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Electromagnetic energy

  1. Apr 5, 2009 #1
    We are constantly surrounded by electromagnetic energy, right?
    In what way does this energy exist? Is it measurable? Is there much of it?

    Side thought, hypothetically, with a pole extended from earth to outside earth's atmosphere, couldn't the friction on the pole from "space" be converted into energy?
  2. jcsd
  3. Apr 5, 2009 #2


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    You might want to bookmark the whole hyperphysics webpage if you haven't discovered it already. There's a good possibility that some of your upcoming questions are covered in there already.

  4. Apr 5, 2009 #3
    Short Answer: Cost-vs-Benefit.

    Long Answer: Sure, there are many available sources whereby energy could be extracted and converted to humanly useful purposes.
    From the most mundane to the exotic, they are available. But, how much does it cost to do this?
    If one spends a billion dollars to set-up a scenario that produces $1,000 worth of electricity per day, it would take 1 million days to pay for itself.

    The science is not wrong, but economics must play a significant role.

    Edit: Not talking about solar cells or wind energy here, rather more exotic approaches.
    Last edited: Apr 5, 2009
  5. Apr 5, 2009 #4


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    Well, before you even get to cost/benefit, you have to ask if a proposal is even possible. Extending a pole/tower into space is not currently possible.
  6. Apr 5, 2009 #5
    More of a theory, just wondering if even possible theoretically. If space is a vacuum, then is there anything to apply friction?
  7. Apr 5, 2009 #6
    The most simple example of using eletromagnetic energy I can remenber now is the http://en.wikipedia.org/wiki/Crystal_radio" [Broken], an ancient radio receiver that needs no battery. Its power source comes from the eletromagnetics waves received from a long wire antenna, It was very popular in the early days of radio.
    Last edited by a moderator: May 4, 2017
  8. Apr 5, 2009 #7


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  9. Apr 5, 2009 #8
    TY dalespam, exactly the thought I came up w/ after posting my first thought of a pole. Maybe not feasible right now, but....
    Next idea that followed, and is not practical, but a track made of copper, wrapping around an entire globe, laid out in relation to the moon revolving around the planet, and a giant tether coming from the track, and bolted to the moon. As the moon goes around the planet, it drags the tether w/ magnetic end and thus, produces constant energy. Not sure on the #'s for the math, but would certainly be an insane amount of energy.
    May be feasible on a planet w/ few weather disturbances and a close moon w/ a quick planetary revolution. Now hook it up to a HUGE tesla coil, and voila, electricity for the solar system.

    Or is that too far out for you guys.
  10. Apr 9, 2009 #9
    Exactly. Many things are possible yet not practical. Perhaps I had not expressed myself correctly. My post stands with corrected interpretation.
  11. Apr 11, 2009 #10
    Well, I'm not quite sure I'd use the word friction, but there is the planet's magnetic field through which satellites pass. Even without the ability to build a beanstalk, there's some energy there for the taking. A number of real experiments have been done in orbit.

    http://en.wikipedia.org/wiki/Electrodynamic_tether" [Broken]
    Last edited by a moderator: May 4, 2017
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