If there is a beam of light from a source in space a million light years away travelling towards the earth, does gradually start to become brighter as it gets closer and fades away as it moves further?

Question

If that is true and the source suddenly disappears, does it mean there is an “arrow” like of light travelling in space until it “goes away” ?

In: Physics

Answer 1

> does gradually start to become brighter as it gets closer and fades away as it moves further?

This is a flawed premise. You don’t “see the beam” like an object that is coming closer and passing you. What you see is the light itself, the photons impacting your retina. So how bright the light appears is its intensity when it reaches your eyes.