Great analogy

Awesome analogy.

Conduction of current

Best yet 👍

If I'm correct a transformer is also electrically isolated. Would it be fair to say current flows through a transformer, or are they not comparable in that regard?

Danny Russell A lot of universities have professors thats sole purpose is research and not teaching.

Danny Russell wait till the full economic effect of that are realized. I love this guy.

Brendan Raymond Actually years ago Universal Scientists who were almost always college professors or consultants to colleges, used to visit honor science classes in public schools. In 42 minutes they gave the entire class an understanding of the universe. I will admit that for weeks to come I was in a mild state of shock, however it was a healthy state of shock. I had things to check out and I did. And sure enough these guys were spot on. Unfortunately one year, I was in the fifth grade, in 1972 while we were getting a college lecture from a universal scientist, he informed us that as of next year 1973 it would be illegal for him to teach the atom, at Federally funded schools. Because the federal government education system had adopted the neutron and attraction forces, as being real. He wished us luck and told us that we had all we needed to make it through the rough times that were coming. For a while I tried to focus on school, however they started changing our science equipment and even chemical formulas on chemicals. In one year I had to learn two different markings for two similar cathode ray tubes. I started losing interest in school. About two years later one of my science teachers said that I had to enter a science fare project or fail my class. So I built a working solar house, and took a second place at my school science fare. My science teacher then said I had to enter it in the Long Island Science Congress, Science Fare at C.W. Post college. Begrudgingly I did, I took a first place and won a scholarship to C.W. Post college. But I had no interest in school anymore, so at 15 about two years later, I dropped out of school and started working full time. My point is that we are functioning at 10% right now. What we have done with science already, and hidden, is the other 90%. The problem or the truth is that matter is not what you have been taught it is. It is just an electrical effect. There is one sub-matter particle in the universe, the particle of electricity or as it was called, an atom of electricity. The atom of hydrogen is the smallest part of matter. An atom of iron is the smallest part of a piece of iron. The word atom used to mean the smallest denomination of a substance. Our problem is not actual science and reality, it is poor leadership and education. In other words science is rather easy and fun. The politics blocking science is not easy or fun. Americas first president said this "There is nothing which can better deserve your patronage than the promotion of science and literature, knowledge is in every country the surest basis of public happiness." George Washington. What Benjamin Franklin knew about science and weapons would shake our military today.

Danny Russell Please tell me that a someone learning electronic engineering at uni is not needing this.

mart fart There is a difference between memorizing things they teach you and understanding the actual basics that make them work.

Wow, that's such an obvious way of saying it, but I never thought about it like that. Thanks!

Transformers do work as you explained, but it's important not to confuse magnetic and electric fields, inductors and capacitors etc. transformers have no (intended) capacitor and have practically nothing to do with this video.

I would say that much more accurate is to say that "electric field travels" through capacitor, not a current. Current is dQ/dt and right in the middle of capacitor, where dielectric is, there are no charge carriers. If there are no charge carriers, there can't be a current. In other words, the dQ=0 so dQ/dt = 0. Current is not flowing inside capacitor, but electric field is pushing charge carriers outside of the capacitor. What Maxwell did with displacement currents is just a modeling trick to balance out the equations. For all the practical purposes it does the job.

or rather more simply - it's an electric field that does the work of a capacitor but NOT a magnetic field as in a transformer. With a transformer - we have electricity converted to an INDUCED current via coils which generate magnetic fields (hence the ability to change voltages across the gap by induction. But with a capacitor, there is no associated magnetic field created beyond what you get traveling through the connected traces or wires. Otherwise you would see capacitors exhibiting magnetic behaviours when you turn a circuit on.

HitAndMissLab actually - i wonder if it would be provocative to suggest that YES - current flows through a capacitor - but VOLTAGE does not (?)

+weylin6 This is the explanation that finally made me intuitively understand what a capacitor is after four years of college. The flexible diaphragm constantly moving back and forth provide the appearance that the current is flowing through barrier when it is just an equal response to the change in movement. No change means that stable, steady, not moving and basically current less.

+weylin6 When "pressure is applied" in your analogy infers a changing pressure which is alternating current. We know that a capacitor does not block AC of adequate frequency but completely blocks a continuous level of DC current since this DC current immediately starts to drop as the capacitor charges. Electric Current will stop flowing but the displacement current is another subject. Any device needs that Electric Current even though this thing called displacement current is existing. It really depends on what we are talking about.

