If heat was a factor of atomic motion, then surely that meant there could be such a thing as total absence of motion, of energy, and of heat. Thomson described this as ‘absolute zero’ – the point at which, well, nothing happens. He formulated his new measure of temperature as degrees Kelvin, which has since become the standard unit for much scientific and high-precision work. On this scale, absolute zero is defined as 0K, or –273.15°C, or –459.67
