Here is one attempt to wave away the "insulation catastrophe".
William Beaty
Electrical Engineer 35yrs, electrostatics hobbyist, Amasci siteUpdated Jun 16
Is it true that electric currents are normally much faster than the actual electrons?
Well …is it true that air currents are much faster than the actual air? Yep.
• If you blow into a hose, the air in the far end of the hose starts moving instantly. Actually there’s a tiny delay before it starts moving: the speed of sound. Currents of air have a “startup-wave,” which is the same as a sound wave. The current moves at hundreds of KPH, while the air itself moves slow. (And, if rather than blowing, instead you sucked on the end of the hose, then what happens? Instead the air-currents travel opposite to the direction of the air! The air moves toward your lips, while the “current” races in the opposite direction, going out to the far end of the hose.)
• Is it true that water currents are much faster than actual water? Yes, water currents travel at the speed of sound. Step into a pool or pond, and the water level rises everywhere at the same time (after a speed-of-sound delay.) All the water moved slightly outward, away from your intruding foot. Now lift your foot back out. A “wave of decrease” races outwards, as all the water is slightly moved towards your foot.
• Is it true that “wood currents” are much faster than the actual wood? Yes, if you pick up a broom from one end, all the wood seems to move instantly. The wood-currents seem to appear everywhere in the wood. But there’s actually a small delay …from the speed of sound inside wood! The wood-current travels faster than the actual wood. (Heh, and if you lifted the broom handle sideways, then you generated a transverse wave, which travels slightly slower than pressure-waves inside wood. S-waves versus P-waves in solids.)
• Is it true that “train-car currents” are faster than actual train-cars? Yep. If you’ve heard a long freight-train starting up, maybe you’ve heard the “booms” as the couplings between cars are suddenly tightened. The train itself moves slowly forwards, and the “boom-boom-booms” races backwards along the chain of cars. Train-currents are very fast! Also, they’re backwards!
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PS
Electric currents have another name: ELECTROMAGNETIC WAVES! That’s why currents (and voltage) in wires will always travel at the speed of light. [1]
When the electricity inside a wire starts to flow, it doesn’t actually all flow at once. Instead, all the movable charges are using e-fields to “talk” with their neighbors. When one electron is forced to move, the surrounding e-fields change, and this moves the next electron in the chain …which changes that electron’s surrounding fields, which then moves the next one. It’s like a long row of train-cars, going “boom-boom-boom-boom.” Wires contain long columns of electrons. Fast EM waves travel along these columns, “informing” all the electrons to start moving.
Heh, electric companies don’t sell “electricity.” Instead they sell electromagnetic waves! (The EM waves at 60Hz frequency.) The electricity just sits inside the wires and wiggles back and forth. Electricity doesn’t travel to your home. The electric companies are actually selling us some 60Hz photons.
Also, these waves of e-fields are not moving inside the metal wires. Instead, the fields are out in the air, in the space surrounding the wires. The “startup wave” is leapfrogging through space, skipping across billions of electrons on the surface of the wire.
In other words, wires are like energy-ducts. Wires behave something like hoses full of air, with sound waves racing along, while the “air” inside moves slowly. Also, the “air” in the hose can wiggle back and forth, while the energy zooms along in just one direction.
Too complicated?
Just remember that the flow-rate of these energy-waves is measured in watts, while the flow-rate of the electricity inside the copper is measured in amperes. Two kinds of flow, with two different units of measurement. For AC circuitry, the amperes are a back-and-forth wiggle, while the watts are an EM wave at the speed of light. (It’s a lot like wiggling air …versus moving sound waves.)
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[1] In wires the current usually propagates slightly slower than light in a vacuum, going slower than “c”. This happens whenever the wire is encased in plastic, not in vacuum. The plastic insulation slows down the waves of current …much like the glass in a prism slows down the light waves passing through it. The electrical waves will propagate at 2/3 of “c,” or even slower, depending on the type of plastic. Search for… “velocity factor” in cables.