Time trip! Is time travel really a possibility?

Question

Einstein had proved the relativity theory. So all can be possible?

Answer 1

The answer depends on what assumptions you make to start off with (postulates in science speak). Steven Hawkings for example, used to argue that it was possible, but subsequently concluded that his postulate was wrong and in fact it isn't possible.

Someone else (can't remember who unfortunately) has shown mathematically that it is possible to travel back in time, but only if someone has already built a time machine in the time and space you want to go back to. Travelling into the future is impossible.

Mathematically speaking, the restriction from Einstein's theory (at least in special relativity, general relativity may add some other constraints) is in travelling at the speed of light, faster than light is possible. Conceptually you would need to reach the speed of light in order to exceed it. In thermodynamics however, there is a similar law preventing temperatures ever reaching absolute zero, but it is possible to achieve negative temperatures (lasers do it all the time).

Remember however that science is all theory. We accept things as fact because they appear to describe what we can observe. Just one contrary observation could change everything (cf Newton's Laws of motion and Quantum / Relativistic Theory)

Answer 2

I am so sorry but talking about time travel does not allow you to speak in terms of special relativity theory nor General theory of Relativity. The difference between this two is acceleration which the relativity theory does not include. We cannot say that time travel is a possibility due to the already proved relativity theory for it in both the theory, it is said that it is not possible that an object can go space like, which is v>c. This is because special relativity implies that all matter must move at less than or equal to the speed of light, V>/=c... or in terms of new jargon, must move on time like or null geodesics. What more, time is also in relation to the things around us, so if you want to know if time travel is really possible, a good way is to prove it on experimental ways, not using the relativity theory.

Answer 3

I'm no expert in physics but I believe the theory of relativity states that time travel is not possible because mass increases with velocity.

Answer 4

No it is not. To produce a temporal wormhole big enough to return the amount of mass of a human being one second into the past would require the energy of all the mass in the Universe. In other words you would have to destroy the Universe to go back one second and in the process destroy yourself.

Answer 5

Sorry, his theory and quantum theories forbid time travel. Can you imagine going somewhere and watching yourself being born. Kind of ridiculous.

Answer 6

You can travel into the future but not back to the past..

In physics, time is described as a dimension much like length, width, and height. When you travel from your house to the grocery store, you’re traveling through a direction in space, making headway in all the spatial dimensions—length, width and height. But you’re also traveling forward in time, the fourth dimension.

Space and time are tangled together in a sort of a four-dimensional fabric called space-time. Space-time can be thought of as a piece of spandex with four dimensions. When something that has mass—you and I, an object, a planet, or any star—sits in that piece of four-dimensional spandex, it causes it to create a dimple. That dimple is a manifestation of space-time bending to accommodate this mass. The bending of space-time causes objects to move on a curved path and that curvature of space is what we know as gravity.

Mathematically one can go backwards or forwards in the three spatial dimensions. But time doesn’t share this multi-directional freedom. In this four-dimensional space-time, you’re only able to move forward in time.

A handful of proposals exist for time travel. The most developed of these approaches involves a wormhole—a hypothetical tunnel connecting two regions of space-time. The regions bridged could be two completely different universes or two parts of one universe. Matter can travel through either mouth of the wormhole to reach a destination on the other side.

Wormholes are the future, wormholes are the past but we have to be very careful. The gasoline necessary to energize a time machine is far beyond anything that we can assemble with today’s technology.

To punch a hole into the fabric of space-time would require the energy of a star or negative energy, an exotic entity with an energy of less than nothing.

Many people who study the subject doubt that that approach has any chance of working. But the basic idea if you’re very, very optimistic is that if you fiddle with the wormhole openings, you can make it not only a shortcut from a point in space to another point in space, but a shortcut from one moment in time to another moment in time.

Another popular theory for potential time travelers involves something called cosmic strings—narrow tubes of energy stretched across the entire length of the ever-expanding universe. These skinny regions, leftover from the early cosmos, are predicted to contain huge amounts of mass and therefore could warp the space-time around them.

Cosmic strings are either infinite or they’re in loops, with no ends, so they are either like spaghetti or SpaghettiO’s.

The approach of two such strings parallel to each other will bend space-time so vigorously and in such a particular configuration that might make time travel possible, in theory.

This is a project that a super civilization might attempt. It’s far beyond what we can do. We’re a civilization that’s not even controlling the energy resources of our planet.

Impossible, for now

Mathematically, you can certainly say something is traveling to the past, but it is not possible for you and me to travel backward in time.

However, some scientists believe that traveling to the past is, in fact, theoretically possible, though impractical.

Maybe if there were a theory of everything, one could solve all of Einstein’s equations through a wormhole, and see whether time travel is really possible. But that would require a technology far more advanced than anything we can muster. Don’t expect any young inventor to announce tomorrow in a press release that he or she has invented a time machine in their basement.

For now, the only definitive part of travel in the fourth dimension is that we’re stepping further into the future with each passing moment. So for those hoping to see Earth a million years from now, scientists have good news.

If you want to know what the Earth is like one million years from now, this is how to do that. Build a spaceship. Go near the speed of light for a length of time—that some mathematician could calculate. Come back to Earth, and when you step out of your ship you will have aged perhaps one year while the Earth would have aged one million years. You would have traveled to Earth’s future.

Answer 7

I've been traveling in time ever since birth....in the forward direction....and its beginning to show.

Answer 8

Anything is possible, just have to wait on technology to catch up.

Answer 9

Only in Sci Fi. where the imagination is limitless.

Answer 10

I think so but it might require both magic and science.