Predicting the future: traversing the dimension of time
Traversing the dimension of time
Since the ancient times the concept of moving through time has fascinated mankind. H.G. Wells, in his famous book titled “The Time Machine” has described a story of an inventor building a time machine to travel to very distant future, which, unfortunately, turned out to be pretty bleak with humans living in cages. I personally thought Jules Vern did a much better job at predicting the future in his stories about futuristic submarines and travels to space in rockets. But, enough with the small talk introduction, let’s get to the juicy stuff.
Time is a very interesting phenomenon. One could compare it to a dimension. But it is not like a dimension, because if you take one of the regular 3 dimensions, one can travel along them freely with varying speeds. In time, however, we can only travel in one direction, forward, and also only at a certain speed.
The fact that is completely fascinating is that time is very much linked with speed, which makes the comparison to a dimension even more substantial. What Einstein predicted and was later proven by scientists was that comparative amount of time is different for two objects when one is traveling close to speed of light when compared to another object. This can be illustrated in a simple example. If we put a person in a spaceship and send them to our nearest star and that person travels close to the speed of light for let’s say 10 years one way, and 10 years back, much more time would have passed on earth than on his spaceship. I am not really sure on the exact numbers, but when he comes back, what was 20 years to him might have been 200 years on earth.
Why is this happening? Clearly, time has a direct relationship to speed. The faster an object is moving compared to another object, the slower time SEEMS to them. Keyword here is seems, and time turns out to be a relative term, just like speed is. Earth is currently moving thousands of kilometers an hour orbiting around the sun. This speed is comparative to the SUN, but we don’t feel it since we judge it comparative to the earth beneath our feet.
Light and it’s speed are two very important points in our discussion. Light, or any other electromagnetic radiation, always moves at a constant speed c, which is about 300,000 m/s. Two important quotes from wikipedia: “locally light in a vacuum always passes an observer at a rate of c” and “the speed c of electromagnetic radiation does not depend on the velocity of the object emitting the radiation”. This is a very interesting concept, since light doesn’t seem to behave like a normal object. Why? Because if you throw a normal object off another moving object, their speeds are combined. Not true with light! Light always seems to travel at a constant to the observer. Can this suggest that the speed of light is always the same relative to vacuum, which means that we could consider vacuum or space stationary, meaning not everything is relative in this world, like Einstein suggested.
Let’s get back to our discussion of time. We’ve established that we can bend time with speed. However, we can only bend time a certain way. If we want to “fast forward” to the future, we get into a spaceship and travel away at a speed of light and come back. What if we want to slow down time? Will standing at an absolute standstill compared to an observer on Earth accomplish that. But standing absolutely still relative to Earth or relative to something else? Since this area of science doesn’t have enough research, we will skip over to the next section.
By Serge Bronstein