"the world above the water surface" viewed from fishes eyes

When light propagates through different medium, its wave speed changed,

The index of refraction of water is 1.33 (4/3.)

When light is traveling from water to air, it will bent away from the norm of the surface.

If the incident angle is greater than 48 degree,

So your pet goldfish in the bathtub looks up to see a reflected view Directly above, it sees a compressed view of the outside world.

The refraction of light is responsible for many illusion:

Would you like to know what is the view from the fish under the water looking at you?

This java applet let you feel it :

Usage: The whole area is divided into two region:

Is it fun! Play with it! Think about it! Enjoy the fun of physics. : )

Fill a cup of glass with water and look at objects behind the glass. Try it!

Your suggestions are highly appreciated! Please click hwang@phy03.phy.ntnu.edu.tw

Author¡GFu-Kwun Hwang, Dept. of physics, National Taiwan Normal University
Last modified :  More physics related java applets