Superconductivity at room temperature??

[sol invictus]

Once it has settled down there are as many charge-carriers as positive charges and all the charge-carriers are moving simultaneously to transport a current I along the whole circuit. There cannot be any accumulation of charge-carriers anywhere.

That's again the Prins argument that proves the non-existence of lakes. It's true that the charge density is constant in time once you reach the steady state, just as the amount of water in the lake is constant once the inflow equals the outflow. It is not true that there cannot be accumulations of charge in the steady state, just as it is not true that there cannot be lakes.

I just realised that you can use two ammeters: One in the middle of the copper and one in the middle of the iron. I am sure that such an experiment will prove your arguments above WRONG as usual!!

As ben says, that measures the current through the ammeter. Away from equilibrium there's no guarantee that's the same as the current through the circuit at any particular point.

What you could do is measure the magnetic field at different points along the wire, which will measure the current at that point.

 

[johanfprins]

The notion that it's some other form of charges besides the "charge carriers" that accumulate at the interface is a semantic absurdity, even apart from the physics of a metal.

So let us get some sense to this discussion: Are you stating that charge-carriers are trapped (immobilised) within the interface and therefore opposite charges (which we know are immobile) are thus present at the opposite interface? Yes or No!

There's no charge at the interface before the wire is connected to the voltage; afterwards there is.

Fine then tell me what it is since it cannot be the charge-carriers that become immobile at the interface.

So, charge accumulated at the interface. But according to Johan, those charges cannot be "charge carriers".

Quite correct: Since the charge carriers can only become trapped when they hit a barrier through which they cannot flow. Thus the change in electric field cannot be caused by an accumulation of stationary charge-carriers within the interface. If something is physically not possible then it is not possible. What really happens is open to discussion, but please do not explain a physical result in terms of paranormal physics. We have far too much of that in then world since 1927.

If you're interested in reality-based physics,

What do you know about "reality"?

the charges that accumulate are of course electrons (on one interface, and a lack of electrons on the other, which means there's a net positive charge there) - the same kind of electrons that carry the current in steady state. They are not "bound charges"

They have to be bound in order to be present permanently within the interface.

because metals have plenty of free charges available to flow wherever the electric fields push it.

Huh, Duh! Water also has plenty of free molecules available to flow where-ever a pressure pushes them, but these molecules can also not accumulate as if they suddenly, through a miracle, become stationary at a boundary through which they are flowing. Please Sol!

 

[ben m]

It seems that we have been arguing past each other since my only argument was that the divergence cannot be caused by the static accumulation of the charge-carriers. If I have been misunderstood because I have been unclear on this, then I do apologise. I hope that my viewpoint is now clear.

Your "only argument"? You have been "misunderstood" and "unclear"? No, Johan:

http://www.internationalskeptics.com/forums/showpost.php...postcount=1843
The divergence of an applied conservative electric field while a current is flowing is ALWAYS ZERO.

Clear as a bell. As of eight pages ago, you were perfectly clear about your belief that the divergence was itself zero. You have now changed this belief because Sol, Zig, and I were patient enough to ignore your insults and walk you five times through the derivation.

It's incredibly annoying; you have now erased the memory of this walkthrough, and twisted it into "I knew all along that Gauss's Law applied to this interface accumulation of non-free charges." No you didn't, you made it up about two pages ago after one of your previous made-up objections collapsed. Again.

 

[D'rok]

What do you know about "reality"? They have to be bound in order to be present permanently within the interface. Huh, Duh! Water also has plenty of free molecules available to flow where-ever a pressure pushes them, but these molecules can also not accumulate as if they suddenly, through a miracle, become stationary at a boundary through which they are flowing. Please Sol!

Well...

Just last month there was an extreme thunderstorm here in Toronto with high winds and intense rain. A huge maple tree right in front of my house cracked in half and fell directly into the street. It formed a perfectly angled, somewhat porous damn across the entire street. On either side of the tree, water quickly began to accumlate and pretty soon there were two "lakes" on each side of the tree even though water was also flowing through the gaps between the tree and the road. Parked cars were nearly floated.

Long story short: water accumulated at a boundary through which it was flowing. I think I can confidently say that none of the water molecules in that accumulation were "bound" or "stationary". Impossible in the Prinsverse?

