Whoooosh! Did you see that? Nope, it wasn’t a speeding train. It was a bunch of penguins at the Pittsburgh Zoo & Aquarium playing around. The penguins were having such a blast after a snowstorm hit.

When a penguin drops onto its belly, its weight spreads across a wider surface, and friction drops. Progress speeds up without extra strain, and over long routes, that shift matters more than raw ...