If I ask you what is time? How will you answer me? One will say time is time. Most of the people don’t have answers for this question. Some might say time is a measurement of days and years, hours. Have you ever wondered what these days, years, hours consist of. I know most of us don’t have time to do that. Time has forever intrigued human imagination. But it’s something that we use daily in our life. Most of us don’t have it. For some it is money , for some it does not pass easily. For some it stands still. Isn’t it amazing?
During my collage days I also encountered same question. Being student of physics I also wanted to find the answer to this age old puzzle. So I started looking for any study material on this subject but i did not find anything which explains time. So i decided to do it on my own.
I sat for hours and hours in my collage library and central library in Mumbai. After many more days of research i came close to understanding time.
We use watch to measure time. Our normal watch consist of 12 hours. It shows the time from morning to night. Total daytime hours are 24 hours. In that 24 hours earth takes one revolution around itself. That means TV tower of Mumbai travelled through complete circumference of the earth. In that same time your clocks hour hand also trevelled in your watch the distance corresponding to 24 hours. Most of you have studied in school the formula for calculating speed is speed =distance /time. So [ time =distance /speed ] earth rotates with very high speed and it also travels over its circumference which is enormous distance as compared to our wrist watch.
What i want to say that what we measure as time is actually the relative distance travelled by anything that corresponds to our 24 hours, our day or earths one revolution. Whereas those who have studied Einstein’s special theory of relativity will understand the concept of relative distance.
Einstein showed in his thought experiments that people travelling at different speeds, while agreeing on cause and effect, measure different time separations between events, and can even observe different chronological orderings between non-causally related events. Though these effects are typically minute in the human experience, the effect becomes much more pronounced for objects moving at speeds approaching the speed of light. Many subatomic particles exist for only a fixed fraction of a second in a lab relatively at rest, but some that travel close to the speed of light can be measured to travel farther and survive much longer than expected (a muon is one example). According to the special theory of relativity, in the high-speed particle's frame of reference, it exists, on the average, for a standard amount of time known as its mean lifetime, and the distance it travels in that time is zero, because its velocity is zero. Relative to a frame of reference at rest, time seems to "slow down" for the particle. Relative to the high-speed particle, distances seem to shorten. Einstein showed how both temporal and spatial dimensions can be altered (or "warped") by high-speed motion. By mangesh wadte
Sr assistant loco pilot,central railway.