WHAT IS TIME? Do you know the consept of time?

WHAT IS TIME?

Time is an important part of our life. There is a proverb saying that “Time and tide waits for none”. But now it is basic understanding of time. Before the invention of clock, the time existed. What time actually is? We can study well it in physics. 

We all know that time is constant to all. But after the invention of light’s behavior and its particle, gives a question mark on this basic idea. But this problem was solved by the world-known scientist Albert Einstein.

According to his classical theory of relativity, there is no thing that is in absolute motion and absolute rest. Everything is relative to each other.

Suppose you see two car A & car B. Relative to you, car A is moving at the speed of 4 m/s to north and the car B is moving 3 m/s. Now relative to the A car, the car B is moving at the speed of (3-4) m/s = -1 m/s. This means the person who sits in car A, sees that the car B is moving backward at the speed of 1 m/s. and the relative to the car B, the car A will see that the car is moving forward at the speed of 1 m/s.

Now the question is what is the actual speed of the two car A & car B. You are also in the earth and the earth is moving. The sun and others is also moving. So there is nothing in absolute rest or absolute rest.

But there occurred a question. Is there nothing constant. In the middle of 19^th century Maxwell proved that light is constant. If you and the two person in the cars saw the light or any other see the light, they all see that the light is moving at the speed of 3*10^8 m/s . So the light is a universal constant.

According to classical theory this will occur “relative to what?” 

Einstein agreed the Maxwell equation. But this equation does not obey the classical theory of relativity. So in 1905 he published the special theory of relativity. And the special particle is light. And he said if the light speed is constant to two particle that are moving at different speed, then the time will slow down to the particle that is moving fast perspective to other to constant the light speed.  Einstein told the phenomena as “Time Dilation”. 

Einstein told that the space and time is equal. Einstein's intellectual leap was to suppose that the exchange rate from a time to a distance in spacetime is universal – and it is the speed of light. If you travel in space at the speed of light then time will stop to you. The light is made with photon particle. And the particle are massless so they can travel at the light speed. But if we try to travel, the mass of us will increase with the acceleration and it decrease the accelaration. So now it is impossible to travel at the speed of light.

If one day we can gain the speed of light, time machine will be probably invented.