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This evening when I get home I will be able to run the formulas for you. Yes you can calculate the vacuum energy density per cubic metre. For that one can get a decent estimate using the critical density formula. (Assuming Lambda is the result of the Higfs field) one line of research. The calculations differ for the quantum harmonic oscillator contributions however that results in the vacuum catastrophe but I also have the related calculations for that as well.

As light climbs in and out of a gravity well it will blue shift or redshift. For example an outside observer looking at infalling material at the EH of a blackhole will see infinite redshift but an observer at the EH will see infinite blue shift. This is due to gravitational redshift The path will be determined by the Principle of least action which correlates the Potential energy and kinetic energy terms. What most ppl don't realize is that the path is never truly straight. That's just the mean average. If you consider all the little infinitesimal changes in direction (sometimes up/down left right etc) then it becomes much easier to understand. As Markus the geodesic equations are the extremum of all the miniscule deviations

Hi, The average vacuum energy is estimated to about 3 GeV/m^3 (the observed). If relying on this value (when the calculated in extremely much higher). -And the Higgs field energy VEV, the vacuum expectation value, is both observed in the LHC experiment and fairly calculated to about 246 GeV. How are these differences explained in QM physics? 3 GeV versus 246 GeV? I understand that the VEV amount is presented without any special volume in mind. But surely the VEV isn't correlated to the cubic meter volume, though must be estimated to the Planck scale. Far minor than the m^3 which the vacuum is given with. The VEV is a universal constant thought to fill all universe with neither any much higher nor any lower energy content. This issue is raised with the condition of both the vacuum energy volume and the Higgs field are without any elementary particles, though being absolutely empty of any visible "matter". -Without even one single photon or neutrino or whatever. The only content is the absolute vacuum itself (3 GeV). The VEV can be regarded for proven with the Higgs boson discovery in 2012. And the vacuum content have with the Planck Collaboration project also been verified. /chron44

Fiber optic cables operate on the principle of total internal reflection, not the photoelectric effect.

Not necessarily. Delusion can be a symptom of mental conditions, but they do not have to be.

To which the first retorts, "Easy for you to say, when your wife makes such good soup!"

A domestic dwelling can have an adverse power factor so the phi in pf = cos(phi) is real and measureable especially if it's heavy on the ac and refrigerator loads (as we are, we've got a mechanic tinkering with our knackered gen set as I type!). The 4,000+ km wavelength I mentioned applies to the time of flight effect over long transmission lines. By the time you see an ac voltage (or current) peak, the last one is long gone. So the phase change over a 10 metre distance is oto 4 second of arc. Good luck measuring that with a multimetre 😊

Thanks. This is what I want to confirm. For the AC case, I really cannot say as the real world and the ideal world may be different.

The latter part of my explanation applies to this. The current is uniform. There’s no way for it to vary.

No, this is wrong. You need to understand the difference between excitation and ionisation. Photons are often absorbed without having enough energy to eject an electron. They just move it to a higher, but still bound, energy state. This creates an excited state of the atom or molecule that has absorbed the photon. The whole of spectroscopy involves processes of this kind.

I am saying the potential difference between the ends of the wire, i.e. a long wire connected to a dc battery.

V here really stands for voltage difference, not absolute voltage. So when you say: Your question reads as if the voltage gradient along the wire is zero. Did you intend that the two ends of the wire are maintained at a constant voltage difference? This would make more sense.

If the voltage is constant (for a real wire) there would be no current. If there is a voltage drop, and thus a current, the current will be uniform even if the voltage drop is not (e.g. if there’s a resistor, or a series of different-valued resistors); there’s no way to vary it. Charge is conserved, so current flowing in to a point equals the current flowing out.

If you repeat your errors I will repeat the corrections. Red light lacks the energy to ionize, so that’s not what’s going on. I’ll leave it to others to correct the biology.

How does a coupling constant appear smaller ? If you apply \(F=G\frac{m_1m_2}{r^2}\) the coupling constant remains constant what changes is the force exerted by the coupling between two masses as a function of radius. Not the coupling constant itself. We describe our observable universe itself in the FLRW metric we know the universe extends beyond that it could be finite or infinite as we can never measure beyond that we deal with what we can Observe and measure. (Region of shared causality)

I don't understand. I = V/R, so how can there be zero current if we connect a AA 1.5 V battery to a long copper wire. My question is whether I is the same at all points of the wire.

