are the coldest and hottest absolute temperatures possible according to theory? Answering the 'coldest' part of the
question is objective and therefore easy: Absolute zero = 0 K = -273.15 °C = −459.67 °F. The 'hottest'
part of the question, sometimes referred to as 'absolute hot,' is harder. Most people who deal with such things consider
the highest possible temperature to be the
Planck temperature = 1.416785(71)x1032 K.
A lesser cited value is the Hagedorn temperature ≈
2x1032 K. With a number that large, I tend to go with the admitted approximate number rather than
then one that claims to have 7(9)-digit certainty. It makes the in-your-head math easier as well ;-)
Posted October 15, 2014