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Does change = entropy?

  1. Aug 17, 2005 #1
    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.
  2. jcsd
  3. Aug 18, 2005 #2
    What does this have to do with String Theory?
  4. Aug 18, 2005 #3
    First up, time = change is a good way to go because it gets you thinking in terms of processes rather than dimensions.

    But order vs disorder is rather observer dependent. In your standard Boltzmann model of entropy - a gas in a box - the system tends to equilibrium. This would be a state of continual local change (gas molecules moving randomly) and apparent global stasis (a single temperature, pressure, etc).

    Of course, the order gets smuggled in here because someone has to construct the walls of the box. These walls reflect the energy of the molecules back into the system and this is the global cause that produces the smooth gaussian distribution measured as a temperature/pressure. Things get much more interesting if you are willing to consider a system of freely wandering molecules (no box - or more interestingly still, a freely expanding box). Now you get fractal scale-free behaviour. So still an emergent form of order, but of quite a different kind.

    Of course, all this has nothing to do with string theory. Unless you want to raise awkward questions about time as a "dimension". For example, is "time" different when we are talking about a closed world that can equilibrate on a Planckian scale compared to the "time" of a freely expanding realm. That is the curled up stringverse vs the open 3D universe.
  5. Aug 20, 2005 #4
    strategic dependence on initial conditions

    it's relevence to string theroy is the background dependence issue and a first cause of change

    the perception of whether there was order to start with or chaos and which way time is running in the system

    change for the better or for the worse is observer dependent and entirely subjective

    Isn't it ?

    btw mcrone no I don't think time is different in that example just scaled up and limited in the open 3d universe to the speed of a photon in our particular vacuum
  6. Aug 21, 2005 #5
    Well others would say there is a difference between a process that has reached equillibrium and one still in transition. One can no longer change (it is now stable in its macro properties) and the other is still open about how it may turn out.

    So light speed may rule the two realms, but the nature of "passing time" would have a qualitative difference.

    You would surely agree here as you invoke the quantity~quality distinction yourself. To say the speed of light is "the same" and so time reduces to a single dimensional measurement is to think in a strictly background-dependent fashion.
  7. Aug 21, 2005 #6
    both are in equilibrium and in constan transition if blackholes/worm holes act as energy transference mechanisms between dimensions to keep our particular vacuum state universe stable and at the other end of the scale if blackholes/wormholes act as energy transference mechanisms between dimensions to keep electron clouds and thus fundamental particles stable.

    so it takes exactly the same time for an electron to transfer from one cloud like universe to another as it does for information to disappear into a black hole and reappear in another.

    given that once something blips out of our 3d universe time has no relevence and neither does distance.

    I'm all for background dependence and multiple dimensions
  8. Aug 21, 2005 #7
    OK, so you are arguing from the perspective of a particular vacuum mechanism. This wormholes story is prima facie unlikely to my way of thinking. But even if it were the way that the vacuum equlilibrates locally, the particles themselves would be still flying freely in this background. And particles are what matter-based histories are built out of.

    In essence what I said was that a particle would have two levels of existence. It would have its string-verse aspect that could equilbrate (and so would appear to reach a stable average over greater than Planck scale observations). And then it would have its open 3D realm aspect where it would - if free of all other interactions - travel in an inertial "straightline" until it circumnavigated a hyperspheric universe.

    So there would be two quite distinct timescales if we are correct in this imaginary picture of particles as effects propagating in spaces. In one space, the string-verse, there would be time for harmonic effects to emerge. In the extended realm of 3D, the journey of a particle would get interrupted by some kind of interaction before even a single circum-universal reverberation was complete.

    The stabilty/flatness of the vacuum is a different question. Probably much more important even!

    Again I think the answer will turn out to lie in self-organisation and hierarchy theory type approaches. The vacuum would only appear to have a Planck energy if observed on the Planck scale. To isolate a region in this way would be "disordering" as without a wider decohering context, it could have any value of energy, curvature, etc. But in the normal universe, where there is a prevailing ambience, then all the Plankian scale regions of the vacuum will become lined up in orderly fashion.

    Given any equivalence between gravity and geometry, I would think that your wormholes story would be about the exporting of "excessive spacetime curvature" as much as a supposed excess of energy. Put that way, the problems might be more apparent.

    A systems approach would say that spacetime is a state of global constraint. Localities are - in theory - free to take on any value up to the Planckian limits of energy, curvature, whatever. But in practice, like the spins in an Ising model, there emerges a common alignment. Energy is minimised by a phase transition.

    In usual entropy models, this kind of phase transition is said to lose heat through the wall of a box. But for a self-making Universe, the cooling is achieved by an expansion towards a cold void. No need for worm holes to balance the books when expansion is doing the trick?
  9. Aug 21, 2005 #8
    I agree about time relative to 3d and time relative to one or multi dimensions being different but for our purposes if it doesnt exist in our universe then it is irrlevent or maybe irrelative would be a better word

    I don't neccessarily take expansion as a given. A static bubble with a swirling membrane gives the appearance of expansion if viewed from within the membrane so depending on where you look things may be either moving away or getting closer

    so maybe in our quadrant/patch of the soccer ball the membrane and eveything we see is swirling away giving the impression of expansion and accounting for your transition to a cold void

    when 3 dimensions come together they don't form a coordinate point in x'y'z space they form a sphere

    a microscopic bubble of a specific vacuum state which when multiplied becomes a hyperspheric, bubble vacuum universe within the membrane of which combinations of light/energy form particles

    but at the scale of a single unit is a planck size bubble sphere of which within the membrane there of exists light/energy of only one type

    when 3 dimensions come together an instant of time is created just long enough to register the mass of a photon as it passes over and through our 3d universe leaving the effect gravity

    gravity then is the connections and residual affect of photon intrusion and interaction with dimensions. Your geometry as it were

    When photons combine they form everything else and registers as energy in the form of light

    the photon then is natures building block at least in our universe anyway if it has mass which i am assuming it does

    imagine a sphere modelled with a 3d program viewed in wireframe mode then given an iridescent skin

    or how about interchangeable spatial dimensions occuring at superluminal speed
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