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Sep
19
comment Equation of everything
@Dimension10 - ok. thanks
Sep
17
comment Equation of everything
I do not like the "i" in the third term in the exponent. It seems incompatible with the i/hbar in front of the integral. Some terms seem to be taken in real time, some in the imaginary time. Also it does not specify over which fields the variables are taken.
Jan
12
answered Estimating atmospheric friction by measuring the change in velocity of a ball thrown straight upwards
Jan
11
comment equivalence of wave equations
yes, my argument is only applicable to functions. Nevertheless what sort of behaviour is to expect around $t=0$? I think that this is just a "step" of height $s(\vec r)$, then $t$-derivative gives $\delta(t) s(r)$, second derivative gives $\delta'(t)s(r)$. The second equation would give the same if we assumed additionally that $\psi(t<0,\vec r)=0$. I guess then the solution may in fact be just a discontinous function around $t=0$ (and of course a distribution by local integrability). The problem is the second equation does not gieanything special about $t<0$
Jan
9
comment equivalence of wave equations
how is it possible that $\psi(vec r, t)$ can be both equal to $s(\vec r)$ and on the other hand to zero? Except for $s=0$ that is...
Jan
9
comment equivalence of wave equations
what do you mean by equivalent? The initial conditions for $\psi(\vec r,0)$ are different provided $s\not \equiv 0,$ so there exists no function that solves both of them
Dec
30
comment What entities in Quantum Mechanics are known to be “not quantized”?
by "closed" you actually mean "compact" ?
Dec
27
awarded  Editor
Dec
27
revised Level of calculus required for physics
added 1 characters in body
Dec
27
comment Level of calculus required for physics
Quantum mechanics requires understanding of linear algebra, then analysis on Hibert spaces. Calculus is useful as well but mainly to solve problems during classes. The only really badly needed thing from calculus is "series method" and solving linear ODE of second order under different boundary conditions.
Dec
27
comment Level of calculus required for physics
"Methods of Modern Mathematical Physics" - this i s a series of 4 books.
Dec
26
answered Level of calculus required for physics
Dec
21
answered Intuition behind Fourier transformed spaces
Dec
20
awarded  Supporter
Dec
20
answered Why don't I feel pressure on my body when swimming under water?
Dec
19
comment Can you tell if a particle is in superposition?
So it means that you do not need a state after measurement any more... nevertheless 0 for "eigenstate" and 1 for "superposition" is very inefficient, as you map virtually whole Hilbert space to 1, and measure 0 set to bit 0. Moreover I think this is also very impractical in general.
Dec
19
answered Can you tell if a particle is in superposition?
Dec
19
awarded  Teacher
Dec
19
answered Intuitive explanation of the inverse square power $\frac{1}{r^2}$ in Newton's law of gravity