Ever wonder how the heart symbol came to stand for the actual heart? And why do we speak of the heart as the seat of love, when love really happens in our brains? Is it true that animals only get a billion heartbeats? This week, we give you enough cool cardiac science to make your heart skip a beat.
How the passing of time on Earth affects life on a variety of levels, from the daily opening of a flower's petals to the evolution of the horse. A swift journey through the seasons demonstrates how caribou spend most of their time on the move, while the flying squirrel's body clock, attuned to the rhythms of the Earth, is revealed to be the most accurate in nature.