I don't know why I was thinking about this.... but it occurred to me that entropy, defined as the "amount" or "measure" of disorder in a system is either the same thing as change or at least very closely related to it. For example: Imagine a group of blocks. They are just lying on the floor - no particular pattern to them. Now, in one sense we might assign a lower "measure" of entropy to the blocks if they are arranged in some "logical order". And higher in the reverse. However, the "logical ordering" is really just our perception or something we apply to the system - not something the system necessarily exhibits, right? (Or am I wrong?) Now, imagine a child comes in and re-arranges the blocks. Now they are in a different "order". In my thinking, regardless of whether the blocks are now perceived as more orderly or not - they are without a doubt more disordered. Why? Because we've introduced a change. There's no way (that we know of) to put the blocks back where they were before the change. Even if we could record the precise molecular or atomic displacement, we would never be able to arrange the blocks in the same time dimension. Therefore, we can never reduce the system back to it's "real" starting state. If we extend that further - we can't reduce any system back to the starting state (or a so-called "previous state") for the same reasons. We can certainly arrive at approximations (much the way we do with forward-predicting mathematics). In some systems this isn't particularly relevant (for example, in a computer system, we can arrive at a close enough approximation of the machine's state as to make programming a viable and practical thing); however, in other systems the vital interacting elements need be reversed not only in space but in time to arrive a new "starting" state from which you could proceed forward. Why? Because as time progresses, the system changes. Or vice-versa, as a result of changes in the system, time must have progressed. By re-assembling a system to a previous state in "space" means you've only gone part way. Thus, if time passing and change are the same thing, and a result of time passing (or change occurring) is the inevitable irreversibility of the system... does that imply an increase in entropy? In other words, if the nature of the system today is different from what it was yesterday, isn't that an increase of entropy, regardless of our perception of order? Doesn't a change in the system mean a reduction in the order of the system? Or conversely, is not an orderly system one which doesn't change? I don't know. These are just the things I think about.