Suppose you are told that the linear size of everything in the universe has been doubled overnight. Can you test this statement by measuring sizes with a metre stick? Van you test it by using the face that the speed of light is a universal constant and has no change? What will happen if all the universe also start the running at half the speed?
As the speed of light is a universal constant, the light
will take double the time to cross a given object. This will give us the idea
that the size has doubled.
When on one fine day we find out that the linear size of all
the objects in our universe has doubled, then we can thoroughly check it by
using speed of light as parameter.
The above scenario is true only when the time rate remains
the same as it was before.
Now, if we have a scenario when the clocks have slowed down
by half, then 1 second in new time frame will be half that in old time frame.
This will imply that light will have only half a second technically to travel
the same amount of distance.
Hence, logically light will travel double the
distance considering the new time frame.
This will lead us to believe that the
universe has not changed its size at all keeping speed of light as parameter.
As the speed of light is a universal constant, the light will take double the time to cross a given object. This will give us the idea that the size has doubled.
When on one fine day we find out that the linear size of all the objects in our universe has doubled, then we can thoroughly check it by using speed of light as parameter.
The above scenario is true only when the time rate remains the same as it was before.
Now, if we have a scenario when the clocks have slowed down by half, then 1 second in new time frame will be half that in old time frame.
This will imply that light will have only half a second technically to travel the same amount of distance.
Hence, logically light will travel double the distance considering the new time frame.
This will lead us to believe that the universe has not changed its size at all keeping speed of light as parameter.