 

[ben m]

They have to be bound in order to be present permanently within the interface.!

Not at all. Who says they're permanent?

If there's a traffic slowdown on the Brooklyn Bridge, there are 5 cars/second entering and 5 cars/second leaving and 300 cars on the bridge. Does this require that the Brooklyn Bridge has 200 cars actually stopped, plus a line of 100 widely-spaced cars moving at full speed?

No, it might mean a queue of 300 closely-spaced, slow-moving cars, all moving, with new cars joining the back of the queue and old cars joining the front.

Does this violate conservation of car-flux, Johan? Everything you have said tells me it does. "You can't have an accumulation of cars when a current of cars is flowing! Conservation of cars says that the 5 cars per second enter, and 5 cars per second leave, and thus no cars are stopping in the middle! Therefore there can never be an excess of cars on the bridge!"

ETA: In other words, Johan, there is a reason that:

a) We have separate expressions for charge and current. They behave differently.
b) We have one and only one equation correlating charge and current; it's div.J = drho/dt. That equation is correct and any alternate version is wrong. "div.J = rho" is wrong, "div.J = zero" is wrong, "rho = 0 if J > 0" is wrong.
c) We use all of the laws of differential and integral calculus, including constants-of-integration. "drho/dt = 0" does NOT imply rho=0, any more than "dy/dx = 0 " implies y=0.

It's for the same reason that "density of cars" and "rate of cars" are different things. It's for the same reason that "rate of cars in " is not always identical to "rate of cars out". Because that's the way the conservation laws work.

 

[ben m]

I can add one more thing to the battle against Johan's intuition. Watch this video:

http://www.youtube.com/watch?v=FvJXCG8IVcA

What's that, Johan? It's a localized excess of water on the St. Lawrence River near Montreal. There is more water at that spot than at neighboring spots. Nonetheless, water is entering this spot, and water is leaving this spot, at the same rate up and downstream---there's no water flow divergence. Water is not "bound" to the spot---the excess is not frozen down or tied down or something. There's not an impenetrable barrier. All of the conservation laws you've tried to apply to electrons, Johan, apply to this water, yet it violates your axiom:

can only become trapped when they hit a barrier through which they cannot flow.

Nope. The axiom is wrong, Johan. Drop it.

 

[johanfprins]

I think I can conceptually understand that, but I still have no idea what Johan means by "excess" charge carriers. In these examples charge carriers = electrons, so what does it mean to say "excess" electrons. It makes no sense at all to me.

A conductor is filled with just as many charge-carriers as there are positive charges, and when a current flows the total charge within the conductor must thus be on average zero. If you now want to claim that there are stationary charges trapped at an interface, which do not move through the interface, there must be excess charge carriers trapped (immobilised) at the interface. This is what I meant by excess. Maybe not a good choice of words.

I hope this makes sense. I have maintained all along that you cannot have such a stationary charge accumulation at an interface while a current is flowing through it. BZC has maintained that such a stationary accumulation of charge-carriers can cancel an electric-field within a superconductor. This is not possible while a current is flowing. Then they came up with the argument that this is proved by Gauss' law. I maintain that Gauss' law does not prove that there are stationary charge-carriers trapped at an interface anywhere while a current is flowing. The change in electric field must be a dynamic effect; not a static accumulation of charge-carriers.

 

[ben m]

I maintain that Gauss' law does not prove that there are stationary charge-carriers trapped at an interface anywhere while a current is flowing.

No one ever said there were stationary charge carriers at the interface. We said there was excess charge density at the interface.

Gauss's Law doesn't care how fast charge is moving; it doesn't care which charge is which. It cares about the density.

 

[sol invictus]

So let us get some sense to this discussion: Are you stating that charge-carriers are trapped (immobilised) within the interface and therefore opposite charges (which we know are immobile) are thus present at the opposite interface? Yes or No!

"Trapped"? "Immobilised"? Is water trapped or immobilized in a lake that has non-zero but equal inflow and outflow?

The accumulated charge will dissipate if, for instance, you turn off the current, just as it accumulated when you turned it on. So no, I wouldn't say it's trapped. It just hit a point of greater resistance, quite like D'rok's tree, and accumulated there.

Water also has plenty of free molecules available to flow where-ever a pressure pushes them, but these molecules can also not accumulate as if they suddenly, through a miracle, become stationary at a boundary through which they are flowing. Please Sol!

