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

Snake or water

  1. Jul 13, 2003 #1
    In the wave/ particle duality paradox of light that modern science claims to exist, is the wave aspect more comparable to a snake moving forwards or a wave in the water?
  2. jcsd
  3. Jul 13, 2003 #2
    A wave in water- I suppose.

    It means it can have wavelike properties.
  4. Jul 14, 2003 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I would say neither, a self propogating EM wave is very unique, it is nothing like either a water surface wave or a snake... What has a snake to do with it anyway?
  5. Jul 14, 2003 #4


    User Avatar
    Staff Emeritus
    Gold Member

    It is not a "claim", but the description of the results from lots of carefully performed experiments.

    Simple example:

    1. In a particle accelerator's detector, you do see the tracks left behind by particles, and in many cases you can even tell if the particle that left such tracks was a muon, electron, proton, etc. Here, electrons, for instance, are clearly behaving as particles.

    2. On the other hand, when you send electrons to a crystal, an interference pattern is formed on the other side, as if they were waves instead.

    Another example is that of "atom lasers". They are similar to lasers, but instead of light, they take advantage of the wave properties of atoms. Here's a link

    There's also the photoelectric effect, the double slit experiment, superconductivity, and lots of solid state physics.

    Actually, the very device you're using to write here takes advantage of W-P duality and other QM effects.

    Out of those two, a wave in the water,... but it is very different from that.

    Do you know some linear algebra? It is more like decomposing a vector: if you choose one basis, you'll get some numbers. If you choose another basis, the numbers are quite different.

    The basis is determined by the type of property you measure.

    (still, this is a very loose analogy).
  6. Jul 14, 2003 #5
    Snake or water?

    I have yet to see anything that I would clasify a definitive explaination of this wave form, and I have looked. Anyone with a link to a grand explaination of this wave form would be greatly appreciated. I'm looking for an actual 3 dimesional drawing of what that damn wave looks like.

    I would add rubber sheet to the mix.
    A rubber sheet that gets stretched outward on a plane where the center is pushed and pulled at a frequency to provide waves throughout the sheet.?
    Last edited by a moderator: Jul 14, 2003
  7. Jul 16, 2003 #6
    the snakes signficance in response to Intergral

    In response to Integral's question about what a snake has to do with me trying to understand this wave aspect phenomenon, I say that if the waves we are talking is a particle moving in a wave formation than you have a single entity that is going forwards. This is different from a wave in the water in which there are no particles moving forwards but only a thrusting of activity. If the wave phenomenon that is contributed to the atomic activity is like a snake, than there is the particles moving ahead but doing so in a wave motion...if the atomic activity is like a wave in the water than there is no particle moving forwards at all, and the photon or electron ceases to exist because these are particles. A snake is a single unit that moves like a wave, it is an entity onto itself and when it goes from one point to another, it does so moving its body like a wave. Do protons move like a snake or is there nothing moving forwards at all like a wave in the water? That is my question? During he wave like phenomenon of light are there particles moving as waves move or is it that there are no photons, no particles, but only a thrust like a wave in the water?
  8. Jul 17, 2003 #7

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Re: the snakes signficance in response to Intergral

    There are neither waves nor particles. Each concept is really just a model that allows our puny little brains to imagine what the math seems to be telling us. Over the last 80 years we have begun to realize that neither model is a corrrect one.

    The wave-particle duality paradox is mostly considered dead.

    The new interpretation is that these things that we measure and observe are described by certain mathematical models for which we have no analogy.

    But, to understand what we mean by a wave...we are really talking about probability waves. We are talking about things that seem to be in many places at once. We are talking about varying energy densities in space-time. We also refer to things like the strength of an electric field varying as a wave – such as with light. Things that we measure at the atomic level change over time and space according to the equations used also for describing things like water waves and the sound waves. This does not make them waves in the sense that we imagine. It makes them waves in a mathematical sense.
  9. Jul 17, 2003 #8
    Does the wave refer to an energy wave or is it purely
    a wave a probability of where the particle might be.
    If it is the second thing and we dont know where the particle is
    without measureing it does that mean that the particle doesnt
    have a precise momentum and location or does that just mean
    we dont know what it is until we measure it?

