Yes, of course. Energy is stuck in the phosphor and there is a slight glow for a little while. The residual is only a tiny fraction of the powered output. On a clear bulb, the wire may be a dark red as the heat energy also has a delay. I'm not sure if its photons (looked and can't find any), but I'm sure that there's something stuck up in there. 😉
However, if the light were the blinking sort (a very slow ac signal) left powered on, then it would be going between bright and quite dim but without any solid dark. I refuse to install that particular light in my bedroom. lol! 😉
Was this a trick question?
I'm seeing spots.
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The entire concept of the "speed" of a conductor is nonsensical anyway. The speed of the wave that travels from one end of the cable to the other is determined by the dielectric constant of the cable's dielectric (and for dispersive structures such as microstrip, to some extent on the geometry), not the conductor properties.
Thank you!
I read this 7 times. 😉
dielectric constant?
Well, that does work.
Doing it backwards from these examples, plus mixing in a clean signal on its own path = reverb and some heat. Is that right?
Let's take the specific example of coax. This type of structure has as its principal mode of wave propagation a thing called TEM mode (transverse electromagnetic). For TEM mode, the velocity of propagation is that of light divided by the square root of the (relative) dielectric constant.
Let's look at the Belden catalog, say Belden 89259 coax. It gives the velocity factor as 78 percent. This means the velocity of wave propagation in the cable is 0.78 that of light. Let's call the actual velocity v and the velocity of light c, and the dielectric constant epsilon. So we have:
v = c / sqrt(epsilon)
therefore,
epsilon = (c / v)2
So epsilon = (1 / 0.78)2
epsilon = 1.64 = "relative dielectric constant"
The speed of light is 3 * 1010 cm/sec, so in the cable, you get 0.78 * 3 * 1010 cm/sec
= 2.34 * 1010 cm/sec
Let's look at the Belden catalog, say Belden 89259 coax. It gives the velocity factor as 78 percent. This means the velocity of wave propagation in the cable is 0.78 that of light. Let's call the actual velocity v and the velocity of light c, and the dielectric constant epsilon. So we have:
v = c / sqrt(epsilon)
therefore,
epsilon = (c / v)2
So epsilon = (1 / 0.78)2
epsilon = 1.64 = "relative dielectric constant"
The speed of light is 3 * 1010 cm/sec, so in the cable, you get 0.78 * 3 * 1010 cm/sec
= 2.34 * 1010 cm/sec
And how does any of this math prove what people hear with their ears and translate by their brain?
Here's a way to relate epsilon to something more familiar: a parallel-plate capacitor. The capacitance C in Farads is given by:
C = epsilon * epsilon_zero * A / d
epsilon is as above, and epsilon_zero is the permittivity of free space. A is this area in square meters and d is the plate separation in meters. What this dielectric constant of 1.64 means is that if you made two parallel-plate capacitors, both with the same area and separation, but one using air as the dielectric and the other using what's in the 89259 (which happens to be teflon), the teflon capacitor would have a capacitance that's 1.64 times that of the one using air. This is because air has epsilon = 1.
Yet another way of looking at this is that if you had a coax cable whose dielectric was air, its velocity factor would be 1 (100 percent).
C = epsilon * epsilon_zero * A / d
epsilon is as above, and epsilon_zero is the permittivity of free space. A is this area in square meters and d is the plate separation in meters. What this dielectric constant of 1.64 means is that if you made two parallel-plate capacitors, both with the same area and separation, but one using air as the dielectric and the other using what's in the 89259 (which happens to be teflon), the teflon capacitor would have a capacitance that's 1.64 times that of the one using air. This is because air has epsilon = 1.
Yet another way of looking at this is that if you had a coax cable whose dielectric was air, its velocity factor would be 1 (100 percent).
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It may also help to relate length to time. Grace Hopper used to hand out one foot lengths of wire which she called "nanoseconds." So a typical cable run represents about 20ns of constant delay.
A dynamic (or ribbon) mic in the back row of a 120 person scoring session in a 5000 sqr foot room. Ballancing only helps with noise that is equal on both legs(+ and -), noise produced inside the conductors isnt this. The point is: 100 ft of conductor with 40 db of gain should magnify 1/f, and thermal noise orders of magnitude more than a interconect or speaker cable.
So all the music you consider great recording was done by morons?
Lets hear something youve recorded.
I'm not a physics guy but I guess if that were true there would be no need for the electromagnetic wave.
That dosnt make sense. Look at two pieces of pipe , one larger than the other,with the same wall thickness (representing the x-section left to conduct when skin depth is considered) The large one has more conductor area and therefore less resistance.
20ns? That's a bit too fast for a reverb. 😉 But, I'll bet you could make some heat and some cancellations if one wire was quite different to another yet both connected the same, carrying the signal "almost" simultaneously. I'm thinking that is possible for this to happen with stranded cable whereby each strand is enamel coated and there is a flaw in some of the strands. This worries me. 😉
To me that strongly suggest that electron movement is controlled by the EM field, not electrons pushing each other. I do however believe that the conductor quality also have an effect.
Sorry Stinius, haven't tested yet, I will do it just for you within the next few days.
Actually a full hose is a good analogy if the hose loops around back into the pump to make a closed cicuit. The water is the free electrons the pressure is the voltage. When you turn on the pump (voltage source) it causes a pressure wave (EM wave) to travel down the hose which moves the water (electrons). The pressure wave travels a lot faster than the water. EM waves travel a lot faster (10^9 m/sec), than the electrons (cm/sec) that give us current.
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