So if the whole apparatus was dipped in a medium where light slows down, would it then take a longer time for the bulb to light up?

Yes. In the same way the dielectric insulation in a coax affects the propagation velocity of EM energy passing though it. I think the main problem people are having with the electrical energy in space vs electrical energy in the wire is the failure is see the wires proper place in the system of energy transport in a circuit. Current carrying wires over-heat when electrical energy enters the wire (Poynting vector) due to the conversion of EM energy in the space surround the wire into the kinetic energy of moving particles with mass (current) inside the wire. This particle KE reduces the electrical energy of the circuit and is usually expressed as wire resistance power losses in circuit theory. So, when we use larger wires sizes to reduce wire resistance we are also decreasing the particle KE in the wire and increasing the ratio of electrical energy surrounding the wires moving to loads.

Electric currents have most of the energy associated with them in the magnetic fields surrounding them. There is a very small amount of kinetic energy in a current with good conductors, it is very small with good conductors because the electron’s mass is small and the average velocity of the charges is small too. We use poor conductors when we want to increase the amount of kinetic energy in the current to cause heating when electrons see a resistive force.

https://courses.lumenlearning.com/austincc-physics2/chapter/20-1-current/
EXAMPLE 3. CALCULATING DRIFT VELOCITY IN A COMMON WIRE

When we do a kinetic energy calculation using the number of electrons, electron mass and the drift velocity in a good conductor it's obvious the energy in the wire is tiny.
https://www.omnicalculator.com/physics/kinetic-energy

 

Great video for the most part but I would say there are many times where the fact the energy is outside the wire matters (even at DC). Any time where the rate of change (wavelength) is a sizable fraction of the circuit dimensions we need to account for the dielectric media (vacuum, air, PCB substrate) the energy passes through as a propagation delay, phase shift and radiation. We can use lump-sum transmission line solutions but IMO that don't give the level of intuition you get by knowing and visualizing the energy flow paths across space. Today we use EM solvers in daily engineering to see the fields so we do care because the tools are much easier to use today with high speed computers on every desk.

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

For the DC case, energy outside the wire is what makes DC motors move and CRT plates deflect charged particles like electrons. The DC circuit transferring energy is not static, it's in a non-equilibrium state.

Circuit theory describes how much energy is transferred, but it never makes any claim about where energy is located within a circuit element nor where energy crosses a lumped element's boundary. There is no conflict here (with energy outside the wire) because circuit theory makes no claim on the question.

https://forum.allaboutcircuits.com/...ic-field-in-a-ground-wire.129568/post-1063006

My missing link from that thread: https://www.tu-braunschweig.de/inde...oken=90bbd237cd4ef87cf2941a99eb3c3d610de3d0d3

In Rick Hartley's video, an interesting, and a lot surprising, thing he says is: that in a long transmission line, when you push energy from one end, the forward and return currents form immediately in both forward and return paths first at the source side...!!

But if you look at the end of the transmission line, there would be no forward and return currents cos the energy has still not reached there...!! Forward and return currents would form only after the energy has reached that section of line...!!!

This assertion is quite different from the usual current flow analogy, where we assume the current to start flowing simultaneously in all sections of the wire immediately upon application of potential difference...!! Ofcourse, its quite a different thing to verify this assertion given that energy would travel way faster than any means we can deploy to measure and confirm it...!!

 

In Rick Hartley's video, an interesting, and a lot surprising, thing he says is: that in a long transmission line, when you push energy from one end, the forward and return currents form immediately in both forward and return paths first at the source side...!!

But if you look at the end of the transmission line, there would be no forward and return currents cos the energy has still not reached there...!! Forward and return currents would form only after the energy has reached that section of line...!!!

This assertion is quite different from the usual current flow analogy, where we assume the current to start flowing simultaneously in all sections of the wire immediately upon application of potential difference...!! Ofcourse, its quite a different thing to verify this assertion given that energy would travel way faster than any means we can deploy to measure and confirm it...!!

The usual assumption in circuit theory is zero length wires, zero ohm connections and no cross coupling of fields. That's not the physical reality of the test circuit here or with most electrical applications. For simplification we can usually ignore the physical reality if speeds are slow and signal phase changes across conductors are small but that's not always the case on closer inspection as the battery, switch, lamp and wire circuit shows.

http://ffden-2.phys.uaf.edu/webproj/212_spring_2015/Christopher_O'Shea/basicct.html

Electronic components, on their own, are quite fascinating. Of course, if they're not connected in a circuit, all you can do is look at them. All electronics are governed by Maxwell's equations, a set of four vector analysis equations in electromagnetism. Analyzing complex circuits using Maxwell's equations is time consuming and not very practical. Fortunately, they are not needed; developments of circuit analysis techniques, largely those from American engineer Oliver Heaviside, have reduced the required equations to simple arithmetic and algebra, provided a few assumptions are made:

1.] The rate of change in magnetic flux outside of the circuit elements is equal to 0.

