If I shone a laserlight to the sky what will happen?

Question

Or a flashlight, will it take light years for the light to hit an object from space? Because light obviously has to hit an object.

Answer 1

The atmosphere will absorb some of the light and some of it will reach into space.

A light beam is composed of small units called photons.

Even a laser beam will spread out as it travels into space because the photons are not traveling perfectly parallel. Also particles and even the effects of gravity help scatter the beam.

If any photon does not hit an object in space, such as a gas atom, it will travel forever. Energy or matter cannot just disappear or fade away.

A photon could hit another atom (or molecule) and be absorbed by it, raising one of its electrons to a higher energy level. Later, the electron can drop to some lower energy level by emitting a photon, but not necessarily at the same frequency. Then the energy from your flashlight will be on its way again.

Answer 2

You better wear a helmet in case your light hits and pierce a planet. And tie yourself strongly to the ground in case your light hits a black hole.

Answer 3

Yes, some photons may make it into space, but the beam of light will eventually become too spread out to be visible. And light doesn't need to hit a solid object to be stopped. When you shine a green laser beam into the sky, you can see the beam in the sky for a considerable distance, because the light is scattered back to you by moisture and dust in the air. None of those deflected photons is going into space, so much of the light energy can be blocked just by the atmosphere.

Answer 4

The light will eventually disperse so that it is much less intense (i.e. a candle in a big room still leaves dark corners), although a laser will take much longer to do so. Also, the molecules that make up air will absorb much of the light and become more energetic, and even in space there are some (very few, but some) particles 'floating' around.