The Coulomb Force

[ion]

For a start, read here:

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elefor.html

Verpies posted something a while back that refreshed my mind on the subject, but I am having difficulty
understanding the Coulomb force.

e.g the illustration talks of the amount of charge required to pass through a light bulb, but we really need to see it for what it is, namely one Ampere of current flow in a conductor for one second equals one Coulomb of charge passing a given point in the conductor.

Can we elaborate on the enormity of the Coulomb force and why we do not see it evidenced in our experiments?

"If such enormous forces would result from our hypothetical charge arrangement, then why don't we see more dramatic displays of electrical force? The general answer is that at a given point in a wire, there is never very much departure from electrical neutrality. Nature never collects a Coulomb of charge at one point".

[/b]

But we can do this in the lab and much more. Note that the voltage across a conductor can be very low, yet we can develop thousand of Amperes of current flow. Input power can be very low for those thousands of amperes if the voltage is in the millivolt range.

Wires are known to explode from the intense repulsion at very high currents, yet input power can be very low. Is this just magnetic repulsion?

I can charge a capacitor to one Coulomb by attaching it to a DC  current source that delivers one Ampere for  one second. Do the capacitor plates then experience the enormous force predicted in the example?

Any help shedding light on this would be appreciated, as the force seems to be enormous for modest input charge.

How can we design systems that best utilize this force, as the current electrostatic motors seem feeble in output by comparison?

Is some way of properly utilizing the enormous Coulomb force a key to OU?

Just asking, as something does not seem right here.

[evolvingape]

1 million tons of repulsion force ? That is a big potential, to say the least! You could have 1 million tons of force in a hhop gen 4 system, if you could build it big enough and the normalising plane was capable of absorbing and equalising that force.

My initial thoughts are that this potential is being balanced within a localised scalar field. Defining this field and the vectors it produces will need some thought.

The possibility that two frames of reference (maybe more) are operating in the same space over very small time frames is intriguing.

[Smudge]

You only have to look at Avagradro's number that is in the order of 10²⁸ compared to the electron charge in the order of 10^—19 to realize that neutral matter has in the order of 10⁹ Coulombs per m³ and that assumes just one electron per atom.  With equal numbers of ions and free electrons at that order of charge density the electron drift velocity is tiny even for high amperage current flow.  As for charging a capacitor at 1 amp for 1 second that sounds easy but to get that 1 Coulomb of charge at a useable voltage requires enormous capacitance, so it is not feasible for the average experimenter.   I have suggested the use of a half cell to get lots of charge released at low driving voltage.
Smudge

[evolvingape]

From your link I want to focus in and understand the relationship of the part of the equation I have circled. The surface area of a sphere and the electrical potential, permittivity of space.

https://en.wikipedia.org/wiki/Vacuum_permittivity

"It is the capability of the vacuum to permit electric field lines. This constant relates the units for electric charge to mechanical quantities such as length and force.[2] For example, the force between two separated electric charges (in the vacuum of classical electromagnetism) is given by Coulomb's law"

[ion]

From your link I want to focus in and understand the relationship of the part of the equation I have circled. The surface area of a sphere and the electrical potential, permittivity of space.

https://en.wikipedia.org/wiki/Vacuum_permittivity

"It is the capability of the vacuum to permit electric field lines. This constant relates the units for electric charge to mechanical quantities such as length and force.[2] For example, the force between two separated electric charges (in the vacuum of classical electromagnetism) is given by Coulomb's law"

So the equation says that the smaller the radius, the larger the force, as it is the divider. The leafs on a electrometer push away from each other when a charge is applied to the knob. This is a very feeble force at low electrostatic levels. What if our plates are made very large?

Note that if you change the sign on one of the bodies, the force is attractive. As capacitors are charged +/- shouldn't there be a huge crushing force between the oppositely charged layers of a capacitor?

Would Smudge agree that if we charge our capacitor (say a 1 Farad capacitor) with a current source limited to one Ampere, we would have a Coulomb of charge between the layers after one second?

[evolvingape]

So the equation says that the smaller the radius, the larger the force, as it is the divider. The leafs on a electrometer push away from each other when a charge is applied to the knob. This is a very feeble force at low electrostatic levels. What if our plates are made very large?

I do not understand the "total energy" relationship over time of that "space" defined as the volume of the sphere and the electrical potential. Plates or spheres ? The equation has no modifier for a leafs 2D area.

