Johannes Kepler was a 17th-century scientist who described the laws of planetary motion, which was controversial science at the time. His approach to science involved "playing" with ideas by using analogies to describe planetary motions.

One analogy he considered was describing planetary motion as a whirlpool, where water moves in a circular motion. He tested this analogy to see where it might break down. For instance, if planets were being pushed through space by a fluid, what would keep them on a constant pathway? He observed how boats traveled in currents and noted that boats needed pilots. Do planets have pilots? What kind of entity would act as a pilot?

Analogies are powerful tools for scientific thinking. They allow us to test theories and apply existing knowledge to new situations. Consider this analogy: You own a restaurant. The situation at dinner time might be considered an equilibrium situation because patrons can only enter when someone leaves.

a. In what ways is this analogy a valid description of a chemical equilibrium?
b. In what ways does this analogy break down, making it not a very good analogy?
c. Describe the value of using an analogy to think about new scientific problems.