Hello and Welcome back on Curiosity.gr. In this article I want to talk about time traveling, how it works and why you actually travel in time every day.
As the “normal” three dimensions we know, time is a dimension too. But while we can freely move in our room dimensions, moving freely in time would be called time traveling. While it is physically doubtful that traveling backwards in time is possible because this would create logical problems like killing your own grandfather, traveling forward in time is possible and you do it every day.
But how is that possible? To understand time traveling, you have to understand first of all the real nature of time: Time is not absolute, but it’s relative. That means that there is no universal time that we all have together but that everyone of us has his individual time which passes more or less fast depending where we are and how fast we are moving.
This phenomenon is known as time dilation and is described by Albert Einstein in his relativity equation. So, if you want to travel to the future you have to make sure that your own time goes by slower than the time of most of the other people. The resulting effect would be that while for you for example five minutes are going by, for the rest of the world five hours are passing. Voila, you’ve just traveled four hours and 55 minutes into the future.
But how can you slow down your individual time? According to Einstein there are two ways to cause a time dilation.
The first of them is motion. The faster you move, the slower time will go by for you. That means, if someone walks around, his time passes by slower than the time of everyone standing still. For the moving person himself time feels normal but when he stops moving, he aged less than everything that did not move. He traveled through time. Unfortunately, there is only a very tiny difference between the two people. Even if one of them would spend the whole day in an airplane traveling around the earth at 900 km/h, he would only age 0.00000003004 seconds less than the one who stayed at home. So, as you notice, all our daily life movement would not be fast enough to cause a real difference. For traveling a few years into the future, you would have to move nearly at the speed of light but at least today, humans are not able to accelerate any objects up to such an enormous speed.
The second possibility Einstein found out about is gravity. The closer you are to a heavy mass, the slower time goes by for you. With a little bit of technological progress, it could maybe be possible one day that an astronaut passes with a rocket nearby a black hole. The enormous gravity exerted by the black hole would make the astronaut aging so slow that after one year flying around it, depending on how close he passes by, over 50 years on earth would have passed by in the same time and he would probably be younger than his own son. That sounds crazy right? Visit us again next week if you want to know more interesting science facts or crazy stories!
Sources: https://en.wikipedia.org/wiki/Time_dilation, https://www.phy.olemiss.edu/HEP/QuarkNet/time.html