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Please update me on humanity's relation to the BIG question

  1. May 18, 2012 #1
    OK, so this question really digs into the heart of determinism in the realm of quantum mechanics, specifically the standard model.

    First lets expose my limited understanding as it exists at the moment: There are known quantities that must be conserved such as mass charge momentum etc, and force laws such as gravitation and the other three (which to the best of my knowledge are formalized en formula as symmetries on or fields proportional to specific properties). These forces are fundamentally described as particle exchanges and transformations which are fundamentally geometric. There is uncertainty in as much as the physical apparatus of measurement creates necessity of it. The current best interpretation for how these interactions occur on a particle exchange level is a probability distribution over all possible interactions.

    My question is this: what is the meaning of all "possible" interactions. Does this mean: the uncertainty in the current known state means that there is a distribution over when and in which direction a photon will be emitted, OR does it mean: the only way to know which way a photon will be emitted in a PERFECTLY known state is to count up every way in which all known conservation laws are obeyed and that is all we can say about what will happen, OR in a PERFECTLY known state there is only ONE outcome that will obey all conservation laws, OR is it theorized that there are conservation laws that are in effect that are not presently known, so due to our lack of knowledge, we can only posit probability distributions, but even if stochastically sampled, they still obey all presently observable phenomena.

    [OR (worst case) once the distributions over all possible conservation law compliant states (sequences?) are made, they need to be further pruned so as to obey force laws?]

    A PROBLEM: It seems as if it were so that photon emission were the only means of transferring electromagnetic force, and if position and momentum vectors were perfectly continuous, and emission was only determined by the complete state of the omitter and anything that made precise contact with it, then the odds of anything actually interacting would be infinitesimal. Is this not an issue? Are particles not points? If not what are they? Wave packets? What does one wave packet do when it fuzzes into another wave packet? Are there laws for this kind of thing?

    Do we know anything more than "Um this thing can come out of this other thing sometimes maybe I couldn't tell you when but um this gravity thing is ALWays true sometimes I think on the large scale at least something to do with probability I guess I really couldn't tell you.."

    THE REAL QUESTION: Is there and extant theory which can take the EXACT state of a system in terms of its most basic KNOWN components and properties and then give its EXACT state at a later point in time? Is it theorized that no such equation exists that could produce such a result, even if it were possible to measure the actual state at a given time to such an accuracy? Is this only a quantum mechanical flaw? Are there equations that currently work with atoms as their primary abstraction that can simulate events on that scale to a degree close enough to observable reality to be useful? Are these models simply built from observations of Atoms with no underpinnings in Quantum Mechanics?

    Thank you for your consideration and understanding.

    P.S. Please fill in any gaps in my understanding, or perhaps explain why these problems are more superficial than they seem because there are ways of explaining observable phenomena without resorting to the exact motions of the fundamental particles which are inherently unknowable anyway, even with entanglement.

    OK ONE LAST QUESTION!!! Does conservation of energy mean anything sensible from a quantum mechanical framework?
  2. jcsd
  3. May 18, 2012 #2
    Please look into some basic Quantum Physics. Pretty much everything here's flawed.

    Simple. There's nothing as a perfectly known state, due to limitations of measurements. These are not a technological limit, they are a limit of the physical laws of the Universe. No matter how good our apparatus for measuring is, the laws of physics give a very well-defined limit to how good our measurements can be.

    Nothing makes direct contact with it other than bosons, by the Pauli Exclusion Principle. Stuff isn't only determined by the complete state of the emitter (which, again, doesn't exist) and anything that makes precise contact with it, we also have uncertainty due to Quantum Physics.

    Yep. We do know "this one particle can be emitted by this other particle, maybe, I couldn't tell you, but I can give a very well-defined probability to it, and this gravity thing is pretty much always true on the large scale, and when we try to put these laws together, we get nonsense."

    No. There is no such thing as an exact state.

    https://www.physicsforums.com/showthread.php?t=511176 [Broken]
    Last edited by a moderator: May 6, 2017
  4. May 18, 2012 #3
    THEORETICALLY?? There is no such thing as exact state THEORETICALLY?? You are doing Baysian Inference and you don't even know what the hidden variables are?? (very stretched metaphor, I know.(I don't know, it just kind of sounded right, you ever have one of those moments, like, hey, this sounds right. I dont know if it is but it SOUNDS right. Yeah. One of those.))
    Last edited: May 18, 2012
  5. May 18, 2012 #4
    Correct. We can give ranges to the values.
  6. May 18, 2012 #5
    So I am to assume that the current state of theory is that particles aren't actually anywhere because hey we can't measure that. Even if it might be useful to THEORIZE that a particle ACTUALLY IS somewhere we won't do that because we will never be able to measure that and anyway we have a perfectly good theory that nothing is anywhere and we are very contented. Am I missing something?
  7. May 18, 2012 #6
    Nope, they're going to be "somewhere within the possible areas they can be." Not really everywhere, but in a certain range of locations. It's not useful at all to theorize a particle actually is somewhere, that would yield results in contrast with observations. Please use bold ([ B ] and [/ B ] without the spaces) instead of caps.

    You finding this confusing? Welcome to Quantum Mechanics.
  8. May 18, 2012 #7


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    I think, if I am interpreting you correctly, that you are still not getting that it is NOT a measurement problem. It is quantum weirdness. An electron, as weird as this is for classical dinosaurs such as me, does not HAVE a position. It has a probability wave.
  9. May 18, 2012 #8
    I guess my real question, then, is to do with emission, absorption, decay, and force interactions in terms of fundamental particles. In calculations to verify the assertions of the standard model, what equations are used to determine, lets say, the emission rate, energy distribution, and direction distribution of photons from a given electron, and are they derived from statistical observation, or theory that predated exact observation? Or were these rates and distributions inferred from what we already know to be true on larger scales? For a photon to be absorbed what needs to occur? Do the to particles need to occupy the same space at a point of intersection, are the particles, in the case of bosons, not actually absorbed, but reconfigured? Is there a window of proximity in which the two can 'jump' a wee bit and then become the same thing with new momentum? Also tell me what E=MC^2 means in terms of the relationship between charge mass momentum and free photons. Are other force carriers energy too? Why is energy configured the way it is and not differently? Why isn't all the energy in the universe not found in the form of neutrinos? What actually triggers an electron to emit a photon?
  10. May 18, 2012 #9
    Please, first, use slightly more specific questions, and second, I can only handle so many at a time.
  11. May 18, 2012 #10
    OK I'm going back to The Flat Earth Society. They are much better about reasoned, critical, responses that are relevant and enlightening. I highly recommend you people join. The more the merrier!
  12. May 18, 2012 #11
  13. May 18, 2012 #12
    "You are welcome to include a link only after reaching 10 posts. Sorry for the inconvenience!"
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  16. May 18, 2012 #15

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