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| visits | member for | 1 year, 8 months |
| seen | 4 hours ago | |
| stats | profile views | 851 |
Actress with an interest in the philosophy of science.
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Feb 27 |
comment |
Form of the Classical EM Lagrangian @SeanD: What is it then, which you know beforehand? There are some invariant quantities, as far as Lagrangians go, of course classically there might be more than one corresponding to the field equations. A notable feature of $F^2$ is that it equals the energy density $u\propto E^2+B^2\propto (\vec\nabla\phi)^2+...$, or the work to collect the electric charges in one spot. |
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Feb 26 |
comment |
Relationship between a formal vector derivative and time evolution of an operator Put shortly, I'd say it's a more mathematical than physical relation, coming from the fact that you express both the vector $V$ as well as the expectation value of $A$ w.r.t. a changing basis. It's $V=V^\mu(x)e_\mu(x)$ in one case and $\langle A \rangle_\psi=\langle\psi(t)|A(t)|\psi(t)\rangle$ in the other. And the $\nabla e\sim \Gamma e$ resp. $\frac{\text d\psi}{\text dt}\sim H \psi$ got plugged in, which are physically fairly different equations. |
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Feb 25 |
answered | Surely space-time Curvature does not explain gravity, it just describe its effects? |
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Feb 15 |
awarded | Popular Question |
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Feb 11 |
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Find the Hamiltonian given $\dot p$ and $\dot q$ You yourself identify $\partial H/\partial p$ with $c\ p+d\ q$ etc. Why not just integrate that? Also, as your system reads $\dot\pi=A\pi$, with constant $A=((a,b),(c,d))$, I guess that the quadratic ansatz $H=x\ p^2/2+y\ q^2/2+z\ pq$ might be worth a try. |
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Feb 8 |
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Why do clocks measure arc-length? @RetardedPotential: It's all explained in the movie/documentary. |
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Feb 7 |
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Why do clocks measure arc-length? @joshphysics: The geometric length is parameter independed, so as soon as you've chosen the curve in the manifold (requirement of extremal length) the quantity depends only on the two points $x_a,x_b$ in spacetime. If your Newtonian wolrd is $\mathbb{R}\times\mathbb{R}^3$, then $t_{ab}=f(I_{ab})$ is the obvious choice. |
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Feb 7 |
revised |
Why do clocks measure arc-length? added 339 characters in body |
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Feb 7 |
answered | Why do clocks measure arc-length? |
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Feb 7 |
comment |
Relationship between frequency and wavelength en.wikipedia.org/wiki/Dispersion_relation |
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Feb 4 |
revised |
Is rate of temperature change constant? added 143 characters in body |
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Feb 4 |
answered | Is rate of temperature change constant? |
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Jan 31 |
comment |
Equivalence principle question Is it taken here that the gravitational effect of the big red ball in the spatially nonzero experimental volume is expressible by a homogenous/constant gravitational field? I.e. how much does the gravitational field of the red ball change within the cube? Can the effect even point in two opposing directions? |
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Jan 31 |
comment |
Are more/other colors posible with other dimensions? I could write about 7 critiques of this question, and only two would contain the word "qualia". |
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Jan 28 |
revised |
Why is the Ritz combination principle incompatible with Classical Mechanics? uncute typo in the title |
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Jan 28 |
suggested | suggested edit on Why is the Ritz combination principle incompatible with Classical Mechanics? |
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Jan 28 |
asked | Specific electron energy gap values $E_{i+1}-E_i$ vs. photons with arbitrary energy $\hbar \omega$ |
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Jan 24 |
revised |
What is the physical meaning/concept behind Legendre polynomials? added 406 characters in body |
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Jan 24 |
revised |
What is the physical meaning/concept behind Legendre polynomials? added 406 characters in body |
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Jan 24 |
revised |
What is the physical meaning/concept behind Legendre polynomials? added 17 characters in body |
