Levitating an object with Earth's electric field

Discussion in 'Physics & Math' started by al onestone, Oct 5, 2015.

  1. al onestone Registered Senior Member

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    The Earth's electric field is roughly 150 Volts/meter directed radially downward towards the Earth. This fades away as you get further from the surface of the Earth. The Earth's surface is negatively charged and the ionosphere is positively charged.
    In order to use the Earth's electric field, E, to levitate an object, the object must be charged up with a net static electrical charge. The net charge, q, must be negative so that the Lorentz force, F, gives the object upward motion in accordance with the relation,
    F = qE
    For a Silicon object of dimensions 1m x 0.1m x 0.01m (weight 2.3kg) we require a net electric charge of 0.15 Coulombs (electrons).
    I believe that this idea is applicable for the technology of elevation. I think the object has to be semiconducting, and that it needs to be emersed in a insulating media (no loss due to arcing through the air). Metal might be too difficult to charge without loss when it is mechanically disconnected from the charging circuit.
     
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  3. origin Heading towards oblivion Valued Senior Member

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    You have an error here. 0.15 C will give a force of 2.3 N not kg, kgs are not a unit of force. The calculation is also for a point source. The force of gravity on 2.3 kg is 22.5 newtons. By the way a Coulomb is a very large amount of charge.
     
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  5. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    One point: Static electric field with divergence (like from a point charge or the Earth's natural electric field) can accelerate (or reduce the downward acceleration of gravity) but can not "levitate."

    A uniform or nearly so E field like between two parallel plates of a condenser can levitate. - In fact did so for Millikan measuring the charge on an electron. See: https://en.wikipedia.org/wiki/Oil_drop_experiment

    Note that very tiny spheres have (in static air) a quickly achieved "terminal fall velocity." - It was measured with the E- field off (zero) to get first the sphere radius then knowing the oil density, the drop's mass and the force of gravity acting on it. That is what the electric force that was applied by the uniform E-field balanced to zero. This is the first, I think, experimental proof that the charge on the electron is quantized.

    IE some oil drops, all of the same size, needed 2 or 3 times less applied E-field strength as those most difficult to levitate, but none would do so with say 2.5 times less than that larger field strength applied. IE drops charged with 2.5 times the charge of an electron do not exist.
     
    Last edited: Oct 5, 2015
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  7. Aqueous Id flat Earth skeptic Valued Senior Member

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    This is a problem in electrostatics, so you want to use Coulomb's Law, not the Lorentz Law, which applies to electrodynamics. Set the force due to gravity equal to the force due to charge in a field. Assume your object is a one meter dipole (rod) of zero volume - a necessary idealization for working with Volts/m. It will be an impossibility, since there is nothing to keep the rod from flipping over -but you can impose the requirement that the rod is held upright inside a rigid tube which is also vertically oriented. At least that will get you started.
     
  8. danshawen Valued Senior Member

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    3,951


    This is video of a very stable levitating ionocraft. Part of the reason this can work is the Earth's electric field. Most smaller ionocraft like this one rely on external high voltage sources, but there is no reason in principle why such lifters could not work without being tethered to external wires if a high voltage power supply could be made small and light enough to be lifted along with the apparatus.

    There also is no reason I can think of, ionocraft thrust could not complement the natural buoyancy of other lighter than air craft or be used in place of propellers for near whisper quiet operation. Ionocraft could also be recharged by means of intermittent high voltage electrical discharges directed at the ionocraft by means of towers or even a simple elevated conducting rail (similar to a monorail) strategically placed along its intended path or trajectory to maintain lifter charge.

    The interesting thing about ionocraft is the large thrust achieved with a minimum of energy expended accelerating ionized air through the lifter.

    As for "electrostatic levitation", Earnshaw's theorem would tend to negate that idea on the basis of its inherent instability (stable electrostatic levitation with fixed configuration of electric charge is IMPOSSIBLE). While Earnshaw can be easily overcome in the case of maglev stability (with time-varying magnetic fields, paramagnetic levitation in very strong static magnetic fields, or the Meissner effect with superconducting- not 'semiconducting' magnets), to the best of my knowledge, no corresponding arrangement is possible with the simple electrostatics and Coulomb's law described in the OP.
     
    Last edited: Oct 6, 2015
  9. al onestone Registered Senior Member

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    Origin, get a calculator please. E=150V/m, Q=0.15C Therefore QE =22.5N which is 2.3kg in weight.
     
  10. al onestone Registered Senior Member

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    An object fixed to travel in one dimension only, upward, (like an elevator) can be levitated by an electric field.
     
  11. al onestone Registered Senior Member

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    Lorentz law, coulombs law, same thing:

    Coulombs Law: F = k*(Q1)*(Q2)/r^2 , E = k*(Q1)/r^2 , there fore

    F = (Q2)*E which is Lorentz law.
     
