Thread: Is time travel possible? At first i ....

Well, time is not dimensional, space is. (space)Time is sometimes called the fourth dimension. So in addition to the three non-relativistic spatial dimensions of space i.e. width, height, and length we can add 'spacetime' as a fourth dimension. When Einstein demonstrated by elegant theory that time was relative, and wrote his papers concerning relativity (to the observer) space/time was born. I want to give credit to Kurt Godel as well as big E. He is almost always ignored even though he was instrumental to Einsteins theories. Godel proposed that if the universe was rotating time travel would be possible so maybe it was Godel that prompted Einstein to pursue his theories? Just a thought.

Special relativity shows that time behaves somewhat astonishingly like the three spatial dimensions. Lorenz equations demonstrate indicate that. Length contracts as speed increases. Time expands as speed increases. Space became linked with time, and are the components of time dilatation. When length contracts and time expands its fairly easy to see how time dilation ie time travel can work at relativistic velocities ie any speed above 99% light speed although there is no set value on relativistic velocities, its a general term.

In my opinion it's only because of big Al's big brain and his beautiful imagination and masterful grasp on geometry and physics that time, spacetime specifically, is now recognized as the fourth dimension. I hope I did not bore everyone to death but I wanted to provide some back ground info so it might be easier to understand why 'timetravel' is indeed possible and has already been accomplished on a very small scale. (the space station astronauts are a fraction of a second younger than they would be if they had spent their entire lives on earth due to time dilation of the slow velocity (compared to relativistic velocities) of the international space station. This has been confirmed by atomic clocks. Two synchronized atomic clocks also confirmed that mass (gravity generated by mass) also 'slows down' time. As does velocity etc (according to an observer).

In fact if we built a space craft that was capable of say, 99.9 % the speed of light and this craft left earth and went to the nearest star (around 25 light years my memory fails me) then returned to earth, the astronauts would have aged a few decades while earth would have aged thousands to millions of years depending on the final percentages of speed. According to science 100% light speed would be impossible because as velocity increases so does the mass of the object being moved. Attempting 100% light speed can not be done because there is not enough energy in the entire universe to attain 100% the velocity of c. There may be shortcuts to faster than light travel such as warping space or entering a rotating black hole but those are pie in the sky science fiction proposals even if theoretically possible.

I hope this helped. Any of the claims made in this reply can be confirmed by validating with a search engine. I would be happy to clarify or expand on any claim made, even though its all from my faulty memory.....

reva

There is no such thing as time, so how is time travel possible? There is no before or after, just now. There is no place to go, just here and now. Time travel theorist are not much different than those who faithfully believe in fanciful theologies and fairytales IMO.

What we call time is nothing more than the naturally occurring physical activity of this universe we exist within. There is no forward or reverse, just now... and now, and now... ad infinitum. What has happened has happened, what has not yet happened cannot be known or visited. But by all means, keep banging your heads against the wall...

Originally Posted by The DARK LORD

Ive always thought it was possible, but not in the ways that are usually expressed. Such as, you cant go back and kill your grandfather, its counterintuative and down right impossible.
I dont think of time in terms of a linear unit, go to the left, and you go back in time, to the right, forward in time.
I see it as a 3 dimensional existence, and once something occurs, its done, over with.
Time is relative, just like everything else, and you can calculate time by the distance of an object, and the speed of light.
Theoretically, you would need to go faster than the speed of light to time travel, but of course we have to figure out how to do that.

EVERY THING we see, touch, hear or taste, is from the past. For example, we know that we can see stars that in fact have burnt out 10,000 years ago and no longer exist. So we are experiencing time from 10.000 years ago.
Now the same can be said of everything else, it may be a min ute amount of time, but it is time non the less.
When you see an object, you dont really see it, you see the light reflecting off of it, which is why we cant see glass, light doesnt reflect off it.
But for objects that do reflect light, by the time we "see" it, time has gone by and we are experiencing the past.

Now, lets say one is adjacent to a star 11,000 light years from earth. One day it totally collapses then explodes, no longer existing, at the moment it stops to exist as a star, you travel to earth, at twice the speed of light.

