A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.
Rules
This is a science community. We use the Dawkins definition of meme.
In an AC system, the pedastal fan in your bedroom is electromagnetically coupled to the turbine at the coal/gas/hydro/nuc power station. They instantly and directly influence each other, and they both are spinning in tandem like two wheels on a car connected by an axel. Slowing the rotation of the fan with your hand technically increases the torque of the turbine, if only by an immeasurably small amount.
Fun Fact: An improperly shielded (or old and deteriorating) fan can be influenced by stray electromagnetic radiation. They'll pick up AM radio signals occasionally, creating an off tone in the fan noise that sounds like a person talking faintly on the other side of the fan.
AC motors are more powerful but also more noisy. You need that power in your kitchen mixer but you need quiet in a fan. Modern WC rooms now have a DC fan, old ones have the loud one.
Whats crazier is that in direct current individual electrons don't travel at the speed of light through the conductor, but only at roughly 1cm/s.
Or, that thanks to the "skin effect" the current actualy travels in a very thin layer below the outside surface of cconductor. Most of the conductor doesn't transfer power but only maintains the magnetic field to keep the current flowing.
No, skin effect only occurs on higher frequencies. That is why coaxial cabel is invented. But then they realized the energy in coax transfers in a completely different way.
why is everyone in this thread telling me to imagine something
Because imagination is everything- probably Einstein
So imagine a bus...
Does it leave every 21 frames?
Steam engine pistons also move back and forth less than a meter at a time, and still could push trains a million kilometers in the forward direction. It's that they're pushing right while moving right and left when moving left. That's like when AC current and voltage are in phase, delivering positive net power. Meanwhile, something that pulls left when moving right is consuming power.
My power company is charging me that much for nothing but vibes?!
They're giving you excitations
Ooh, exciting!
Elections merely facilitate the transfer the power, like (the non-leading edges of?) a drive shaft or cogs.
Even with DC you need a loop (well, a difference).
Carbon fuel one-use mentality where you burn your supply (chemically stored energy) doesn't apply, tho non-rechargeable batteries make it seem so.
It’s even crazier than that. It’s not even the electrons at the “leading edge” it’s the EM field they create even separate the of the wires that actually contain the electrons.
And the follow-up with a physical experiment after the first video started a huge drama.
God I hate that video, he explains everything so badly to the point of completely misinforming viewers. He's talking about a special situation of AC current, but uses DC in the thought experiment. He makes it seem as if the field travels to the load in a direct path and the wires don't matter. No, the EM field is completely based on the wire.
No, the leading edge of the mechanical transfer of power - I was trying to make a faux comparison that electrons would be the inside of the shaft/cog & the fields the leading edges (that transfer the power & are moving more).
I mangled the comparison, should have given up on it. Vibes are hard to compare with anything non-vibes.
Great youtubing in the links, that's how you get them views (benefit several creators and spread science)!
(*I just skimmed them for the general vibe, I'm not voicing support in case they are weird ppl, I don't know them.)
Edit: while speeding through I noticed a very cool simulation (software), yt/mcez0ri9yPY, these are very neat visuals.
non-rechargeable batteries
Yeah, why are they still a thing? Recharchables have all the advantages but more.
Low self discharge. Good for ultra low power devices like remote controls or lights only used on occasion where a rechargeable battery would self discharge faster than the rate of actual use.
Let's hope those paper batteries by Flint (shown at CES) aren't bs marketing (that they truly aren't harmful as waste & are comparable to normal batteries).
The microwave doesn't heat your food, it just vibrates the water.
Heat is kinetic energy and the water is part of your food, so the microwave does heat your food.
It's just the one electron.... Allegedly
Can you imagine being the guy who just, like, claps his hands together and kills the electron, snuffing out all existence
The voltage(electrical equivalent of force) is what travels.
It's analagous to pushing something away from you with a really really really long stick, then pulling it back again. The stick didn't move much but you still affected something far away.
