OMG not another water analogy.
I‘ve never been able to understand what the hell electricity actually is and how it works.
I‘ve never been able to understand what the hell electricity actually is and how it works.
> I can’t explain that attraction in terms of anything else that’s familiar to you. For example, if we said the magnets attract like rubber bands, I would be cheating you. Because they’re not connected by rubber bands. I’d soon be in trouble. And secondly, if you were curious enough, you’d ask me why rubber bands tend to pull back together again, and I would end up explaining that in terms of electrical forces, which are the very things that I’m trying to use the rubber bands to explain. So I have cheated very badly, you see. So I am not going to be able to give you an answer to why magnets attract each other except to tell you that they do. And to tell you that that’s one of the elements in the world – there are electrical forces, magnetic forces, gravitational forces, and others, and those are some of the parts. If you were a student, I could go further. I could tell you that the magnetic forces are related to the electrical forces very intimately, that the relationship between the gravity forces and electrical forces remains unknown, and so on. But I really can’t do a good job, any job, of explaining magnetic force in terms of something else you’re more familiar with, because I don’t understand it in terms of anything else that you’re more familiar with.
He also explains seeing, heat, electro magnetism, elasticity and mirrors among other things.
His academic lectures are just as good but too long and hard for laymen to follow.
- Every time I switch on an electrical device I hear Feynman say 'Zzzzinggg' and I see the copper bars jiggling across town.
- Every time I see a cup of hot liquid I hear Feynman say "jiggling atoms"
- Watch his hands and fingers telling the more accurate science story, simulating the electrons and atoms.
- I would say that this the most important video to see for any human being on the planet. De second most important thing would be half of Alan Kay's lectures https://youtu.be/FvmTSpJU-Xc?t=2067
Great video's to watch with your kids! (from 3-4 years and older).
Electric charge has a magnitude (arbitrarily, we have labeled the axis such that protons are positively charged and electrons are negatively charged, but it's symmetric such that if everything in the universe swapped positive to negative nothing would change). Particles with opposite charges attract, particles with same charges repel. When a source of positive charge and a source of negative charge are separated, there is potential energy. We simplify our math a bit by factoring out the charge that would be moving from the positive to the negative out of our potential energy calculation to get "electric potential" or simply "voltage". When there is a path that charge can flow through between a high potential and low potential, it creates a flow of charge between positive and negative sources of charge that we call "current". As the charge flows, the potential energy decreases, meaning other energy has to be released. The most common way this happens is simply by creating heat. Some materials allow charge to flow through them more easily than others: the ratio of the potential (voltage) across a component to the rate of electric charge that flows through it as a result (current) is approximately constant for most things, and we call that resistance. This gives us Ohms law : V = IR
In general, though, the water analogy is actually quite good. The electron gas in conductors behaves a lot like a normal fluid. It easily covers linear components like resistors, inductors, and capacitors. Nonlinear components like transistors and diodes require more extensive analogy that is no longer very accurate.
The rest of the video seems pretty good though.
Did you invent this? It's fantastic. Lots of people misunderstand electricity as just "tiny little balls colliding with other balls", or think that the electrons themselves must be zooming around the circuit, rather than the wave they participate in.
"Electron gas" sounds right to my ears for these simple analogies. Just like sound oscillates, but still moves from speaker to ear, so too does AC current oscillate, but the energy has a single direction.
Sound behaves about the same if you entrap it inside a tube. The largest difference is that the electron gas is almost completely incompressible.
A loop of marble and tube is static: the marbles all push against each other and are drawn to the tube.
If you pump some marbles up the tube, they’ll clump into other marbles, which will want to repel. They’ll scurry away, pushing the next barbles, and so on. That pump is a voltage, and the movement is current.
A resistor is a sludge that the marbles pass through. They can, but only if they’re being pushed by a voltage.
All matter is composed of squintillions of tiny things called "atoms", which are composed of a core having a certain positive integer (its atomic number) that represents its charge and a certain number of tinier things whizzing around the core called electrons. If the number of electrons whizzing around an atom's core is not the same as the atomic number, the atom gets mad and will either try to fob excess electrons off to surrounding atoms or steal them from surrounding atoms (depending on if it has more or fewer electrons than ideal).
Thus, if you decide to pick a few atoms and kick electrons out of them, it starts a chain reaction of electron motion that is observable on the macroscopic scale. These chain reaction is an electron current, which is measured as going in the opposite direction of the way electrons flow because Benjamin Franklin guessed wrong. The number of electrons flowing in unit time is the current (as a measurement), measured in amps (approximately 10 million trillion electrons per second).
It also turns out that you can vary how ferociously these electrons are hitting atoms: the voltage (amount of energy per ~10 million trillion electrons). Different materials are better or worse at absorbing (or resisting, if you will) the ferocity of electrons, and this is the resistance. If the resistance is high enough, it basically becomes impossible for the electrons to flow, and you get an insulator.
But how do you get the electrons to start moving in the first place? The easiest to explain involves chemical reactions: sometimes, atoms decide they'd rather be in a different orientation, and in the process of moving to that orientation, they need to emit some electrons first. With some cleverness, you can set things up so that electrons have to go around the "long way" (through a wire), and something that is set up to be able to do this is more commonly known as a "battery." The other main way you can do it is by creating changing magnetic fields, which are kind of created by changing electric currents, and explaining this in more detail basically requires throwing away everything I've described, starting from scratch with the actual physics, and still coming to the realization that mathematical equations are not satisfactory answers to the question "what is it."