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Thread: The electromagnetic spectrum

  1. #1
    Faulkner Guest
    OK, we are taught that energy mutates from radio waves (low-frequency) right up to cosmic rays (high-frequency). But the spectrum is a continuum. What's either side of the spectrum? - ie what's "higher" frequency than cosmic rays etc?

  2. #2
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    If you're referring to a chart describing the spectrum, it's probably something different in each display. Otherwise, the sides of the spectrum are like the center and edge of the universe...verbal constructs devoid of useful meaning.

  3. #3
    Faulkner Guest
    the sides of the spectrum are like the center and edge of the universe...
    Ah, simple question, simple answer. I like it!

  4. #4
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    I guess new names would only be added once radiation of higher and lower frequencies was actually found.

  5. #5
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    Its kinda like asking what's the next element on the periodic table of elements. We know we can add more by finding them, but we don't have them until we do :-)

    (Its a little different because there's a naming convention, but this would have been a good answer 50 years ago).

  6. #6
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    Actually, I don't think any higher or lower are there. The lowest frequency relates to matter at absolute zero (ie 0&#33 the highest to Gamma Radiation. Beyond that, you move into the realm of Relativity and Quantum flux.

  7. #7
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    Silly question, aren't cosmic rays 'beyond' gamma rays?

  8. #8
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    Same as Gamma ray I think, but higher energy or higher frequency.

  9. #9
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    Actually, gamma rays and cosmic rays are two different things. Cosmic rays are particles that are accelerated to extremely high speeds, whereas gamma rays are a form of radiation.

  10. #10
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    This is one of my favorite subjects, here is the best page I have found on the subject;
    http://www.altair.org/specmap.htm
    Check it out



    My Webpage on the subject (just links)

    I think of Cosmic Rays as where the Em Spec runs into the Periodic Table, Cosmic rays come in Low Medium and High energy levels and have atomic nueclei up to Fe (Iron, 28 on the Periodic Table) as far as I understand, stripped of electrons, a positive charge, so they are still electromag energy, all be it positive charge only.

    I am interesteded in the gravity waves and the radiation/spectrum given off by the elements themselves, particularly the Millimeter Radiation of Molecular Hydrogen Homepage of the Harvard MM wave group



    MW web site, source of the above picture

    I am curious of the effect of the neutrino sky



    Spaceflightnow source for picture

    I think of an ocean of waves washing over each other from all directions, and I have said before, I don't beleive in the big bang

  11. #11
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    :unsure: This discussion begs the question: What is the maximum energy (hf) a gamma ray can have? Above some level does it collapse into proton/antiproton pairs? Is there a way to guess (maybe even calculate) how long such a high energy photon could exist as such before creating the proton/antiproton pair? If it lasted long enough and with sufficient surplus energy, would it decay into a pair with relativistic velocities (e.g., cosmic rays)? What sets the limits for their generation and their time duration of existence? Are these skull scratchers or what? I hope I have not asked a question for which I can not understand the answer? :unsure:

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    I have thought of a possible source for the high energy gammas I positied in my last post which is synchrotron radiation from the material in the accumulation disk just outside the event horizon of a black hole or perhaps a magnetar. Also, supernova explosions probably generate temperatures commenurate with such gamma generation.

    The antiproton from such a pair formation must rapidly collide with a proton generating yet another gamma which will decay into yet another pair, etc.,. How does this end

  13. #13
    Guest Guest
    This is a generally accepted chart, however the extremely high energy cosmic rays can't even be measured.and if converted to heat, the earth would be instantly vaporized.

    http://www.geocities.com/physicspoint/app/emspec.htm

    Prime

  14. #14
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    The lowest frequency you can get is 0 Hz. Though the maxamum? I'd say would be be EM radiation with a wavelength of 1 planck length. Which would require a lot of energy.

  15. #15
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    FWIW
    The longest wavelenght possible is equivalent to the diameter of the visible universe. The shortest wavelenght possible is what is called the Planck lenght. Between these two extremes is what we teach is the "electromagnetic spectrum."

