General > General Technical Chat
"Veritasium" (YT) - "The Big Misconception About Electricity" ?
TimFox:
That may be your impression of atomic structure, but the "clocks" are based on the energy levels of the different orbitals, otherwise known as spectroscopy.
Electrons whizzing around in planar orbits is an outdated concept, found only on graphics.
Again, the reason why time is the basic dimension that can be measured to an incredible accuracy and repeatability is the existence of these well-defined energy levels and their corresponding frequencies.
In current practice, the meter was re-defined by postulating the speed of light, since it can now be measured to better resolution than the previous wavelength standards. We now, therefore, "measure" the meter using the defined value of the speed of light and measuring a time interval: very roughly, this means that the foot is now a light-nanosecond.
Note that even if your aetherwind affected dimensions of the circuitry in the control system of a cesium clock, the circuitry adjusts itself to agree with the physical frequency of the atomic transition. Similarly, vibration, stray magnetism, humidity, and temperature could cause the synchronization to fail, but they don't affect the atomic physics at the center of the system.
aetherist:
--- Quote from: TimFox on March 02, 2022, 11:48:06 pm ---That may be your impression of atomic structure, but the "clocks" are based on the energy levels of the different orbitals, otherwise known as spectroscopy.
Electrons whizzing around in planar orbits is an outdated concept, found only on graphics.
Again, the reason why time is the basic dimension that can be measured to an incredible accuracy and repeatability is the existence of these well-defined energy levels and their corresponding frequencies.
In current practice, the meter was re-defined by postulating the speed of light, since it can now be measured to better resolution than the previous wavelength standards. We now, therefore, "measure" the meter using the defined value of the speed of light and measuring a time interval: very roughly, this means that the foot is now a light-nanosecond.
Note that even if your aetherwind affected dimensions of the circuitry in the control system of a caesium clock, the circuitry adjusts itself to agree with the physical frequency of the atomic transition. Similarly, vibration, stray magnetism, humidity, and temperature could cause the synchronization to fail, but they don't affect the atomic physics at the center of the system.
--- End quote ---
The self-adjustment via a control would overcome ticking dilation from other parts of the clock, but of course we would still be left with the ticking dilation of the control itself.
The latest atomic clocks use photons instead of em radiation, & ions usually, & i still suspect that the vibration of the ion has a preferred orientation/plane, but a quick scan of articles duznt throw any light on that.
OPTICAL ATOMIC CLOCKS Andrew D. Ludlow1,2 , Martin M. Boyd1,3 , Jun Ye1 https://arxiv.org/pdf/1407.3493.pdf
And i still suspect that it involves an orbit of the ion (plus a spin perhaps). Anyhow even if there is no preferred orientation/plane there will allthesame be a length contraction affect on the ticking of the ion (whatever that ticking is).
Re the metre & the second being defined by lightwaves, this is so obviously so great a circular blunder that i can't believe that even Einsteinist's fell into that trap. It will bring grief in some instances.
Up till now this circular silliness appears to be getting away with it, but in this super-accurate era the wheels will fall off in a big way sooner or later. The problem aint so evident when the standards & the tests are in the same lab, or nearby.
For example the silly circular standard will almost certainly guarantee that the speed of light (& electricity) will be doomed to always be measured to have a constant value (at least in vacuum).
We use lightwaves to define length & time & speed & mass & c.
And thems lightwaves are radiations from certain atoms.
This can be ok if the experiment or test or design work or somesuch is in the same room as the equipment used to give the length/time/speed/mass.
But if it is in a different room, or if it is on a different day, or if it is at a slightly different level, then that might not be ok.
However, no matter what standard we used, we would face the same kind of problem.
The thing is that we must be better off if we understand the problem, & allow for it if possible.
Or, we can stick our fingers in our ears & close our eyes really tight, & shout
lalalalalalalalalalalalalalalalalalala…… the speed of light is constant the speed of light is constant the speed of light is constant … lalalalalalalalalalalalalalalalalalala.
adx:
--- Quote from: aetherist on March 01, 2022, 02:40:42 pm ---<^ link>
--- End quote ---
This whole post was a lot more solid than I was expecting (or perhaps used to), and I have to agree with a lot of it, or even most of it. Minus the guesswork - for me a lot of the theory is too far away from observed reality (or too reliant on offensively dubious (to me) experimental observations) to fit into my brain - but that's just me, and I am light on the meaning of conventional theory as it is. So I am reasonably happy with what you said here.
--- Quote ---I wonder what electricity would be like if it were due to drifting electrons. The speed of propagation of the electricity would be the speed of the wavefront of the electron to electron bumping, say 10 m/s for DC. Computers would take 57 years to do something that should take 1 second. Free surface electrons might flow at c/1000, instead of the 0.1 mm/s of the drifting electrons. But the idea of electons hugging wires comes from the need for electricity to propagate at c/1 on bare wire & 2c/3 on insulated wire.
