Something from nothing

13

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  • SolaRevolutionSolaRevolution Solar Expert Posts: 407 ✭✭✭✭✭✭
    Re: Something from nothing
    niel wrote: »
    when you are out that far there is very little gravity present to counteract the centrifugal force. that would be spinning around the earth at many thousands of mph in near free space. the filament won't be strong enough to hold it.

    Yea. Sounds nutty doesn't it? The craziest thing is that many aerospace engineers believe it to be possible.

    My inadequate understanding of it is:
    Geosyncronous satelites orbit at an altitude where the centrifugal force balances the gravitational pull at the velocity which matches the Earth's rotation. Usually around 36,000 km (22,000 mi). The thinking is that the space elevator would have to be a bit longer to be able to pull hard enough to overcome the gravitational attraction. The filiment would be relatively very light and most of the apparatus would be subjected to less than one G. The main stress would be while lifting a load at ground level. Some believe the nanotubes have a high enough tensile strength to weight ratio that this will be possible once a polymer is found which can bind the fibers into a filiment with an adequate strength.



    nsaspook's link about the space shuttle's experiment to extract energy from the ionosphere using a tether: http://www-istp.gsfc.nasa.gov/Education/wtether.html got me wondering if there may be an orbital trajectory where the drag caused by the tether could be balanced by the orbital velocity. If the tether was retractable it would increase or decrease drag. Unfortunately it seems that a geosynchronous orbit would be too high to harvest any energy from the ionosphere. :confused:

    From the tether article:
    "Back on Earth the frayed end of the tether aboard the space shuttle was examined, and pieces of the cable were tested in a vacuum chamber. The nature of the break suggested it was not caused by excessive tension, but rather that an electric current had melted the tether."

    Wow.
  • mike95490mike95490 Solar Expert Posts: 9,089 ✭✭✭✭✭
    Re: Something from nothing
    john p wrote: »
    Are you willing to state in a difinitive manner that you do not believe that science will ever find a way for us to tap into the Earth's magnetic field as a useful energy source? Im willing to state that if you are putting off buying a new battery for your vehicle,and intend to use the power the earths magnetic field to power the starter motor,I hope you are very fit as you may end up doing a lot of pushing.

    Why yes, I would state it. If you /we /everybody starts pulling energy out of the mag field, it will be reduced. Or earth's rotation speed will slow. Or gravity would stop (ok, gravity would still work). Or we collapse the magnetic shielding. around our planet. (if switched off, - how do we switch back on?) They have found tidal energy harvesting does slow the earth down.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
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  • JeanLafeteJeanLafete Registered Users Posts: 1
    Re: Something from nothing

    Hello and great sight you have here. Can I inject a note here about the electrical energy and that's what Tesla was trying to do in the early 1900's. If it wasn't for JP Morgan and Edison the world would be much different if Tesla had been able to finish Wardenclyffe Tower. I believe his goal was to pull power from the ionosphere?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Something from nothing

    The world is already quite a different place thanks to Mr. Tesla and his Alternating Current.
    However he wasn't right about everything. Since his initial proposal of broadcast power (and the like) others have tried to achieve this dream - without success.

    Frankly if there were enough power "floating through the air" to do any real work we'd all be in trouble. Think static electricity to the nth degree. Florescent tubes lighting up all the time. Zapping discharges everywhere knocking CMOS chips into an early grave. It's hard enough to control electricity with wires.

    The Earth's magnetic field is rather weak compared to that of a dynamo. It does a fine job of making pretty auroraea, but is there enough sheer power there to make a dent in the megajoules used around the world? Doubtful. And like Mike said, tapping in to it is bound to have consequences. I have a vague recollection of it being important to blocking harmful solar radiation from reaching the Earth's surface (sunspot initiated EMF's that we have so much concern about) and no doubt the energy dissipated by ionizing the nitrogen and oxygen is at least enough to cause trouble. Further, if we were to take that energy away and use it, what would happen to the atmosphere (and weather) as a result of the loss of the ionization of the gasses?

    Nothing is ever as simple as it seems.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Something from nothing
    mike90045 wrote: »
    Why yes, I would state it. If you /we /everybody starts pulling energy out of the mag field, it will be reduced. Or earth's rotation speed will slow. Or gravity would stop (ok, gravity would still work). Or we collapse the magnetic shielding. around our planet. (if switched off, - how do we switch back on?) They have found tidal energy harvesting does slow the earth down.
    All the energy we humans will ever consume is a trivial portion of a trivial portion of a trivial portion of the energy contained in the rotational momentum of the spinning planet Earth. Not to worry.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Something from nothing
    ggunn wrote: »
    All the energy we humans will ever consume is a trivial portion of a trivial portion of a trivial portion of the energy contained in the rotational momentum of the spinning planet Earth. Not to worry.

