A harmless thought "experiment" .

[geordief]

Just for the sensory payback.

 

Imagine you are in a spacecraft and have departed from Earth . (this is a bit like Star Trek)

 

You are sitting in an onboard cinema with a big screen that is bathed in light being sent in your direction from the now receding Earth.

 

With your popcorn in your hands you look at the screen (no film is playing -it is just reflecting back to you the light that is continuously arriving at the spacecraft.

 

So the spacecraft keeps accelerating and , as you look at the screen the light changes progressively from blue tint to red tint.

 

As you approach very close to the speed of light ,the reflected light becomes entirely red shifted and almost entirely faded out and yet the speed with which it reaches you from the screen is unchanged.

 

 

That is all. I am not asking a question . It is just that that seems pretty vivid to me .

 

Well the only question is whether I might have misunderstood the situation (I don't think I have)

 

We are just sitting there looking at an extremely faint ,"reddish" screen which is nevertheless reflecting this faint glow back to the "spectators in the cinema" at exactly the same speed as it ever was..

Edited May 20, 2016 by geordief