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Why waves ?

  1. Feb 9, 2008 #1
    hi all

    why do many things in physics move in waves ?

    in fact , if im not mistaken , everything apart from mass moves in waves :

    electromagnetism ( and light ) , heat ( not ? ) (do phonons move in waves or lines ? ) ,
    radioactiv rays , weak nuclear force , gravitons (?) and many " tiny tiny things".

    why in waves ?

    spacetime curvature does not cause the wave behavior or does it ?

    i hope for a simple answer ( since im no expert in physics )

    regards
    garfield1729
     
  2. jcsd
  3. Feb 9, 2008 #2
    I don't know why they associate everything with waves (and personally I don't believe in any wave other than mechanical waves). There are de-broglie waves associated with matter too! So there is nothing in the universe which is not a wave(according to the scientists).
     
  4. Feb 9, 2008 #3

    russ_watters

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    De-broglie wavelength has been experimentally proven for electrons showing interference patterns.

    I'm not sure the OP question is answerable, though. It's just the way things are.
     
  5. Feb 9, 2008 #4

    daniel_i_l

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    Well, you usually get a wave when a change in one point causes changes to other points around it in a time dependent way.
     
  6. Feb 9, 2008 #5
    I am not so sure. Something moving must be a kind of energy. And energy changes from one form to another and vice versa, that's the way it holds itself when moving.
    Hope to hear from others.
     
  7. Feb 10, 2008 #6
    @garfield1729:

    It's actually a very interesting question. In fact mass DO move in wave, in a circular or otherwise conical trajectory. They do not get 'transported' -that's it.

    However, any movement should be steady like a jet erupting from an, medical syringe or oscillating, with peaks and troughs. The easiest describable of oscillating movement is via simple harmonic waves.

    Waves that are mathematically describable at ease are rather much investigated (after all, mathematicians also prefer easier problems to tackle first).. and popularized ;-)

    Unfortunately, nature also seems to prefer simple harmonics.

    Answer to this preference is stated like this: Force = -(a positive constant)*(displacement) results in Simple Harmonics. So wherever thee situation gives a force in opposite direction and directly proportional to displacement, you know what it means.

    I rather wander, whether it is really Simple Harmonic, or appears as so. Thus I am trying to set up experiments to see in depth.

    ________

    http://moonforhumanity.zxq.net
     
  8. Feb 10, 2008 #7
    I don't know the answer to this question, except that maybe as adastra mentions mathematics has thoroughly analyzed waves so we have many “off the shelf” components ready to go for building wave-based models in science. (“When you're holding a hammer, everything looks like a nail.”)

    One thing that I've always thought was interesting in relation to the prevalence of waves in science is that it's been mathematically proven that any function, including sine and cosine and other trigonometric functions and combinations of them, can be approximated to any degree of accuracy by a polynomial expression (). And by the way higher mathematics utilizes infinitely long polynomials all the time.

    Grrr, image code is off here, but look at this:
    [​IMG]

    The colored lines are polynomials written to match sine near to the the origin.
     
  9. Feb 10, 2008 #8
    Whenever I see 'wave' (unless you are talking mechanical waves), I always think 'wave of probability'.
     
  10. Feb 10, 2008 #9
    I've gotten the impression that ‘wave’ is probably not the greatest term to describe quantum stuff. Sure the isosurfaces of electron shells, et cetera, are curved but the equations that describe them don't employ trigonometric functions and they aren't even cyclical, which is a basic proprety of waves in the classical sense. I think the only reason ‘wave’ has made its way into things like the ‘wave function’ is due to the pre-quantum ‘particle/wave duality’, which is an obsolete quandary that quantum mechanics replaced.
     
    Last edited: Feb 10, 2008
  11. Feb 13, 2008 #10
    what i believe that wave motion is far more generalised than just to mechanical systems .
    what wave tell us is about a self propagated change in some property of any spatial continous medium ( i dont know much about abstract science or wave in hyperspace)
    so trying to make it simple ,wave is not just a harmonic motion but a propagating change induced from particle to particle.
     
  12. Feb 14, 2008 #11

    Andy Resnick

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    It's an interesting question that shows the value of conceptual abstraction, and the "gift" of mathematics to formulate laws of physics.

    First off, what's a wave? That's not so easy to answer without being very specific. So let's go the other way- what are some observed phenomena that do not fit into a Newtonian point-mass conceptual description? There's lots: Fluid surface waves. Sound. Light, under some conditions.

    It's important to recognize the difference between the description of a phenomenon and the phenomenon itself. For example, consider light. Originally, it was thought that light was made of particles (corpsicles), as was heat (caloric). Then additional experiments showed that light can behave like a water or sound wave- interference, diffraction, spreading, etc. Maxwell's equations describe light as a wave. Then came quantum mechanics and the idea of a photon. However, it was recognized by then that light can act as a particle and as a wave, and it was possible to observe both properties (not at the same time, but in the same apparatus).

    So in truth, things are not only waves or particles. What they 'are' is not relevant in science, what is relevant is how accurately can predictions be made or how accurately can an experimental result be described.
     
  13. Feb 14, 2008 #12
  14. Feb 14, 2008 #13
    CaptainQuassar, this reminds me of Fourier stuff (sorry if I misspelt) .. But this can be one with only certain limits of accuracy. Well you can increase accuracy by iterating the process over and over, that's a bit tiresome .... wondering for some smarter idea.
     
  15. Feb 14, 2008 #14
    Funny thing is it's literally a limit. The more times you repeat the process the closer it approximates the target function ad infinitum. There's a proof of that somewhere.

    I just mean to say it's interesting and I wonder if it says something deeper about the universe, when wavelike phenomena are everywhere, that polynomials can approximate waves in that fashion.
     
  16. Feb 14, 2008 #15
    Nice question. You mean the physical significance of this phenomenon? I am interested from top to bottom, really.

    I wish to set up an experiment, maybe you will help me please!
     
  17. Feb 14, 2008 #16
    Yeah, something like the physical significance, though I was thinking at a really high level, like some sort of congruence between wavelike and non-wavelike phenomena.

    I could try to help you with an experiment but we'd have to come up with a more specific hypothesis first.
     
  18. Feb 14, 2008 #17
    thanks, amigo .. I will report to you soon.

    I will help you with experimental facilities in earth AND moon.

    ________________

    http://moonforhumanity.zxq.net
     
  19. Feb 14, 2008 #18
    To infinity and beyond!
     
  20. Feb 18, 2008 #19

    Andy Resnick

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  21. Feb 18, 2008 #20
    You're using pejorative language, man. That's more unscientific than wondering what something is.

    Asking what something is, what mechanism or phenomenon underlies is, is straight-up science. That's where you get the hypotheses you're going to test.

    And by the way, the scientific method - the empirical process you use to test things experimentally? That's a form of philosophy. Called Empiricism.

    Trying to characterize these sorts of questions as some sort of quixotic philosophical quest is silly and mean-spirited.
     
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