If you were to send a beam of laser light to a space station above the atmosphere and just aboce the horizon would you aim the laser above below or at the visible space station?

Answer 1

This is tricky.

The question is based on the fact that the true, straight-line direction from you to an object

that you see near the horizon is actually below where the object appears to be, because

atmospheric refraction has bent the light from it, and caused it to appear higher that it really is.

However, the questioner is not considering the fact that the laser beam he intends to zap toward

the space station is going to be influenced by the atmosphere in exactly the same way as the light

from the space station was, and it'll follow the same path in reverse.

So the laser should be aimed exactly toward the spot where the space station appears,

even though that's not the true direction to it.

Answer 2

You would aim the laser slightly above the visible space station. This is because of atmospheric refraction, which causes light to curve slightly downwards when passing through the Earth's atmosphere. Aiming the laser above compensates for this effect and ensures that the light reaches the space station.