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My academic interests are in power plants of all types, shapes, and sizes, and how well they play with each other. My hobbyist interest are kind of all over the place. I like the maker movement, I'm most interested in the sensors and data, the "internet of things" kind of stuff. In physics, I'm probably the most curious about general relativity topics, but I'm all over the place. We once had a Nuclear Engineering proposal on Area 51, but it failed.


1d
answered Is an atom charged after undergoing beta emission?
2d
awarded  Nice Answer
Mar
25
comment What would it be like “inside” a star?
@DevSolar That is exactly what I had in mind. However, I was hesitant to elaborate on one detail, and upon further research, my doubts are warranted. As you go deeper into the sun, the visible wavelengths will not decrease in intensity, because increasing temperature only adds more in shorter wavelengths, but doesn't subtract from long wavelengths. So you'll be microwaved, but you'll still be blinded in the visible spectrum.
Mar
25
answered What would it be like “inside” a star?
Mar
11
comment Could a Nuclear Reactor Run (controllably) in Prompt-Critical Mode?
@DOS4004 I had to look check, but I think I know where you get the "delayed-supercritical" wording from. This is specifically the scenario where the reactor is increasing power. In this state, you could say that it is "prompt-subcritical", because the prompt neutrons alone are insufficient to maintain criticality. You're asking if we could replace the regular ramp-up with a controled prompt-supercritical ramp-up. I don't know of any control element which is non-mechanical. Unless you can find a truly electric control method, then I think the control could be fast enough.
Mar
10
awarded  Popular Question
Mar
10
answered Could a Nuclear Reactor Run (controllably) in Prompt-Critical Mode?
Mar
8
comment Why are neutron absorption cross sections high at low incident energy?
It seems pretty clear that out of the 2 possibilities the OP laid out, it is the 1/v behavior dominating. We just have a multitude of justifications for that behavior operating at different levels of physics. I read this question as asking for a genuine quantum explanation of that 1/v behavior, which is a perfectly valid question.
Mar
7
comment How to calculate the colour a human eye sees when looking at a light spectrum?
@ByteCommander The sensitivity curves are applied in a simple convolution integral. To apply that to a single spectral line, you just multiply the intensity by the value of the sensitivity curves at that wavelength. After that, there is a matrix to directly convert to RGB. You may want to adjust the gross brightness of your final result because that's divorced from the hue. I wrote an answer which covered the steps, which I assume is the same mathematically as what the other user suggested. physics.stackexchange.com/questions/46574/…
Mar
7
comment Why does the value of gravity decrease as we dig into the Earth, but also decrease as we enter the upper atmosphere?
Gravity does not decrease as you dig into Earth (initially) because it is not uniform as the question implicitly assumes.
Feb
25
answered In terms of scale, where does the concept of Reynold's number cease to have meaning?
Feb
22
answered Hooke's Law vs. Elastic Potential Energy
Feb
22
comment Hooke's Law vs. Elastic Potential Energy
To begin with, in your 2nd attempt 132/0.0593=2225.9, whereas you dropped an order of magnitude. From there, you're trying to explain the factor of 1/2.
Feb
20
answered Why do nuclear weapons create a blast wave?
Feb
19
awarded  Notable Question
Feb
12
answered Coexistence at Lagrange points
Feb
10
answered Pressure and Tall Buildings
Jan
30
answered Is there any evidence that subatomic particles are affected by gravity?
Jan
23
comment Is there an alternative metric for isentropic efficiency that remains valid when broken up into multiple segments?
You have me on the same page now. When you mentioned "isentropic" efficiency versus "polytropic", your equations reflected that the latter is a differential statement of the former. Looking into it, the Pv^n quantity can not be held constant, not even for a fully isentropic expansion. I now believe that approach fails, but the differential form works.
Jan
23
comment Is there an alternative metric for isentropic efficiency that remains valid when broken up into multiple segments?
Numerical method isn't a problem, I just want to know what the first principle is. Let's say I implemented $P v^{Cp(P,h)/Cv(P,h)}=C$, where Cp and Cv are lookups for the combined mixture, along with lookups for specific volume. That's messy, but that's not a problem. I just want to know if this is the correct principle. You previously mentioned a $\eta=dW_a/dW_s=dh/dh_s$ metric. Say I used a iterative and integrative technique to make this value constant over the expansion and fits the inlet/outlet conditions. Would that be right? That's all I'm trying to ask.