+Steve Seifer buy today pay tomorrow

When I was in electronics classes in college (I've really not used it since), I built circuits that used in series caps to disentangle DC from AC. The DC was effectively blocked while the AC flowed straight through. Obviously I did the choke to do the opposite and allow AC to be disentangled from DC and effectively blocked the AC. It was really while learning about chokes that magnetic fields came into play. So why did my circuit work, presumably?

I understand that that AC is not truly passing through, but is due to the reversal on AC. What I don't understand is why my circuit supposedly worked (disentangling DC from AC) if caps pass DC current through an electromagnetic field in the cap (which is what he appears to be saying). Is the AC collapsing the DC EMFs?Also, I noticed his current meter went up, then went down and stayed down. I know it can take 5 seconds or so before a cap fully charges, but it was at least a couple of seconds on 0 after that initial sharp rise. I double checked, the circuit was still closed. If you offer any assistance in this, I'd greatly appreciate it..

This answer Michael is more correct to me. Dave is obviously a sharp cat, but his answer sounds more philosophical.

I agree, Michael. The way I think - it's like electric field crosses the capacitor to push those electrons from another plate, to leave wholes, instead of electrons. Up to a point where there is nothing to push (no free electrons in the capacitor's plate), and thus current stops. So, in AC, when the electromagnetic field is reversed, the capacitor on one side has too many electrons, and on the other side, too few. So, electrons don't pass capacitor (in an ideal capacitor), but the electromagnetic field does pass through to affect electrons on another plate of the capacitor thus making electrons move, thus creating a current. Another point - any broken wire is a capacitor. Except that capacitance is so small, that it's not being considered as a capacitor. So, just blindly saying that current goes through a capacitor is like saying that current flows through a broken wire. so, the answer is a bit complicated. So, technically, current doesn't flow through a capacitor, electric fields does, affecting nearby electrons up to a certain distance).

@@hcetink He explained the same thing. No difference. In my words, current yes, electrons no. And an animation will be a better explanation.

@@johnyang799 uhhh ..... have you ever swam in a current without water?

@@hcetink Current is electrons flowing doesn't mean it has to flow through! Using your analogy, if there is a way that controls the water on one side of a barrier and controls the water on the other side. The current/information is essentially flowing through. But not the same water flowing through. Understand?

The best ending for this video! he made me laugh. excellent !!!

interesting concept

Come on, press the envelop. Let go the concept of a fundamental particle and embrace the reality that everything is an electric field, just balanced in different ways that limit and control the interactions with other fields. You just might come to realize that magnetic fields are like shadows... but that's for the advanced class. Meanwhile you can begin to distinguish the actual field attributes and how to take full advantage, unlimited by the artificial restrictions of particle physics.

Yes! It's good to keep the goal in mind: why are we moving charge through the circuit? Just to move energy to do some work elsewhere.

@BMan18, I agree most of fundamental physics is still wrong. . . I've come to the conclusion that our "reality" (energy/forces and matter) is fundamentally the movement (waves) of aether, which is everywhere, even in "empty" space. . .We don't really have physical substance, the aether does. . .Nikola Tesla know decades ago.

+eqlipse333 No magnetic fields are involved. Applying a voltage across the plates allows electrons to be added to one and subtracted from the other.

Lols. +1 for batteriser ref

moyrml: Thats a chicken and egg situation, its hard to imagine 'spaces' moving, so its better to use electrons in the description.

Current ratings are specified in terms of temperature raise...

It's only WEIRD if you don't understand how it's easily explained by simple physics. The MIT guys were having a bit of fun with the naive.

fred brooks Are you saying the video was a fake? I've read about this experiment enough places to have taken it for fact. But, I do have all the gear here to put it to the test if you're telling me these videos and accounts are hoaxes...

It's not fake or a hoax. It's a running joke that hides the fact that the surface charge (on a thin film of water from the air as the conductor) on the glass inner and outer surfaces receive the charges from the metal plates when they are removed (via high voltage corona discharge) and hold the energy in a electric field with the glass as a insulator (not a dielectric) and is transfered back to the metal plates when reassembled.

fred brooks That is absolutely fascinating! Thanks for that explanation. I had heard that Franklin fooled himself in doing this experiment, but never heard the reason why. I'm currently reading 3 books on electrostatics as it's something I've had a long term hobby interest in (I also do a kids electrical show with tons of HV gear). I do see claims, in several places in the books I'm reading that charges are in fact stored in the dielectric and not in the plates. I love to experiment. If I were to reproduce the MIT experiment, but heat everything up as hot as possible with a heat gun to avoid moisture, would that be a good control to eliminate the possibility of moisture? I do also have a vacuum chamber where everything could be placed after heating, but it would be more of a pain to rig... Would I be wasting my time?

actually...current does not physically flow through the capacitor. The whole circuit is set up by an electric field, there is an electric field induced inside of the capacitor, not actual current.

