Snell's window horizon ho rizurl water If you look upward from underwater you will see a round visual field that contains all the above-water scenery (compressed and distorted, somewhat like a fish-eye camera). Outside that round field everything is black; see the picture to the left. This phenomenon is called Snell's window, in honor of the Snell of Snell's Law. 1. Calculate the angular width 6 ofSnell's window. To get you started, think about the ray diagram on the right. 2. Assuming the alligator was 4 feet long, estimate from what depth this picture was taken. 3. As a bird flies across the field of view, it will appear smaller at the edges and larger in the middle. (In other Snell's window pictures, you can see that objects at the edge of the window seem very small). Show (by calculation) that a 10 cm bird standing I'm away will appear to be about 13 times smaller than a 10 cm bird flying overhead at a height of 1 m. Since the apparent size of an object is determined by the angle that its image subtends at your eye, you are trying to prove that a $2 ~ 13. To simplify, assume that you are looking upward from just beneath the surface of the water. 10 cm 1 m 10 cm/ 1 m D