Is it possible to time travel? If yes, how? If no, why?

Answer 1

Time travel is the concept of moving backward or forward to different points in time, in a manner analogous to moving through space. Additionally, some interpretations of time travel suggest the possibility of travel between parallel realities or universes.

Some theories, most notably special and general relativity, suggest that suitable geometries of spacetime, or certain types of motion in space, may allow time travel into the past and future if these geometries or motions are possible. Concepts that aid such understanding include the closed timelike curve. The Keiser/Hart theory of propulsive length contraction sets forth a theoretical schema by which an instantaneously massless vessel may reach a distance x in a time that is less than the amount of time light would require to travel the same x.

Albert Einstein's special theory of relativity (and, by extension, the general theory) very explicitly permits a kind of time dilation that would ordinarily be called time travel. The theory holds that, relative to a stationary observer, time appears to pass more slowly for faster-moving bodies: for example, a moving clock will appear to run slow; as a clock approaches the speed of light its hands will appear to nearly stop moving. The effects of this sort of time dilation are discussed further in the popular "twin paradox".

A second, similar type of time travel is permitted by general relativity, where a distant observer sees time passing more slowly for a clock at the bottom of a deep gravity well, and a clock lowered into a deep gravity well and pulled back up will indicate that less time has passed compared to a stationary clock that stayed with the distant observer.

These effects are to some degree similar to hibernation or hypothetical suspended animation (which slow down the rates of chemical processes in the subject), and only allow "time travel" toward the future: never backward. They do not violate causality. This is not typical of the "time travel" featured in science fiction (where causality is violated at will), and there is little doubt surrounding its existence. "Time travel" will hereafter refer to travel with some degree of freedom into the past or future of proper time.

Many in the scientific community believe that time travel is highly unlikely. This belief is largely due to Occam's Razor. Any theory which would allow time travel would require that issues of causality be resolved. What happens if you try to go back in time and kill your grandfather? Also, in the absence of any experimental evidence that time travel exists, it is theoretically simpler to assume that it does not happen. Indeed, Stephen Hawking once suggested that the absence of tourists from the future constitutes a strong argument against the existence of time travel—a variant of the Fermi paradox, with time travelers instead of alien visitors. However, assuming that time travel cannot happen is also interesting to physicists because it opens up the question of why and what physical laws exist to prevent time travel from occurring.

The "presentist" view
Some theorists have argued that the matter of the universe only exists in the present moment. Thus, if one were to travel back from the 'present' to an earlier time, none of the material universe would be found there, because it will have remained in the present: the traveller alone is the only part of the universe to have gone back to the earlier time. In terms of a 4-dimensional spacetime, the traveller (or, more generally the atomic particles that comprise the traveller) would have travelled 'back' to an area of spacetime corresponding to an earlier value of 't'; but none of the other particles that form the universe will have done so, so the traveller finds precisely nothing when arriving back at the earlier time. This viewpoint eliminates all of the supposed paradoxes about time travel.

The equivalence of time travel and faster-than-light travel
If one were able to move information or matter from one point to another faster than light, then according to special relativity, there would be an observer who sees this transfer as allowing information or matter to travel into the past. Additionally, faster than light travel along suitable paths would correspond to travel backward in time as seen by all observers. This results simply from the geometry of spacetime and the role of the speed of light in that geometry.

Special spacetime geometries
The general theory of relativity extends the special theory to cover gravity, describing it in terms of curvature in spacetime caused by mass-energy and the flow of momentum. General relativity describes the universe under a system of "field equations," and there exist solutions to these equations that permit what are called "closed time-like curves," and hence time travel into the past. The first and most famous of these was proposed by Kurt Gödel, but all known current examples require the universe to have physical characteristics that it does not appear to have. Whether general relativity forbids closed time-like curves for all realistic conditions is unknown. Most physicists believe that it does, largely because assuming some principle against time travel prevents paradoxical situations from occurring.

Answer 2

well the guy with long and long explanation above has the most technical answers you would probably get. However, mostly all conclusions are something like mostly based on Einstein's special and general theory of relativity. These therories kind of says time travel is possible whilst denying that it is really a time travel. It is very contradictory topic. ... If you don't know about physics and don't understand what does the Einstein's theories means....keep watching Discovery channel . It frequently show programs which may give you some knowlegde to some extend..

Answer 3

The way i see it, unless what is happening this present has already happened to someone else, then yes i suppose somehow you can time travel forward, because other then that how can one travel to something that hasn't existed yet or occurred.

How to do this i have no idea, seems impossible. only way i can think of is, you freeze yourself for 1000 years or whatever (hoping by then some sort of time travel device exists) then go back in time from there to the point where your froze yourself. Other then that, it really seems impossible to go to a time that hasn't happened yet. It's just common sense.

One way to turn back time tho i guess, is to rotate the earth backwards, SURE time wont wizz by in front of you and everything goes backwards in time, but with the earth spinning the other way, doesnt that mean time goes in a negative turn, not a forward movement =P

Answer 4

Yes... It has been done! By who? Well the Astronaunts. As you may know as a person travels faster time slows down. Well it is very insignificant until you reach near light speeds but it is measurable. So when someone say an astronaunt travels fast to the moon. When they get back, they have moved into the future (earths future) by a fraction of a second measured by difference between an atomic clock in the capsule and one on earth apon return.

As far as going back. I don't know :-)

Answer 5

Albert Einstein's special theory of relativity (and, by extension, the general theory) very explicitly permits a kind of time dilation that would ordinarily be called time travel. The theory holds that, relative to a stationary observer, time appears to pass more slowly for faster-moving bodies: for example, a moving clock will appear to run slow; as a clock approaches the speed of light its hands will appear to nearly stop moving. The effects of this sort of time dilation are discussed further in the popular "twin paradox".