The *electrons* don't physically cross the gap. But what about the current? (Does the word "current" really just mean "moving electrons?" Always?) For example, is there a current just in front of each flowing electron? And just behind? A clamp-on ammeter says yes. A clamp-on ammeter thinks that electric currents are a particular type of magnetic field: the relative change in each electron's moving e-fields. The ammeter doesn't have to detect each electron. Instead it just has to detect the motion of the radial e-field surrounding each electron. If we look at things in this way, then whenever a cloud of electrons is moving, the "current" isn't concentrated inside each moving particle, but instead fills the space between them. If we look at capacitors from this viewpoint, then the current fills the capacitor's dielectric gap, since those changing fields extend out ahead of the electrons entering the negative plate, and also extend behind the electrons leaving the positive plate. Get a capacitor with a wide gap between its plates. Apply a high-freq AC current. Slide a clamp-on ammeter along the capacitor terminals, and across the gap. The ammeter cannot see the gap. It thinks the current is continuous.

Hey it's wbeaty! I remember your website from nearly 20 years ago! Your pretty much right we can pretty much consider current to be where ever we have a magnetic field, which includes the displacement current in the gap in a capacitor. There *really* is a magnetic field in the gap in a capacitor because of the changing electric field. if you were to put a wire there, 'electron' current would flow (imagine putting two extra plates inbetween connected to give you effectively two capacitors in series. charge moves from one plate to the other as it charges. there really is current in a capacitor!

wbeaty Yes current is the amount of moving charge per cross sectional area, if you look a certain distance in the capacitor you will not see current on the phyiscal level. What you will see is an electric field in the gap wether it be air or a di-electric with ions. Also it doesn't matter if the ammeter cannot see the gap, what do you think a battery is? Batteries induce current via electric field, those electrons are not in the battery, they are in the wire itsself.

You will find Maxwell's Displacement Current, the fundamental discovery which led to all modern EM technology. Displacement current is the same as all others in that a clamp-on ammeter measures it as current. It's different in that it's part of the fields around moving charges, and not described by the charges themselves. In SI definition of Ampere, the definition involves forces between currents, *not* amounts of coulombs transferred over time. So as we define "amperes," displacement current produces real forces just like any electric current. Of course these forces originate in the increasing charge on the capacitor plates. When a capacitor plate has an increasing charge, we find displacement current in the plate, in the adjacent dielectric gap, and in the capacitor lead wires. But no moving charges in the gap, if a vacuum capacitor.) > Batteries induce current by electric fields Wrong. They induce current by charge-transport, same as any power supply. The moving charges are in the battery electrolyte, as well as in the connecting wires. A battery is inherently a conductor, with a short circuit between its plates (conductive salt water or acid, etc.) Don't be misled by erroneous grade-school textbooks which erase the current between the battery plates. To learn correct battery physics you have to go to college-level texts (and un-learn the incorrect garbage we were taught about batteries in earlier grades.)

I agree with you

Woow, I had never read any such explanation.

Les Carpenter, the problem with your analogy is that if you hold the (+) charged side of the capacitor to the (+) charged battery terminal voltage by attaching them together, when you connect the (-) charged terminal of the battery to the (-) charged terminal of the capacitor according to your theory none of the particles of electricity from the (-) battery terminal should make it through the capacitor, yet they certainly will. When they changed Ben Franklin’s markings on a battery they really messed things up nicely, that is what caused all the confusion.

Well, if you want to be specific, if you put n electrons into a capacitor, n electrons will come out the other end, but they will not be the same electrons that you put in. So yes, one could say that no current flows through a capacitor because no electrons go all the way through a capacitor. However, seeing one can't id individual electrons (and even if you could it would be a waste of time), there is no effective way to tell the difference. Electrons go in, electrons come out, current flows.

If you will take LED, resistor, battery and big capacitor and connect it all in series you will see that led will turn on for a short time. So current is flowing. Same thing like at the end of video, but LEd instead of meter. What else you need to know to convince you that yes current flowing thru cap. Current flow from battery, LED, resistor to capacitor and than out from capacitor back to battery. So what is going on in capacitor ? Current using teleportation from one electrode to another ? Doesn't matter, same current goes in as goes out. So You can tell that it flows thru. And If you wil take compensating capacitor for example from linear fluorescent luminare (classic one with magnetic ballast) and connect it in series with light bulb (not powerfull) and connect it to 230/110V AC 50Hz bulb wil glow. In AC circuits you can calculate Z or Xc of capacitor.

