avicenna

I believe this is the real deal, but only for those with some foundations in AC circuit theory. I will see how things relate to what I am investigating. @Carrock. I am trying to reduce AC circuit to DC circuit "instantaneously". I don't want coaxial cables which complicates things. Say I have a simple ac generator that generates fairly good sinusoidal voltage source at 50 Hz (If possible at all?). I connect a long resistive wire to the terminals in a huge circular loop. When the wire is at thermal equilibrium with the environment, we know that all power will be dissipated as IR radiation loss, purely resistive loss - assume ideally. So we could always apply ohm's law of I=V/R where R is the resistance of the wire, V the instantaneous voltage. It seems that there will be the usual charge conservation along the wire as if the current is a dc current. The current should be a constant at that moment of consideration. My setup would eliminate capacitance, inductance etc. Instantaneously, we only have the magnetic fields around the wire which we assume "steady". How is such an analysis.

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.

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

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.

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.

Maybe no easy answer because we know too little yet about light. The wiki says it is the bound electrons that absorbs radiation; then how the electrons energy get transferred to the nucleus kinetic energy. I think temperature not dependent on the KE of electrons, but only in the KE of the nucleus or center of mass.

I'll like to know the actual physical mechanism how matter absorbs EM radiation. Take the specific example how copper metal absorbs IR radiation and the copper having its temperature raised.

In a capacitor discharge through a plain resistor, the capacitor power supplied at any instant is VI; the power dissipated in the resistor is I²R. So VI = I²R. Consider a railgun operated with a capacitor bank. At any instant of capacitor discharge, the power supplied is VI. The total power supplied for ohmic loss is sum I²R for two rails plus the resistance of the armature. Question: Since VI = total I²R, how can the power equation include the kinetic energy supplied to the armature?

I think correct about plasma.

"he continuous emission spectrum is due to the surface temperature of the Sun. According to the Bohr model, light of a specific frequency is emitted due to the difference of two energy states of one (? or a few) element. Why a white hot iron bar can emit white light?

The spectrum of sunlight is a continuous spectrum as in the rainbow. But superimposed on the spectrum are dark absorption lines of some specific frequencies. From the absorption lines, we are able to tell that the main elements of the sun is hydrogen, iron, carbon, helium and some others. My question is why the continuous spectrum ? Elements have characteristic emission line spectra. So every specific wavelength in the sun's continuous spectrum is associated with one (?) element which has that wavelength in its line spectrum. Does it mean that the sun has all 108+ known elements? [edit] Or the emission lines of the main elements in the sun - iron,carbon, etc. - sufficient to form the continuous spectrum.

Yes.This Steiner paper exactly satisfy what I am looking for. It gave the first value of h to around end 1910. It also gave the method used to measure h historically, basically the photoelectric effect in the earlier years. I am not able to access any peer reviewed articles. Thanks. I posted the same question over physics stack exchange. Because they can't give me the information, they insist that there is no reason for me to to look for such information as the "different values should not be comparable". At other time physics stackexchange do give good answers.

It would probably mean you and I are not up-to-mark to view those papers.

I looked all over to get the various accepted value of the Planck constant since 1900. But there is never any record about the history of this mysterious number.

You may say so. But if Bragg's method can be used for all gamma ray, does it not bypass the relation E=hν. What if there is a method so "direct" that it requires 99 more relation in between? Can Bragg's method be used for all gamma rays?