Submitted by MaestroGaz t3_126l1uj in askscience
Sorry maybe it is a stupid question but I don't understand why we often hear that the concept of "arrow of time" is counterintuitive because Newtonian physics is time-reversible.
To me a simple oscillatory system with damping is not time-reversible, since you would notice it immediately if it was played backwards. I don't see where entropy is involved in this case ?