Current does not flow. Current is a name that means flowing. And is a term that is used to represent the charge flow rate. In Coulombs per second. So to say "a current flows" is the same as saying "The rate charges flow flow" which does not make any sense. But amazingly everyone keeps saying sentences like "current is flowing". Which will be totally confusing for beginners. It is only charges that flow, never ever current. Its as wrong as saying "a river current flows". Also displacement current is the term used to describe the "rate of change" of the electric field between the plates of a capacitor. For example in an air gap capacitor there is no polarization current (dielectric charge effects) at all. So its all just dE/dt only, which itself comes about from the changing PD between the plates. That is all that displacement current means.

Kevin O'Brien so if current doesn't flow what does it do?

Shamel Sanders Current means 'charge flow'. So if you see a sentence in a text book like so "In the circuit there is a current of 4 amps" That is perfectly correct. And is just another way of saying "In the circuit there is a 'charge flow' of 4 amps" which is also perfectly correct. But if the sentence in your text book (sadly many of them make the same mistake) is like so "In the circuit there is a current flow of 4 amps" That is incorrect use of the English language, as it translates to the following. "In the circuit there is a 'charge flow' flow of 4 amps" It is not that the person who writes or says this does not understand about circuits etc. Its purely a semantic error only, but one that is very difficult if English is not your first language. It might seem pedantic to pick up on this, but I think it is important for many who will be confused by this wrong use of the English language. So the following examples below, are all incorrect uses of the word current. I have added a correct usage afterwards. (Looks like many comments on this video is making same or similar errors) In every correction below, if you just substitute the word "Current" with "charge flow" you will see they still read correctly, where as the ones I am correcting you will see very clearly (if you make the same substitution), that they are all grammatically incorrect. here is an example where the same error has been done twice. "Displacement current flows but electric current does not flow" A proper way to describe the above is as follows: "A Displacement current exists but an electric current does not" Here is another wrong sentence "Does current flow through a capacitor" Here is one correct way to describe that. "Do capacitors plates have a current between them" here is another wrong sentence "current never flows through the dielectric of the capacitor" And the correct way to express that meaning. "Current does not exist within the dielectric of the capacitor" etc etc.

MrHydroguy sure the electrons don't accumulate on the negative? Conventional current is wrong.

It's charging both surfaces (one subtracting and the other adding electrons). +johnDon No electron accumulation was mentioned though.

If the current is not flowing through the capacitor we should be able to disconnect one side of the capacitor from the circuit and it should work the same way. BUT in that case the capacitor dosen't charge, why: because the freaking current has to flow through the capacitor!!

totally agree

Caps in SERIES is like ONE cap with a GREAT distance between the plates (the first cap's plate, and the last cap's plate) In PARALLEL it's like ONE giant cap with HUGE plates. So, in series, the capacitance will be smaller than the smallest cap. In paralled, they are all additive (their cap values)

That's a shame you had that experience. When I was doing electronic engineering at the university of kent it was one of the first things taught and explained very clearly. For circuit anyysos and design we used conventional current flow but were taught about actual current flow in solid state physics.

Having diplomas or degrees means you have diplomas or degrees. It means you are SUPPOSED to have an understanding of what's happening. Whether you do or not depends on the quality of your teachers and the quality of your effort (which is largely dependent on your interest).

We learned electric current flow the 1st day of introduction to electric circuits 101. The electrons, the charge carriers in an electrical circuit, flow in the opposite direction of the conventional electric current.

