Question

Why Time slows down when we increase speed and stops completely when we attain speed equal to speed of light ? Explain using an example !!

Answer 1

Time does not slows down. At the speed of light everything around you seems to slow down.

For example, OK this might not be the perfect one but have you seen the movie Flash. For those who don't flash is a superhero who can run at very high speeds. He usually tricks his enemies by doing some of his fast actions. For him everything seems to slow down.

Now what happens to the other objects, for them the object at speed of light seem to slow down in time.

For example, when our good old superhero flash does his tricks, the poor enemies think that he had slowed in time as he does it all in seconds.

It's just simple relativity.

Hope it helps :)

Answer 2

"The speed of light in EVERY FRAME OF REFERENCE is constant and is equal to
299 792 458 m/s " This is what Einstein said in Relativity theory .

let's take a simple example ;

Suppose a particle is moving with speed of light ( Forget what Einstein had said for sometime ) in reference of Stationary observer . Let's say it's speed ( light's speed ) be 'c' ( I don't want to write that value again ) .
Now suppose The observer started moving with a constant velocity ( say 'v') opposite to the velocity of the particle . Now according to relative motion concept the RELATIVE VELOCITY of that particle in reference of that observer becomes :
(c+v) m/s
That is to say the particle has acquired the speed greater than the speed of light.
( Now remember what have Einstein said ) The speed can't be greater than the speed of light . And also will be CONSTANT to very REFERENCE FRAME .
Then how can this constancy be maintained ????
It is the place where Role of Time Begins .
we know that ;
velocity is inversely proportional to Time . In our case velocity of particle ( Relative to moving frame ) became greater than the speed of light ; To maintain ( here to decrease it ) it Time dilates itself ; means duration of second got increased ; called somewhat "Time-Dilation" . Time slows down for that moving frame of reference .

Now if that observer moves along the velocity of the particle ( means both the observer and particle are moving in same direction) ; The Relative velocity of that particle relative to observer becomes :
(c-v)m/s
That's what again a result against what Einstein had said . As for one Reference particle has speed equal to speed of light and for another smaller than it . The speed of light must be constant to every frame of reference ; to maintain this constancy Time contracts ; means duration of second got decreased to that Frame of Reference !!!

We talked about speed of light .

Now consider Two Spaceships are moving towards each other . When they crosses each other ... the observer at one of the spaceship sees the clock at the other spaceship moving slower than the one in his own spaceship .
If suppose both these spaceships are moving along the same direction with equal velocities then there is no relative velocity of one wrt another observer . The clocks ll seem to both observers agreeing in Time .
Einstein gave an equation relating rest time duration ( ∆t) , moving time duration ( ∆t') with speed of particle (v) and speed of light (c) :

∆t' = ∆t/√(1-v²/c²)

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hope it helps!!