funfact.wiki
AboutGuidelinesTermsPrivacyContact

Content is available under CC BY-SA 4.0.

Sprinkle water on a very hot pan and the droplets ball up... | funfact.wiki | funfact.wiki
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.
  • Water
  • Physics
  • Liquid nitrogen
0
DiscussionHistory

Related Cards

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.
  • Water
  • Insulator
  • Electricity
  • Ion
  • Chlorine
  • Science
  • Chemistry
0
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.
  • Water
  • Mpemba effect
  • Aristotle
  • Physics
  • Ice
0
In 1818, Siméon Denis Poisson argued that if light were a wave, a bright spot should appear at the center of a circular object's shadow — which he thought was absurd. But when Arago actually ran the experiment, the bright spot appeared, proving light's wave nature.
  • Siméon Denis Poisson
  • Light
  • Wave
  • Shadow
  • Physics
  • Diffraction
0
A train's left and right wheels share one axle, always spinning together. Yet turns are possible because the wheels are conical. On a curve, centrifugal force shifts the train, changing each wheel's contact diameter and allowing a smooth turn.
  • Train
  • Wheel
  • Physics
0
A straw can only suck water up about 10 meters. So how do trees over 100m tall move water to the top? The secret is transpiration: as water exits the leaves, molecular cohesion pulls the column up like a chain. Trees use 95% of their water just for this.
  • Tree
  • Transpiration
  • Physics
  • Plant
0