Why are shadows never sharp?

Question

Why are shadows never sharp?

In: Physics

Answer 1

The atmosphere diffuses the light, causing some of it to come at you from angles other than the sun. Your shadow as seen outside is really “less light,” not darkness.

Fun fact, this is why solar eclipses look so different from, say, blotting out the sun with your thumb. Solar eclipses block the sun’s light before it hits the atmosphere, so the sky actually darkens enough to see the sun’s corona.