Non-Music YouTube Videos

Making transistors the hard way!

1 Like

The Big Misconception About Electricity - YouTube

8 Likes

Wonderful video.

Thanks, Ted. That was really great!

The graphics are particularly good.

I am continually astounded scientists figured so many of these things out ~150 years ago. Incredible minds.

1 Like

I wonder why we don’t get a shock touching a hot cable if the energy source flows about it? What is the cable insulating inside the cable that will shock you if that wire is breached? :crazy_face:

Maybe this is in some way a response to audio cable nay-sayers? :thinking:

2 Likes

This is pretty interesting, and probably applies to how a signal travels through speaker wire and interconnects as well. Except it doesn’t actually travel through the wire itself.

Already posted above by Ted, less than a week ago (see, above). It is a good video.

Originally posted elsewhere by John:

I’ll admit I know squat about this (aside from Ted posting the original video, and when I texted it to Darren, he said it was the best explanation of electricity he’s seen, so I’m happy to have their opinions work for me) - But - around 3m this guy erases (“cuts”?) the wires at the half-light-second-distant “ends”. He completely lost me there. Can anyone justify that exercise, or what follows? Thanks.

As he said long wires are radio transmitters / receivers. Closing the switch produces an impulse which theoretically has all frequencies so it transmits very well. There’s good coupling with very long wires so the bulb gets essentially the whole impulse. The impulse will die away as the bulb dissipates its energy but (if the wires are connected at the ends) eventually the circuit as a whole will provide the power to keep it lit. With the wires cut only the impulse will get thru. But the original question was how long would it take for the bulb to light and that’s limited by the speed of light between the transmitter and the receiver: darned quick compared to going all around the loop.

1 Like

But isn’t that (“cutting the wires” out around the orbit of…whatever planet) akin to completely changing the equation/proposition? I admit again that I am at sea here.

I get that the whole light-second-long cables is a theoretical thing - that they do not have any of the properties of meatspace cables. But cutting them?

He was simply making the point that they don’t need to be connected to understand why the light bulb lights when the switch is closed. I.e. he was trying to help those that understand radio, etc. to see that they already had the tools to understand the thought experiment - and they didn’t need to be confused by having the wires connected together out there.

1 Like

Ok - I think, however I am confused by the notion of wires NOT being connected out there. Otherwise, I don’t get the illustration. If you cut the wires, what does it matter how long they are?

And if you cut the wires, does the bulb still light?

Is this one of those theoretical math-y things I failed to grasp in high school?:cowboy_hat_face:

The impulse that happens when the switch is closed is RF transmitted to the other antenna and hence will light the light bulb (for a little while). The longer the antennae the more efficient the RF transmission is. None of this cares whether the wires are connected or not. After that impulse (if the wires aren’t connected) the impulse will die out as its energy is dissipated as heat in the bulb. If the wires are connected then the bulb can remain lit.

1 Like

Or is it a modern YouTube thing where I grasp my head in disbelief and write “WTF?!?” in large type and get a boatload of hits?

So where is the line here between a theoretical discussion spurred by the original video, and something that would actually/potentially work in meatspace?

Sorry - but I’m back to the original thing where the “Wires” are a “real imagined” light-second loop. If they are NOT, via being cut or whatever, does that not change the premise of the original video?

If we’re writing at cross purposes, feel free to ignore.:pray:t2: