Brits riding a heat wave

As the United Kingdom basks in a rare heat wave, scientists at the UK’s National Physical Laboratory (NPL) have performed the most accurate measurement yet of the Boltzmann constant, an important parameter in physical chemistry and chemical physics calculations. The team has determined the constant with a precision of 0.7 parts per million, which is twice as good as the best recorded uncertainty. The scale on a thermometer is usually defined with reference to the triple point of water but with extremely hot or cold scientific experiments this temperature 0 defined as 273.16 Kelvin - seems arbitrary and misplaced. Boltzmann's constant offers a way to define temperature based on a fundamental physical property and independent of any specific substance.