Davie Cooper was struggling to analyze the results of a Thanksgiving Point exhibit on the nature of light.
"Goes," said the 3-year-old, on vacation from Grand Rapids, Mich., and visiting his grandparents in Riverton.
"Goes," he repeated, pointing at a rubber ball small enough to roll under a wooden crossbar.
"Doesn't go," he then said, pointing at a larger rubber ball, too big to roll under the bar.
Davie couldn't read the sign, but he had just learned about the concept of filters.