2.] The rate of change in current inside of the circuit elements is equal to 0.

3.] The physical length of the circuit is much, much smaller than the wavelength of the electromagnetic waves travelling through it.

The first two rules eliminate the interference of magnetic fields within and out of the circuit. The last rule lets us assume that the electrons are travelling so fast they can be said to be affecting all points of the circuit at the same time. In very large circuits, such as cross-continent power and communications networks (and even in very small circuits such as microprocessors running at very high clock speeds) this assumption is no longer true. We also assume that the wires in the circuit have no resistance; thus there is no potential difference drop through the wires and all the action happens in the circuit components (though in reality the non-uniform potential differences on the surface of the wire are what forces current through the circuit in the first place).

Obviously these assumptions are not actually true but they greatly simplify circuit calculations of results if we ignore exactly how those results happened by using those assumptions. The problem is many people have been seen those assumptions as gospel instead of mathematical tools for easy circuit computations. When you shake that faith by pointing out the limitations CA (circuit theory) has to explain electrical results of experiment some people get defensive.

 

It's funny, I haven't considered this option before. Looks a little weird

 

http://amasci.com/miscon/energ1.html

ELECTRICITY IS NOT
A FORM OF ENERGY

Before I go too far with this, I must admit that I am playing a small trick with words. In the above statements, I am using the word "electricity" in the way scientists have used it since Electricity was first investigated. (This can be confusing, because it's not the way our textbooks describe "electricity!") I am using the word "electricity" to name the stuff that flows inside the wires; where a quantity of electrons is a quantity of electricity, and where the flows of electricity are called "electric currents."


Why is this a trick?

It's a trick because most people use the word "electricity" in a completely different way. They begin by defining the word "electricity" to mean electrical energy! Electric companies do this (think of kilowatt-hours ...of electricity.) So do the science textbooks written for grades K-6. So do many dictionaries and encyclopedias. This causes endless confusion, because while the electricity flows in complete circles, the energy does not. In an electric circuit the electricity flows in a complete closed circle without beginning or end.

Physicists try to tell us that the charges of electricity are not energy, and that a flow of charges is not a flow of energy. But then what is an electric current? Electric currents aren't flows of energy, so under the newly-altered definition of "electricity" used by all the modern grade-school textbooks, an electric current IS NOT a flow of "electricity!"

Huh? Confused? You SHOULD be confused. There's something very wrong here.

Note: my above paragraphs, my fact-collection, would be accepted by most scientists throughout history, including Ben Franklin, Michael Faraday, J.C. Maxwell, Michael Faraday, Robert Millikan, Albert Einstein, etc., etc. I'm using the word electricity in the same manner as they did: electricity is the positive and negative "stuff" that's found in all electrons and protons. It is the "substance" that flows along during electric currents inside of the wires. When it flows, these scientists would call it a "current of electricity." They'd say that any charged object has a "charge of electricity," and that electrons and protons are "particles of electricity." When electricity moves, it's called "current," and when positive and negative electricity are separated, it's called "electrostatics" or static electricity.

Without realizing it, the electric companies and the K-6 science textbooks are trying to re-define the original scientific meaning of the word electricity. How can such a thing happen? I'll examine this, but here first are more facts about "electricity" as scientists use the word.

• In an electric circuit, electrical energy does not flow inside the copper. Instead it flows in the empty air surrounding the wires.This fact is usually hidden because we calculate the watts of energy-flow by multiplying the voltage times the current. And just FYI: College-level physics books describe a complicated, but less misleading, method of measuring the flows of electric energy:
  

  Take the vector cross-product of the E and M components of the electromagnetic field at millions of points in a plane penetrated by the wires. We call this the Poynting Vector field. Add these measurements together, and this tells us the total energy-flow (the Joules of energy which flow each second through the plane.)

  In other words, in order to discover the rate of energy-flow, don't look at the flowing electrons. The electricity-flow tells us little. Instead look at the electromagnetic fields which surround the wires.

 

http://amasci.com/miscon/energ1.html

ELECTRICITY IS NOT
A FORM OF ENERGY

This is all pretty interesting and so begs the question: how fast do electrons move within a lightning strike? the same? very very slowly?

 

This is all pretty interesting and so begs the question: how fast do electrons move within a lightning strike? the same? very very slowly?