So when you arrive on earth, which took 5,500 light years, the light from the star is still on its way, so you can see an object you already know doesnt exist, for another 5,500 light years of time. You have experienced something that has occured 5,500 light years ago.
So, when on earth, you have already experienced the death of a star "which is still there" so you were back in time when next to the star, in relation to earth time.
So, "what time it is" present, future or past, depends on how far away an object is, and how fast you can travel.

I dont believe in alternate universes.

If you want to prove that time travel is possible, you either have to show that it's possible to travel faster than light or find some alternative means (and demonstrate that).

I'm told it's possible to essentially distort time by traveling very near to the speed of light, such that time passes more slowly for you than for Earth and every other slower-moving mass, but obviously that's not getting back to the past.

I for one see the notion of sending one's self back to the past as purely impossible, because we're talking about separating ourselves from spacetime and arbitrarily mucking about in a way that is simply not possible in our normal condition. I feel that we are ultimately too much an ingrained part of the universe to be able to break its fundamental laws.

Originally Posted by leftlegmoderate

There is no such thing as time, so how is time travel possible? There is no before or after, just now. There is no place to go, just here and now. Time travel theorist are not much different than those who faithfully believe in fanciful theologies and fairytales IMO.

What we call time is nothing more than the naturally occurring physical activity of this universe we exist within. There is no forward or reverse, just now... and now, and now... ad infinitum. What has happened has happened, what has not yet happened cannot be known or visited. But by all means, keep banging your heads against the wall...

Agreed 100%. Time is an illusory concept for describing the pace at which the observable happens. We are entirely subject to spacetime, as much a part of its matrix as every other form of matter and energy. The concept of time travel is pure hubris (and flawed thinking).

Originally Posted by RevAnarchist

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Special relativity shows that time behaves somewhat astonishingly like the three spatial dimensions. Lorenz equations demonstrate indicate that. Length contracts as speed increases. Time expands as speed increases.

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I was really amazed at that concept when I saw Carl Sagan describing it in an episode of Cosmos. The idea that something going that fast could be "squashed" in the direction it's moving is certainly a strange thought. Personally, I'm thinking it has everything to do with the expansion of spacetime since the Big Bang. I don't know how the speed of cosmic expansion and the speed of light compare - I expect the rate of cosmic expansion is considerably slower. I get the inkling, though, that if something could in fact reach the speed of light, that would completely alter its state and quite possibly obliterate it completely. Further, it's like the expansion of the universe is what actually gives us a 3D universe in which to play, and when something gets up to light speed, it cancels that effect out, and so leaves existence (or, as is said, reaches a "barrier" and cannot proceed beyond it. Since it would cease to exist otherwise, this makes sense in a way).

Originally Posted by Durandal

I get the inkling, though, that if something could in fact reach the speed of light, that would completely alter its state and quite possibly obliterate it completely.

I recall reading somewhere that matter becomes 'energy' at that point. Hypothetically at least.

Originally Posted by leftlegmoderate

There is no such thing as time,>>>snip for brevity<<<But by all means, keep banging your heads against the wall...

Well, that is another argument. We could argue that and I may agree because I subscribe to Godel and Einsteins version or reality. There are two kinds of time that physicists recognize. One, intuitive time is denoted by a lower case 't'. The other, space-time or time in reference to its merging with space as a coordinate is denoted as an uppercase 'T'. I would claim that T surely exists. However t is a measurement of entropy and I also feel comfortable saying that both exist. Physicists also claim there is also an arrow of time (best to Google it, its too complicated to explain in this reply). But there should not be. In other words a glass should unbreakable as easily and as often as it breaks. There is no physical law that prohibits a glass from spontaneously reassembling itself. So we are certainly missing something eh? Trust me I gave up on science as the messenger of truth. Its at best the a good guess for the time that a question is asked of it. Its also a remarkable tool when used as 'applied science'. However I am interested in real truth and that is why I study both science and metaphysics/religion. Anyway you might be interested in a little book called ;

A World Without Time: The Forgotten Legacy of Gödel and Einstein
www.ams.org/notices/200707/tx070700861p.pdf
by J Stachel - Cited by 1 - Related articles
Book Review. A World Without Time: The Forgotten Legacy of. Gödel and Einstein. Reviewed by John Stachel. A World Without Time: The Forgotten Legacy of ...