    So we put great big coils in stationary orbit above the Earth, run feed lines down at the poles, and turn the planet into a giant generator ...
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Something from nothing
    niel wrote: »
    when you are out that far there is very little gravity present to counteract the centrifugal force. that would be spinning around the earth at many thousands of mph in near free space. the filament won't be strong enough to hold it.

    Enter carbon nanotubes. Some who have done the tensile calculations are convinced that nanotubes can handle it.

    A nontrivial task in designing a space elevator will be to design a means of traversing the 22,000 miles of cable between the Earth's surface and a station at the geosynchronous point in a reasonable amount of time. It's about 8 times the distance from New York to San Francisco.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: Something from nothing

    Welcome, JeanLafete. If I remember right Tesla was worried that his big machine could be used as a weapon - it was activated and there was an earthquake on the other side of the Earth. Unlikely he was right, after all there are earthquakes all the time. Either way, as others mentioned, the intent was to push energy into the air which would have caused many problems.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Something from nothing

    there could be several problems with this the first of which is that the earth doesn't just have one north and one south magnetic pole as i recall from a pbs (or was it nat geo or one of the other science channels?) that multiple random poles of various strengths are pockmarked around the planet. if i remember right it had something to do with nasa and one of the space programs or satellite programs. maybe apollo? anyway they discovered it as every time a passover occurred over a chunk of south america and that adjacent area of the atlantic ocean that they were experiencing problems and they narrowed it down to minipoles. i wish i could remember more specifically what program it actually was, but i think it was about the apollo program.

    another possible problem can rear its head as nobody would be satisfied with running long lengths of expensive copper wire (or any other highly conductive wire) and they would attempt to concentrate the magnetic fields much like they do already with transformers. if successful to any degree in doing so it could weaken the field elsewhere and leave dangerous gaps in our magnetosphere allowing some solar storms to penetrate more readily to the surface of the planet.
  • solar_davesolar_dave Solar Expert Posts: 2,368 ✭✭✭✭
    Re: Something from nothing
    So we put great big coils in stationary orbit above the Earth, run feed lines down at the poles, and turn the planet into a giant generator ...

    So it is equal to the Frank Zappa song Dynamo hum?
  • SolaRevolutionSolaRevolution Solar Expert Posts: 407 ✭✭✭✭✭✭
    Re: Something from nothing

    This link for Nasa Science News has some good models of the Earth's shifting magnetic fields.

    http://science.nasa.gov/science-news/science-at-nasa/2003/29dec_magneticfield/

    Dynamo hum, hum, hum.8)
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Something from nothing
    solar_dave wrote: »
    So it is equal to the Frank Zappa song Dynamo hum?
    Wheah dat Dynamo cummin' from?
  • nsaspooknsaspook Solar Expert Posts: 396 ✭✭✭
    Re: Something from nothing
    JeanLafete wrote: »
    Hello and great sight you have here. Can I inject a note here about the electrical energy and that's what Tesla was trying to do in the early 1900's. If it wasn't for JP Morgan and Edison the world would be much different if Tesla had been able to finish Wardenclyffe Tower. I believe his goal was to pull power from the ionosphere?

    Tesla was wrong. A freshman course in "near field" EM theory proves it. What he was trying to build was a "G-line" transmission system with the earth as a conductor and the air as a dielectric but his lack of training in basic EM theory lead him to a dead end.
    http://en.wikipedia.org/wiki/Goubau_line
  • SolaRevolutionSolaRevolution Solar Expert Posts: 407 ✭✭✭✭✭✭
    Re: Something from nothing
    nsaspook wrote: »
    I think the next big leap will be the development ... electronic devices that operate and control energy at the quantum level on a macro scale.

