What is entropy? Also, can anyone explain how it relates to matter, gravity, time, other physics terms?
In: Physics
Lots of good answers here, so I want to add to those by saying: we don’t really know what entropy is all that well. Relative to other thermodynamic quantities (free energy, enthalpy, etc) entropy is not well understood. So, while many of the explanations given in this thread are good, they are just explanations of what we do understand about it. The amount we don’t know about entropy is significant.
A big reason for this is that thermodynamics was developed with equilibrium assumptions. However, many process are out of equilibrium. In out of equilibrium systems, entropy is much more relevant. Non-equilibrium thermodynamics is actually a relatively new branch of study.
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