I read it years ago and it was very enlightening, and I bet it will also cover much of what you are claiming. Its a easy read with very little technical stuff in it, just as I like it!

reva

Originally Posted by Durandal

If you want to prove that time travel is possible, you either have to show that it's possible to travel faster than light or find some alternative means (and demonstrate that).>>>> snip<<<<

Time travel has already been proven. The effects of time travel are evident to an unaided observer only at very high velocities ie around 99% light speed. In miles per hour that is around 660 million miles per hour. However time travel has been proven by putting atomic clocks on two plodding jet aircraft traveling at 600 mph and another stationary. The Jet flew across the USA and back. Atomic clocks can cut a second up in to more than a billion pieces. The stationary clock was a few billionths of a second older than the clock on the jet. In another similar experiment the space station was used. It is orbiting at more than 17 thousand mph. The results were the same. In still another experiment one clock was suspended a thousand feet higher than the clock on the ground, yep the clock on the ground was older than the clock a thousand feet high. Anyone know why? It was because the clock on the ground was closer to the center of the earth and gravity was stronger. Gravity stretches ie slows time. That is why time stops in the singularity of a black hole. So the question of time dilation aka time travel has been PROVEN. That is old news really, however you guys do not seem to believe me so here are some resources that confirm what I have claimed;

Hafele–Keating experiment - Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/Hafele–Keating_experimentThis effect called time dilation was confirmed in many tests of special ... That is, clocks at higher altitude are ticking faster than clocks on Earth's surface. ... tests of general relativity, such as the Pound–Rebka experiment or Gravity Probe A. ... using more precise atomic clocks during a flight from London to Washington, D.C. ...

Pair of aluminum atomic clocks reveal Einstein's relativity at a ...
http://www.sciencedaily.com/releases...3142436.htmSep 23, 2010 – ... comprehensible scale than previous measurements made using jet aircraft. ... The moving ion acts like the traveling twin in the twin paradox. ... NIST physicists compared a pair of the world's best atomic clocks to demonstrate ... (Oct. 20, 2011) — General relativity, the joint theory of gravity, space and time ...

NOVA | The Fabric of the Cosmos: Ser...
http://www.pbs.org/wgbh/nova/physics...cosmos.htmlOur perceptions of time and space have led us astray. ... Space. It separates you from me, one galaxy from the next, and atoms from one another. ..... BRIAN GREENE: For over a year, Gravity Probe B orbited the earth, while the team nervously ...... To do this, all you need are a couple of atomic clocks and a jet airplane.


reva

Sorry for the naivety but i suck in physics .
The earth is moving fast , i don't know the exact speed but let's say 60.000km/h if you go 1 hour back in time wouldn't you end up 60.000km away from earth ?

I suck in all math and it was torture to learn it by rote over and over and over while my friends seemed to get it the first time. If I had not had been so curious I would have burned my math text books...Its like playing chess or checkers or a vid game though. After you learn the basics which drive you nutty it gets real easy...

Anyway I think you are talking about light speed. The earth is orbiting the sun in relation to a stationary object in the solar system at about 67,000 mph. However the sun in relation to a stationary object is moving at over 500,000 mph! Then there is the speed that our galaxy is moving in relation to the other galaxies....but I digress....

So even at the incredible speed of 500,000 mph, its not even a light second (a light second is how far light travels in one second, which is about 186,000 miles per second) or about 186,000 times 60 a min. But to answer your question in a ball park fashion (sorry I am in a hurry and lazy too) if you went back in time one second you would be in another universe! (backwards time travel is not possible but we will say we have learned to travel back in time by going faster than light). The reason being is to avoid a paradox. But that is all speculation and barley theory. The universe you entered would be nearly the same as this one according to our best minds....

reva