Posted 24 November 2010 - 02:37 AM
Space is what separates matter, but time is what separates events. Time is that which separates events based on our own methods of measuring time. When we measure or observe time, we are just comparing one event to another. The earth orbits the sun and we call this a year, a clock-hand makes one revolution and we call this a minute or an hour, the earth makes one revolution on it's axis and we call this a day. We can note the rate at which a Cesium atom cycles or absorbs and releases energy and call this an atomic clock.
In any case, the method of measuring time (i.e., a clock) is just a physical event that we observe and then compare with another event i.e., an event in your life, when you need to be at work, how fast you want you car to go, etc., in order to use & observe *what we call* time. In reality, all we are really doing is comparing one event to another. If all motion were to stop in the universe and there were no more events taking place, time pretty much seems to disappear which makes you wonder if it ever really existed as anything other than a concept or mental tool that we use.
I know of the experiments where they put a clock on a plane and due to the high speed, the clock on the plane seemed to slow down a little compared to a stationary clock not on the plane. However, all this means is that one physical device slowed down compared to another physical device. A clock is not time and just because a physical device on a plane slowed down does not prove to me that time slowed down.
Many say you must have time to define speed, but perhaps we should forget time and say things are traveling *with a certain amount of energy* instead of saying they are traveling at a certain speed.
Things are moving and/or happening in our universe and when we compare things that are moving or happening we call this time. However, this does not mean time is moving or that time is an actual *thing*, or a dimension, or something that can be traveled through or *end*. Time exists as a concept and a mental tool that we use, but I'm not convinced it exists as anything more than that. This *thing* that separates events would seem to only exist in our minds. Einstein once noted that the distinction between past, present, and future, is only a stubbornly persistent illusion.