3 facts
The third law of thermodynamics states that it's impossible to cool a system to absolute zero (0 Kelvin or -273.15 °C). As an object gets colder, it requires exponentially more energy to remove smaller amounts of heat, making the final step of reaching true zero an infinite challenge.
This phenomenon, known as the triple point, occurs at a precise temperature and pressure where water's solid, liquid, and gaseous phases coexist in thermodynamic equilibrium. It's a critical reference point in thermometry.
This counterintuitive phenomenon, observed by Erasto Mpemba, suggests that under specific conditions, hot water can freeze before an identical volume of cold water. Scientists are still debating the exact mechanisms, with supercooling and convection being among the leading theories.