Word of the Day
2 March 2026
absolute scale
A temperature scale whose zero corresponds to absolute zero such as the Kelvin scale or Rankine scale.
Why this one
Celsius and Fahrenheit zeros were pegged to convenient substances, so doubling the number means nothing physically. On an absolute scale ratios hold, which is why gas law and efficiency work runs in kelvin or rankine.
In use
Convert it to an absolute scale before you touch that pressure ratio, or the numbers come out nonsense.
Written by our editors to show how the term is used, not a recorded quotation.