    Also a mechanical wave traveling through water....
    Is that simply energy moving through a medium (water)?
  10. Jul 17, 2003 #9

    From your words - I would guess you could draw on a piece of two dimensional paper...a three dimesional figure that comes close to the mathematical readings.

    Go for it Ivan!!

    It's never been done before that I know of. Seriously

    My interpretation is that it's like the pond wave that continues to expand outward like the ripples in a pond. To add to that the description is moving at C in whatever direction it started out at. In other words - A photon coming from the Andromeda galaxiy (toward us) could be detected in just about any location in the Milky Way. The reading may be different, but still be the same photon.
    Last edited by a moderator: Jul 17, 2003
  11. Jul 17, 2003 #10

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I want to check on something so as not to speak wrongly...write wrongly?...post wrongly? I will answer a little later. :smile:

    [I've got to be careful here or someone may crucify me!]
  12. Jul 19, 2003 #11

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    QUOTE]Originally posted by RobMan
    Does the wave refer to an energy wave or is it purely
    a wave a probability of where the particle might be.

    Depending on the context, we could mean the probability of finding a particle over some interval in space. In another context, we might mean the electric and magnetic field strengths associated with a photon for example. We might mean the tension in the fibers of a rope, or the pressure in a hydraulic system, or the position of a moon about its planet. Any periodic motion can be described by wave models. In Quantum Mechanics we find these equations apply as well. This was one contribution by Schrödinger - the famous Schrödinger’s equations. A guy named DeBroglie surmised that matter has a wavelength according to its momentum, and Schrödinger surmised that the equations of wave motion would fit the experimental results for this wavelike property of matter. This spoke to the odds of finding the particle in a particular place. Then came the implications.... and LOL did yesterdays meal hit the impellers! Schrödinger once commented that he regretted starting the whole mess. In the end the wave function describes the state of the particle.
    If we consider Heisenberg’s Uncertainty Principle, we find that as we squeeze more and more information out about the exact position of a particle, we destroy or lose more and more information about the momentum. Likewise, if we try to measure the momentum exactly, we loose all knowledge of position. Other pairs like this exist, for example energy and time can have this relationship, depending on the application.

    The question is: Does something [subatomic] exist in a unique state if we don't measure it? The correct interpretation of this has been argued for 70 years. The EPR paradox implies that a unique state does not exist. Einstein and friends sought to prove just the opposite. This question has killed cats - Schrodinger's cat - and created universes - the Many Worlds Theory.

    Yes. The energy is transmitted as a longitudinal wave by compression - water does compress slightly - and by gravity. For example, sound waves travel through water by transferring pressure as a longitudinal wave – meaning that the water molecules are perturbed or compressed in the direction of the wave motion. A simple ocean wave is viewed as a type of transverse wave that moves by dislocating or perturbing the water molecules in a direction transverse to that of the forward motion; typically upwards. In reality a wave in water moves [transfers energy] as a function of both of these mechanisms.
    Last edited: Jul 19, 2003
  13. Jul 19, 2003 #12


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I actually recall seeing three dimensional renderings on two dimensional pieces of paper of the Schrodinger wave function. It only makes sense that such a thing should exist; if it didn't, that would imply that we can't mathematically evaluate the wave at all points in space. The drawing basically looked like a complex set of hills and valleys... if you are dying for it I can try to dig up the book and scan the picture.
  14. Jul 19, 2003 #13
    Although a person is supposed to
    abandon the effort to understand
    these things in the form of a
    mechnical analogy I very much
    empathize with the urge to com-
    pare it to a snake or anything
    that makes it possible to grasp.
    According to Planck energy must
    come in discrete bundles. These
    bundles, though, are required to
    also perform the gymnastics of
    the continuous wave in certain
    I solve this in the privacy of
    my own mind by envisioning particles that don't like each
    other, which is their main impetus
    to radiate-to get as far away
    from each other as they can. This
    explains why they continue to
    spread apart after going through
    slits but why they can also, as essentially particulate entities,
    knock individual electrons off of
    metal atoms.
    Somehow I can't even start think
    ing about abstracting it mathema-
    tically untill this need to have
    a concrete physical model, even
    an incorrect one, is satisfied.
    So, I enjoyed the snake.
  15. Jul 20, 2003 #14

