1. Fish and Spheres
a world containing a fish and two spheres. Each sphere has a radius of 0.25 meters. One sphere is blue, the other is red. Position the fish and two spheres in a sea floor world. The spheres have magical properties. If the fish eats the red sphere it doubles in size and the sphere disappears. If the fish eats the blue sphere it shrinks to half its size and the sphere disappears. When the world begins to play, the fish turns to face the closest sphere, swims to it, and eats it. Then the fish turns to the other sphere, swims to it, and eats it. You need to decide what happens to the sphere visually when the fish eats it. You might modify this world so that there are, say, 5 spheres, and the fish always swims to the closest one, until there are no more spheres.