"Actual" charge flow is too complicated: electrons flowing in metals, protons flowing in battery acid and in proton-conductors. In salt water it's flowing +Na and -Cl ions. In alkaline electrolyte it's -OH ions. In wet dirt and in human bodies it's +Na and -Cl ions, same as in salt water. In sparks and gas discharge it's electrons flowing one way and positive ions flowing the other, going past each other in opposite directions. Cont... So, which is the REAL direction of electric currents? (The answer must apply to conductors, not just metal wires.) Think carefully: when you're getting electrocuted, no bare electrons are flowing in your body, but opposite-charged ions are flowing in two opposite directions. Physics has the answer: we hide the complexity behind a simplified concept called "Conventional Current." To do this, we add up all the flows to form a single current. For example, in wet dirt, if pos and neg ions are flowing in opposite directions, that means the negative charges that flow backwards must add together with the positive charges flowing forwards. (A double-negative makes a positive current, so negative charges, flowing backwards, will give the same amperes as positive charges flowing forward.) Wet salty ground has a single amperage made of conventional current. (We don't need to think about the many charge flows in the dirt: the +Na and -Cl and +K and +Mg and +H and -OH.) For those who want the REAL currents, and not the simplified version, it's not enough to just say that "current equals electrons." Current in copper wires is actually electrons flowing past positive copper ions ...so if we move the wires backwards at just the right speed, then the electrons stop moving, and the electric current is now composed of positive copper ions going backwards! (See, the REAL current was never just a flow of electrons. It had always been a *relative motion* between the copper atoms' nuclei and the copper electron clouds.) Conclusion: if we want simplicity, where we just deal with a wire's volts and amps, then we use Conventional Current to hide the actual charge motions. But if we want reality, then we'll end up with Ben Franklin's Kite String, the famous twine which is an acid-based conductor. Ben Franklin's kite string used +H ions as its charge carriers. Only the protons were flowing along his twine, not electrons. (Heh, so when Franklin assumed that the charge-carriers within conductors were positive, HE WAS RIGHT?!)

Do you think that learning from the internet will make you an electrical engineer (EE) in time? Have you seen the curriculum of (EE) from a major university?

I liked my humans fried, double fried like my chicken! hahhahaha! ;-)

All your proving is that current did at one time flow into the capacitor and at one time flowed out of it into your body and killed you ;) this video should explane it all, maybe watch it again?

***** Har, har, har.

OK, connect one side of the capacitor to your wall socket, and hold the other side with one hand. Now, ground your other hand and you'll know for sure if current flows through the capacitor, or not, because if the current flows it will roast you. (it will roast you, don't try it; use a meter like in the video)

Really, no current "flows through" the capacitor, in an AC circuit. It just "appears" to do so. Unless a capacitor's dielectric is "ruptured," there is no current actually "through" the cap. It just "appears" that currect is flowing "through" the cap. The cap just "charges, discharges, charges (in the opposite direction) then discharges. Current looks like it is moving "through" the cap, but really is not. (yes, you would feel the effects of that AC :) An electrolytic cap, in a DC circuit, will pass "the affects" of AC, but will block DC. No current will actually "pass through" the cap. If there is an "AC ripple" riding on the DC value, the DC will be blocked, but you would see that ripple on both "sides" of the cap. Or, am I wrong? I

+BlueCosmology That is exactly what I was thinking !

+BlueCosmology If that were the case, capacitor would be conductor no? Why does it stop repelling electrons on the other side?

quadcatfly A capacitor is a conductor, electric current flows across it. Once the plate becomes charged enough, it requires too much energy to put more electrons onto the plate, due to the electrons on the plate repelling them away, so it stops conducting.

You should brush up on electric conductivity of dielectric materials. Especially the part where it says "dielectrics are insulator". All those electrons being piled up on one side of dielectric would immediately clot and prevent (e.g. repel) any new electrons from coming in, let alone push electrons from the other side of the plate (btw since when we have free electrons in dielectrics?). While you are contemplating this try to come up with explanation of how many capacitors IN SERIES could possible work based on your theory. If I place 20 caps in series the last in line would NEVER be charged because the first one (closest to -) will have charged and cut off the supply long before. But that is not how it works in a real world.

"All those electrons being piled up on one side of dielectric would immediately clot and prevent (e.g. repel) any new electrons from coming in, " Yes, that is exactly what I just said. "let alone push electrons from the other side of the plate (btw since when we have free electrons in dielectrics?)." A capacitor is in its simplest form just two plates. Put one electron on one plate, it will push the electron off the other plate. Continue to put more on, you'll keep pushing them off the other plate, until eventually it takes too much energy to put an electron on the first plate. "While you are contemplating this try to come up with explanation of how many capacitors IN SERIES could possible work based on your theory." Completely trivially? There is nothing magic about putting two capacitors in series. The electron that is pushes off the first capacitor goes and charges up the plate on the second capacitor and so on. "If I place 20 caps in series the last in line would NEVER be charged because the first one (closest to -) will have charged and cut off the supply long before." That is nonsense. You put one electron on the first plate of the first capacitor, one electron comes off the second plate. The time it takes is irrelevant.

Old post, I know...if the current changes medium it's still current. I.E. Current in a wire being turned into radio waves, transmitted, received and transmitted back through a wire. Did the current actually flow "through" the air? Yes, yes it did. Just because it wasn't some visible plasma arc doesn't mean it didn't flow. Same idea here.

hattt be chutiye..

Because of that Benjamin Franklin who was banging his chicks all day night