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Feb
2
comment A Neutron Star and an Atom are Similar
But if this really is the mechanism for your "millisecond pulsar", doesn't this answer in the affirmative the question of whether a charge radiates when accelerated by gravity? I thought that was still an open question.
Feb
2
comment A Neutron Star and an Atom are Similar
@rob jeffries yes you are right, I misread the density on Wikipedia. That brings my frequency down to 2 kHz which is in your ballpark; and of course also brings the speed down below c.
Dec
17
comment Why doesn't a lighter flame cast a shadow?
If they emit light in the visible range, then they must also absorb light in that range. That's how it works. If it were different, you could construct a closed system where heat flows from low to high temperature.
Dec
17
comment Why doesn't a lighter flame cast a shadow?
doesn't sound right to me. If a flame can emit light, then it can also absorb light.
Nov
25
comment Why is the trajectory of the alpha particle in a cloud chamber almost straight?
You're assuming the alpha particle actually has to strike the nucleus directly. What about coulomb scattering, which is effective over a much larger cross-section?
Nov
21
comment Why isn't a meter defined from a kilogram of water?
Except you'd have to worry about how much deuterium was in the water. That's a complication.
Nov
21
comment Why isn't a meter defined from a kilogram of water?
Contrary to the comments so far, this is a very good question. We could have defined a kilogram as the standard mass of so-and-so many hydrogen atoms, and then the definition of the meter could have followed as the linear dimension of one cubic megagram of water at 4 degrees celsius. The density of water would have been 1.000 by definition. Instead, we have to determine the density of water by experiment, from the standard meter and the standard kilogram. So how close is it to 1.00 anyways?
Nov
21
comment Is Wikipedia wrong about Huygens-Fresnel Principle?
The business of anomalous behaviour in two dimensional seems like a huge red herring which is irrelevant to the question at hand. It is not even mentioned in the Wikipedia article which I am calling into question. According to that article, Fresenel needed to make an angular compensation correction even in regular 3-space. I just don't buy it.
Nov
21
comment Is Wikipedia wrong about Huygens-Fresnel Principle?
If's there's only one wavefront, then it does propagate both ways, forwards and backwards. You need the whole forward-moving wave train to cancel out the backwards-propagating waves.
Sep
1
comment Is it possible to have things orbit around us?
Yes, I see. It is the same constant, give or take a factor of 2*pi or so.
Aug
31
comment Is it possible to have things orbit around us?
Yes, you did it very cleanly. I'm surprised that time and density are related by a universal constant.
Aug
20
comment How to interpret physical quantities in a superposition state?
I like where you say this is one case where superposition "can't even pretend to be mysterious."
Jul
20
comment What's wrong with this argument that aerodynamic lift really does rely on Bernoulli?
@Dunlavey And yes, I've been a big fan of the John Denker website since I first saw it about ten years ago.
Jul
20
comment What's wrong with this argument that aerodynamic lift really does rely on Bernoulli?
The wing pushes air down because of the angle of attack. But I don't know any way to calculate exactly HOW MUCH air gets pushed down, either from the angle of attack or by some kind of Bernoulli's Principle analysis. But assuming that the wing is actually functioning properly (not stalling or anything like that) I think you'd get a pretty good estimate by multiplying the effective cross section by the velocity of the airplane.
Mar
30
comment Why do lines in atomic spectra have thickness? (Bohr's Model)
Thanks for the edit, Noah. And thanks for my first lesson in LATEX. Now I know that the code for 10^(-8) is DOLLARSIGN\ 10^{-8}DOLLARSIGN (with actual $'s instead of DOLLARSIGN).
Mar
21
comment Can quantum fluctuation happen outside space-time?
It's easy to make fun of an outsider who asks this kind of question. But it seems to me that serious physicists are responsible for the claim that "the big bang was the result of some kind of quantum fluctuation". If that's the kind of statement that legitimate physics deals with, then I really don't see what's wrong with the question. Because it's about as meaningful as the statement which inspired it.
Mar
20
comment How wrong are the classical Maxwell's equations (as compared to QED)?
Thanks, @FraSchelle. What is especially baffling is that more than 100 years into the new paradigm that is quantum physics, I am still considered a kook on the internet for drawing attention to these obvious and readily verifiable truths.
Mar
11
comment How wrong are the classical Maxwell's equations (as compared to QED)?
You didn't answer my question, Jerry. Am I right about the black body radiation, the atomic spectra, and the laser?
Mar
11
comment How wrong are the classical Maxwell's equations (as compared to QED)?
Oh come on. You get the wrong answer when you apply Maxwell's Equations to orbiting electron because you're using the wrong model for the hydrogen atom. There's nothing wrong with Maxwell's Equations. When you apply them to the Schroedinger atom instead of the incorrect Bohr atom, you get the right answer for the spectral lines and the linewidths.
Mar
11
comment How wrong are the classical Maxwell's equations (as compared to QED)?
I think in the first paragraph where I said you don't need to quantize the energy, I meant the e-m field energy. You still get discrete energy levels in the mechanical system when you solve the Schroedinger equation. Those states have stationary charge distributions. But any system in a superposition of those discrete states will have an oscillating charge density, and that oscillating charge emits and aborbs radiation strictly according to classical antenna theory.