For a long time humanity has entertained the idea of going back in time to change the past, or going forward to see what the future holds. Physicists have been exploring ways of accomplishing this for almost as long as the idea has been around. Even though they haven’t been able to prove that a certain method will definitely work, there are several theories which show how this can be achieved. It is not expected that this will be done in our generation, but with continued research and exploration our civilization will one day make that physical journey through the ages. Some of the ways in which we may get there are:
- Going through an Immense Black Hole – Black holes are extremely dense, so moving through one significantly slows down the speed at which time passes. If a spaceship enters a black hole its physical movement would be half the speed of one that was moving anywhere outside. This would enable it to enter in one period of time and reappear in another.
- Travel at the Speed of Light – Light travels at the unbelievable speed of 186,000 miles per second. If a spaceship was able to accelerate at the same speed it would be possible for it to leap into the future. Unfortunately, even if we were able to achieve this, the spaceship would have to make the journey without passengers as the human body would be unable to withstand the pressure resulting from the jump.
- Cosmic Strings – Cosmologists have observed these one-dimensional cracks in the universe closely enough to conclude that they might be the key to allowing humans to travel in time. They are thought to be either infinite or looped and each contains a large amount of mass. This makes it possible to twist time around them, if two of them are parallel. This connection would then create a bend in time and space, allowing us to make the journey. In order to facilitate this, our society would need to drastically increase the control we have over our energy resources.
- Wormholes – These are connections, or bridges, through time and space that scientists are certain exist throughout the universe. So far no wormholes have been discovered, but time travel would be possible by manipulating their entrances to make a path or road from one to another. The only problem physicists think might prevent us from using this method, if the possibility arises, is the fact that there might be a significant amount of radiation caused by the manipulation.
Einstein’s theory of general relativity proves that time travel is possible, and as our knowledge of the universe expands scientists will continue to work towards finding a way to make this possibility a dream come true.