Galilei and the Discovery of Time by Galileo
Time is often described by us as being a change of place. Time may be thought to have no beginning and no end, the fact is however that time has always been around. Time can only be perceived as a function of a dynamic system. Space, time and the universe are one. Space, time and the universe are three aspects that we come into direct contact with everyday.
Time is represented by motion, for instance the circular movement of the earth around the sun. Time has been defined as a clock, a device for keeping time. The passage of time as indicated by a clock is indeed very closely associated to the idea of space. The general theory of relativity states that space, or the entire universe, developed at the very beginning of time. From this perspective there is no way to escape time. The passage of time then is nothing other than a process of the expansion of the universe.
Einstein’s theory of relativity states that time does not exist independent of a reference frame, it is a relation between two events that are stationary. Let us illustrate this with an example. Light from a light bulb traveling in a vacuum will reach its destination after a definite time interval. But this time interval could be different for different reference frames. We can now say that the light from the bulb will arrive earlier if we consider it in our solar system reference frame and later when we use the earth reference frame.
In Einstein’s theory time is a special feature of clocks. He explained that clocks do not run at all unless some outside source acts on it. For this he postulated the existence of a time ray, which travels faster than the speed of light. This time ray would act exactly like a laser beam. It would split the clock up into two parts and send information across the divide. According to Einstein it could only be the source of these time rays that was important and not the clock as such.
The question raised by Einstein’s theory is the problem of how time may be measured without a reference frame. The answer to this is that time will always appear to come to a halt for a unified field. This unified field can be an idealized place like our planet or a vacuum. For a long time scientists had concentrated their efforts on studying the clocks that operate on the planet and the Sun, ignoring time dilation.
Einstein’s special theory of relativity solved this problem. He suggested that time dilation must be an observer function, which means that it varies according to how an observer views the situation. So for instance two clocks are used to measure time by measuring their own clocks, but they will both tell different times. That is to say, one clock is shown as being slower than the other. Einstein believed that this was simply due to an observer bias.
When Einstein applied his special theory of relativity to special cases, it allowed for clocks to be used without reference to any external source. Time and space then were independent of each other. But, he was not content with this. He went on to show that nearly all physical laws will work for the same instances under identical circumstances. For example, the Law of Gravity still works for free falling, even though no two bodies are touching.
In Galilei’s day, clocks were used to measure time more accurately than ever before. But, Galilei realized that it was possible to measure both time and motion correctly through the use of a new technique that he invented, the motion-timing device, and put to use on one of the most beautiful periods in history, the return of the voyages of Christopher Columbus. Galilei’s clock helped to show that a global flood, rather than a seasonal phenomenon, occurred every calendar year, proving that the Earth was not round.