Relation between the arrow of time and entropy

[vitorvenancio]

What is the relation of the arrow of time and entropy according to thermodynamics?

 

[Dale]

The arrow of time points in the direction of increasing entropy

 

[vitorvenancio]

So is it correct to say that a good definition for time can be a succession of interactions of matter and energy, generating changes in their initial states?

 

[Nugatory]

... a succession of interactions of matter and energy, generating changes in their initial states?

and that increase the entropy. If they don't increase the entropy they're reversible, and reversible process don't help much with establishing an arrow of time.

 

[Dale]

So is it correct to say that a good definition for time can be a succession of interactions of matter and energy, generating changes in their initial states?

I don’t think that time is the same as the arrow of time. So no, I would not say that is a good definition.

 

[weirdoguy]

a good definition for time

Time is what a clock measures. This definition is good enough.

 

[Dale]

Time is what a clock measures. This definition is good enough.

For some reason there are people who seem to object to that definition. Some seem to want to go in a mystical woo direction and say that time is an unknowable mystery. Others seem to want to go the opposite way and say some variant of “time is clocks”. The standard definition works well, I don’t get the desire to add unnecessary confusion either direction.