The SI unit of specific heat is joule per kelvin and kilogram, J/(K kg). The temperature coefficient is approximately constant for temperatures above about 20 kelvin. This Thomson effect was predicted and later observed in 1851 by Lord Kelvin (William Thomson). He wrote biographies of Michael Faraday and Lord Kelvin. The thermodynamic definition of temperature is due to Kelvin. He has three brothers, Chris, Curtis and Kelvin. He was later replaced by Kelvin Fletcher. On the absolute kelvin scale this temperature is . A helium-3 refrigerator uses helium-3 to achieve temperatures of 0.2 to 0.3 kelvin. Henson got engaged to former NFL player Kelvin Hayden on May 13, 2018. The Seminoles scored on their next drive courtesy of a pass to Kelvin Benjamin. They have temperatures in excess of 30,000 kelvin (K). The use of laser cooling has produced temperatures less than a billionth of a kelvin. This was supported by Thomson (Lord Kelvin). The Royals bullpen, anchored by Wade Davis and Kelvin Herrera, also provided a strength.