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A principle of energy

  1. Jul 13, 2005 #1
    This is a simple question, and no one has been able to help me thus far, so i post on a forum.

    There is a principle that describes the ability to send multiple data streams down a single conductor without them interacting due to phase differences. i understand this to be the basis of pipelining in cpu's. I also understand that it is not limited to data streams, but any wave-energy, such as transmission signals through a line before an antenna (relating to rf, etc.), and the like.

    I simply would like to know the name of the principle(s) behind this, and maybe a brief explanation before I go off to explore it further.

    Thank you for any help you are able to provide.

    -Liam
     
  2. jcsd
  3. Jul 14, 2005 #2

    ZapperZ

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    Superposition.

    Zz.
     
  4. Jul 14, 2005 #3
    If you are speaking about sharing data from various devices via a single bus(or a transmitting medium) then check for CSMA-CD(carrier sense multiple access - collision detection), CSMA-CA(collision avoidance) technologies. Also check Token Pass Protocols. Each device is coded with a unique address and this is checked for sending and receiving data. When two devices are talking at the same time, one withdraws itself for a programmed period of time and then again starts sending data if there is no collision(CSMA-CD). CSMA-CD technology uses token pass protocols. A token is passed through the bus. If the data from a device is attached to the token, it is identified by a single bit(generally 1) and no other device communicates. If there is no data attached then the single bit value is 0 and another device starts communicating.

    However, I have a gut feeling that this is not what you want. :frown:
     
  5. Jul 18, 2005 #4
    I will look up superposition, thank you.

    In regards to data-buses, I'm most familiar with this principal being used in serial fashion, though, all parallel transmission is is a number of serial connections equal to the full byte-width of the data being transmitted.

    Thank you both for your help.

    -Liam
     
  6. Jul 18, 2005 #5
    ZapperZ, thank you very much for your help, that is right on. However, looking back into it, I realize that this should have gone into the quantum physics area of the forum, though superposition does apply to standard waveforms. Look for my postings there after I've done a little more reading into all this. (My physics knowledge is patchy, and fills in as needed. My calculus...that's just forgotten.)
     
  7. Jul 18, 2005 #6
    Superposition is part of the answer. The mechanism you are looking for
    is called the "orthogonality of propagating modes" along a waveguide.

    Superposition is the general mathematical principle which says that wave
    amplitudes add linearly as they move down the wire. The orthogonality of propagating
    modes is the principle that says that the energy moving along in mode "A" will not
    couple into mode "B" and vice versa.

    It is possible for energy of the same frequency to be in a different mode. In free
    space you would call two such modes "Vertical and Horizontal" polarization.

    It is also possible for energy at two different time-harmonic frequencies but both
    polarized vertically to have seperate modes. The energies at frequency 1 and
    frequency 2 will not mix (on average) even though by superposition it appears that
    they might. This is how it is possible to overlap multiple radio stations all
    transmitting in the same polarization.
     
    Last edited: Jul 18, 2005
  8. Jul 19, 2005 #7
    Cool, antiphon. As a ham, I understand wave propogation, and polarization. So, now to delve into quantum thought: Having done more reading into Quantum Superposition, I've learned that it assumes that the waves in question are linear vector spaces through quantum media (space, as a dimension I assume). How does this relate to Spherical Wave Structures?
     
  9. Jul 19, 2005 #8

    Claude Bile

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    Reading the OP, you might be referring to what is called Quadrature multiplexing. Signals multiplexed in such a way can be recovered because the carriers are orthogonal to one another.

    This sprung to mind because you mentioned that the technique you were looking for relied on phase differences between data streams.

    Claude.
     
  10. Jul 19, 2005 #9

    ZapperZ

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    This is getting a bit mysterious because, being the suspicious person that I am, I'm detecting a "hidden agenda" here.

    If you have looked in this thread

    https://www.physicsforums.com/showthread.php?t=82522&highlight=spherical+wave+structure

    you would have noticed a direct question to you asking for what is meant by "Spherical Wave Structures". So now it is TWICE already that you have attempted to being this phrase into existence.

    Unless you are willing to define what it is, the question "How does this relate to Spherical Wave Structures" will remain something that was just put together without a rhyme or reason.

