Kelvin Celsius, which has the same magnitude. The definition implies that absolute zero (0 K) is equivalent to . In 1848, William Thomson, who later was made Lord Kelvin, wrote in his paper, "On an Absolute Thermometric Scale", of the need for a scale whereby "infinite cold" (absolute zero) was the scale's null point, and which used the degree Celsius for its unit increment. Kelvin calculated that absolute zero was equivalent to −273 °C on the air thermometers of the time. This absolute scale is known today as the Kelvin thermodynamic temperature scale. Kelvin's value of "−273" was the negative reciprocal
What Is Life? movement of the celestial bodies and the behaviour of mechanical devices such as clocks. But even those are influenced by thermal and frictional forces. The degree to which a system functions mechanically or statistically depends on the temperature. If heated, a clock ceases to function, because it melts. Conversely, if the temperature approaches absolute zero, any system behaves more and more mechanically. Some systems approach this mechanical behaviour rather fast with room temperature already being practically equivalent to absolute zero. Schrödinger concludes this chapter and the book with philosophical speculations on determinism, free will, and the mystery of human consciousness.