Obviously, compared to normal electronic circuits the KE and drift speed of charged particles is much higher with plasma acceleration potentials that measures into the millions of volts but that particle KE is still not a form of electrical energy. The lightning plasma core acts more like a copper wire with a longer relative mean-free path. This generates heating effects during discharges just like a wire getting white hot when overloaded to the melting point from particle collisions as they gain KE. The stored electrical energy in the cloud/earth static electric field is converted to heat, light, sound and EM energy.

Electron Accelerating Voltage speeds. It's more complex for a lightning bolt because of ion acceleration.
https://www.ou.edu/research/electron/bmz5364/calc-kv.html

https://www.physicsclassroom.com/class/estatics/Lesson-4/Lightning

The contact point between ground charge and cloud charge rapidly ascends upward at speeds as high as 50 000 miles per second. As many as a billion trillion electrons can transverse this path in less than a millisecond. This initial strike is followed by several secondary strikes or charge surges in rapid succession. These secondary surges are spaced apart so closely in time that may appear as a single strike. The enormous and rapid flow of charge along this pathway between the cloud and Earth heats the surrounding air, causing it to expand violently. The expansion of the air creates a shockwave that we observe as thunder.

 

Obviously, compared to normal electronic circuits the KE and drift speed of charged particles is much higher with plasma acceleration potentials that measures into the millions of volts but that particle KE is still not a form of electrical energy. The lightning plasma core acts more like a copper wire with a longer relative mean-free path. This generates heating effects during discharges just like a wire getting white hot when overloaded to the melting point from particle collisions as they gain KE. The stored electrical energy in the cloud/earth static electric field is converted to heat, light, sound and EM energy.

Electron Accelerating Voltage speeds. It's more complex for a lightning bolt because of ion acceleration.
https://www.ou.edu/research/electron/bmz5364/calc-kv.html

https://www.physicsclassroom.com/class/estatics/Lesson-4/Lightning

Thanks!

 

 

 

 

A update. How Electricity Actually Works

 

 

A update. How Electricity Actually Works

The results he achieved for voltage appearing nearly instantly across the loop was because he used a loop that was transmission line.
If instead it was a series loop with an adjacent series bulb, battery, and switch in a large circle, such as around the earth, than it would indeed take the time for light to go around the loop before the lamp lit.

 

The results he achieved for voltage appearing nearly instantly across the loop was because he used a loop that was transmission line.
If instead it was a series loop with an adjacent series bulb, battery, and switch in a large circle, such as around the earth, than it would indeed take the time for light to go around the loop before the lamp lit.

Plus long time current rising because of loop's big inductance:

 

The results he achieved for voltage appearing nearly instantly across the loop was because he used a loop that was transmission line.
If instead it was a series loop with an adjacent series bulb, battery, and switch in a large circle, such as around the earth, than it would indeed take the time for light to go around the loop before the lamp lit.

Transmission line theory and operation is simplified field theory. The bulb, battery, and switch are in series per circuit theory.

A large circle, such as around the earth? SO what! What you've made is a very large antenna.

Changing the geometry of the circuit doesn't change the fact the energy of the circuit will be in the fields traveling at near c (the earth and wire transmission line form a complex impedance slowing wave propagation to a fraction of maybe .9) instead of the slow movement of the drift current of about 8cm per hour in the 40,000 kilometer wire loop. The energy that lights the bulb will have always traveled as EM field energy to the bulb where that energy causes local accelerations of free charges in the bulb resistance transforming EM energy to localized thermal energy.

 

A large circle, such as around the earth? SO what!

You apparently missed the point the person in the YouTube video made, that there was energy transferred directly across the gap in the loop between the switch and the bulb.
I'm saying that wouldn't happen if the wire went around the earth, instead of a narrow loop that makes a transmission line.
That's "what".
I was not making an inference that the energy was not carried by the EM wave travelling at the speed of light, which I understand.

 

You apparently missed the point the person in the YouTube video made, that there was energy transferred directly across the gap in the loop between the switch and the bulb.
I'm saying that wouldn't happen if the wire went around the earth, instead of a narrow loop that makes a transmission line.
That's "what".
I was not making an inference that the energy was not carried by the EM wave travelling at the speed of light, which I understand.

You say that like it's some sort of revelation that possibility changes the science of his experiment. It obviously doesn't.

The wire around the world just makes a different type of transmission line configuration that will also prove his point..

 

You say that like it's some sort of revelation that possibility changes the science of his experiment. It obviously doesn't.

It's not a revelation, just an observation.
There's a difference, you know.

And it does change the results of his experiment, even if you don't understand that.

 

It's not a revelation, just an observation.
There's a difference, you know.

And it does change the results of his experiment, even if you don't understand that.

BS, I understand exactly. You are presenting a strawman on an 'observation' that changes nothing about electrical misconceptions. Stop wasting our time as an experiment as you suggest would prove exactly the same points even if you don't understand that.