    Zz.
     
  11. Jul 20, 2005 #10
    I'll cut the kid some slack Zz and assume he's not good at asking questions.

    As I said with radio waves in vertical or horizontal polarization, these could
    be thought of as different modes or "mathematical energy channels." Spherical
    wave modes are mathematical functions which describe these same ideas
    when you are near a point source. That is, if you are near a tiny antenna
    then spherical-shaped waves come out. These are most easily described in
    spehrical coordinates which is where those functions you ask about come from.

    The same types of functions can be used effectively to describe how an electron behaves
    near a proton because the system is very spherical in shape.
     
  12. Jul 20, 2005 #11
    Yup. There is an agenda here. I can't really get into it too much here, but as for your deffinition of Spherical Wave Structures...I'm referring to the Spherical Wave Structure of Matter proposed by William Clifford, and expanded upon by Schrodinger and Einstein and others. It's fascinating stuff, though I am notorious for jumping into the deep end without knowing first how to swim (when it comes to physics). I started reading Hawking when I was 10. I take the really hard stuff, and learn the easy stuff required by the hard stuff as I go along. I'm good at it. Anyway, I'd divulge more information to someone who is willing to work with me on my subject here.
     
  13. Jul 20, 2005 #12

    pervect

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    "Huygen's principle" - good
    "Spherical Wave Structures" - bad

    I have the feeling the original question is more about Shannon's channel capacity theorem, or the Hartley-Shannon law. Assuming that it is NOT just someone's attempt to call anything that in any way shape or form relates to spheres by some made-up name.

    (Shannon's channel capacity law eventually winds up being about how many hyperspheres can be packed into a unit hypervolume, with the theoretical limit being that a perfect packing has no wasted space.)

    I'm not sure of any good websites to recommend to describe the Shannon channel capacity law offhand, though.
     
  14. Jul 20, 2005 #13
    Check out the work of Ernst Mach, Milo Wolff and Geoff Haselhurst. This area of physics converges with Metaphysics and Philosophy, but it works on paper. Einstein's General Relativity is based on work by William Clifford and Erwin Schrodinger in this matter.
     
  15. Jul 20, 2005 #14
    If I remember right, Shannon's work with Bel Labs dealt with data transmission. Shannon's algorithms are still used to determine the maximum data rates that can be transmitted on any given frequency, that the higher the frequency the more data you can put through, which is why you can get faster baud rates on the 70cm (440MHz) band than you can on say 2 meters (145MHz).
     
  16. Jul 20, 2005 #15

    pervect

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    metaphysics and philosophy waste a lot of time - I'd rather stick to physics. There are a lot of applications of spheres in physics - as per the old physics joke "Consider a uniform spherical cow".

    If you can't provide a _physics_ reference for "Spherical wave structures", I will continue to assume that it's just some crank theory (or some philosophical theory :-)). I don't recall running across the name in any legitimate physics textbook, frankly it looks like goobledygook.
     
  17. Jul 20, 2005 #16

    pervect

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    You wanted to find the bit-rate capacity of a wire on an IC as I recall. This is a bandwidth limited channel, and Shannon's theory applies to it.
     
  18. Jul 20, 2005 #17
    that wasn't my original goal. Superposition is exactly what i was looking for, though Shannon's laws will be able to aid me in another aspect of what I'm doing. Sorry to be so vague.
     
  19. Jul 20, 2005 #18
    it is the basic form of matter that I'm looking at, Wave Structure of Matter vs. discrete particles.
     
  20. Jul 20, 2005 #19
    Ah, well that is another type of spherical cow altogether.

    Superposition in signals on a wire is well understood. Superposition
    in quantum mechanics is a mystery to our science. We can describe
    it via the Schrodinger equation, but mankind has no idea what the
    physical mechanism of QM superposition is.

    There's nothing magical about spherical wave function in this context.
    They are merely the mathematical tools with which you get solutions
    to the differential equations. They do not explain or illuminate the reason
    why QM superposition exists in nature.
     
  21. Jul 20, 2005 #20

    ZapperZ

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    Please give exact citation to the origin of "Wave Structure of Matter". Don't just drop names. If this isn't part of established physics, this thread will be locked.

    Zz.
     
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