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There are two types of time travel which are shown in movies.

  1. When you sit in time machine , in fraction of second you are in future.It is completely new world , and you know nothing about it.

  2. When you time travel , everything moves in fast forward . You remember what you are doing and what happens around you . Then you are into the future ,and you everything about it. It is just the time moved faster.

Which of the above time traveling method is real and correct? Which will be possible in reality?

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closed as primarily opinion-based by o.m., Alexander von Wernherr, Aify, Frostfyre, DaaaahWhoosh Feb 14 '17 at 14:26

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

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    $\begingroup$ No method of time travel is currently practical. There are some theories which I won't consider sound until someone demonstrates that matter can survive the trip. So the answer is impossible to tell and I'm voting to close. $\endgroup$ – o.m. Feb 14 '17 at 6:32
  • $\begingroup$ @o.m. I have heard space travelers body is slightly younger ,so I believe ...Time travel actually exist .. $\endgroup$ – Amruth A Feb 14 '17 at 12:31
  • $\begingroup$ @AmruthA that's because they travel at relativistic speed. If you stay still, you travel at the same time as the things around you. $\endgroup$ – PatJ Feb 14 '17 at 12:55
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    $\begingroup$ Both forms of time travel in your question are fictional. As fictions they are both correct, depending of which fiction they appear in. In terms of reality both forms of tiem travel are incorrect (as far as current science tells us). $\endgroup$ – a4android Jun 27 '18 at 4:56
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The only method of time travel yet proven is to travel into the future at exactly 1 hour per hour.

This is just like your second option, only without the fast forward bit :-)

I think, though, that whichever of your two options you decide to use (or any one of the other theories used in sci-fi) you are doing the right thing in looking at what your perception of them would be, as that can be an excellent plot device.

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  • $\begingroup$ "exactly 1 hour per hour" : (some noticeable variation may apply while traveling at very high speeds or very near to the event horizons of very large black holes) $\endgroup$ – Murphy Feb 14 '17 at 12:46
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    $\begingroup$ @Murphy No, no, your clock inside your vehicle (I assume you ain't gonna be running) will still show that you travel at one hour per hour; you will still become one hour older for each hour spent traveling. An external viewer, on the other hand, might claim that you are aging at a different speed. $\endgroup$ – Mrkvička Feb 14 '17 at 14:19
  • $\begingroup$ Fair enough, I should have noted "depending on reference frame." but still: "one hour older per hour traveling" would apply even if you were in a working fiction time machine. From your reference frame much more than an hour per hour of your time may have passed on a planet you departed from and returned to. $\endgroup$ – Murphy Feb 14 '17 at 14:42
  • $\begingroup$ @Murphy That is true - I was mainly objecting to that the variation will not really be noticeable until one returns as the ship clocks will claim that one is still going at the same 1h/h. One could, ofc, add a time dilation function to at least one clock on the ship to let it show roughly how fast time flows on the planet one departed from, but then there is also the problem with accurately establishing ones own speed while traveling so fast. $\endgroup$ – Mrkvička Feb 14 '17 at 14:56
  • $\begingroup$ To be accurate you need to be more precise (more significant figures or a smaller time unit). "exactly 1 hour" as written can be anywhere from just over 30 minutes to just under 1 hour and 30 minutes :) $\endgroup$ – Samuel Feb 14 '17 at 20:09
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As of current scientific knowledge, time travel is mainly speculation.

You only ask about forward time travel though, which is not necessarily impossible (though highly improbable).

As far as we know, there is continuity in the universe: you can't teleport but only can move. In fundamental physics, time and space are kinda the same so most probably you can only slide in time, and not jump. That is a good point toward your second possibility.

However, how would that be felt by your traveler? Maintaining senses seems very complicated: if you get light while "traveling two times faster than normal", you'll get twice as much light. Maybe even the same could happen with gravity. So, a fast-forward moving traveler in possibility 2 would be blinded, burnt, irradiated and possibly crushed by earth.

The only non impossible solution I see is to have sliding through time, but in a state where your traveler (and its machine) can't interact with the physical world. That would feel like your option 1 even though it's actually option 2.

Bear in mind though, that it's just the "not impossible" thing assuming handwaved physics. Whatever the how, time travel is highly improbable.

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    $\begingroup$ Forward time travel is possible. We're doing it right now! :-) $\endgroup$ – Kramii Reinstate Monica Feb 14 '17 at 9:51
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If you used special relativity or general relativity — the only real ways to affect time in this way — you would be slowed down relative to Earth.

In reality your machine would not be resting in a lab, but be a ship boosted to nearly lightspeed. You’d fly away and then back. If you monitored a webcam left in the lab, you’d see effects due to the changing communications delay as well. If you corrected for that, you would decide that time on Earth was passing at some fractional speed, and you need to wait long enough to reach the desired future time, and you’ll see everything back on Earth happening at high speed.

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The movies may show two forms of forward time travel, but they are just fiction. Indeed it is unlikely to be correct in reality.

Apart from the normal process of advancing into the future at the rate one second per second, there are several ways of getting into the future "faster". This is where "faster" means apparently faster than the usual one second per second time travel.

Special relativity is the most reliable. This requires accelerating to close to lightspeed in an extremely advanced spaceship, travelling away from the Earth, slowing down, accelerating back to Earth again. With luck and good management your space traveller will come back many years in the future on a much changed Earth. Of course, there is no way of returning to the time he or she departed. The real problem is that such advanced space travel close to lightspeed is so incredibly difficult that it is next to impossible in the sense of being so absolutely impractical as to be effectively impossible.

If your spaceship is even more advanced your time traveller could place his vessel in orbit around a black hole. The extremely strong gravitation will slow down time. This will be combined with the spaceship's relativistic orbital velocity.

The other method involves suspended animation or biosuspension. The time traveller is placed in cryogenic hibernation and sleeps through the centuries until he or she is woken up again.

If there exists a network of wormholes spanning interstellar space, then stepping through a wormhole will carry your time traveller to somewhere many light years distant but also many years in the future. Let the wormhole exits one hundred light years away and this will be one century in the future. If there is another wormhole to take the time traveller back to Earth, then they will arrive back there a century further in the future.

The main drawback with wormhole network time travel is that we don't have access to such a network. Also, we don't know if this is scientifically possible or practical, wormhole are speculative science. The idea can be entertained conceptually.

There are a number of hypothetical ways of forward time travel. None of which look like what we see in the movies. Most of them we do not know if they are possible or practical in reality or in the future. But the science is much more interesting and exciting than what the movies show.

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  • $\begingroup$ @Sefa A good edit. Much appreciated. Thanks for helping to improve my answer. $\endgroup$ – a4android Feb 15 '17 at 1:15

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