our past. What does that mean? To comprehend this, we must look at the many possible repercussions of time travel.

 

Theory A - Fate (Circular Causation) - Travel back in time to save someone's life only to discover that it cannot be avoided, or worse yet, you were in fact the cause of the person's death in the first place. This is amongst the most plausible theories.

 

Theory B - Alternate Universe - Travel back in time to save someone's life, succeed, return to your time to discover that nothing has changed... you've only changed the timeline of an alternate quantum reality. This theory is also amongst the most plausible.

 

Theory C - Success - Travel back in time to kill your great-grandfather and succeed. This theory is very unlikely since if you were to successfully kill your great-grandfather, you would inevitably never be born, and therefore never go back in time to kill your great-grandfather. Thus the paradox and the implausibility.

 

Theory D - Observer Effect - Travel back in time to alter history and succeed, but the only persons capable of differentiating between the reality left behind and the new reality are those directly associated with the time travel... the time traveller. The extent of the paradox rests in how the time traveller is affected. Existing "out of time", he may not be affected by whatever changes he inflicts on the timeline, thus the time traveller himself becomes a stranger in this "new" present. He may, in fact, go back in time, kill his great-grandfather, and return to the present to discover that there are no records of his own existance.

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