[jakeinspace]

I'm no physicist, but I wasn't sure whether the goings on of quantum mechanics (virtual particles) in a vacuum is sufficient for entropy to occur. It seems like a timeless process, with forward and backward interactions equally likely. Of course, if the underlying fields are slowly changing with time, then that would likely be entropic.

[crazydoggers]

Good point. But I think there is a distinction between measuring entropy and the passing of time. From my understanding entropy provides the arrow of time, meaning the non symmetrical past vs future. Whereas time by itself could still be measured as flowing, though whether forward or backward you may not be able to determine.

Obviously if something like a human brain was there to observe things, you'd have the entropy of your neurons to be sure of the direction as well. =D