    What would this look like?:confused:

    Alex
  • nsaspooknsaspook Solar Expert Posts: 396 ✭✭✭
    Re: Something from nothing
    What would this look like?:confused:

    Alex

    One idea would be a device that could be transformed into any possible electronic circuit configuration. A blank module with set of instructions could turn into the lastest CPU model without the several billion dollar factory needed today.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Something from nothing

    "but his lack of training in basic EM theory lead him to a dead end."

    these were the times of discovery and when theories and definitions where being developed. much of what was discovered was by tesla among some others and there wasn't too much one could go reference to at that time. he helped to develop much theory so it wasn't a case of not going down to the library to brush up on em theory. maybe you are correct on what he was trying to do with that tower, but we may never know for sure as that guy was on a plane of thought far beyond even the other iq gifted discoverers of the time. even with all of his contributions to the field of electricity they tossed him aside and he died pennyless while others where making profits due to his genius.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Something from nothing

    True that Niel. I always felt bad for how things turned out for Tesla
  • nsaspooknsaspook Solar Expert Posts: 396 ✭✭✭
    Re: Something from nothing
    niel wrote: »
    "but his lack of training in basic EM theory lead him to a dead end."

    these were the times of discovery and when theories and definitions where being developed. much of what was discovered was by tesla among some others and there wasn't too much one could go reference to at that time. he helped to develop much theory so it wasn't a case of not going down to the library to brush up on em theory. maybe you are correct on what he was trying to do with that tower, but we may never know for sure as that guy was on a plane of thought far beyond even the other iq gifted discoverers of the time. even with all of his contributions to the field of electricity they tossed him aside and he died pennyless while others where making profits due to his genius.

    I admire Tesla for his vision but not for genius as he seemed to have lacked or maybe just rejected the formal training needed to understand the basis of his wireless energy devices. The theory of electrical wave transmission and propagation was written by James Clerk Maxwell and should have been in any reference library since 1865 but that would have interfered with his vision of wireless energy promotion. How a man as smart as Tesla in the electrical engineering field, with real inventions and engineering feats in his past wasted so much time and energy on it does make one feel bad for him as he became a mad man of eccentric activities and behaviors.

    http://en.wikipedia.org/wiki/A_Dynamical_Theory_of_the_Electromagnetic_Field
    This man was a true genius in this field and compared to him Tesla was but a mechanic.
    http://en.wikipedia.org/wiki/James_Clerk_Maxwell
    Maxwell is considered by many physicists to be the 19th-century scientist who had the greatest influence on 20th-century physics. His contributions to the science are considered by many to be of the same magnitude as those of Isaac Newton and Albert Einstein.[6] In the millennium poll—a survey of the 100 most prominent physicists—Maxwell was voted the third greatest physicist of all time, behind only Newton and Einstein.[7] On the centennial of Maxwell's birthday, Einstein himself described Maxwell's work as the "most profound and the most fruitful that physics has experienced since the time of Newton."[8] Einstein kept a photograph of Maxwell on his study wall, alongside pictures of Michael Faraday and Newton.[9]
    It is only recently, looking back, that people have begun to realise the immense impact the theory had giving the basis for the development of the theory of quantum mechanics, along with many others. In the words of Richard P. Feynman, Nobel Laureate:

    From a long view of the history of mankind - seen from, say, ten thousand years from now - there can be little doubt that the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics. [27]
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Something from nothing
    nsaspook wrote: »
    One idea would be a device that could be transformed into any possible electronic circuit configuration. A blank module with set of instructions could turn into the lastest CPU model without the several billion dollar factory needed today.
    Programmable gate arrays (PGAs) have been around for decades. They are useful for short product runs but they are very inefficient in terms of silicon real estate. They also run slow compared to optimized custom circuitry.
  • nsaspooknsaspook Solar Expert Posts: 396 ✭✭✭
    Re: Something from nothing
    ggunn wrote: »
    Programmable gate arrays (PGAs) have been around for decades. They are useful for short product runs but they are very inefficient in terms of silicon real estate. They also run slow compared to optimized custom circuitry.

    Correct, this proposed device would be very similar to a FPGA but would be photonic instead of electronic in nature with a speed and memory capacity far in excess of anything possible today. http://en.wikipedia.org/wiki/Quantum_optics
  • SolaRevolutionSolaRevolution Solar Expert Posts: 407 ✭✭✭✭✭✭
    Re: Something from nothing

    It isn't "something from nothing" but it is certianly getting something from what is now being wasted:

    "Researchers are developing a technique that uses nanotechnology to harvest energy from hot pipes or engine components to potentially recover energy wasted in factories, power plants and cars."
    http://phys.org/news/2012-04-nanocrystal-coated-fibers-energy.html

    From the article:
    "The ugly truth is that 58 percent of the energy generated in the United States is wasted as heat," said Yue Wu, a Purdue University assistant professor of chemical engineering. "If we could get just 10 percent back that would allow us to reduce energy consumption and power plant emissions considerably."

