Think for a minute about time. Some of the questions that come to mind may be questions like what is it or does it even exist and, is there a way to prove that time does not exist? People have searched for the answers of these questions since the beginning of civilization to say the least. Very sophisticated ways of measuring time have evolved to what they are today, but time on Earth as we know it does not prove anything about a true concept of time.
The concept of time is that something has a beginning and an end. The period in between is what many people consider time. It is broken into intervals such as days or seconds as it has been throughout many civilizations as long as it is consistent. The movement of the sun and the shadow it casts has been a popular and accurate way of measuring the concept of time. Time is now measured by atomic clocks and by mechanical devices such as pendulums through systems of gears and springs.
Even though time can be defined as a progress from a start to a finish and we have ways of consistently measuring it, does that mean time actually exists? If it does exist then that means we would be able to manipulate it. It has been proven that astronauts are slightly younger when they return from orbit because according to Einstein and his theory of relativity they are traveling much faster than those on Earth, which slows down time. This also holds true with the satellites orbiting the Earth used for GPS. The clocks must be programmed to account for the difference in rate of time. Furthermore, if a person were to travel at the speed of light then time would stand still according to the theory.
The strongest evidence supporting the absence of time is the inability to reverse time. The fact that we have to adjust the satellites could be due to something that is not completely understood. The speed of space travel will need to be accelerated in order to reach significant manipulations of time. The ultimate obstacle concerning time is traveling to the past. Without the ability to move forwards and backwards it is hard to accept the existence of time.
It is clear that time is an abstract thought and that it may never be tangible. For that reason it is practically impossible to either prove or disprove its existence. The same theory that proves time and space are related actually raises doubts about time being an actual dimension. Time is supposed to be consistent but if it travels slower at higher speeds then there is no consistency. As a result the idea of time is specific only to Earth.