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bio website math.stackexchange.com/users/…
location Champaign, IL
age 36
visits member for 3 years, 8 months
seen Oct 9 at 6:59

Amateur mathematician, professional software engineer. Interested in all kinds of math, becoming a better mathematician, and helping others do the same.

email: jdb1729 (at) gmail.com

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Mar
13
comment Knotted token-ring network
Indeed. Maybe it would make sense if each node had information about the angle formed by its adjacent neighbors?
Mar
13
comment Why can one bend glass fiber?
I think it depends a lot on how the glass is formed. en.wikipedia.org/wiki/Prince_Rupert's_Drop youtube.com/watch?v=6V2eCFsDkK0
Mar
13
comment What is the effect of temperature on electrostatic-gravitational balance?
Georg, I am not sure what would be the meaning of temperature if we assume point mass-charges. Does the weaker assumption d>>r imply an attractive force or is does it still depend on the temperature increase?
Mar
13
comment Paradoxical interaction between a massive charged sphere and a point charge
That is interesting, however this thought experiment works just as well with protons, because it is the gravitational mass of the electric potential energy that is causing the dominant effect, not the gravitational rest mass.
Mar
13
comment What is the effect of temperature on electrostatic-gravitational balance?
Of course, the system cannot be completely stable because of black-body radiation lost to the vacuum. But it seems like if the time interval is short enough then this can be neglected.
Mar
13
comment What is the effect of temperature on electrostatic-gravitational balance?
Edited question to include force of radiation pressure.
Mar
13
revised What is the effect of temperature on electrostatic-gravitational balance?
specifically it is my description being refuted
Mar
13
comment How much energy can be extracted from hydrogen?
Do baryons have a minimum mass?
Mar
13
revised What is the effect of temperature on electrostatic-gravitational balance?
typo
Mar
13
comment What is the effect of temperature on electrostatic-gravitational balance?
The initial system is stable by hypothesis: charge is increased on each sphere until it exactly counteracts gravity, then we begin heating one of them. The question is will they start pulling or pushing? I am not sure what happens with a dielectric object but I will think about that too about maybe that will help.
Mar
13
revised What is the effect of temperature on electrostatic-gravitational balance?
because of mention of mass-energy equivalence
Mar
13
asked What is the effect of temperature on electrostatic-gravitational balance?
Mar
11
comment How much energy can be extracted from hydrogen?
Does the Standard Model imply this? How do you know there is not some other nucleus with an even smaller relative rest mass?
Mar
11
comment How much energy can be extracted from hydrogen?
dmckee, why not also p + e -> gamma + 2 u + d + e -> gamma' + 3 u + nu_e? I understand nu_e is an electron neutrino with L = 1 but I know very little about QCD and I am not sure how to interpret 3 u as energy.
Mar
11
revised How much energy can be extracted from hydrogen?
edited tags
Mar
11
comment How much energy can be extracted from hydrogen?
So without assuming any GUT, how much energy can be extracted? Does it all turn into iron-56?
Mar
11
comment How much energy can be extracted from hydrogen?
The wikipedia article says this happens in "some GUT models" and names them with an expression I am not familiar with. Does the Standard Model not allow destruction of hydrogen?
Mar
11
revised How much energy can be extracted from hydrogen?
fix "only" usage
Mar
11
asked How much energy can be extracted from hydrogen?
Mar
11
comment Knotted token-ring network
I doubt it too: my shoelaces don't know how to untie themselves! Is it possible in principle? What would be required?