  12. al onestone Registered Senior Member

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    I don't know about ionocraft, so I dismiss this. But I like your response about Earnshaw's theorem. You cannot levitate an object with a field when the object is not constrained in any direction of motion. This only applies when we have a 3D range of free motion. If we simply consider the possibility of constraining the motion to upward/downward like an elevator, then my idea becomes applicable and Earnshaw's theorem doesn't apply.
     
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  13. origin Heading towards oblivion Valued Senior Member

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    You are right, I have no idea how I came up with the wrong number??
    The force on the charge is 22.5 N, which is the same magnitude as the force of a mass of 2.3 kg in a gravitational field with an acceleration of 9.8 m/s^2.

    The amount of charge you are talking about is still huge, a lightning bolt typically transfers about 15C of charge!
     
    Last edited: Oct 6, 2015
  14. danshawen Valued Senior Member

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    Great. Do you also understand that anything connected to Earth ground (such as the shaft of an elevator) causes the electric field you want to discuss harnessing for flight to spontaneously curve around it so that there is no means for using that potential in the manner you suggest? If airplanes could make use of that potential for lift, theoretically an airfoil would not be required.

    I was attempting to answer your question in a manner that could suggest work arounds for that harsh reality, as opposed to dismissing it or offering equations that are beside the point because charges in an atmosphere are not "fixed" as they are on the surface of a solid, conductor or insulator.
     
    Last edited: Oct 6, 2015
  15. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Yes it is well known that ionic exhaust rockets work and have some practical application as the exhaust mass can be quite small compared to a chemical rocket. IE separating the energy system from the exhaust mass can give much higher specific impulse. But this is NOT electrostatic levitation. Read post 3 again to understand the very special condition that permit that; However electrostatic acceleration is easy - a silk rubbed rubber comb and some tiny pieces of paper can demonstrate that, but not stable levitation.
     
    Last edited: Oct 6, 2015
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  16. al onestone Registered Senior Member

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    OK, now I have to insulate the bottom of the elevator.
     
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  17. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    And make sure it is not mainly metal. The E-field inside a conductor or a shape with metal walls is always zero.
     
  18. danshawen Valued Senior Member

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    3,951
    It won't work simply to "insulate the bottom of the elevator", but at least you are closer to a practical solution. The electric field you are trying to exploit is from static electric charges in the atmosphere. If atmosphere circulates anywhere near Earth ground anywhere in the vicinity of the elevator, the elevator will still behave as if it were a "floating" plate of a capacitor, and repel the charges in the atmosphere, but I can think of an easy way to remedy this, in the same manner you would treat a problematic dielectric between the plates of a capacitor.

    Solution:

    1) insulate the bottom of the elevator, AND
    2) suck enough air quickly through the elevator shaft and convect it in order to make certain the charge of the atmosphere breaches the electrical force that otherwise cause the charge to behave as a repulsive electric laminar fluid surrounding the shaft. The fan blades or turbine which circulates or convects the charged atmosphere must be insulated at least as well as the base of your elevator.

    Other problems this solution may generate:

    Any elevator shaft that well insulated from Earth ground might prove to be a problematic engineering accomplishment in terms of the foundation construction, to say the least. Solid unvulcanized rubber does not have the strength of concrete. What happens when it rains and the outside of the elevator shaft gets wet?

    But if you need to go to all that trouble to exploit the charge in the atmosphere, you might as well go to a pneumatic elevator arrangement and forget about using atmospheric electric charge to propel it, yes?
     
  19. Aqueous Id flat Earth skeptic Valued Senior Member

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    The term Lorentz Force is generally used to refer to the force on charged particle moving across a field, which interacts with (due to its generation of) any magnetic fields present. I understand you dropped the cross-product v x B, but this is more appropriately called Coulomb's Law, and that was the point here. This is minor, so let's move on.

    When you set the Coulomb force equal to, and opposite of, the force developed under gravity, then you arrive at a better understanding of what you are trying to accomplish. I am trying to encourage you to write these out so you will see what I am talking about. Hint: the result (as the problem has been stated so far) is independent of distance from Earth. Do you agree? What do you think of it? What are some considerations that may invalidate what I just said? What do you think of the issue about having to create a dipole that stands on its end - and doesn't flip over - in order to make levitation work this way?

    I like Origin' s mention of the transfer of 15 C charge in a typical lightning bolt. Why then is the lightning so (potentially) destructive and what other considerations do we need to make about this in the problem stated here? When you get a final answer here, what are the parameters you will need to specify for your device to work? (I mean: you rarely see Coulombs specified in a design plan.) And: for levitating off the ground, how do you avoid generating your own lightning strikes? Tesla was evidently aware of the issue, and yet his big electrostatic radio tower did not withstand the forces of nature! Does this issue even come up in your proposed device, or am I off track? BTW I think a device that harnesses lightning is a great idea - but how useful is it? On a similar note, since levitation is useful in high speed trains - have you noticed how electric trains handle the issue of electric safety - I mean in general, not even the mag-lev trains.

