Bigger Under Water
Name: Bob R.
Why do things look bigger underwater?
If you are under water and your eyes are in direct contact with the water,
objects are not magnified -- it only seems that way. However, if you are
looking into the water from above, objects are not where they appear to be.
This is because light rays are refracted (bent) when passing from one medium
into another. Put a pencil into a glass of water so that some sticks out and
then look at it through the side of the glass. You'll note that the pencil
appears to have a kink in it where it intersects the surface of the water.
Too see something, light must travel from what you see into your eyes. When
you see something under water, light travels differently from seeing it in
the air. When the light passes from the water to the air, it acts like a
magnifying glass. Everything underwater looks a little CLOSER than if the
water were not there. Looking closer makes the underwater things look
Dr. Ken Mellendorf
Illinois Central College
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Update: June 2012