    Actually - I am dying for it. However - I am looking specifically for a photon wave form, and I would prefer it would be a drawing made of a photon out in the dead of space. My expectation for a 3D drawing is that it has at least some aspect of all three dimensions shown in the drawing, or a view of it from three directions with each view in a one dimensional sense. My contention is that if there is any understanding of a photon at all - The capability should be there to draw it up.
    Last edited by a moderator: Jul 20, 2003
  16. Jul 20, 2003 #15

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    A wave has no definite location. How do you draw a picture of something that has no there? Your question really results from the confusion between wave and particle models...both of which are an incomplete description of the thing observed.

    If you go to a chemistry site and look up the shapes for the S, P, D, and F orbitals, you are really looking at the probability distribution for the electron about the nucleus. This is like a picture of the probability wave function. But it is important to remember that that this form is a probability space. It is not the wave function, or the electron, nor is it really a picture of anything. It represents the chance of finding the electron for the given energy state as shades of gray.
  17. Jul 20, 2003 #16
    Ivan, (or anyone)
    Can you link me to Heisenberg's
    actual words in pointing out
    the impossibility of knowing
    location and momentum? I have
    only read paraphrases and all
    differ enough from each other
    to make me wonder if I would
    agree that any caught the gist.
  18. Jul 20, 2003 #17

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    His exact words were: ΔxΔp>=h/2pi

    I'm joking a bit but not really. Math, not words, is the language of physics. Edit: It is this very dilemma, to put math into words, that creates a great deal of controversy around physics. You see the problem is, it seems that some of the math cannot be put into words. Many people are starting to think that this may be a fundamental limit to our understanding of reality.

    Follow this link and those at the bottom of the linked page for some discussions. http://www.marxists.org/reference/subject/philosophy/works/ge/heisenb2.htm

    egad I never noticed the marxists.org bit. Still, the physics discussion are good...as long as you don't bring up the free market.
    Last edited: Jul 20, 2003
  19. Jul 20, 2003 #18


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I didn't have time today to look up the graph I spoke of. Hopefully I can dig it up for you tomorrow. But the reason I respond now is becasue Ivan Seeking said:

    Two things. First, yes, the graph I am thinking of IIRC is a probability wave describing the likelihood of finding the particle at any given coordinate, not a 'literal' physical depiction of the particle itself. BUT, it has been my understanding that this probability function IS the Schrodinger wave function. If this is not the case, then what is the official name of this probability wave, and what is the (interpretted) meaning of the Schrodinger wave?
  20. Jul 20, 2003 #19
    Thank you very much for the time
    and effort in finding that link
    for me. I have saved it and will
    read it carefully when time per-
    mits. (It is quite long and dense.)
    I grasp that there are some
    situations where it isn't usefull
    to try and translate the math into
    words but I don't fully agree with
    the statement that "Math, not words, is the language of phys-
    ics." My reason is that a large
    part of physics involves grasping
    spatial and physical concepts, and
    this often requires no math. As
    a child I used to assume vision
    was a function of invisible feel-
    ers people sent out from their
    eyes. Using words alone my older
    sister proved vision was a fun-
    tion of light coming into my eyes.
    It was my first taste of quantum

    Thank you, again.
  21. Jul 20, 2003 #20

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    You are absolutely correct. The probability wave functions discussed all derive from Schrödinger’s Equation. The complete form of this function tells us the state of the system. By this we mean the observable, measurable characteristic we find if any particular measurement is made. Depending on which operator we use [which mathematical process we apply to the state function] we can derive things like the chance of finding the particle at a particular position, and perhaps at a particular point in time. Other things like the expectation value for energy, momentum, angular momentum, and spin can also be calculated from this. This says nothing about what the "particle" actually looks like. In fact it tells us that "particle" is an incomplete description of whatever it is that we observe.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Snake or water
  1. Water water everywhere (Replies: 16)

  2. Water pump (Replies: 2)

  3. Water nozzle (Replies: 2)

  4. A water slide (Replies: 5)