by Alva A

Created on: December 23, 2009

Why do shadows happen? Have you ever tried to make animal shadows on a wall when you were a child, by wiggling your fingers in the beam of a bright torch? Shadows happen because there are lots of things that light can't shine through such as walls, furniture, even your own body. We call these opaque, meaning that we cannot see through it.

Light travels in straight lines called rays. When the rays hit something that they can't shine through, the light is blocked and a dark shadow, shade or silhouette forms on the other side.  Light is also a kind of energy. Plants use the energy in sunlight to make food for themselves in their leaves. Light is responsible for so many things. Have you ever noticed the Sunflower? It always faces the sun and turns towards it as it moves across the sky. The sunflower thrives from the light.

Ever wonder why you can see through a glass? You are able to see through it because it's transparent, meaning It's clear and therefore allows light to shine through it creating reflection but this ought not to be confused with shadow. A shadow is an outline while a reflection is more likeness and allows you to see exactly what is going on. But can light bounce? When rays of light hit something that they are not able to shine through, they bounce off it, just like a ball bouncing off the ground; reflection it is of course and we are able to see things because light is reflected off them in our eyes.

When you look down into a puddle you are able to see yourself because the smooth water reflects the light straight back into your eyes. Even the moon reflects light from the sun. It has no light of its own. As light passes through water, it changes the way we see things. Ever seen your shadow in the water? Ever try to catch a fish with a net in the sunlight; this makes it tricky to net fish as they aren't where they appear to be. To catch one you have to aim below the place where you actually see it.

Try cutting a hole in a piece of card and stick clear tape over the top, carefully put a drop of water on the tape and look through it at something small, like a ladybird. It will make it look bigger. This is what happens when light passes through a single drop of water.

Last but not least, why do your legs look shorter under water?  Think you may figure this one out? Looking down through the water in a swimming pool, your legs look very short and dumpy. Don't worry, they aren't really!  What really happens is that when light enters water its rays travel more slowly than they do through the air and this change the way we see things.

So, why do shadows happen? It's all about light. Next time you see your shadow, no need to wonder. We have a wonderful and most powerful creator who makes things happen.

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