    I've got a thermoelectric fan for my wood stove. It powers the fan with electricity converted from the heat differential between the base (in direct contact with the stove) and the top which constantly receives cooler air via the turning fan. Some heat is turned into work to move the air but it ends up making better use of the stove's heat by actively spreading it out into the room instead of just relying on convection.

    It isn't something from nothing, but it makes better use of my cord wood without me having to provide any additional input. Using new technologies to harvest waste heat would be similar. I wonder how much more efficient a generator would be if the waste heat was harvested using nanocrystal coated fibers.
    Attachment not found.

    Alex Aragon
  • SolaRevolutionSolaRevolution Solar Expert Posts: 407 ✭✭✭✭✭✭
    Re: Something from nothing

    Here is another new electricity source which comes from what was previously considered "thin air".
    http://phys.org/news/2012-06-power-generating-knee-hints-batteries.html

    Could be used to power a light?
    Cell phone charger?

    -Alex
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Something from nothing
    Here is another new electricity source which comes from what was previously considered "thin air".
    http://phys.org/news/2012-06-power-generating-knee-hints-batteries.html

    Could be used to power a light?
    Cell phone charger?

    -Alex
    Again, there's no free lunch. Whatever power the unit produces is ultimately made from resistance to movement in the knee joint. Whether it's noticeable or not to the wearer I don't know.

    When I was a kid I had a little generator on my bike that powered a light. It mounted on the frame next to a wheel and had a little rubber roller that rode on the rim and spun its armature. I could definitely feel the drag from it. Of course, part of that drag was due to the low efficiency of the incandescent light; with LEDs it probably would have been a lot less.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Something from nothing
    ggunn wrote: »
    When I was a kid I had a little generator on my bike that powered a light. It mounted on the frame next to a wheel and had a little rubber roller that rode on the rim and spun its armature. I could definitely feel the drag from it. Of course, part of that drag was due to the low efficiency of the incandescent light; with LEDs it probably would have been a lot less.

    I put a diode and capacitor on mine. Couldn't resist tinkering even then. :D
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Something from nothing
    I put a diode and capacitor on mine. Couldn't resist tinkering even then. :D
    Hahaha Mine was before the days of solid state diodes, but it sure got a lot of use! We used to see if we could go fast enough to burn out the bulb. Never did, but did it ever get bright! lol
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Something from nothing

    why the diode? a cap is semi understandable. did they not rectify the output on the bike generator?
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Something from nothing
    niel wrote: »
    why the diode? a cap is semi understandable. did they not rectify the output on the bike generator?
    Nope, pure AC right from the single coil. The faster you went, the higher the Hz. If you hooked it to a loudspeaker, you could really make it scream :)
    It would also work as a synchronous motor if you hooked it to a door bell transformer, but ya had to give it spin to get it started. Hahaha The things I did as a kid, and then failed to grow up :D
  • john pjohn p Solar Expert Posts: 814 ✭✭✭
    Re: Something from nothing

    before solid state diodes we only had selenium rectifiers. they were about 3in sq and about 1in thick. And from memory not very effecient. on a bicycle dynamo its doubtful if you would have got enough out to light a bulb. for audio/amplifiers/radios etc a "rectifier valve' tube was used. Not so good on a bicycle.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Something from nothing

    The losses of trying to force current through a selenium rectifer would have drastically cut the overall efficiency of the system, and for what? Even a silicon bridge rectifier would cut the voltage to the bulb. A capacitor would likely bring the voltage back up, but you'd still have the losses of the rectifer, and when you only have about 3 watts to work with, and you had to produce it yourself while trying to peddle the bike, any loss would be unwanted. The "generator" did add a very noticeable load, but nothing young legs couldn't handle :D
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Something from nothing

    I'm familiar with both the rectifier valves (obviously not a choice on a bicycle - even as a kid I'd know that) and the selenium monsters (fins!). Germanium and silicon rectifiers have been around for over 60 years. And if your dad worked in radio repair they weren't hard to get a hold of. :D

    These days kids should be hooking their (LED) bike lights to lithium-ion batteries and devising controllers to recharge them from solar panels. I wouldn't doubt that somewhere out there they are. At least I hope they are, else where will the next generation of solar forum members and moderators come from? :cool:
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