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ananthu

- 106

- 1

I will be happy if anybody throws light on the following concepts:

(1). In the case of time dilation it is said that a clock in a moving frame appears to go slow to an observer in a resting frame.It leads to the famous twin paradox in which 'A' who spends some time in a spaceship and returns to the Earth appears younger to 'B' who is his twin and stays on Earth at the time A leaves earth. With respect to B , say, 20 years had passed on the Earth but for A, say, only one year has passed in his ship. Here I don't understand one point.

If the theory of relativity says that A will appear 20 years younger than B, is it just an apparent one or real one? During the journey in the spaceship had the body cells of A really slowed down in its metabolism of aging? This point is highly confusing.

(2). According the theory of relativity, the mass of a body increases with the increase in its velocity. In that case, since a photon behaves like a particle, does it acquire mass because of its velocity?

(3). When the velocity of a body increases its mass increases while its length should decrease. Let us suppose that a rod approaches the velocity of light ( not become equal to it ). Then while its mass approaches infinity its length should approach zero! How is it possible for a body to shrink to an almost zero size but at the same time possesses nearly infinite mass?

I know the theory of relativity is a highly a complex one to comprehend. Still if anybody has simple explanations for my above doubts I will be very happy.