Ocean

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.

Diving deep into the ocean causes symptoms like alcohol intoxication — the "martini effect." Every 15 meters of depth supposedly equals one martini. Rising water pressure dissolves more nitrogen into the blood, producing a narcotic effect on the nervous system.

During World War II, the US Navy found the ocean floor seemingly rising every night on sonar. The culprit was millions of lanternfish forming a 'deep scattering layer'—hiding in the deep ocean by day and rising near the surface at night, their swim bladders reflecting the sonar signals.