Note that if you change the sign on one of the bodies, the force is attractive. As capacitors are charged +/- shouldn't there be a huge crushing force between the oppositely charged layers of a capacitor?

hhop gen 4 is based on this concept. Net force of a mass does work in a direction for a period of time, then it's state is switched from a vector to a scalar frame of reference. The polarity changes, the net force changes vector (direction) and magnitude. How do we do this electrically ? Solid state preferably, switching the internal energy state of the system. (solid scalar field)

[evolvingape]

What is 4 pi r squared?

http://www.answers.com/Q/What_is_4_pi_r_squared

It is the formula for finding the surface area of a sphere which is 4*pi*radius2

So if the Coulomb Force is related to the surface area of a sphere how is the volume of that space related ?

https://en.wikipedia.org/wiki/Critical_mass

Explanation of criticality

When a nuclear chain reaction in a mass of fissile material is self-sustaining, the mass is said to be in a critical state in which there is no increase or decrease in power, temperature, or neutron population.

A numerical measure of a critical mass is dependent on the effective neutron multiplication factor k, the average number of neutrons released per fission event that go on to cause another fission event rather than being absorbed or leaving the material. When k = 1, the mass is critical, and the chain reaction is barely self-sustaining.

A subcritical mass is a mass of fissile material that does not have the ability to sustain a fission chain reaction. A population of neutrons introduced to a subcritical assembly will exponentially decrease. In this case, k < 1. A steady rate of spontaneous fissions causes a proportionally steady level of neutron activity. The constant of proportionality increases as k increases.

A supercritical mass is one where there is an increasing rate of fission. The material may settle into equilibrium (i.e. become critical again) at an elevated temperature/power level or destroy itself, by which equilibrium is reached. In the case of supercriticality, k > 1.

The boundary plane can be solid and normalise (zero potential) or it can be "polarity flipped", potentially inserting a velocity component along with a net force vector. A mass has both a vector potential and a scalar potential in the same space at the same time, the vector is external from the separating boundary and the scalar is internal to the boundary. It is possible to isolate these two properties, specific parts of the system over certain time periods, and create a reciprocal imbalance that changes polarity along with force direction, creating an oscillator.

[evolvingape]

Coulomb's constant

https://en.wikipedia.org/wiki/Coulomb%27s_constant

Taking this integral for a sphere, radius r, around a point charge, we note that the electric field points radially outwards at all times and is normal to a differential surface element on the sphere, and is constant for all points equidistant from the point charge.

Electromagnetism units

https://en.wikipedia.org/wiki/Natural_units#Electromagnetism_units

In SI units, electric charge is expressed in coulombs, a separate unit which is additional to the "mechanical" units (mass, length, time), even though the traditional definition of the ampere refers to some of these other units. In natural unit systems, however, electric charge has units of [mass] 1⁄2 [length] 3⁄2 [time]−1.

Vacuum equations, electromagnetic waves and speed of light

https://en.wikipedia.org/wiki/Maxwell%27s_equations#Vacuum_equations.2C_electromagnetic_waves_and_speed_of_light

In addition, E and B are mutually perpendicular to each other and the direction of wave propagation, and are in phase with each other. A sinusoidal plane wave is one special solution of these equations. Maxwell's equations explain how these waves can physically propagate through space. The changing magnetic field creates a changing electric field through Faraday's law. In turn, that electric field creates a changing magnetic field through Maxwell's addition to Ampère's law. This perpetual cycle allows these waves, now known as electromagnetic radiation, to move through space at velocity c.

[Smudge]

So the equation says that the smaller the radius, the larger the force, as it is the divider. The leafs on a electrometer push away from each other when a charge is applied to the knob. This is a very feeble force at low electrostatic levels. What if our plates are made very large?

Note that if you change the sign on one of the bodies, the force is attractive. As capacitors are charged +/- shouldn't there be a huge crushing force between the oppositely charged layers of a capacitor?

Would Smudge agree that if we charge our capacitor (say a 1 Farad capacitor) with a current source limited to one Ampere, we would have a Coulomb of charge between the layers after one second?

I do agree with that and there is a crushing force on the dielectric.  1  Farad is a huge capacitance value, well it was in my day but perhaps not now with supercaps.  I find it interesting that supercaps are a form of cell using chemical change to get the high quantity of charge stored.