Don't be stupid - of course they can. Don't they have lakes or dams or sinks or bathtubs in South Africa?

 

[johanfprins]

It's simple, Johan. You refuse to consider that you might be mistaken.

I deny this with contempt. That is all I can do since this is one of those false statements that strengthens the deliberate lie on which it is based the more the person who is libelled by it argues against it. Is this an example of the tactics you use in court?

Instead, it's the entire discipline of physics that has been getting at all wrong for the last 80 years.

Here again you are deliberately distorting the facts: I never stated that it's the entire discipline of physics that has been getting it all wrong for the last 80 years.

What I strongly believe is that when you have to invoke paranormal effects to interpret physics, you are not doing physics. Invoking the paranormal has been done since 1927: For example:
1. Wave particle duality: This is the idea that Nature is so paranormal that we cannot understand it, and just have to accept that it is as we perceive it without being able to explain it.
2. The double slit experiment which is explained in terms of the paranormal concept that when looking through which slit the particles are moving, the particles know this, and acts differently from when you are not looking.
3. Tha paranormal concept that our universe is constantly splitting into near similar multiverses.
4. Wheeler's delayed choice experiment which is interpreted in terms of the paranormal concept that what we do at present affects the past.
5. The paranormal concept of a "participatory" universe where waves are moving into a point from infinity.
6. Tha Aharanov-Bohm model according to which an electron can be affected in a paranormal manner by a magnetic field while not moving through the magnetic field.

Why physicists prefer to interpret physics in terms of the paranormal, while there are adequate interpretations which do not require paranormality, stuns me. And why they excommunicate people like, for example, Shariar Afshar (there are many similar examples), when he does a double slit experiment that proves without any doubt that Bohr's concept of "complementarity" is wrong, I will never understand.

And when you come against math and/or established physical laws, it is the latter that is incorrect rather than you.

Another misrepresentation by you. I just oppose it when established laws are incorrectly applied as Ben does when he claims that a current flowing through a conductor past positive charges is the same as a current flowing through vacuum, and thus not past positive charges, when it comes to the generation of a magnetic field around the current. I will expand on this issue when I come to Ben's post below.

Possible, but highly improbable.

Improbable is not impossible. This is one of our biggest transgressions at present: Physics manuscripts are rejected because the editors think that it is "improbable'. They forget that all paradigm shifts have been considered improbable until they were proved possible. Thus, to reject manuscripts on "improbability" is throwing out the baby with the bathwater. A manuscript should only be rejected if it can be meticulously proved that it is really impossible. My manuscripts on superconduction has all been rejected since the editors considered it improbable that the BCS model, which has been invoked by hundreds of thousands of physicists over a period of more than 50 years, can be wrong.

 

[D'rok]

I deny this with contempt. That is all I can do since this is one of those false statements that strengthens the deliberate lie on which it is based the more the person who is libelled by it argues against it. Is this an example of the tactics you use in court? Here again you are deliberately distorting the facts: I never stated that it's the entire discipline of physics that has been getting it all wrong for the last 80 years.

What I strongly believe is that when you have to invoke paranormal effects to interpret physics, you are not doing physics. Invoking the paranormal has been done since 1927: For example:
1. Wave particle duality: This is the idea that Nature is so paranormal that we cannot understand it, and just have to accept that it is as we perceive it without being able to explain it.
2. The double slit experiment which is explained in terms of the paranormal concept that when looking through which slit the particles are moving, the particles know this, and acts differently from when you are not looking.
3. Tha paranormal concept that our universe is constantly splitting into near similar multiverses.
4. Wheeler's delayed choice experiment which is interpreted in terms of the paranormal concept that what we do at present affects the past.
5. The paranormal concept of a "participatory" universe where waves are moving into a point from infinity.
6. Tha Aharanov-Bohm model according to which an electron can be affected in a paranormal manner by a magnetic field while not moving through the magnetic field.

