Temperature can be measured from absolute zero (no heat, no motion). The resulting temperature scale is the Kelvin temperature scale, named after its inventor, Belfast-born British mathematical physicist and engineer William Thomson, First Baron Kelvin (also known as Lord Kelvin; 1824–1907), who devised it in 1848. The Kelvin (symbol K) has the same magnitude as the degree Celsius (the difference between freezing and boiling water is 100 degrees), but the two temperatures differ by 273.15 degrees (absolute zero, which is -273.15 degrees on the Celsius scale). For example, the normal human body temperature of 98.6°F is equal to 37°C and 310.15 K.