--- End quote ---
A point I had meant to make about that, was that no existing theory works this way. Consider a barrel of charge contained in a CCB (charge confinement barrel, electrons, protons, electons, whatever). If the barrels are 1m apart, then pushing one, pushes on the other at the speed of light. It doesn't matter if the barrels are connected by a piece of wire. The electron to electron bumping in effect acts over the metre not angstroms.
aetherist:
--- Quote from: adx on March 03, 2022, 01:52:24 am ---
--- Quote from: aetherist on March 01, 2022, 02:40:42 pm ---<^ link>
--- End quote ---
This whole post was a lot more solid than I was expecting (or perhaps used to), and I have to agree with a lot of it, or even most of it. Minus the guesswork - for me a lot of the theory is too far away from observed reality (or too reliant on offensively dubious (to me) experimental observations) to fit into my brain - but that's just me, and I am light on the meaning of conventional theory as it is. So I am reasonably happy with what you said here.
--- Quote ---I wonder what electricity would be like if it were due to drifting electrons. The speed of propagation of the electricity would be the speed of the wavefront of the electron to electron bumping, say 10 m/s for DC. Computers would take 57 years to do something that should take 1 second. Free surface electrons might flow at c/1000, instead of the 0.1 mm/s of the drifting electrons. But the idea of electons hugging wires comes from the need for electricity to propagate at c/1 on bare wire & 2c/3 on insulated wire.
--- End quote ---
A point I had meant to make about that, was that no existing theory works this way. Consider a barrel of charge contained in a CCB (charge confinement barrel, electrons, protons, electons, whatever). If the barrels are 1m apart, then pushing one, pushes on the other at the speed of light. It doesn't matter if the barrels are connected by a piece of wire. The electron to electron bumping in effect acts over the metre not angstroms.
--- End quote ---
A year ago i made an Excel of electrons bumping electrons, where each electron influenced 3 electrons ahead. But i had a look at my effort recently & i couldn’t follow my methodology.
My Excel had the (3 No) electron to (3 No) electron bumping via a dielectric field acting at the speed of light, which i assumed was c/1 km/s. So, koz electrons have a (small) mass, & a large charge, the wavefront propagates at something less than c/1. Lets say that it is c/2 (i forget my actual calc). That’s too slow to explain electricity.
But, the correct speed of light in Cu is only 10 m/s, which is c/30,000,000. And, we all assume that the speed of em radiation is the same as the speed of light (except that i don’t think so). So, the speed of electricity here must be less than 10 m/s, lets say 5 m/s. That’s too slow, it is c/60,000,000.
The speed of electricity in my Excel will of course be sensitive to the electron to electron pressure, the closer the electrons at the start then the faster the electricity. I assumed one free conduction electron per Cu atom, for the initial spacing. But lets assume that the spacing was such that electrons were 0.001 of an atom apart. That duznt help much, koz in any case the speed of electricity must always be less than the speed of em radiation.
If the speed of em radiation is 0.999 of 10 m/s then the speed of electricity is still only say c/59,940,000.
If it is 0.999999 of 10 m/s, then we have c/59,999,940, ie not much better.
If the barrels were touching, pressed hard up to each other, u might be tempted to say that pushing the first barrel by 1 mm would give an instant push of 1 mm to the last barrel. But the push would not be instant, it would propagate at the speed of sound for barrels. And it would require at least a part of each barrel to move at at least the speed of sound for at least a small time.
So, likewise, even if the conduction electrons in Cu were so close that they were touching, the speed of old (electron drift) electricity in Cu would still be limited to a max of 10 m/s, assuming that the speed of the internal em radiation inside an electron was the same as the speed of the em radiation outside the electron.
And, once we start thinking in terms of electron to electron pressure, then how much pressure can the electrons withstand before they start shooting out of the Cu wire sideways. And, how fast would they be going when they shot out. Almost the speed of light? Do we ever see anything like that?
TimFox:
"The self-adjustment via a control would overcome ticking dilation from other parts of the clock, but of course we would still be left with the ticking dilation of the control itself."
Could you re-phrase that statement so that it makes some sense?
The reason why the definition of the meter was changed was that with cesium atom clocks, the repeatability of the "second" is better than the old repeatability of the speed of light measurements based on the wavelength definition of the meter.
Have you ever seen a description of the way in which the speed of light was measured by simultaneous measurements of the temporal frequency and spatial wavelength of a "dye-stabilized" laser beam? It was a very clever straightforward measurement, applying a microwave frequency to an electro-optical amplitude modulator that produces a "carrier" center frequency and two "sideband" frequencies, in the same manner of an AM radio system.
You adjust the microwave frequency (with a servo) to get an interferometer to lock up on all three frequencies, then measure the characteristic length of the interferometer with a tape measure to determine the integers that define the relationship between the frequencies. No handwaving required, just arithmetic. See: https://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/measure_c.html
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