The electrons don't move very quickly either. Like, a sluggish one millimeter per second is more current density than most metal conductors can handle without melting. Thankfully, there's lots of mobile electrons carrying charge (coulombs) so that's a lot of current. "Electricity" only travels near the speed of light because voltage is like a force sending waves through the electric field (simplified). And it's instantaneous current (amps = ~~joules~~ edit: coulombs / second) times voltage (electric field potential difference in volts = joules per coulomb) that delivers power.
Simplifying to a single harmonic (pure 50Hz/60Hz sine voltage source and a passive, linear RLC load), you need not only multiply the voltage's and current's effective amplitude (that gets you apparent power in VA, voltamps) but also their power factor or cos φ (the cosine of phase beetween them) to get power in W (joules per second). If the cosine is one, it's a purely resistive (R) load (like a heater) with a phase difference of 0°. If the PF is zero, it's a purely reactive (L/C) load (a freewheeling synchronous motor is much like that) with a current phase of ∓90° and no power is consumed overall. If the cosine is negative, power is actually being generated by the device you're measuring (for instance, old elevators and escalators with synchronous motors are actually delivering power into mains when enough people are travelling down).
Amps are not joules / second;- that would be Watts. Amps = Coulombs / second, and Volts = Joules / Coulomb. That's why multiplying them gives you power in Watts.
That's true instantaneously but as you say, if the current or voltage are alternating then you can't just use the AC current and voltage to get real power like you can with DC.
You are correct, that was a mistake.
However, although symbols of units named after scientists (V, A, W, C, J, Ω, H, F, T, Hz, S, K, N, Pa, Bq, R, Ci) are uppercase, they are lowercase when written out (volt, amp(ère), watt, coulomb, joule, ohm, henry, farad, tesla, hertz, siemens, kelvin, newton, pascal, becquerel, roentgen, curie) to differentiate them from the surnames. Also be careful with degrees (Celsius, Fahrenheit, Rankine, Réaumur...) and grams (g, not G or gr), unrelated to the bacteria-ranking Christian Gram. And yes, the l/L debate is why the Claude Litre hoax was created. (In Unicode-capable applications I use 𝑙 BTW)
Kind of like how a piston in an engine also kinda just "shakes about" (because of explosions or steam or whatever) and yet delivers a lot of power.
Fyi, it isnt fully correct and a lot of electricity related channels were a bit annoyed by it. But overal its a good video hehe
Do you happen to know a good video about the issues?
AlphaPheonix has a few amazing electricity videos including this one where he actually does the experiment.
Veritasium's video was so bad, like 15 channels made response videos within a week. Just search for, "is veritasium wrong about electricity". It's not that he was completely wrong, he was just doing lots of hand waving and making electricity sound like voodoo.
Watch mehdi electoeboom and Steve mould's follow up argument about who is right.
Veritasium also made a follow-up video addressing their arguments. After that, they kind of went silent and seemingly sided with Veritasium
My main concern with his video was a lack of a real explanation. He never once used the word induction, for instance.
The AlphaPhoenix video I linked proves Veritasium "true". It wasn't even a rebuttal, really. It's just that he had a problem with what Veritasium was saying about current and what it means to light up a light bulb.
Just because no one made another video after Veritasium made a follow-up one, just means everyone was tired of the subject. I have not watched Veritasium's follow-up video because his first one offended me so much I blocked his channel. It's not the content that was wrong, necessarily, it was the way he presented it. It was all hand waving without trying to get people to truly understand the thought experiment. It pissed me off.
(I just edited my original comment to change rebuttal to response. Also, I removed all the other links because I haven't watched them yet, so I can't say anything about them.)
He really showed only induction in that video, that everyone knew about. And a very small current only goes in the first pulse. Rest of the current flows as you would normally expect. Electroboom explained it pretty well and this video didn't really disprove or argue against that at all
Yep, exactly why it works so much better over distance than DC.
That's not correct. What you need for long distance is high voltage, and it's easier/cheaper to step up/down AC voltage than DC. If conversion costs were eliminated, DC is actually more efficient.
If you get to even longer distances of over 300+ miles, DC's efficiency becomes worth the additional cost of conversion. There are many HVDC interregional connections.
At distances closer to a quarter wavelength you can also have some pretty gnarly reactions if a line goes down. That's why stuff like the Kahora Bassa power plant uses HVDC for transmission.