Can Macroscopically Distinguishable Objects Have the Same Entropy?

  • Context: Graduate 
  • Thread starter Thread starter shimzz5
  • Start date Start date
  • Tags Tags
    Entropy
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
Sign up Log in
3 replies · 1K views
shimzz5
Messages
4
Reaction score
1
I'm kinda confused on the concept of entropy of everyday, low entropy states like macroscopic objects. It is said that the entropy is a measure of disorder, or distinguishability between macroscopic states.

Can two objects which are macroscopically distinguishable/look different have the same entropy, despite the fact that their atomic structure/configuration is different? Or the only states which can possesses the same entropy are completely indistinguishable macroscopically?

Thanks in advance.
 

Discussion

Physics news on Phys.org
What definition of entropy are you using?

A house and a football are distinguishable, but I wouldn't say that's to do with having different entropy, per se.
 
The Boltzmann entropy -the number of microstates.

We can imagine two balls of the same volume but which are macroscopically different - can they have the same entropy?
 
shimzz5 said:
The Boltzmann entropy -the number of microstates.

We can imagine two balls of the same volume but which are macroscopically different - can they have the same entropy?
Yes, obviously. Entropy is a single variable. One dimension. Macroscopic appearance is multi-dimensional.

Consider a red ball on the one hand and a green ball on the other. Either they already have the same entropy or one can be adjusted in size to have the same entropy as the other.
 
  • Like
Likes   Reactions: vanhees71