1:41 AM
@EmilioPisanty Oh, uh... stressful.

3 hours later…
4:31 AM
@rob I'm impressed. Partly that your kid is starting to understand what makes questions interesting, but mostly that you managed to set forth the case for him. Well done.
2

Yo. Anybody emotionally prepared to listen to me talk to myself?
So, I'm getting confused about how polarized E&M interacts with a detector. Polarization add up incoherently on the detector right? But I'm confused what happens if we can actually detect the field's phase (idk, a maser). So, can the Ux part of the field interact with the Uy part of the field? Supposedly not, but what is the physical reason?

3 hours later…
7:50 AM
0

For a wavefunction: $$\Psi(\textbf{x}) = e^{ikz} + \dfrac{f(\theta)}{r}e^{ikr}$$ Where $z = r\cos(\theta)$. The probability current $J$ is then given by: $$J(\textbf{x}) = J_1(\textbf{x}) + J_2(\textbf{x}) + J_{12}(\textbf{x})$$ Where $J_1$ is the current due to the first term(plane wave) an...

8:17 AM
@Blue Can you just rethink of that thought, quite wierd how one have to seem standard to ownself, kinda cogntive dissonance.

@AjayMishra Sorry. I don't get what you're trying to say.

It was a reply for a particular message.

@AjayMishra I saw that.

Why you want to be a place just for grad stuffs? I dont mean to make it like quora either.

> Why you want to be a place just for grad stuffs?
@AjayMishra I never said that I want this to be a place only for grad stuff. You're drawing wrong conclusions.

8:21 AM
One would only get the bigger picture if one have the elements of understanding

I simply said that for grad-level/research-level stuff and undergrad-level/high-school-level stuff to co-exist, the bar for the latter needs to be high.

have to defined that?
To = you
Actually, is there a definited of
that
?

@AjayMishra Definition of what?

Definition of level of questions?
Leave it, I got the bigger picture, its we, who have to do that in order to make this better place.

8:41 AM
@AjayMishra We don't need precise definitions where common sense suffices. This is a community driven by humans who can make judgements (such as the level of a question) based on their experience and knowledge.
@AjayMishra Thanks for understanding.

9:22 AM
32

Watch Star Wars in terminal telnet towel.blinkenlights.nl

Wtf, this is awesome :D

9:58 AM
I've known that since 6th grade
Never watched more than 10 minutes though

10:10 AM
@AvnishKabaj Oh, well, I'm clearly behind the curve :)
Discovering it the first time is surely fun. Watching - not so much

Quantum circuits to implement full CI for open shell molecules. The circuit has constant depth independent of the number of spin states present in the molecules
hmm... so we are in full CI now

3 hours later…
12:52 PM
Random thought: Since energy and entropy are interrelated, I wonder if there is an interpretation of what energy is in terms of the number of microstates a system can have, or even the number of trajectories that converge to some given point in phase space
So something is of higher energy if there are less trajectories that can satisfy a given constraint
2

I have been reading the book "The Black Hole War," by L.Susskind, which states: Temperature is the increase of a system's energy when an entropy bit is added. Until now I was thinking that, on the contrary, it is the entropy that is increased when energy is added. No matter how you define e...

2 hours later…
2:52 PM
Thus temperature becomes something where for every unit of increase in microstates, how much the number of favourable states is reduced
79

The simplistic undergrad explanation aside, I've never really understood what energy really is. I've been told that it's something when converted from one kind of something to another kind, or does some "work", as defined by us, but what is that something? Moreover, if the total amount of energy...

Why is the phase shift $\phi = 2\pi \dfrac{-0.056}{0.314}$ rad, rather than $\phi = - 0.056 \cdot 60 \cdot 2 \pi$ rad?

3:59 PM
Early on the tag was made a synonym of the tag, which leads to a lot of wrong tagging. I wonder if we should introduce an umbrella/master tag? Thoughts?

4:19 PM
@Qmechanic boy, that's an ugly tag name
does it even fit?
what kind of wrong tagging is at play here?

The tag seems to a synonym of . Wouldn't the other way round be more intuitive?

1 hour later…
5:47 PM
Can the sum of all elements in a continuous interval converge to a real number?
Actually more generally, just some uncountable subset of $\mathbb{R}$

@ACuriousMind Huh, interesting. Welp, can we find an abelian group $S$ such that the sum of elements in some uncountable subset is an element of $S$?

@SirCumference As soon as you're summing more than finitely many elements, you need at least a topological group for that to even be well-defined

Guess I need to take topology

1 hour later…
7:03 PM
Has anyone used any of the Nutshell books not by Zee?

Keep using bits of them every now and again
I*

Which ones? How are they? I was thinking about the EM or Stat Mech ones, but there seems to be one for just about everything

Oh sorry I read that as Zee's ones, I've looked in some of the non-Zee ones and wasn't impressed tbh
They just seemed like any other book, I guess that's the point though?
Zee's nutshell books compared to the other nutshell books are like Zee's story about Witten as his TA
"I had the enormous good fortune of having Ed Witten as my teaching assistant and grader. Ed produced lucidly written solutions to the homework problems I assigned, to the extent that the next year I went to the chairman to ask “What is wrong with the TA I have this year? He is not half as good as the guy last year!”"

7:27 PM
Ahh I've enjoyed the bit of the GR one I've been through and wondered if the non-Zee ones would be similar. I should probably do the sensible thing and just get through the mountain of books I already have though

2 hours later…
9:30 PM
Now on SMBC: math jokes with physics subtext.
Oh yeah. No onebox support for SMBC.

9:47 PM
Now that's my type of proof

10:01 PM
astro.physics.sc.edu/goldstein makes me hope for a 4th edition of US Classical Mechanics, or were you doing algebraic geometry?

If the phase curve tends to $<-180 ^\circ$ in the Bode plot for an open loop system, that means the static gain is infinite, yes?

HG and Poole and Safko*