Is time travel feasible?

Question

If the future has not happened, how would it be possible to travel through it? if someone goes back in time and kills their grandparents, would the granchild cease to exist? Also, if that grandchild travelled back in time, how can they travel forward in time to get back home if the future does not exist?

Is time linear or is there or are there alternative time lines, if so, are they linear too? If we travel across time and do something in an alternative time line, would that affect other time lines?

Answer 1

no, time is an artificial construct imposed for convenience.

Time varies within different frames of reference because the things we use to measure time change according to Lorenz contractions.

Answer 2

I heard of a guy that said time travel was only possible going back but not forward into the future as the future hasn't happened yet

Answer 3

To travel in time you would need to travel at the speed of light which is impossible because it requires infinite energy which is impossible because there isn't infinite mass.

Answer 4

Yes.

At the moment  we have a very limited knowledge in this area, and seems impossible to us at this time, but just because we can't understand it doesn't mean it's impossible.

It will probably be possible in the future when we have a better grasp on how the universe works and on ways to manipulate time.

Answer 5

The future has not happened for us but actually in the sight of God everything has happened and finished. We have died and reached our destiny heaven or h**l but we do not know it. Second point no one the exact definition or nature of time except God so we cannot say much about it.

Answer 6

Travelling at high speeds (as close to the speed of light as possible) is in effect travelling to the future. If you're the traveller, your time slows down in relation to the earth. At the speed of light, your time stops completely. Then, when the time comes for you to "pop out" of the speed of light, you will instantly find yourself in whatever year or millenium you do that.

Travelling back in time would be much more difficult, if not impossible.

Answer 7

it's certainly theoretically possible, but it appears it would be extemely difficult in practice, so it's probably not a practical proposition.

Answer 8

it is, but it is a very very very complex process (and theory),

so because it has seldom or never been actually accomplished, most people choose to say, "no"

Answer 9

According to Professor Stephen Hawkin, yes. He explains the theory in a Brief History of Time, I didn't understand a word of it.

Answer 10

Einstein published his Theory of General Relativity in 1915 but it was not until the late nineteen forties that, the Austrian mathematician, Kurt Godel found a time travel possibility within a solution to some relativistic equations. He found, that if the universe is rotating then time travel in both directions should be possible. By both directions, I mean, into the past and back or into the future and back. Alas, recent observational work used to study the cosmic back-ground radiation has indicated that the universe has not rotated significantly since its creation. Hence, time travel into the past would appear to be impossible.

However, Einstein's theory of Special Relativity allows 'time-dilated' travel into the future. If an astronaut sets off on a journey travelling at a high percentage of the speed of light, then his on board clock will run more slowly than an equivalent clock here on Earth. Thus, when the high speed traveller returns after a few years of his elapsed time; here on Earth many hundreds of years may have elapsed. The time dilation equation is given below: -

t(Earth) = t(traveller)

..............._________

...............√(1 - (v/c)²)

Where 'c' is the speed of light and 'v' the traveller's velocity, which may be expressed as a percentage of the speed of light ((say) 0.99999c).

So, to summarise, the answer appears to be that you cannot travel through time into the past but you can travel into the future - at least theoretically!

Answer 11

No.  Besides violating causality (the grandfather paradox that you talked about), you could violate several other laws such as conservation of energy/mass and having the same matter exist in two places at the same time.  Time travel is the result of wishful thinking.

However, time warping is possible and has been experimentally verified.  With sufficient energy, you could travel at an extremely high speed relative to the Earth, essentially allowing you to travel into Earth's future.  For example, if you maintained an acceleration roughly equal to Earth's gravity to the nearest galaxy and back, it would take you on the order of 30 years...meanwhile 10s of thousands of years would have passed on Earth.

Answer 12

It all depends on who you ask in regards to this question.

First, the question you posed about a grandchild killing their grandparent and ceasing to exist is the basis for what is known as the Time Loop Paradox. Some have gotten around this by suggesting that their are alternate dimensions, or that one is created by traveling in time...so that both the grandchild can and can't kill the grandfather. This also leads into whether or not time is linear.

Time travel has been suggested to be feasible, but HIGHLY IMPROBABLE.