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What are waves made of?

  1. Apr 10, 2008 #1


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    This is a simple question by a simple reader. What are waves made of. We seem to know that molecules are made of atoms and atoms are made of sub-atomic particles and there is speculation that sub-atomic particles are made of waves (in very simplistic terms). So, I'm wondering what makes a wave a wave.

    There must be a dense to less-dense ratio that helps define a wave. What makes up the density and what offers the medium that is less dense so that the wave is able to vibrate at various frequencies?

    If this question belongs somewhere else, feel free to put it there, thank you!
  2. jcsd
  3. Apr 10, 2008 #2

    Ivan Seeking

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    Sound: Pressure variations in the air or other fluids.
    EM [raio, light, X-Rays, etc]: Varying electric and magnetic fields
    Matter: Varying probabilities for the state of the system, such as the location of a particle.

    Strictly speaking though, a wave is a mathematical concept that is often represented by a simple sine function. When a dynamical system can be described mathematically as a wave, we call it a wave.
    Last edited: Apr 10, 2008
  4. Apr 10, 2008 #3


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    Thank you Ivan. I'm sure this is physics 001.

    As with sound and pressure variations, are there density variations of em in order to distinguish em radiation from empty space?
  5. Apr 10, 2008 #4
    Comparing it to the ripples in a pond, where the displacement of the water (above or below the level of the undisturbed pond) is zero at particular point in space at a particular point in time: With an electromagnetic wave, the electric field and the magnetic field are zero at a particular point in space at a particular point in time.
  6. Apr 11, 2008 #5


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    Can I compare morse code to the manipulation of light waves through fiber optics as a means of transferring information? Is it the manipulation of wave frequencies (configured as 1s and 0s) that encodes light with data?
  7. Apr 11, 2008 #6
    Morse code is turning something on and off in a meaningful pattern. It doesn't have much to do with the properties of waves. Morse code uses a wave just so that it can send a large number of cycles, then interrupt the signal, going some time without sending any cycles.
  8. Apr 11, 2008 #7
    Fiber optics work by the principle of total internal reflection. A wave in a medium in which it travels slower can under some circumstances pass through a barrier to a medium in which the wave can travel faster. If the angle in the first medium is beyond a certain critical angle then a wave in the first medium is reflected back into the first medium instead of passing through the boundary to the second medium. So bend the fiber any way you want, and the light inside of it won't be able to escape through the sides to get out.
  9. Apr 12, 2008 #8


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    Thank you mikelepore,

    Is background radiation a wave or a field?
  10. Apr 13, 2008 #9
    If you mean the background radiation that comes from all directions in the sky, it's electromagnetic waves in the microwave band of frequencies (lower frequency than infrared).
  11. Apr 13, 2008 #10


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    I mean the background radiation that is considered to be throughout the universe.


    1). Is there a difference between a field and a bunch of waves radiating in every direction?

    2). Whenever this is radiation, is it always in the form of waves?

    Thank you.
  12. Apr 13, 2008 #11
    Your're welcome!

    (1) A field doesn't travel anywhere, it's a mathematical mapping that assigns a value to every point in space. For example, the electric field, it's a what-if consideration, if some electric charge were placed here, and here, and here, and every other point in space, what force, magnitude and direction, would it experience? A mathematical expression that expresses that hypothetical force per unit charge, for all points, even when no charge is there, is called the electric field. A gravitational field expresses, if a mass were inserted at each arbitrary point in space, what gravitational force per unit mass, magnitude and direction, would it experience? Note that nothing is moving there, it's just a kind of map that has a value for every location. So you don't want to confuse a field with a wave. A wave actually travels somewhere, and it carries energy with it.

    (2) There are just a few instances in which the word "radiation" has been used to refer to something other than waves, probably the most famous one being the alpha rays -- some people have said alpha radiation -- which are not electromagnetic waves but are streams of particles, each alpha particle consisting of two protons and two neutrons. Generally, though, a reference to radiation is about waves. It's also correct to refer to the radiation of sound waves, although we don't hear that phrase too often.
  13. Apr 14, 2008 #12


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    You're a wealth of knowledge here mikelepore.. thanks a billion.

    I guess "radiation" refers to the configuration and action of waves in that they "radiate" from the source in every direction possible (water being restricted by its medium).
  14. Apr 14, 2008 #13
    "Radiate", like "radius", just comes from the Latin word meaning to go outward from a central source. It's not really technical. The petals of a daisy or the spokes of a wagon wheel are sometimes described as radiating.
  15. Apr 19, 2008 #14


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    Right you are. What hasn't been addressed is whether or not the radiant energy radiates inward.

