I beleive it is possible. Time does exist, just not in they way you would think of it, like a clock. Once it has gone by, it is not truly gone. This concept may be easier to understand if you think about how light travels. Everything you see is light bouncing off of matter or being absorbed into it. Something you see that is white, is light bouncing back. Black objects are light being absorbed into the matter of the object. The way in which light is reflected and refracted is due to the chemical composition of the object. This also means that everything you see is from the past, even though it was an octillionth of a second of delay to reach your eye. When you look into the sky at night and see stars that are lightyears from earth, you are looking billions of years into the past. So, through this concept of light traveling great distances through a vaccuum, time travel is possible. It depends on the speed at which something, such as light, is traveling. These ideas may be hard to understand, but let me explain a bit further: Wormholes, Black holes, and White holes are the three extra terestrial phenomenons that lead us to the beleif that actually traveling through time is possible. On this thought, Wormholes are thought to be holes in time and space that are like a shortcut through space and time. Black holes are similar, except matter sucked into a black hole is condensed so much a person would be one million times smaller than a standard skin cell. White holes are the opposite of Black holes. White holes seem to endlessly pour matter into space. There is thought to be a relation between White and Black holes that suggests matter from a black hole ends up coming out of a white hole in a different time and place, acting similar to a worm hole. White holes and Black holes stay active for millions of years before dissipating, and worm holes may last as long or only for a fraction of a second. Now besides what I have learned, here is my theory: we have broken the sound barrier in speed, but for time travel to be possible we need to go faster than light. We will never go this fast in a shuttle or spacecraft, it is not physically possible for a human to be moved at that speed. In my eyes, time travel will be possible through worm holes ( shortcuts, or folds in space and time ). These holes are unstable and unpredictable though, and could spit you out in another time and place. We must learn to open wormholes, keep them open, and control them for our own use. I don't think it will be possible for a long, long time after our generation or the next 30 generations have gone by. Oh, but time travel is most definitely possible, and will be made so sometime in the future. but research on time and space travel will cost so much. There's likely other planets like ours that are inhabitable, but the human race will likely destroy themselves in wars and self conflict. Greed is the instinctive way of the human race. And no i didn't steal this from a website or article, this is what i have learned and this is my theory. Maybe you learned from it or developed your own set of ideas. Whatever the case, may my knowledge enrich your mind =p.