Time Travel - What's It All About?

Question

Could someone explain to me the theory of 'time travelling' in a nutshell (if that's possible) please?

PS: I've read the Wikkipedia but couldn't understand the jargen

Answer 1

Only a few minutes before leaving work, so I'll give you one aspect on the theory. Generally speaking, let's discuss Einstein's theory of relativity. Basically, velocity and time are relative. If I'm floating in space and you float by me...I can say I am stationary and you are moving....OR from your perspective, you can say you are stationary and I am moving...Time plays out kind of funny with this too.

Assume the earth is your point of reference as a "non-moving body." The faster an object moves relative to the earth, the slower time moves. This has been proven with atomic clock tests...For example, synchronize 2 clocks. One is on the surface of the earth. A second is loaded on a plane and flown at 600 mph around the world...Compare the clocks...the one on the plane will be slightly behind the one that was "stationary." The math to prove this can be found in any modern physics textbook.

NOW, the faster and faster you go, the more pronounced this time-dilation effect is. Light is massless, and always has a constant velocity, c (186,282 miles per second). Einstein's theory says that c is the absolute speed limit in the universe. An object like you or me in a spaceship can get closer and closer to the speed of light, but can't ever quite get there. Also the closer we get, the slower and slower time passes for us relative to those on Earth. So if we jump into a rocket ship and streak away at 99.99% the speed of light, turn around and come back... maybe a year passed for us, but on Earth, 2 years went by...this is sort of like time travel into the future but is really more of a difference of experiencing time ticking by as opposed to actual time travel (by the way, I'd have to work the numbers--I'm not sure of the actual time difference off the top of my head if traveling at .9999c).

Also, the closer and closer you get to the speed of light, the more massive you become and the more energy it takes to go even faster...which is why nothing of mass can ever reach the speed of light. IN THEORY, if you did reach the speed of light, it would take infinite energy, you would occupy every point in the universe simultaneously, and time would stand still. If you exceeded the speed of light, you could literally travel through time as opposed to the "time trick" of 2 different reference points experiencing the passage of time at different intervals as in our rocket ship at 99.99% c example demonstrated.

Answer 2

along with other esoteric explanations about Einsteins view of the world, its necessary to understand that the prediction was that space and time is in fact spacetime, turning it from a 3-dimensional habitat to something which is in fact 4-dimensional.
whenever something is moved in relation to something else time is a variable, cause einstein showed, that the speed of light is fixed to approx. 300.000 km/sec
now time along with that means: The more you get up to this speed, the more the rest of the universe speeds up in time.
so once accelerated to a good portion of 'c' and slowed down again, you will notice that your time ran slower than the time of an external observer.
This prediction was already proofed with an atomic clock onboard of an airplane compared to a clock on the ground.

so we have evidence that travelling forward in time is possible and HAPPENS but just in very tiny ammounts since we aren't fast enough.

Travelling back in time is a totally different thing.
this was believed to be possible creating a so called wormhole (mathematically described bei Einstein/Rosen) which was like warping space(time) to the point that two different points in spacetime get very close to each other, by means of using a strong gravitational force.

calculations later being done by Kip Thorne showed that such a hole can in fact exist, but is too small to pass through, and can't kept open long enough, even by 'inventing' exotic matter for especially that purpose.
the idea of using such a whormhole was to put the exit in a position in spacetime near the entrance at a time prior creating the entrance... spooky ? yep
and theoretically it works for a tiny tiny fraction of time.

according to Feynman describing Quantumnelectrodynamics
such a behaviour of subatomic particles happens here and there, but unfortunatly just below the planck scale.

its widely believed that such functionality on our scale should be ruled out by physical laws, and as long as there is no satisfying theory how the quantumn world is connected to our scale the question of time travelling remains unsolved

Answer 3

I normally want floor return and forth, yet for long journeys, air return and forth is a lot quicker, so i might desire to apply it if i'm in a great hurry. i've got moved from the East Coast to the West Coast, and positively one of those holiday takes approximately 4 or 5 days by motor vehicle, if i do no longer quit long everywhere, yet there is a lot exciting environment alongside the way that I omit by air return and forth.

Answer 4

Time travel, concerns us of present time moving into either our own physical past or future, and it is impossible. The physics trilogy: E = mc2, m = E/c2, and c2 = E/m describes the formation of our universe. The last of these is that of a field of physical time, or that of a field of gravity. Notice that in these equations that the value of "c" is the basis of each. In the "E" value mass is multiplied by "c". In the "m" value energy is divided by "c".

The value of "c" itself is one of velocity. It is this velocity that forms all mass and energy. It is for this reason that all physical time passes from the "present" into becoming that of the "past" at the same speed. This value states that there is nothing existent in our universe but "present time" at any one instant, then "present time" immediately becomes that of the "past". Because there can only exist "present time," there is no manner for mankind to exit this value - nothing exists to us but "present time."

The physics trilogy also states that as the universe is composed of the value of "c", that this also includes ourselves. We are totally composed of physical time. The end result of the limitation of "c" means that all people who have ever lived, have their physicial existence upon earth yet today, their bodies have changed into dust and gasses. Those who shall exist in the future also have the basis of their existence within present time of today, they just haven't been put together yet. There can only exist to us the "present" and nothing else can exist to us.

Lastly, there is the twin paradox. Where one of two people move through space at the speed of light and the other remains home. The one in the spaceship does not age and the one at home does. This is due to a mass becoming one with physical time as they approach the speed of light.

There is a short writing at http://360.yahoo.com/noddarc "Time, Gravity, and Energy" that may be of interest.

Answer 5

Time is the fourth dimension, so it should be theoretically possible to move along it. It would take an INTENSE amount of energy though. Black holes are able to warp space time in this way.

Answer 6

As the song goes ---It's impossible

Answer 7

http://en.wikipedia.org/wiki/Time_travel