The scientific answer to a question I’ve never asked:
As you stir pancake batter clockwise, only a bit of the mixture moves in tandem with your whisk, while the rest swirls in the opposite direction, counterclockwise.
@JohnPhilpin Since the researchers are at Harvard I assume Northern. But I don’t know what happens in the Southern. I guess some university will have to write a proposal for funding to find out 😉