We believe in the laws of thermodynamics because they are?

#a)# theoretical
#b)# derived base on mathematical analysis
#c)# empirical and nobody disproved
#d)# mere statements

Original question here

2 Answers
Mar 8, 2018


We "accept" them as the current best model of observed phenomena. "Belief" is a separate issue, and really is not a proper part of the scientific method.


C) is the best answer, as they are derived from physical observations. The mathematical analysis was derived from the observations, not the other way around.

Mar 8, 2018

Yes, they would be believed due to being mere statements...

Even though statistical mechanical calculations will show lots of things quite accurately and SHOULD be believed, people won't believe calculations as easily as they believe seeing things with their own eyes... that's the unfortunate state of our world.

The laws of thermodynamics boil down to

To prove these laws indefinitely requires

  • sampling the entire universe to verify that energy was not lost in any process ever.
  • sampling the entire universe to verify that the entropy of the universe did not decrease.
  • getting down to precisely #"0 K"# to verify without ambiguity using a perfect crystal that it only has one microstate (not macrostate, microstate).

To get 100% accuracy and precision on such experiments and the feasibility of such experiments is technically impossible. Sampling the entire universe would not be feasible, and nearly every crystal has a nanodefect somewhere.

Furthermore, the choice of zero entropy at #"0 K"# is arbitrary and for our convenience, so that is also a "mere statement".