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"head" in the name refers to the Mathematica concept. That was the first account I created. I kept the name.


7h
comment Young's Double Slit Experiment : What would happen if the “first slit” was too wide?
So the top picture is what you have if there is a point-like pinhole. If you were to shift the position of this pinhole, that would just have the effect of shift the pattern on the right up or down. Now if you have a finite sized slit, this slit is the same as a superposition of shifted pinholes. By linearity, the electric field is the superposition of shifted electric fields from the pinholes. The superposition of shifted copies looks like the original copy, but blurred out so the peaks are lower and valleys are higher.
1d
revised Quality Factor in a Parallel LC Circuit
added 6 characters in body
1d
answered Quality Factor in a Parallel LC Circuit
2d
answered If I shoot a hockey puck on ice, is the force of me shooting it applied throughout its travel, or is it a one time force?
2d
comment Is there a surface charge density?
Here is a link to a pdf I found by googling.
May
16
awarded  Nice Answer
May
11
comment How do you go from a sum over frequencies to an integral?
Ok I rewrote my whole answer (v1 $\to$ v2). I think it is an improvement. You were right about the $g(\omega)$ mistake in the second equation. Hopefully the meaning of $\Delta \omega$ is clear from the second version. Basically, it is the length of a segment you are averaging over.
May
11
revised How do you go from a sum over frequencies to an integral?
added 1844 characters in body
May
9
answered How do you go from a sum over frequencies to an integral?
May
4
comment Compatible Observables and Measurement
The process of measuring $A$ doesn't know anything about $B$, so how could it know to collapse to one of its eigenkets. Instead of $B$ you could just as well contrive another compatible observable $C$, which has a completely different basis of eigenkets spanning the degenerate eigenspace of $A$. Then would measurements of $A$ project onto an eigenket of $B$ or $C$?
May
4
answered Do changing magnetic fields always produce solenoidal electric fields?
Apr
30
awarded  Yearling
Apr
28
comment Why doesn't atmospheric pressure crush thick walled structures?
Which way does your net force point?
Apr
25
answered Electrostatics and two electric charges
Apr
23
comment Is sound a Nambu-Goldstone mode?
Now you were probably looking at it from a field-theoretic point of view, where the fluid is represented by density, pressure, and velocity fields. In that case the ground state does have translational symmetry (zero velocity, uniform density and pressure), so there does not seem to be a broken symmetry, and so you would be led to say that sound is not a goldstone mode. That is an interesting point and I didn't think about that.
Apr
23
comment Is sound a Nambu-Goldstone mode?
I think you are saying that you do see how sound in solids is a goldstone mode, because there is a continuous symmetry that breaks and gives you a discrete symmetry. Now when I was talking about liquids and gases, I was referring to a particle based model. This model has a continuous symmetry that is broken, and the state with a broken symmetry has no remaining symmetry because particles in a liquid and gas are disordered.
Apr
22
revised Is sound a Nambu-Goldstone mode?
edited body
Apr
22
answered Is sound a Nambu-Goldstone mode?
Apr
14
comment Shouldn't the currents be time-continuous here?
I got slow and fast backwards in my explanation. The slow system with smaller resistance is more susceptible to changes in flux, and it is the one whose current increases as a result of the fast system's fast change in flux. I will fix my answer later.
Apr
14
answered Shouldn't the currents be time-continuous here?