Roger Critchlow wrote circa 10-07-13 09:07 PM:
The proposition of entropy causing action at a distance reminded me of a notorious demonstration. A beaker of water and a beaker of sugar dissolved in water are sealed together inside a bell jar. Over time the level of liquid in the beaker of water will drop and the level of liquid in the beaker of sugar water will rise.
For better or worse, I can't stop thinking about this concept that gravity is an entropic force... perhaps especially because I'm lacking a good (any?) understanding of the physics and math.
It seems to me that entropic forces can be described as the tendency of systems to move toward, stay in, and return to densely populated regions of configuration space. I.e. if there's a (small/sparse set of) configuration(s) that's isolated (in some sense) from larger, denser sets of configurations, then saying "entropic force" is just a term expressing that the system is more likely to be found in and move toward those larger, denser sets.
And then if gravity were such an entropic force, I would be forced to think that, somehow, the close proximity of any two bits (pun intended) of matter allows more configurations than if those two bits are far apart. That would be why gravity is attractive. There are more ways for the bits to interact if they're closer together.
I'm not sure why, but this seems counter intuitive to me. I just naively assumed that it doesn't matter how far apart two bits of matter are, the measure of the configurations of the system they constitute is constant.... like two entangled photons at opposite sides of the universe.
I suppose my fundamental confusion could be caused by the unnaturalness of cosmic time scales, quantum entanglement, and action at a distance. But it seems inverted for me. I suppose having worked in simulation for so long has brainwashed me. E.g. parallelism can be simulated by serialism, time can be compressed to make slow interactions equivalent to fast interactions, occluded interactions can be ignored as long as there are no side effects of the hidden events, etc. I suppose I've come to think that the universe really does submit/adhere to the closures we stamp onto various sub-systems (holons). But if that were the case, then gravity as an entropic force would not make sense because the configuration space has a constant size no matter how close any bits of matter are.
So my question to y'all is: Am I interpreting "entropic force" correctly? What have I misunderstood?
-- glen e. p. ropella, 971-222-9095, http://agent-based-modeling.com ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
