woodchurch science

absolute zero is a term used in science to define a point at which the motion of particles which constitutes heat is minimal. that temperature is -273.15°C or zero kelvin. degrees kelvin are named after the physicist sir william thompson, lord kelvin (1824-1907), who first worked out this point.

The dane anders celsius decided the point at which water froze was the ideal base for his scale of temperature. lord kelvin decided to maintain the celsius scale but make the starting point the coldest temperature possible to achieve. thus absolute zero is 273.15°C lower than water’s freezing point.

at absolute zero strange things are hypothesised to happen to matter. It is known that the hotter a substance is, the more energy it has and the more the molecules jiggle. The colder the temperature, the slower the molecules move and at absolute zero the molecules do not vibrate at all and the matter contains minimal energy.

this diagram shows three ways of explaining the same thing.

here’s a load of resources for teaching 8i (heating and cooling).

here’s a link explaining how thermometers work as well as information about other ways of measuring temperature.