Submerging your face in cold water triggers the "diving r... | funfact.wiki | funfact.wiki
Submerging your face in cold water triggers the "diving reflex." Heart rate drops 10-25% and blood flow shifts to protect the brain and heart. This ancient mammalian reflex is especially strong in babies under six months.
Menthol makes your mouth feel cool without changing the actual temperature. It raises the activation threshold of cold receptors, making you perceive coldness at temperatures that would not normally trigger it.
Close one eye, extend your thumb to align with a distant object, then switch eyes. The object appears to shift. Multiply that apparent shift by 10 to get the actual distance. This works because the ratio between your eyes and your arm length is roughly 1:10.
Walking with same-side arm and leg moving together (lateral walk) is actually the most common gait among mammals — dogs, cats, elephants, and deer all walk this way. In Edo-period Japan, people also walked this way, using a style called "nanba."