    We can and have defined the two endpoints of the spectrum. Is that all there is?
    Well, each day the universe expands by some amount. Humm....

    Regards,
    MH

  16. #16
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    EM, periodic table and harmonics

    Please excuse ignorant questions.

    If hydrogen was the first atom created in big bang, then helium, how was one born of the other? and so on for next atoms.

    How are they related then? Is there some sort of cascade or evolution going on?

    What relationship exists between em spectrum and atoms on periodic table?

    Is there any harmonic or interval based meaning able to be derived from these relationships?

    If so, when you integrate and reorganize both tables according to this relationship, what gaps appear? What do they mean?

    Could understanding this cascade and evolution of particles and waves (if thats what it is) give us a new way of understanding things?

    Thank you for speculation.

  17. #17
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    Duane correctly typed: Actually, gamma rays and cosmic rays are two different things. Cosmic rays are particles that are accelerated to extremely high speeds, whereas gamma rays are a form of radiation.

    So gamma rays are photons that have no mass, EM = electromagnetic radiation. The shortest wave lenghth is though to be plank length, but we have not observed any that short yet. Possibly we will call these even shorter gamma rays something else when, and if, we find any about plank length.
    Galactic cosmic rays travel at less than the speed of light, but possibly 0.9999999999c because they are matter, possibly any kind of matter, but more often the nucleus of an atom, stripped of all or most of it's electrons. Even more massive nucleii than iron have been detected, possibly even element 116 made famous by Bob Lazar.
    Slow cosmic rays are usually called ions such as the 500 kiliometers per second solar wind = mostly hydrogen and helium nucleii.
    Please note the chart by Zypher shows E-20 for the lowest frequency in hertz. I think one picohertz has been detected = E-12 which is one trillionth of one hertz. Frequencies of one hertz generally cannot be modulated except with frequencies below one hertz, so they are not useful for most human applications. Neil

  18. #18
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    Quote Originally Posted by mfbpc68 View Post
    If hydrogen was the first atom created in big bang, then helium, how was one born of the other? and so on for next atoms.
    It's called "nuclear fusion", and is what is going on in the core of the Sun right now, as well as in tokamaks on Earth, sorta. It's not an "ignorant question" though, in the sense that we've known the answer only within the last 70 years or so.
    What relationship exists between em spectrum and atoms on periodic table?
    Energy, basically. If you have enough energy, and two particles to collide, you can get pretty much anything, within certain general conservation laws.
    If so, when you integrate and reorganize both tables according to this relationship, what gaps appear? What do they mean?
    You get the "standard model of particle physics". I've no idea what it means, but a particle physicist usually has a pretty profound view of that.
    Could understanding this cascade and evolution of particles and waves (if thats what it is) give us a new way of understanding things?
    It can, it has, and doing more of that is the driving idea behind supersymmetry and string theory, etc.

  19. #19
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    Huh?

    Quote Originally Posted by Guest View Post

    however the extremely high energy cosmic rays can't even be measured.and if converted to heat, the earth would be instantly vaporized.

    Prime
    Reference?

  20. #20
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    Quote Originally Posted by John Mendenhall View Post
    Reference?
    The post is almost four years old, from someone who didn't register with the forum.
    I'm not optimistic about your getting an answer.

    On which subject:
    mfbpc68, welcome to the forum. We're glad to have your questions, but for future reference we'd rather you started a new thread rather than resuscitating a long-dead one.

    Grant Hutchison

  21. #21
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    It's likely that the recent new poster intended to start a new
    thread, but used the same title as an existing thread by chance.

    -- Jeff, in Richfield, MN

  22. #22
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    Quote Originally Posted by Jeff Root View Post
    It's likely that the recent new poster intended to start a new
    thread, but used the same title as an existing thread by chance.
    I haven't tried the experiment, but it seems to be possible to have two threads with the same name without posts becoming mixed, even if the threads run concurrently.
    For instance:
    Spinning Moon (2006 Jun 20)
    Spinning Moon (2006 Aug 30)

    Grant Hutchison

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