    So, if you have a radioactive isotope, does its radiation radiate toward its microscopic make up?

    This begs me to ask the question... what is the original source of an em wave? You might tell me its the atom of such and such an element but, does the radiation only radiate outward or does it radiate in both directions?
  16. Apr 27, 2008 #15
    I fail to see any logic in this statement. How can there be any reason to ask a question if not to derive an answer? I think we all agree that yes indeed the questions you ask can be nearly or even just as important as the answer, but the answers will always have value regardless of how trivial. Many times questions lead only to more questions but as of yet in human history answers lead to nothing but more and better questions. I refuse to allow the only point of me being alive to be the simple biological functions my body has been shaped to perform. I want to learn and to know and that is impossible to do without answers to the questions you ask.

    Also yes people do and will run there mouths on what they do not understand, but who are you to say the people how have been trying to help baywax do not know what they are talking about? Do you personally know a single one of them? Didn't think so.

    You would have died long ago without the accumulated knowledge of many great people who have come before you. Unless you have grown up in the wild and learned how to survive complete isolated from any human you have no right to make the claim that it is wrong to assimilate the knowledge of our predecessors. Just because an idea did not originate in your brain does not mean that you can not fully understand all the implications of that idea. If you are directing these comments towards people who don't care why and only want the how, then I apologize for my misunderstanding and I agree with you.

    Humans are a socially animal by nature. It is utterly retarded to suggest that you should not ask questions to others who may or may not be able to help you. How can you expect to be able to answer ALL of your own questions? Agreed you should always try to find the answers for yourself first, but intelligent cooperation is a wonderful method for the advancement of knowledge. Information can still be considered knowledge even if the information did not originate from yourself (this statement deserves repetition).

    As to what it is that vibrates, it has already been stated that waves are only a mathematical representation of something that cannot actually be seen. You can not comprehend what an EM wave is made of because there is no facet of the human mind that can comprehend energy with no mass, all we can do is see what it bounces off of. This is why we use math to describe their properties. And no I did not find by myself that EM waves do not have mass and propagate at a finite rate, but I do consider it part of my accumulated knowledge.

    (please keep in mind i am by no means a big dog, actually im still in high school, how bout that just a name?)
    As far as current goes, i am not far enough along in my studies to give you a confident answer, however as far as EMR goes, no space is not distorted in any way by emr but gravity waves do distorted actual spacetime. Heres a good link to get you started:http://www.gothosenterprises.com/gravitational_waves/" [Broken]
    Last edited by a moderator: May 3, 2017
  17. Apr 28, 2008 #16


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    Thanks for the link.

    Current will be next... but lets stick with waves... assuming current is different from waves.

    I've found a very interesting site (french translated to english) with lots of animations concerning waves. The author goes about convincing us...

    <<link deleted>>

    This guy has some bizarre ideas about waves and the waves that make up matter. His specialty is optics and physics.

    Here's his challenge about his page on electrons (interesting because of the current question)

    Go for it robertm!!
    Last edited by a moderator: May 3, 2017
  18. Apr 28, 2008 #17
    Well I think I'm going to attempt to answer this question, because I think I actually know. :-)
    What is a wave made of?
    A wave (photon) is not made of anything at all ........ It's a concept.
    A wave (gravitational) is not made of anything at all .... It is also a concept.

    What makes a wave go?
    Waves move by way of self interaction, there is a front, back, and lateral component to a photon, and gravitational wave, and their self interaction is always in repel mode.

    I've said enough ... lest you actually be curious. :-)
  19. Apr 29, 2008 #18


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    I'm curious.

    What are concepts made of?
  20. Apr 29, 2008 #19


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    Here's what I think concepts are made of:


    Concepts are a result of electromagnetic waves that are emitted by the action of osmosis between sodium and potassium on either side of the membrane of a neuron's dendrites, axion and cell. What generates the pulse is a chemo-electric reaction caused by neurotransmitters in the synaptic gaps between neurons. What causes the chemical changes that cause the neurotransmitters to transverse the synaptic gap is related to two things. 1. Hormones. 2. Cell (neuronal) behaviour.

    When a stimulus that resides either outside or inside the neuron generates a reaction from the nervous system, there is a translation process that takes place in the cerebral cortex. This process is similar to the general workings of other neurons but is specific in that it finds stored information that matches the external or internal stimulus.

    The translation that takes place in the cerebral cortex is often called a "concept" or "idea".

    So, when castlegates says that waves are a concept you are partially correct, because concepts are organically generated em waves. Theoretically speaking.
  21. Apr 30, 2008 #20
    All waves tend to suggest a medium though don't they.
    How do we know empty space is not simply full of stuff we cannot detect?
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