Earth has a heartbeat This video visualizes the pulse of photosynthesis on a planetary scale, using real satellite data. The red waves represent fluctuations in sun-induced fluorescence (SIF) — a faint glow that living plants emit as they convert sunlight into energy. This subtle light reveals how active vegetation is in absorbing carbon dioxide (COz). By combining SIF data with other indicators — like the greenness index, which tracks chlorophyll by measuring how leaves reflect near-infrared li