At a precise combination of temperature and low pressure known as the 'triple point,' water exists simultaneously as ice, liquid, and vapor.
For pure water, the triple point occurs at 0.01 °C and 611.65 pascals of pressure. At this exact equilibrium, ice crystals form while liquid water violently bubbles into vapor right beside them.
Interactive Micro-Discovery Feed
Open this card in the vertical discovery feed, lock your guess, and earn +20 XP.
Quick Guess: What is the state called when solid, liquid, and gas coexist in equilibrium?
Verified Answer: Triple point
Quiz Question: What is the state called when solid, liquid, and gas coexist in equilibrium?
Correct Answer: Triple point
At the triple point, pressure and temperature balance all three phases simultaneously.
Below 2.17 Kelvin, liquid helium-4 enters a zero-viscosity quantum phase and forms a microscopic Rollin film that creeps upward over beaker walls.
According to Einstein's general relativity, weaker gravity at higher altitudes causes clocks to tick faster by billionths of a second.
In sonoluminescence, intense acoustic waves crush a microscopic water bubble so fast that trapped gas briefly flashes at over 5,000 Kelvin—as hot as the Sun's surface.
An average white cumulus cloud floating overhead holds as much water weight as roughly 100 elephants.