A second, similar type of time travel is permitted by general relativity, where a distant observer sees time passing more slowly for a clock at the bottom of a deep gravity well, and a clock lowered into a deep gravity well and pulled back up will indicate that less time has passed compared to a stationary clock that stayed with the distant observer.

Answer 6

Time travel exists, but not in the way people imagine it. Over 99 % of people watch too many science fiction movies, and they think that time travel means transfering yourself to a different "time instant". However, this is not true. There is only one "time instant" for the whole universe, so wherever you go you will be in the same time instant like all other things in the universe. You canot travel to a "replicate of our universe as its was 10 years ago or 10 years in the future" if you know what I mean. The scientific definition of time travel arises from the fact that "at speeds comparable to the speed of light, time dilates and hence you leave the spacecraft feeling that you have spent and grown 10 minutes, while the outer world has spent and grown 10 hours for instance. However, you end up in the same ordinary "time instant" once again, simply because there exists no other "time instant" but the ordinary one.

Answer 7

It is theoretically possible to travel through both time and space. In the 60s, some physicists worked out a couple of theoretical ways to travel through time, and even slapped together a few rough sketches of how to make the time machines.

Sadly, all their time machines seemed to involve the use of black holes, moving faster than the speed of light, or perfectly straight rods of infinite length, and no diameter.

These physicists didn't worry much about time travel paradoxes, such as "If I go back in time, and kill my mother before she gives birth..." which movies tend to work out to some degree.

Movie time machines have generally had simpler designs, such as a delorian with a blender on it, a phone booth with antennae, or a large machine of folding mirrors, or spinning glass sections.

Movie time travel has also provided us with the "Time travel paradox paradox," which has played out in every time travel scenario ever put into fiction. The time travel paradox paradox states:

"For every movie, rules to avoid time travel paradoxes will be discussed, and every rule that is metnioned will then be broken to avoid enormous plot holes."

Answer 8

It is not possible to travel back in time because the past only exists in our minds it doesn't exist in actuality, it is an abstract. Thinking of time linearly, once time has passed a certain point, that point in time no longer exists. For instance, you can not travel back to the 1800's because the 1800's no longer exist, time has passed that point. We have pictures/ photographs, books, and other publications and writings that demonstrate for us what that time period was like, but you cannot travel back to that time period because it is not there. What has happened has happened and it is done, it is no more. It is only in our minds that the past exists. We study history, but that is all we can do. We cannot relive it because it no longer exists. We can revive historical themes, but it will never be exactly as it was in the time period we are attempting to revive. We cannot travel into the future for a rather simple reason, it has not happened yet. We don't know for a certain what the future holds for any of us. Consider this, five minutes from now you could be dead, but you don't know that now. I know that it is a depressing and distressing example, but you get the point. You must also understand that the future is an abstract not something that actually exists. Just as it is with the past, the future exists only in our minds, it is not actual yet. There are many possible futures for any of us. For example, think of this, there are well over 6 billion people on this planet and each one of those over 6 billion people have choices that they make each one of those choices not only affects their lives, but the lives of people around them and this affects the choices those people make and their choices affect the choices you make and it goes on and on and on in this fashion, bouncing back and forth that way.There are many doors which one can choose to walk through and each one of those doors lead to other doors which lead to still other doors and so on and so forth and again, what about the doors those around you choose and the affect that may have on your choices and the affect your choices may have them... it is this way for all the over six billion people on this planet. People live and die and are born every second on this planet, consider this. Contemplating this for to long will make your head ache. So the future, as we consider it to be, is a highly involved and complicated issue. This is why I don't believe in psychics because no one can ever know enough to predict an exact future for anyone. This is why one cannot travel forward in time, other than the fact that it doesn't exist yet so it is not there, there are an infinity of factors, possibilities, and determinants to be considered and that is beyond any human ability to calculate. I will humor you, lets say it is actually possible, if you were to able to travel to the future which one out of an incalculable number? Consider the consequences.The point is that in actuality only the present exists and all other considerations of time are in our minds.

Answer 9

Yeah Its possible to time travel. You can travel back to your own time. Unless its done consciously. Physical time travel in never possible.

To my experience level. I have traveled back to my time till 18th century. Yeah its possible. There is a link in you with your inner. As there is carbon dating, there is also a date back with you. A bank of information is with in you.

Next comes How to travel. One thing is the de-hypnotism therapy and hypnotize to go back to your past. Its like your being getting back the data from your own memory bank. Unless you become a master with all your conscious then only you can travel.

Caution Don’t ever try to Hypnotize your self to travel back. If you get back and caught at any instance you’ll stant there and will not able to come back to present.

There were a lot of l method to travel back.

Answer 10

Besides travelling at 1 sec/sec like you currently are, no.

To oversimplify, time is the result of matter existing. Without matter there is no spacetime. Time is not fixed. It is not like a river that you can go back up.

Now, if our physical bodies were able to take it, we could slow time for ourselves by going faster through the matter that makes time happen. But, no going backward. If we can ever freeze ourselves you will be able to take a one way trip forward, where you'll wake up probably very poor and ignorant.

Answer 11

yeah. it has been pr oven that if a plane goes fast enough, time will slow down withing the plane, but normal time is a constant outside of the plane.

If the plane goes fast enough, you could actually travel to the future. The problem with that is you only go a few minutes into the future

If you leave earth's atmosphere and go at a rare of 100,000 miles per second, you could slow time down further around you, propelling you into the fut ire by say....40,000 to 60,000 years form now. you could reappear with your ship that you left earth with in that time. But the problem is, you cannot travel back into the past, so you will be stuck there.

there is a website that came up with a theory on how to travel in the past, but it is missing a few principles on relative time-space principles mentioned in the second link