Sci-fi movies have always been quite popular, harboring extensive technology which we just don’t have right now. This can be time travel, cloaking devices, force fields, and even faster than light travel. I’d like to reveal however, that we actually do have quite a few therories on how to get these ‘extreme’ sciences working in reality. The only drawback is that we don’t have the equipment necessary to actually pull them off.
A few people (including myself), have always been fascinated by the concept of being able to travel through time. This is actually not as difficult as you’d think to pull off. This, of course, is implying that you can control space and do as you please with it. The theory I am going to be tackling deals with wormholes, spatial anomalies where if you go in one end, you should come out of another end somewhere else in space. Of course, nobody really knows how these things work completely, again those are more theories.
Using these wormholes, there are two approaches to achive time travel. Both of these make use of a little theroy Albert Einstein is well known for, relativity. There are two kinds of relativity, but for this case we will only be focusing on one: special relativity. More specifically, the time dialation effect. Time dialation is basically where if something approaches the speed of light, or is next to a very high density mass (such as a massive star) time actually ‘slows down’ slightly.
For the first approach of time travel, take one end of the wormhole, and accelerate it to extremely high speeds. Speeds which we cannot even hope to accomplish within our lifetimes. Lightspeed for this example would do quite well. Time from this specific end of the wormhole would seem to slow down by a large margin. The other end of the wormhole however, is still floating at the normal time and space. If you were to merely pass through the non-accelerated wormhole, you would actually emerge from the side which has been slowed down. Or in the past. For example, a clock on the stationary end would read 2020. However, the clock on the accelerated end may only read 2012.
The second way of going about this is using a large gravity source, thus taking use of the other part of the reletivity theroy. You place one end of a wormhole at a super-massive body. Granted this would need to be more dense than any star in existance. Using the time-slowing motion there, you merely pass through one end and yet again emerge in the past.
The one quirk to these method, is that you can only travel back in time to the spot on which the wormhole was accelerated or slowed with a gravity mass. You cannot go furthur than this was setup. No visiting the cavemen it seems.
The ability to move one end of a wormhole however isn’t necessarily possible with our capacities. Nor is it something which seems to be a projected project in the future. No visiting the past within our lifetimes sadly.