Why physicists prefer to interpret physics in terms of the paranormal, while there are adequate interpretations which do not require paranormality, stuns me. And why they excommunicate people like, for example, Shariar Afshar (there are many similar examples), when he does a double slit experiment that proves without any doubt that Bohr's concept of "complementarity" is wrong, I will never understand.
Another misrepresentation by you. I just oppose it when established laws are incorrectly applied as Ben does when he claims that a current flowing through a conductor past positive charges is the same as a current flowing through vacuum, and thus not past positive charges, when it comes to the generation of a magnetic field around the current. I will expand on this issue when I come to Ben's post below.
Improbable is not impossible. This is one of our biggest transgressions at present: Physics manuscripts are rejected because the editors think that it is "improbable'. They forget that all paradigm shifts have been considered improbable until they were proved possible. Thus, to reject manuscripts on "improbability" is throwing out the baby with the bathwater. A manuscript should only be rejected if it can be meticulously proved that it is really impossible. My manuscripts on superconduction has all been rejected since the editors considered it improbable that the BCS model, which has been invoked by hundreds of thousands of physicists over a period of more than 50 years, can be wrong.

None of this makes your position appear reasonable. All of it makes you look more stubborn and foolish.

Consider, Johan, that you may be mistaken. Consider, just for a moment, that you may not be Galileo fighting the Catholic church.

 

[D'rok]

I never stated that it's the entire discipline of physics that has been getting it all wrong for the last 80 years.

Oh really?

The Physics Delusion

• How the decline in scientific objectivity has transformed physics into a dogmatic, fundamentalist, organised-religion.
  
  
  http://www.cathodixx.com/books.asp

 

[johanfprins]

Nope. You're measuring the current through the ammeter. In a circuit that has (as you say) "not settled down", it is not true that the current is the same everywhere.

It is strange that Ziggurat argued that superconducting charge-carriers can be accelerated since when switching on an electromagnet, the charge-carriers must start moving and must keep on moving at every position along the superconductor in tandem. Now you argue that this is not so.

Let me put it this way: If you only have one material, say iron, and you switch on the voltage, is it true that the electric-field starts to act near-instantaneously at every point along the conductor, and that the charge-carriers must thus accelerate equally at every position? While the current is increasing towards equiilibrium, they already start to scatter: In fact, they must, since it is the frequency of acceleration and scatterring in conjunction with the magnitude of the applied voltage, which determine the magnitude of the equilibrium current. Thus, clearly, the current must at every position along the conductor, increase at the same rate, and reach the same equilbrium value. So even before settling down, the current will be the same at every position.

 

[johanfprins]

That's again the Prins argument that proves the non-existence of lakes.

Can you explain to me where lakes come into the picture when we are considerring the flow of currents through "pipes" which are already filled to the brim with the constituents that are flowing. A lake can increase its height when more water is flowing in than is flowing out: A pipe, already filled with water that is flowing under pressure, cannot fill up more than the water it contains. I am really getting sick and tired of your irrelevant examples.

It's true that the charge density is constant in time once you reach the steady state,

At last the acknowledgement

just as the amount of water in the lake

There is not any equivalent to a lake within an electrical circuit: If you want to comapare to water, you must use a pipe through which the water flows: When the pipe is filled with water that flows, there cannot be any accumulation of water at any position along the pipe.

As ben says, that measures the current through the ammeter. Away from equilibrium there's no guarantee that's the same as the current through the circuit at any particular point.

When you have an element with resistance R and you switch on a voltage V, the current through an ideal ammeter will reflect the current through the resistor which will be the same at every position along thye resistor. When the inductance of the resistor can be neglected you will find in many text books that (d/dt)V=R*(d/dt)I; which means that both the voltage and current change proportionally to each other while the current builds up to equilibrium.

What you could do is measure the magnetic field at different points along the wire, which will measure the current at that point.

Good idea: And you will find that it will build up equally at all positions along the conductor.

 

[sol invictus]

Can you explain to me where lakes come into the picture when we are considerring the flow of currents through "pipes" which are already filled to the brim with the constituents that are flowing.

That might be the picture you have in your head, but it's not the one the rest of us have, and it's obviously wrong. I've already explained that to you. For one thing, if charge carriers in conductors were incompressible, it would be impossible to charge a capacitor.

The lake example is simply to illustrate that your assertions about the mathematics are manifestly false.

When you have an element with resistance R and you switch on a voltage V, the current through an ideal ammeter will reflect the current through the resistor which will be the same at every position along thye resistor. When the inductance of the resistor can be neglected you will find in many text books that (d/dt)V=R*(d/dt)I; which means that both the voltage and current change proportionally to each other while the current builds up to equilibrium.