I should have mentioned that house loads like tv and computers are more capacitive, and motor stuff (washers, vacs, fridge compressors, induction stoves, ballasts, anything with lots of coils of wire) are inductive loads. So impedance would depend on which dominates a circuit. And in houses it is mainly inductive reactance, given the heavy current draw of appliances, furnace blowers, AC, etc. Good question. And beyond me, given am not sure how compressibility is defined in this context. Smaller holes? 🙂 I understand that In AC circuits where there are reactive elements the V and I may not reach the same amplitude peaks at the same time. This time difference, AKA phase shift, which ranges from 0 to 90° - Seth is saying this isn't significant in the length of a house circuit (usually a single phase circuit, unless your home contains some sort of cottage industry), if I'm following this. I am mainly (NPI) a guy with some cable and a Klein multimeter who tinkers with house wiring, so I just aspire to be less stupid and not burn the place down.

Because the gravitational constant appears smaller at a distance. This dynamic is literally missing dimensions when you use calculus, it is the difference between how the cylindrical portion of the cone constantly decreases from base to dip to how that same cylinder constantly curve from top to bottom on a half sphere. Look, if the universe has said volume, is that the volume of a cube or of a sphere?

I think the correct answer to this rather odd question is yes, though if the wire has any resistance then that uniform current is zero. In the absence of reactive elements (capacitors or inductors) a constant current implies a constant voltage gradient. If the load is purely resistive, then the current is in phase with the voltage. A purely capacitive load will make current lead voltage by 90o. A purely inductive load will cause a 90o lag. Practical loads fall somewhere in between these extremes. The variation 'along the wire length' needs to take into account that the electrical field propagates at some substantial fraction of the speed of light, so the wavelength is oto 4,000 km at 50 Hz.

I wonder, though, whether this question may be about something else, viz. the "elasticity" of the current-carrying electrons in the circuit. For instance is the voltage is at its maximum value at one end, what will be the phase of the voltage 10 metres along the wire. Will that also be at the max, or is there a phase lag due to the compressibility of the current carriers?

Thank you for repeating that. Proteins are made out atoms which have electrons. So at the very most basic level what is happening is literally ionization from light in the dna composing the retina. Yes when you get to the cellular level things like photosynthesis seem more complex but it's all just light and electricity interacting with each other just like the computer.

Is there a load on the circuit, and is it a dumb load (lightbulb, e.g.) or a smart load (electronics)? When your current passes the load in a series circuit, there is a voltage drop from hot to neutral (the return leg). Even without a service load, more than 50 feet of cable (like 12 or 14 AWG in a house) will cause a voltage drop. Good old R. (well, Z actually, in an AC circuit) The voltage drop across the load is proportional to the power available to be converted in that load to some other useful form of energy. In an AC circuit we speak of impedance. Several factors at work there. Besides resistance, AC voltages have a second opposition to current flow called reactance. The sum of resistance and reactance is the impedance. (Z) Z will depend on the frequency of the AC and the magnetic permeability of electrical conductors and electrically isolated load elements.

The limitations on Ukraines use of supplied conventional weapons would disappear. Why would the West continue to tell Ukraine not to use them on Russia proper when they are being attacked from there? The West's concern with Russia's nuclear threats are the only thing stopping them from allowing that and likely more. Russia can't match the West economically, even if they saved the costs of nuclear weapons maintenance and improvements. Their war factories would suffer from conventional means. How would anyone justify allowing them to continue to produce weapons considering how they use them, if they had ready means to stop them? China might take a liking to Putin's current way of thinking and view the eastern parts of Russia that are closer to Beijing than Moscow as "historically" their own, or at least decide they better "save" them from the West.

If the voltage across a long wire is constant, is the current uniform throughout the wire length. In a 50 Hz ac voltage across a long wire, at a certain moment how does current vary along x, the wire length.

This is clearly right as it has been shown experimentally. Do you have any other (or complementary) intuitive ways of sitting this process in our pattern of thoughts? I have always tried to think of this as some kind of "work done" as a body travels through both space and time, following different possible paths but that approach doesn't satisfy me (and is probably wrong as well) I find no fault with your description but I wonder could there be other ways to describe this using words.