With regard to e-ape's question about the 4Pi r squared if you appreciate that an electron is constantly absorbing and emitting virtual particles it is those emitted that carry the electric field information.  And the density of those emissions in term of numbers per square meter follows that range law.
Smudge

[ion]

I do agree with that and there is a crushing force on the dielectric.  1  Farad is a huge capacitance value, well it was in my day but perhaps not now with supercaps.  I find it interesting that supercaps are a form of cell using chemical change to get the high quantity of charge stored.

With regard to e-ape's question about the 4Pi r squared if you appreciate that an electron is constantly absorbing and emitting virtual particles it is those emitted that carry the electric field information.  And the density of those emissions in term of numbers per square meter follows that range law.
Smudge

Nowadays, 1 Farad, 16 volt capacitors are commonplace and inexpensive, due to their wide use in propping up high power car audio systems surge current requirements.

http://www.ebay.com/itm/iXOS-1-Farad-Capacitor-For-Sale-/132106173249?hash=item1ec2243b41:g:Cn4AAOSw4GVYN8XP

Some types are available that are 30 Farad at 16 Volts

http://www.ebay.com/itm/Rockville-RFC30F-30-Farad-Capacitor-Blue-Voltage-Display-/301777221262?hash=item464352f68e:g:-REAAOSwaB5Xn~Pj&vxp=mtr

The question remains, how do we get a reasonably large charge onto a couple of spheres and measure the repulsive or attractive force. We don't need a million tons of force, a pound of force at one meter would satisfy.

I guess Graham could easily create a large electroscope from a couple of metal plates and charge it with his VanDeGraaf.

[Centraflow]

http://www.maxwell.com/products/ultracapacitors/k2-3-series

3000Farads at 3v

Regards

Mike

[Chet K]

at 32:28 mark in Walter Lewin"s electrostatic  lecture
he mentions this and goes on to compare gravity and electricity ,a monstrous disparity

https://www.youtube.com/watch?v=x1-SibwIPM4

I love Lewin's lectures ,in this case trying to understand [for me ] the Coulomb force.

hard to get my head around it [the enormous power and size]

[evolvingape]

Graphene-like substance generates electricity when stretched:

https://arstechnica.com/science/2014/10/graphene-like-substance-generates-electricity-when-stretched/

A single molecule thick layer of this stuff sandwiched between the dielectric could be pumped!

"In contrast, flakes with even numbers of MoS2 layers produced no output. For a single-layer of MoS2, voltage and current outputs increased with increasing strain. Single layers exhibited a decrease in current and an increase in voltage when resistance was cranked up. Finally, cyclic strain and release studies demonstrated single-layers were stable for an extended period of use."

This is an interesting situation because it reminds me of the hhop gen 2 hybrid and hhop gen 3, which both use a gas compression phase without a combustion cycle. The same principle in a capacitor would see pulsed DC output from the Coulomb Force, without using any of the electricity that is on it's way to the load, except for resistance loss through the capacitor.

Add the two outputs together would it be COP>1 ?

[ion]

Those 3000 Farad caps are amazing and available!!

http://www.ebay.com/itm/New-USA-Maxwell-2-7V3000F-super-capacitor-K2-2-7V-3000F-Connecting-piece-G721-XH-/172209971661?hash=item281883a1cd:g:7CgAAOSwIzNXOwuA

I wonder if anyone would like to calculate the charge held inside those caps

Lets see: charged from a constant current source at one Ampere would take 3000 seconds to reach one volt,
x2.7 Volts = 8100 seconds  or 135 minutes to fully charge to 8100 Coulombs. Calculate the strength of the attractive crushing force of 8100 Coulombs.

Correct this if I missed a decimal point or the concept is wrong.

Looking at the last example from the link in the first post, with the copper spheres being repelled, I now see that manipulation of the charge on a body would lead to interesting antigravity effects on a much larger scale.

One fellow wrote this:

The charge of 1 coulomb (1 C) has about 6.24×1018 electrons.

The electric force which would be produced by two charges of 1 coulomb held 1 meter apart is about 8.99 giganewtons (GN), which is equivalent to about 2 billion pounds of force. This is derived from Coulomb's law:

FE=k|q1||q2|r2

and setting q1=q2=1 C and r=1 m, where r is the distance of separation.