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    One more thing came to mind as I was about to post this: Looking at the force needed to demolish that tower, how does that force develop, as compared to your equation. I mean: what is the direction of the force, and where does it come from?
     
  20. danshawen Valued Senior Member

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    3,951
    The Warden cliffs project was NOT electrostatic. Tesla's idea with this tower was to transmit his AC power @ 8 Hz via the ionosphere. No electrical power wiring would have been necessary; only a suitable gain antenna to collect the power on the consumer end. It is also possible that Tesla used a smaller prototype of the system to beam electrical power for charging batteries to his electric car.

    Tesla's plan may or may not have actually disrupted communications systems developed later, but at that low frequency, possibly not. It was problematic in one other respect that Tesla's friend Samuel Clemens (Mark Twain) evidently helped him to work out in terms of being an willing human guinea pig. It turns out that 8 Hz is not a good rate of vibration to expose the human body to. It is a most effective laxative (which Twain wrote about), and also a more serious side effect is that this is also the frequency that resonates acoustically with the brain cavity of the human skull. Although the power distribution system would no doubt have worked, the hum from 8 Hz AC power transformers that would have been required everywhere would have had those and perhaps other unforeseen and unfortunate effects. For all his genius, it is highly likely that Tesla related these problems to J. P. Morgan, and this is why the Warden Cliff tower came down, not because Tesla's vision of a wireless power distribution system would not have been a simple and effective way to wire everyone to electric power with a small number of synchronized power towers without a heavy reliance on stringing or burying power cables.

    I read this much from the "declassified" portions of Tesla's confiscated notebooks, which began appearing on the internet about 15 years ago. Please don't ask me to cite specific references about these notes. It took a very long time for me to glean this much from his notes and to reconstruct much of what he was attempting to do. There can be no doubt, this man was a genius well ahead of his time. An affection for pigeons in no manner detracts from this. Near the end of his life, he was found feeding pigeons in a nearby park while he was supposed to be receiving the "Edison Prize". I can't fault him for that behavior either, although some may have thought this eccentric.
     
  21. al onestone Registered Senior Member

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    I don't think so, but I'm not an atmospheric physicist and neither are you. The atmosphere that contains the positive end of the charge build-up is the ionosphere which is roughly 60km above earth. There is a good description at the wiki link:

    https://en.wikiversity.org/wiki/Natural_electric_field_of_the_Earth#cite_note-Labrador-1

    I understand what you mean by the air becoming a "compensating mechanism" to the charge on our object. Because the air is fluidic it will allow positive ion flow in accordance with the demands to counter the net charging of our object. But the question is, how prevalent is this effect at ground level? I don't think this would be a significant problem if we meet a couple criteria:

    1) Insulate the charged object.
    2)make the elevator shaft out of insulating material/wood
    3) Only allow the object to contact any metal in the shaft during charging and discharging
    4) Completely protect the whole mechanism from any rain/elements with insulating material
     
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  22. danshawen Valued Senior Member

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    My oldest son is a PhD atmospheric physicist, but I haven't asked him about your elevator. I might if you wish; I think it's a pretty cool idea, actually. Not only that, but I can imagine other scenarios (lauching spacecraft from the surface of the moon or mars, for instance), where it might be possible to make better use of your idea with a more controlled release of electrically charged atmosphere.
     
  23. Redshifter Registered Member

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    I once evaluated a downed UFO up in Springfield, CT back in 1982. The UFO used a nanoparticle material that was composed of micrometer sized, hexagonal, amorphous grains of fused silica. The matrix of the material was comprised of amorphous titanium metal that was very thin. I analyzed this material with a 1000 power microscope to identify the fused silica grains. Its density was that of fused silica. I identified the titanium metal with an x-ray fluorescence unit. This material could hold a high charge for levitation from the Earth's surface. This was because of the many grains holding the charge. It did not short out or loose its charge because the peripheral of the material was fused silica. The titanium also super conducted and did not dissippate its energy with heat. I have since found out that time is controlled by radiation I call the redshiftwaves. These redshift all matter and energy in the universe. The redshifted light from the distant galaxies is an effect of this redshiftwaves and not the doppler shift. When I applied my theory to the material I found out that the electrons in the charged material at the distance of the silica grains radius created a radiation I call the blueshiftwaves. These reverse time and allow the titanium to superconduct. I worked in a company named Emhart Industries at the time located near Hartford, CT. I was an engineer and I had access to the equipment to analyze the material. I told the executives of the company about my findings and I was terminated with no reason. The cover up. To date no one has researched this material and we do not have anti-gravity cars. I surmise that the material could be manufactured by making small fused silica beads and coating them with titanium metal, pressing them togehter and then sintering them together into a tile in an vacuum electric furnace. The electron's charge I have found out are space waves being emtted from the electron that push off of the Earth's surface. They have a very small viscosity to make the Earth feel an anti gravity force. If you care to believe then cudos to you. If not then this is just a science fiction tale.
     
    Last edited: Mar 4, 2019
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