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location France
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visits member for 1 year, 11 months
seen Oct 3 at 8:35

Interested in mathematics and theoretical and mathematical physics.


Jan
21
awarded  Yearling
Jan
5
awarded  Autobiographer
Jan
3
comment What is the status of Mpemba effect investigations?
Have you yourself done any experiments on this?
Jan
3
comment What is the status of Mpemba effect investigations?
Thanks for the link. The winner's conclusion is that the effect in largely due to supercooling and convection (see rsc.org/mpemba-competition/mpemba-winner.asp), quite in contradiction with the answer by John Rennie and Ron Maimon. Does this mean that the investigations have not yet given a good commonly accepted answer?
Nov
5
awarded  Citizen Patrol
Sep
21
comment Best books for mathematical background?
Spivak's "Physics for Mathematicians. Mechanics I", see mathpop.com/mechanics1.htm. Even though this is not just on math background, but rather a very math minded physics text book.
Sep
13
awarded  Scholar
Sep
13
accepted What are the equations of motion of a hole in a soap bubble?
Sep
10
awarded  Nice Question
Sep
10
awarded  Student
Sep
10
asked What are the equations of motion of a hole in a soap bubble?
Sep
8
comment Weight registered of a falling chain
Yes, that's the standard text book reply. It seems that this impossible to verify experimentally and there is some reason to doubt that the point mass mechanics argument fully apply in this situation. See Addendum 3A in Spivak's book "Physics for Mathematicians: Mechanics 1" and the references therein.
Aug
30
comment Necessary condition for square integrable functions?
Ok, so this shows that a function that is bounded below by $C>0$ and that converges to $C$ as $x\to\infty$ can not be in $L^2$. But you realise that this is a very special case, yes?
Jun
2
revised How is multiplicity given by 2S+1?
corrected minor typo
Jun
2
awarded  Informed
Jun
2
awarded  Suffrage
Jun
2
suggested approved edit on How is multiplicity given by 2S+1?
Jun
2
comment Is Brownian motion a deterministic system?
But since we believe that our world is quantum, a more realistic model would probably give additional randomness that doesn't just come from lack of information... When you describe the collisions on a quantum level, then - even if you know perfectly well the initial states of all molecules - you can only predict the probilities with which the Brownian particle will be in a certain place, when you measure it.
Jun
2
awarded  Commentator
Jun
2
comment Is Brownian motion a deterministic system?
Well, I guess it depends on how you choose to describe Brownian motion or what exactly you mean by the term. If you stay within the framework of classical mechanics and thermodynamics, i.e. you describe your Brownian particle as a little billiard ball bouncing around inside a liquid consisting of zillions of other billiard balls, then the randomness comes only from lack of knowledge.