time travelling?

Question

they say its impossible to travel through time, no matter how advanced technology is. Why?

Answer 1

You can't move through something that doesn't exist! Time is not a NATURAL feature of the universe but simply a concept invented by our species to separate events into past, present and future. There is no Cosmic Master Clock that keeps track of absolute, universal time. There is no physical "past" trailing along behind the "present," nor any physical "future" waiting up ahead for us to get there.

Answer 2

I am not sure if you are asking why "they" say this or whether you are asking why it is impossible. Anyway, I will try to answer both questions.

"They" say it is impossible, partly because if it had been done, or if it will be done, then someone would have/will have done it, yet there is no record of us having been visited by someone from another time (unless you include the speculation about UFO's).

So, now to the question as to why it is impossible......

In my view, personally I do not want to travel back in MY time, because that would mean that my biology would reverse, my heart would reverse, I would be breathing in CO2 and breathing out O2....basically it would not work, and THAT's what you have to remember.

If you are talking about travelling through someone else's time, then that is a different matter. As individuals, we cannot travel faster or slower through our own time. We simply travel "forward" at one second at a time.

Anyway, that is simply MY limited view.

Answer 3

In all of science, the there are only two instances where it might be possible to somehow USE time. It is correct that we cannot control it as previously stated.
One would be a wormhole. This is two black holes touching and creating a tunnel which due to the tremendous gravity bends time and space. Thus theoretically if one were to enter a wormhole, they would enter a different time or dimention.
The second is speed. According to Relativity, if one were to go the speed of light, time would slow down considerably.
The problem with the first theory is that a wormhole has never been detected and black holes themselves are quite hard to find. The problem with the second theory is that in order for something to achieve the speed of light, it would require an infinate amoun of energy. Thus impossible for any form of matter.

Answer 4

Time travel in the conventional sense (e.g. Back To The Future movies) is impossible.

The universe is a non-deterministic entity until it hits the "present". Quantum mechanics is a good demonstration of this. In quantum mechanics, you don't know the state of something like electron until you measure it. But once it is measured, it has been changed.

In order for you to travel to the future, that future would have to deterministic. This would imply that even having knowledge of the future, you would be unable to change it.

As the universe is non-deterministic, if you tried to travel to the future, you'd see a big grey haze as the very act of you observing the future would change the future. A good demonstration of this type of feedback effect is taking a video camera, hooking it up to a TV, and then pointing the video camera at the TV.

Now what about going into the past. The famous grandfather paradox. You build a time machine, go back into the past, and kill your grandfather.

Well, you run into the same problem. Despite the fact that the past is set, the very act of you appearing in the past immediately causes the time you came from to become non-deterministic again. You'd immediately phase out of existence at the same moment you appeared in the past.

How it would appear to you is that you hop in your time machine and nothing would happen.

This is with our current understanding. There are a number of hypothesis out there that could allow for time travel but not in the conventional sense.

For example, time travel to the past and future would be possible if the act of observing spawned new timelines (seperate universes). Unfortunately this would mean one way trips, since as soon as you travelled you'd be in the new timeline and have no way to get back.

Other hypothesis suggest that if you exceed the speed of light or are in a strong black hole, space-time could be warped enough to bend back on itself, essentially running time in reverse. Not that you'd really be able to observe anything since under such circumstances as all 3 spatial dimesnions would be inverted. Try picturing that one.

With our current knowledge though, there is a lot of evidence to suggest that time travel is highly unlikely. That's not to say that it can't be done, just that it would be exceptionally difficult and present all sorts of problems.

~X~

Answer 5

Actually, we can travel through time. According to Einstien, when you accelerate, time slows down for you. Every time you board an airplane and accelerate, you travel into the future with respect to those on the ground. This has been demonstrated with the advent of atomic clocks. Extremely accurate atomic clocks were synchronized, then one was put on an airplane and sent on a trip around the world. After it came back, the time shown on the traveling clock was slightly behind the time on the clock that remaind behind. The clock on the trip traveled into the future of the clock on the ground.

Answer 6

And be careful what you say. Not everyone agrees that it's impossible.

Relativity already shows that we can "go forward in time" by approaching speeds close to the speed of light. Getting someone to go the speed of lights the tricky part. Going back in time is even trickier yet. That requires a bit more research than a yahoo answers forum though ;).

While all of this is RIDICULOUSLY Improbable, also remember that it was impossible to get on the moon before people knew how ;).

Answer 7

Because you cannot displace yourself from this existence in time and place.
Remember, also, that the Earth is moving at about 30 kilometres per second, and the solar systen is moving around the galactic centre at about 230 km per sec. So if you disappeared for 2 minutes, and appeared at the same spot, the Earth and Solar system would have moved on in their orbits, leaving you either in space or deep within the mantle. Perhaps people have tried time travel, but forgot this bit of information.

Answer 8

This is because there is no other alternative life which is going on now.If there 1806 alongwith 2006 then there would have been a machine to take you to the past.You can make a machine which takes you to the past:In a room have a huge television covering the whole 4 walls.Then just tune it to say 1956 and just have a slideshow of pictures on 1956 cities and events.

Answer 9

I don't think it's physically impossible for time travel to be attained. It's the time and space "paradox" that's confusing the issue. If you travel to the past and kill your grandfather, how then do you exist in your present and the eventual future of the past moment? That's the paradox supposedly. I think eventually time travel will be possible. Scientists in Australia have managed to "move" particles from one place to another.

Answer 10

Because we cannot (at this time, no pun intended) control time. Time is one of 2 forces we cannot control (along with Gravity). We can control every force except time (and gravity). And until we find a way to control time we will never be able to time travel. And until their is proof we can control time it is considered impossible.