Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

What is wrong if I define temperature of a small system (I mean, a system which has not a large number of particles) by

$$1/T = dS/dE$$


share|improve this question

1 Answer 1

up vote 3 down vote accepted

Nothing - that is the correct definition.

One little caveat is that small systems are usually in contact with a larger system with a temperature that's more easily controlled or measured (the "heat bath"), and $T$ usually stands for the temperature of the heat bath rather than the small system itself. However, this doesn't make a lot of difference in practice, because the small system will very rapidly attain the same temperature as the heat bath anyway.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.