Go back to ben's series of examples that interpolate between Cu-Fe-Cu and Cu-nothing-Cu (i.e. a capacitor). In the limiting case of the vacuum capacitor, the current in the middle (which is vacuum) is obviously always zero. And yet in that case, when the voltage is first switched on, the current in the copper is quite high at first. That by itself contradicts your assertion that the current must be the same everywhere in the circuit.

Now think (if you can) about the current in the cases where there's a material with non-infinite but very high resistance sandwiched in between the pieces of copper. Do you really think the transient currents must be the same in the copper and in that material? Do you really think it's so completely different from a capacitor with vacuum in the middle?

 

[ben m]

Let me put it this way: If you only have one material, say iron, and you switch on the voltage, is it true that the electric-field starts to act near-instantaneously at every point along the conductor, and that the charge-carriers must thus accelerate equally at every position?

Your intuition on this is terrible, Johan. You know darn well that, given equal electric fields in copper and in iron, you'll get more current in the copper and less in the iron.

Yet suddenly you think it's super-important to consider the first twenty femtoseconds---yes, that's the number---during which this may not be true. Let me be blunt: you've been ignoring these twenty femtoseconds all along, and you've just discovered them now because you're flailing for any excuse to ignore it.

The fact is, Johan: sure, maybe there's a 20-fs super-transient before Ohm's Law tells you how much current there is. Fine. Also, changes in electric field only propagate at about 10 microns per 20fs, did we consider that?

So, yeah, during the first 20fs maybe the currents are equal. Therefore during the first 20fs the electric fields are also equal. . This is the problem, Johan. If you find an approximation that allow you to ignore the material differences, and ignoring the fact that the materials respond differently to electric fields ... well, you're never going to find a reason that the copper's electric field winds up lower than the iron's.

Of course, it's easy---even if, as you now seem to insist, we look at scattering instead of Ohm's Law. We turn on a field, constant everywhere. In the iron, charges accelerate. In the copper, charges accelerate. The copper charges continue accelerating for 20fs. The iron charges scatter after 10 fs. Look at the copper-iron boundaries, then: charges are arriving from the left at high speed but are getting scattered just as they try to leave. (Or vice-versa.) That's unequal currents, like we've been saying all along. Unequal currents means charges start piling up at the boundary. The charges piling up at the boundary begin reducing the electric field, or repelling the incoming charges (vice-versa for the other contact) until charges arrive from the left at the same rate as charges that leave on the right---you get to an equilibrium where the incoming charges are arriving slowly (because they have long mean free paths in the weak field) and the departing charges are departing slowly (because they have short MFPs in the strong field). The equilibrium conditions stop the pileup from getting worse, but they don't clear away the pileup that's already there.

Recall that we've already done this---remember how you insisted on using Drude's Law, then Newton's Law, instead of Ohm's? What made you think that "zooming in" to these 20fs would change the answer this time when it didn't last time?

 

[ben m]

If you want to comapare to water, you must use a pipe through which the water flows: When the pipe is filled with water that flows, there cannot be any accumulation of water at any position along the pipe.

Nonsense.

The analogy between fluid flow and electric current is extremely well-known; it's called the "electric-hydraulic analogy".

http://en.wikipedia.org/wiki/Hydraulic_analogy

The equations that describe the amount, flow rate, and pressure of electric charge are NOT the same as the equations of flow rate and pressure in a closed pipe. Instead, they're the same as the equations of flow rate and pressure in a unsealed pipe, or one with hydraulic accumulators and standpipes where water can indeed "pile up".

By insisting on an analogy to a closed pipe, you're deliberately making it impossible for charge to accumulate. A system of closed pipes is the hydraulic analogy of a circuit with zero capacitance. Why would you choose that inappropriate hydraulic analogy? Because you wanted it to match your axiom.

 

[Reality Check]

johanfprins: What are your charge-carriers

I am delighted that you at least understand this!

That is dumb - I have understood this for over 30 years. My thesis included looking at the resistitvity of of dilute alloys sucha as RhFe (basically scattering from the isolated atoms).
I have been the one trying to see if you understand this basic QM fact.