The energy released by the mutual repulsion of two +1 C charges let go at the separation of 1 meter, and thus also the energy which would be required to bring them to within that separation of each other, is given by the potential energy:

UE=kq1q2r

with, again, q1=q2=1 C and r=1 m, giving that UE≈8.99 GJ, or over 2 tonnes of TNT's worth of explosive energy. Most likely, a spherical object of graspable size, brought up to a charge of +1 C, would self-explode with a comparable, if not greater (because its size would be smaller than 1 m), amount of energy due to internal stresses set up by the mutual repulsion. Actually, it would explode well before the charge reached that value.

The order of magnitude of 1 coulomb of charge is attained in thunderstorms, where the charge-retaining objects are thunderheads many km in size, and several coulombs are transferred by a lightning strike. This gives you some idea of the scale of the object required to retain a charge of 1 coulomb or thereabouts, and also of the power that a charge imbalance on that scale carries -- it's literally like a bolt of lightning.

[evolvingape]

As capacitors are charged +/- shouldn't there be a huge crushing force between the oppositely charged layers of a capacitor?

Would Smudge agree that if we charge our capacitor (say a 1 Farad capacitor) with a current source limited to one Ampere, we would have a Coulomb of charge between the layers after one second?

I do agree with that and there is a crushing force on the dielectric.

A standard capacitor, no matter its capacitance ability, cannot utilise this crushing force on the dielectric as it is absorbed and equally returned by the solid wall normalising plane.

The elephant wearing stilettos comes to mind when thinking about high voltage cap shorts that breach the dielectric at the weakest point and blow the cap.

In what way can a standard ultra capacitor, and in what system, demonstrate the ability to measure the Coulomb Force as an independent output from system output ?

[evolvingape]

http://www.physicsclassroom.com/class/estatics/Lesson-3/Coulomb-s-Law

The force of repulsion of two +1.00 Coulomb charges held 1.00 meter apart is 9 billion Newton. This is an incredibly large force that compares in magnitude to the weight of more than 2000 jetliners.

[evolvingape]

Comparing Electrical and Gravitational Forces

Electrical force and gravitational force are the two non-contact forces discussed in The Physics Classroom tutorial. Coulomb's law equation for electrical force bears a strong resemblance to Newton's equation for universal gravitation.

The two equations have a very similar form. Both equations show an inverse square relationship between force and separation distance. And both equations show that the force is proportional to the product of the quantity that causes the force - charge in the case of electrical force and mass in the case of gravitational force. Yet there are some striking differences between these two forces. First, a comparison of the proportionality constants - k versus G - reveals that the Coulomb's law constant (k) is significantly greater than Newton's universal gravitation constant (G). Subsequently a unit of charge will attract a unit of charge with significantly more force than a unit of mass will attract a unit of mass. Second, gravitational forces are only attractive; electrical forces can be either attractive or repulsive.

The inverse square relationship between force and distance that is woven into the equation is common to both non-contact forces. This relationship highlights the importance of separation distance when it comes to the electrical force between charged objects.

[evolvingape]

"The order of magnitude of 1 coulomb of charge is attained in thunderstorms, where the charge-retaining objects are thunderheads many km in size, and several coulombs are transferred by a lightning strike. This gives you some idea of the scale of the object required to retain a charge of 1 coulomb or thereabouts, and also of the power that a charge imbalance on that scale carries -- it's literally like a bolt of lightning."

Would 2 ultra cap banks, both internally wired in parallel, provide the capacitance required for 1 Coulomb of charge? A small plate either side of that graphite sheet would squeeze it producing an electrical output proportional to the force, up to a maximum limit.

[ion]

Would 2 ultra cap banks, both internally wired in parallel, provide the capacitance required for 1 Coulomb of charge? A small plate either side of that graphite sheet would squeeze it producing an electrical output proportional to the force, up to a maximum limit.

You don't really need ultra cap banks, Q in Coulombs= C (in Farads) x Volts

A one Farad capacitor charged to one Volt is one Coulomb of stored electrostatic charge

A 0.001 Farad capacitor (1000 microFarads) charged to 1000 Volts has the same electrostatic charge

Between those values, there are a lot of low cost high quality capacitors to play with, you need not go

to the leading edge of high cost, high Farad  capacitors.

see this:

http://www.electronics-tutorials.ws/capacitor/cap_4.html

I'm quite happy to work at medium voltages with good quality computer grade capacitors,

but don't really know where to go with all this.

One interesting experiment would be large capacitor plates with a slightly compressible dielectric, and measure the compression force of one Coulomb.

