Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How can continuous thought realize discrete processes?

  1. Jun 11, 2006 #1
    How can the mind objectify discontinuous phenomena if the mind itself is continuous?
  2. jcsd
  3. Jun 11, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Is there any reason why the mind should not be able to objectify discontinuous phenomena? You seem to think that the mind being continuous would be an obstacle -- why?

    Incidentally, "discrete" means something different than "discontinuous". The word "discrete" applies to things like sets of points, but the words "discontinuous" and "continuous" applies to things like functions.
    Last edited: Jun 11, 2006
  4. Jun 11, 2006 #3


    User Avatar
    Staff Emeritus
    Gold Member

    I'm pretty sure he's not talking about how the mind can operate on functions and mathematical objects. I think he is questioning the nature of sense data. We have a continuous flow bits of information heading into our retinas, yet we recognize discrete objects. This is actually somewhat of an artificial intelligence problem, as we do have a great deal of difficulty getting robotic vision systems to do the same. Things like edge recognition and the ability to locate oneself in a three-dimensional space of objects and determine which are obstacles and which are not, takes loads of time and processing power in a computer, yet a human can perform thousands of the same operations each second. We can run at top speed through an obstacle course without hitting any obstacle (think of slolam skiing for a great example), something that a robot still cannot do, despite the fact that its mental substrate is actually much faster than our own. Given this fact, it seems clear that the computer method of discerning and recognizing objects is not the same as ours.

    So unfortunately, Loren, the answer to your question is that, as of right now, nobody knows. We obviously know that the human mind can do it, which seemed to be the question Hurkyl was answering, but we still do not know how the human mind does it. The people to look to for hypotheses are the robotic vision guys (incidentally, robots are somewhat better at doing these things when they use sonar rather than vision), but frankly, none of them have quite figured it out just yet, despite working on the same problem for several decades. It isn't an easy problem to solve.
  5. Jun 11, 2006 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Actually, I wasn't really trying to answer anything! I was just responding based on the general principle when something seems "impossible", it is often very useful to reflect upon why you think it's "impossible" in the first place, than to try and have others explain to you why it's not "impossible".

    IMHO, such explanations usually aren't too useful anyways, unless they happen to hit directly upon the reason you were thinking it was "impossible".
  6. Jun 12, 2006 #5
    Why need the mind be continuous?

    Best Regards
  7. Jun 12, 2006 #6
    What are you referring to as mind the imput data or the output data?

    The brain scans the invironment continuously and makes changes to the internal memory.

    Here is an interesting paper:

  8. Jun 12, 2006 #7
    Thanks for responding. I was positing that self-consciousness (or better, perhaps, its rememberance) is eventually a continuous reality (from personal observation), as opposed to its constructs that simply represent discontinuity (I will try to remember your distinction regarding discreteness, Hurkyl). In this belief, the continuous mind only symbolizes discontinuity, never actually justifying its existence per se.
  9. Jun 12, 2006 #8


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    If we restrict ourselves to vision, the input is not continuous; individual photons interact with individual molecules in the retina. Each of these is a single interaction and sends a single signal to the visual cortex. And lots of evidence (Dennet discusses it in Consciousness Explained) shows that the visual scene we are aware of is an elaborately constructed fiction, constructed by our brains.
  10. Jun 12, 2006 #9
    In practice, the wavefunction amplitude of impinging photons tends to zero as it approaches infinity spatially, requiring any seeming discontinuity within to actually require a smooth slope.

    Rods and cones have leakage which just compensates for the continuity of their boundary condition, so there are occasions due to continuity when the photon capture by these pixils does not register as a signal through their corresponding nerve.
  11. Jun 13, 2006 #10
    What evidence or reason do you have for believing that self-consciousness is a "continuous reality" (as opposed to being discrete)?

    When we watch a film being played back it appears to us as if the actors in that film are performing continuous motions, whereas the frames in the film can be discrete.

    This may be the case for an individual photon, but the point is that the discontinuity (or discrete behaviour) is a result of the fact that each photon is a quantum, it interacts with the retina in a quantised and discrete fashion, along with all the other photons doing the same. There is no "continuity" amongst the mass of individual discrete photon interactions with the retina, just a large number of discrete interactions.

    Best Regards
    Last edited: Jun 13, 2006
  12. Jun 13, 2006 #11
    moving finger,

    Thanks for typing. The example of the movie film is a classical one reducible to quantum continuity, since there is no quantum analog to such discrete frames.

    "Wavefunction collapse" suggests a discontinuous process, but it is merely a visual device for the continuous classicism of measurement. Say, extending the film analogy, "one" photon strikes a film, exposing a dot. The electrons in the film, being excited, have emitted photons whose wavefunctions disperse throughout space. Not only does the dot have a finite width that spreads smoothly across the film, but the "original" photon's action next affects the film thermally, and so on, in a continuous process.

    (Consider that wavefunction collapse is better represented by having internal to real space potential measurements for all interacting particles, a condition possible from entanglement at the big bang, which I attempt to explain on my website.)

    I suppose I should say that a premise of continuity, or discontinuity, may be a self-fulfilling prophesy. The observer could work with physically realizable wavefunction, continuous or discrete, but not both simultaneously. "You get what you look for."
  13. Jun 14, 2006 #12
    It seems you assume a premise of continuity at the quantum level. We already know that the world is discontinuous (quantised) in mass/energy (that is precisely what led to the foundation of quantum mechanics), and it may also be the case that it is discontinuous (quantised) in time and space. At lengths and times of less than approximately one Planck unit, quantum theory as presently understood no longer applies. The Planck unit of length is 1.6 x 10-35 metres, and of time 5.4 x 10-44 seconds. Space and time may be discrete (discontinuous, quantised) at shorter lengths and shorter times.

    Best Regards
  14. Jun 15, 2006 #13
    Thanks again.

    How can one say with surety that what appears a discrete quantum is not actually an entity that is quasi-discrete? Modulated by vacuum Planck potential, observed discontinuities could have their "edge" smoothed off. Even Planck units rely on parameters which in an infinite universe are doubtfully constant, and thus representative of continuity.
  15. Jun 16, 2006 #14
    I agree. My point is that we cannot say with certainty. The world may be fundamentally discrete, or fundamentally continuous. There is no way to tell with certainty. Your original post, however, asked a question which assumed a premise of continuity. All I am doing (ever since replying to that post) is pointing out that your premise may be false, which would make your original question very different.

    Best Regards
  16. Jun 16, 2006 #15
    Quite right, I appreciate your correction. I interpret that thought is much like an action compatible with its given environment, singular or wavelike.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: How can continuous thought realize discrete processes?