The question remains: Do you understand it. The rest of your post suggests not.

You ignored tha actual question:

johanfprins: How do you stop your charge-carriers from scattering?
First asked 7th September 2011 (5 days and counting)
​

And for that matter - What are your charge carriers?
They cannot be electrons since they will always scatter (see below).

It is impossible for any free charge-carriers that can be accelerated; whether the charge-carriers are fermions or bosons is immaterial in this regard.
...

If there are no states for the charge-carriers to be scattered into then they cannot be scattered.
The fermion or boson nature of the charge-carriers is crucial for this.
Fermions tend to occupy every state up to the Fermi surface. This means that they can scatter off the lattice into states above the Fermi surface. In addition thermal excitation empties states below the Fermi surface. This allows electrons to scatter into these states. Scattering = resistivity as you agree.

Bosons like to share states. They tend to leave an energy gap below the Fermi surface. Thus bosons such as Cooper pairs cannot scatter because there is not enough energy to allow them into allowable states. No scattering = no resistivity as you should agree.


Adding thermal energy will allow the electrons to access states into which they can scatter. That is why the classical (BSC) superconductors have a critital temperature.

A “good description” in the main stream literature will not be enough to illuminate why this model cannot explain superconduction.

Then you are out of luck. The actual BSC theory does explain superconductiviuty.

 

[Reality Check]

johanfprins: Where is the "divergence in electric-flux" in Gauss's law

What I am pointing out is a conundrum: When you apply Gauss' law you obtain a divergence in the electric-flux:
...

What you are pointing out is your ignorance about Gauss's law. There is no "divergence in electric-flux" in it. There is a divergence in the electrical field.
The intergral form does have electric flux in it - this is the electric flux through a surface, not a divergence.

Gauss's law does not give anyone a "divergence in the electric-flux".
It is a relationship that is obeyed by electric flux through a surface and the charge within that surface or equivalently the divergence of an electric field and the charge density.


If you know the charge inside a surface, you can calculate the electric flux through a surface (or vice versa).
If you know the electric field then you can calculate the charge density and vice versa.

And as pointed out before by me, ben m, sol invictus and understandable by (hopefully) anyone with undergraduate physics knowledge:

The Cu-Fe-Cu sandwich example explicitly gives a different charge density at the interfaces from the body of the layers. This is an accumulation of charge at the interfaces.
​

Try actually reading and understanding: Gauss's law

Gauss's law may be expressed as:

where

is the electric flux through a closed surface S, Q is the total charge enclosed within S, and

is the electric constant. The electric flux

is defined as a surface integral of the electric field:

Because the flux is defined as an integral of the electric field, this expression of Gauss's law is called the integral form.
Gauss's law can alternatively be written in the differential form:

where ∇ · E is the divergence of the electric field, and ρ is the charge density.

 

[Reality Check]

Right here you are already going wrong. The issue is not unspecified charges but charge-carriers that accumulate by becoming immobile at the interface. The latter is not physically possible.

Right here you are already going wrong. No one is talking about electons stopping at the interfaces except you. This is obviously physically impossible.

What is physically possible and really simple to show is that there is a higher charge density at the interfaces than the rest of the layers as in the rest of my post that you ignore

We know that copper and iron have different resistivity. Thus the resistance of the layers is different. In theory we could change the width of the layers until they had the same resistance but that is just a wire!

There is a constant current so the voltage across each layer is different. Thus the change in electric potential is different across each layer. Thus the electric field within each layer is different (the gradient of the potential).

That is as far as we can go without doing a 'spherical cow' approximation. This is

• Use a constant electric field within each layer.
• Use 1D so that divergences just become a simple differentation.

So we have E_CU in the first copper layer, E_FE in the iron layer and then E_CU in the second copper layer. This is a square wave (or inverse square wave if you want E_FE > E_CU).


What does Gauss's law say about this? It says that the divergence of the electric field is proportional to the charge density.
We have an electric field. We can calculate its divergence!

The constant sections of the square wave differentiate to zero (no charge density). That leaves the 2 step functions. The result of differentiating these is a Dirac delta function, i.e. a finite charge density at the interfaces.

This is a charge accumulation at the interfaces.

It is this higher charge density that is an "accumulation of charge" at the interfaces. It is not that any electron stops at the interface. It is that they spend more time there.