An animated lesson from TED-Ed on how our bodies measure time.
Did you know that our circadian rhythms of sleeping and waking continue even without external cues like clocks, or light and darkness? How are we able to calculate the speed of people or objects moving around us? In this TED-Ed lesson, Marco A. Sotomayor teaches us about the biological and chemical systems our bodies use to sense time.
If you want to know more about the TED-Ed project check out their site here. There are lots of fantastic lessons on their YouTube channel, too.