Glad that you are interested, EA

I find the attached excerpt the most interesting. Consider if it were possible to do this:

The radius of a one cm3 sphere is 0.62 cm, so we will treat the force as that between two point charges 2.48 cm apart (i.e., twice the sphere diameter apart). Using Coulomb's law, this requires a charge of 7.8 x 10-8 Coulombs. Compared to the total mobile charge of 13,600 Coulombs, this amounts to removing just one valence electron out of every 5.7 trillion (5.7 x 1012) from each copper sphere. The final result is that the removal of just one out of roughly six trillion of the free electrons from each copper sphere would cause enough electric repulsion on the top sphere to lift it, overcoming the gravitational pull of the entire Earth!

Note that the Earth carries a negative electric charge of roughly 500 thousand Coulombs and you know where I'm going with this.

[TinselKoala]

http://www.youtube.com/watch?v=AX-jrlGC-aA

[ion]

Nice demonstration of electrostatic force in action.TK.

After watching Prof Lewin's elementary lecture on electrostatics, I noticed he does not go into the finer points.

Watching those little pieces of confetti fly off the top of the Van DeGraaf at high speed, makes me wonder if a large plate capacitor would also be repelled by the force on it's negative side.

Can anyone imagine levitation of a large craft based on this principle?

500,000 Coulombs is quite a charge on the earth.

[Smudge]

Nice demonstration of electrostatic force in action.TK.

After watching Prof Lewin's elementary lecture on electrostatics, I noticed he does not go into the finer points.

Watching those little pieces of confetti fly off the top of the Van DeGraaf at high speed, makes me wonder if a large plate capacitor would also be repelled by the force on it's negative side.

Can anyone imagine levitation of a large craft based on this principle?

500,000 Coulombs is quite a charge on the earth.

And the Earth is quite large so the surface charge density is quite small.  It amounts to an electric field at the surface of about 300 V/m.  So a body carrying 1 Coulomb of charge would get a force of 300 Newtons.  Now you can get 1 Coulomb easily in a supercap but that is stored as both positive and negative charge on the two plates as mutual capacitance.  What we need is a self capacitance of supercap proportions.  Self capacitance is a one terminal capacitor that some people find difficult to comprehend.  Because self capacitance relates to the size of a body, to get 1 Coulomb onto a reasonably sized object requires huge potential that is impossible to generate.  If you think of a half cell (a single electrode in an electrolyte) then maybe you can get charge released as ions when a reasonable potential is applied.  So perhaps you could have a small sphere surrounded by electrolyte as your object.  Of course it would need a container but that could be thin glass or plastic.

Smudge

[ion]

Hi Smudge

Thanks for your response and input. I was thinking of a large hollow sphere comprising an outer conductive layer, and a dielectric sandwiched in between an inner conductive layer. A HV power supply inside the device would create the charge on the two layers of the spherical capacitor. To the outside world it would be like a monopole.

There used to be a local company (Dynasciences I think) that made a device that could be attached to helicopters and airplanes that could beam off or otherwise electrically discharge the electrostatic charge buildup with EM waves of some sort.
I wonder if such a device actually exists, and could it work in reverse?

[evolvingape]

Glad that you are interested, EA

I find the attached excerpt the most interesting. Consider if it were possible to do this:

Note that the Earth carries a negative electric charge of roughly 500 thousand Coulombs and you know where I'm going with this.

Yes I am interested but have very little time to work on this subject. This article is interesting:

http://www.veteranstoday.com/2014/07/13/vt-nuclear-education-anti-gravity/

[Smudge]

Hi Smudge

Thanks for your response and input. I was thinking of a large hollow sphere comprising an outer conductive layer, and a dielectric sandwiched in between an inner conductive layer. A HV power supply inside the device would create the charge on the two layers of the spherical capacitor. To the outside world it would be like a monopole.

To the outside world it would look like an uncharged sphere.  The positive and negative charge would appear on the inside surface of the outer conductive layer and on the outside surface of the inner conductive layer.  The dielectric would carry the E field between these two layers.  There would be no E field escaping to the outside world.

There used to be a local company (Dynasciences I think) that made a device that could be attached to helicopters and airplanes that could beam off or otherwise electrically discharge the electrostatic charge buildup with EM waves of some sort.
I wonder if such a device actually exists, and could it work in reverse?

Airplanes have wick dischargers to get rid of charge by corona discharge.  They are simply sharp points where the charge concentrates to create a high E field there high enough to ionise the air and create corona.  The corona discharge is impulsive so the dischargers create EM noise, but the discharge is not basically EM waves.
Smudge