This question already has an answer here:
The second law of thermodynamics states that;
The total entropy of an isolated system can only increase over time or it can remain constant in ideal cases where the system is in a steady state (equilibrium) or undergoing a reversible process. The increase in entropy accounts for the irreversibility of natural processes, and the asymmetry between future and past.
So if there was a universe made up of antimatter will the entropy of that universe increase or decrease?
Because according to my research;
The Feynman–Stueckelberg interpretation states that antimatter and antiparticles are regular particles traveling backward in time.
Will the entropy of a universe made up of antimatter increase or decrease? Or is there any possibility that there can be a universe made up of antimatter because the entropy always increases by time? And what will happen to such a universe assuming that the entropy decreases? (because antimatter travel backward in time)