Verified answer

Traveling forward in time is something we all do every day at a pretty constant rate of 60 minutes every hour. In fact, we cannot prevent this. Every 6o minutes, the Universe becomes one hour older. Someone mentioned traveling at near light speed, but this doesn't alter anything. In the spaceship involved, an hour will still last 60 minutes, and time to an outside observer will last the same. It is only when the inside of the ship is visible to the outside observer will a difference be seen. This isn't really time travel in any meaningful sense. Travel into the past will, in the minds of most physicists, never be possible. This is because of the violation of several fundamental laws of physics. Firstly it would violate the laws of cause and effect, that is, every event has a cause which MUST precede it. Secondly, it would violate the laws of conservation of energy and mass, in that the time machine would have to exist in an infinite number of time frames all at once, but what is also not often realized, it would violate the law of conservation of angular momentum. The Earth, in it's orbit around the Sun would likely be in a different place in that orbit, leaving a putative time machine not on the Earth's surface, but in space. Even more extreme, the Solar System itself would be in a different point in it's orbit around the galaxy. It also would involve a reversal of the laws of entropy, and akin to a broken glass reassembling itself and jumping back onto a table. In the quantum world, the probability of this is not exactly zero, though it is vanishingly small. In the macro world, the probability is nil.

Going forward is possible, in a way, if you go a bit faster than lightspeed out of the solar system for around 7 years eath will have aged around 500 years while you only seven. Not sure who's theory this is but it is true.

no, that's impossible, its all sci fi, traveling at light speed makes it possible to leave earth and return several years later, you'd look the same but people on earth would had passed a lot of time while you were traveling, but we don't even have such space craft to do that. we can't even get to mars which is our neighbor. hey, not even the moon! we will have to wait like until 2020 for those missions to get place! at this pace i see time travel impossible

Idk. There are many theories out there, but they are just theories, and even if it is, currently we do not have the technology to test it because I bet it would require a lot of energy, maybe even the energy of the entire sun (I don't know) or more.

But there are theories that say time travel forward is possible but not backward.