Where does all the shadows lit with the sun go?

Answer 1

To answer this, you must first understand that a SHADOW and LIGHT are two different things. Light is what is given off by the sun, for example, and is something you can see. When there is no light, you see a shadow. So, when you look at a shadow, you are actually looking at a place where there is not enough light, so it appears dark.

When the sun gives off light to, say, the Earth, the side that isn't facing the sun doesn't receive light, so the entire area is covered in a giant shadow (the side that doesn't receive light is experiencing night time). If you were on another planet that faced the dark side of earth, you wouldn't be able to see it mostly because you would be facing the shadow, not the lit region. So, why doesn't the earth cast a shadow?

You must remember that the sun is VERY large and VERY bright - bright enough to shed light on even the farthest planets in our solar system. The sun releases light waves - long rays of light energy that travel in every direction away from the sun. Light rays have the ability to bend, too, if they have enough room to do so. The earth is ridiculously small compared to the sun, so, even though the earth should cast a shadow, the light rays are powerful enough that, by the time they reach your eyes, they are powerful enough and bend enough to illuminate the area the earth is blocking. If you don't understand it, try this:

Turn on a flash light and face it toward a wall. Pretend the flashlight is the sun. Hold up one finger in front of the light beam. Make sure to keep your finger closer to the flashlight than to the wall. Your finger casts a shadow across the wall. Even though there is a shadow, you can still see the wall - the shadow is not entirely black. This is because, in the space between your finger and the wall, the light had enough room to bend and light up the shadow a bit. Now try moving your finger closer to the wall. The shadow gets darker, because now the light doesn't have enough room to bend and light up that area.

I hope you understand because there is one last point we need to cover: If you are on a planet, like Mars, you won't see Earth's shadow because the light bent around it and lit it up. If you are on a space ship, however, and are close enough to the earth, the light won't bend enough to reach your eyes, and you'll see the dark side of the earth, and it will cast a shadow on you as well. You must also remember that space isn't something you can touch - space is actually nothingness (not to be confused with air, because air is a gas. Wave your hand around right now - you're waving it through the air. There's actually stuff around you right now, but space doesn't even have air!). Since you can't cast a shadow on NOTHINGNESS, you won't find a shadow of the earth floating in space - you'll only see a shadow on something that is actually there, like on a planet or space ship.

In short, the shadows the sun makes disappear over a long distance because light waves bend over the shadow and light it up anyway. So, there's you answer.