7,980 reputation
1435
bio website sjbyrnes.com
location Massachusetts
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visits member for 4 years, 1 month
seen 2 hours ago

Apr
6
answered Blackbody radiation and emissive power
Mar
31
answered Unit consistency
Mar
24
awarded  Nice Answer
Mar
23
comment Can a nuclear bomb be used as the power source for a laser beam
See en.wikipedia.org/wiki/Nuclear_pumped_laser but I don't know any details
Mar
18
revised Classical Hall effect when current has neutral charge
add link title and author
Mar
18
answered Classical Hall effect when current has neutral charge
Mar
10
answered Sign convention in optics
Feb
16
comment What is thermodynamic equilibrium?
@EnochArden - The laws of thermodynamics are not axioms handed down by God. They are consequences of statistical mechanics, just as all macroscopic laws of physics can be derived from microscopic starting points. See any statistical mechanics textbook for detailed derivations.
Feb
16
comment What is thermodynamic equilibrium?
@EnochArden - The velocity distribution of a gas is macroscopically measurable - look at doppler shifts of spectral lines for example - as is whether light satisfies a blackbody distribution etc. I take the Boltzmann distribution as a starting point: P~exp(-E/kT). There's a letter "T" in that formula, it's a parameter, and everybody refers to this parameter as "temperature". That's all I mean by "temperature", there's nothing circular there.
Feb
16
answered What is thermodynamic equilibrium?
Feb
13
comment Confusing Chemical potential of mixtures
I don't think there is any sensible or useful way to define chemical potential for a liquid mixture. So I would say it has no chemical potential. Lots of things do not have a chemical potential: The color orange, beauty, etc. :-D Chemical potential is a useful concept to the extent that something maintains its identity in different environments, and is usually (or always) conserved, loosely speaking. So it's a very useful concept for atoms or molecules, but not really for a liquid mixture, since the composition can easily and smoothly change.
Feb
12
comment Confusing Chemical potential of mixtures
What is "chemical potential of the total fluid"? I suspect that there is no such thing.
Feb
4
comment Probability of fluorescence: matching of binding energy and incoming radiation energy?
The binding energies are given by the "K edge", "L edge", etc.
Jan
29
answered Why are $2\pi$ factors included in the definition of the reciprocal lattice?
Jan
26
answered Phase shift in back-reflection generated at the mating point of two fibers
Jan
18
awarded  quantum-mechanics
Jan
14
revised Tunable Optical Band Pass Filter
added 121 characters in body
Jan
10
comment Local EPR-experiments with photons in vacuum?
Indeed, the line from A to B is something called a "null interval" which is totally entirely completely unrelated to the concept of "empty intervals" of real numbers in high-school math. These two things are just as unrelated as the "intervals" in music theory and in aerobics. That's why I still think you should mentally rename it a "null shminterval".
Jan
10
answered Tunable Optical Band Pass Filter
Jan
9
comment Local EPR-experiments with photons in vacuum?
Indeed, I am saying that the term "null interval" in special relativity has a very very different definition than an "empty interval" in the sense of intervals of real numbers. If you don't believe me, try looking up the former definition in an SR textbook, and then looking up the latter definition in a high school math textbook. You will see that they are completely different and unrelated.