Pure water is an insulator. Electricity passes through wa... | funfact.wiki | funfact.wiki
Pure water is an insulator. Electricity passes through water not because of the water itself, but because of dissolved ions. Tap water conducts electricity well because it contains ions like chlorine from disinfection.
Hot water can freeze faster than cold — a phenomenon called the Mpemba effect. Known since Aristotle but still unexplained, it was named after Tanzanian student Erasto Mpemba, whose question physicist Denis Osborne took seriously enough to research together.
The "photic sneeze reflex," nicknamed ACHOO syndrome, causes people to sneeze when suddenly exposed to bright light. It's surprisingly common—affecting 18–35% of Americans and about 25% of the Japanese population.
Members of the cat family cannot hold water in their mouths because their cheeks are not fully sealed. Instead, they dip their barb-covered tongues into water, creating a momentary water column, then snap their jaws shut to bite off the column.
Pufferfish venom blocks sodium channels in nerves, while monkshood venom activates them. Because the two poisons work in opposite ways, taking them together delays their effects. In 1986, a murderer in Japan exploited this principle to delay the time of death and fabricate an alibi.
Sprinkle water on a very hot pan and the droplets ball up and float—the 'Leidenfrost effect.' Instant vaporization creates a steam cushion preventing direct contact. The same principle lets you briefly pour liquid nitrogen at −196°C on bare skin unharmed.