The h Bar

Secret

16:09

[Integral bomb]

$$\int_0^{\infty} \prod_{i=1}^7 \ln \left(1+\frac{1}{m_ix+n_i}\right)dx=\int_0^{\infty}e^{ \int e^{\left(\sum_{i=1}^7\frac{(\ln(1+\frac{1}{m_ix+n_i}))'}{\ln(1+\frac{1}{m_ix+n_i‌‌}) }\right)}}dx$$

to derive this, use do nothing technique on ln and multiplicative calculus on the LHS integral

As for that LHS integral, it is from a maths challenge in maths chat

Despite it looks really scary, it has a rather nice physical interpretation of the total potential on a line, where the potential are consists of 7 cylindrical potentials overlapping with each other

$$\int^{\infty}_0 \prod_{i=1}^7 \ln \left(1+\frac{1}{m_ix+n_i}\right) dx -\sum_{k=1}^{\infty} \prod_{i=1}^7\ln \left(1+\frac{1}{m_i k +n_i}\right) = q \zeta (7),q\in \Bbb{Q}$$
The challenge, in physics terms, is basically: find all parameters $m_i,n_i$ such that the difference of the total potential with that at integer points is equal to some value of the riemannian zeta function

The Dark Side

"That's trivial, left as an exercise for the reader".

:: Mathematician walks away ::

Secret

What I have done so far in the past 2 days is that I ruled out $m_i=0$ as solutions, and also the $\ln ()$ is always defined since any value that will make the ln complex will result in x dependent $n_i$ hence inconsistent

Abcd

Wavelength of radiations emitted when an electron jumps from a state A to a state C is 2000 A and it is 6000 A when the electron jumps from state B to state C. What will be the wavelength when an electron jumps from state A to state B?

A = angstrom

The Dark Side

@Secret "Being trivial, it is left as an exercise to the reader"

Abcd

How do I approach/solve this question?

The Dark Side

16:18

@Abcd Hint: $E_f - E_i = h c / \lambda$

John Rennie

@ACuriousMind: I just knew this was going to make the HNQ. I don't know why, but sometimes I see a question and know it's an HNQ candidate.

Although it has received surprisingly few upvotes for an HNQ question.

Abcd

@TheDarkSide Thanks.

The Dark Side

:)

ACuriousMind

@JohnRennie It's HNQ?

Only 100 views so far

Mithrandir24601

@JohnRennie Eh? 2 upvotes, 100 views, asked 5 hours ago - how'd that make it on the HNQ? (I haven't read it - just asking based purely on views and votes in that time)

John Rennie

16:20

@ACuriousMind Afraid so :-)

ACuriousMind

Ugh.

Well, we've had much worse on the HNQ

Danu

@BenNiehoff yes, it is always one. CP^n has only cohomology of rank one is even dimensions. It is generated by the powers of the Kähler class, hence of type p,p.

John Rennie

Bottom of the first page at the moment.

ACuriousMind

I'm kinda fine with that one being there (although I wouldn't have advocated for it to go there in the first place :P)

Danu

(Thanks for the heads-up @ACuriousMind)

ACuriousMind

16:22

Knew you'd know that one :)

Danu

You should too ;-)

ACuriousMind

::shrug::

Danu

CP^n is the best

John Rennie

Well the weather is quite hot at the moment :-)

Danu

@ACuriousMind Klemm is here next week

I'm considering asking him about PhD positions haha (I'm pretty desperate atm)

ACuriousMind

16:26

@Danu Nice

Abcd

@TheDarkSide Can you explain why this has to be used here? I can't understand the problem.

ACuriousMind

Maybe I should come to Munich and ambush him with a bunch of $G_2$ questions :D

Emilio Pisanty

g*******t, this piece of nonconstructiveness made HNQ now.

John Rennie

Why did you star out goddammit? It that an obscenity worth starring out?

ACuriousMind

@EmilioPisanty That's not a duplicate?

Emilio Pisanty

16:28

@ACuriousMind is it?

The Dark Side

@Abcd write down that equation for the two transitions specified, and eliminate the common energy level between the two. Everything on RHS is well known.

Emilio Pisanty

of what?

@JohnRennie it felt like it coming out

ACuriousMind

I feel a question of the type "How do we know there are no hidden variables" must've been asked before, and that's effectively what it's asking, right?

Emilio Pisanty

@ACuriousMind probably

ACuriousMind

E.g.

3

Q: How do we know that there isn't a classical solution to the measurement problem/Quantum Mechanical uncertainty?

It was mentioned to me that it can be shown that there is no classical explanation for the uncertainty in Quantum Mechanics -- i.e. that there are no hidden workings that we have just not yet seen, which could be explained classically and would explain the probabilistic nature of Quantum events i...

7

Q: How can we be sure that nature isn't "faking" quantum statistics?

In a recent publication, Experimentally Faking the Violation of Bell’s Inequalities (Gerhardt 2011) (arXiv version), the statistics of quantum mechanics is faked using classical light sources. But if it is possible for physicists to fake an experiment to imitate QM, how can we be sure that natur...

quantum-mechanics bells-inequality

look pretty close to duplicates to me

John Rennie

16:31

@Kaumudi.H: there are people who will do your shopping for you. They're called personal shoppers :-)

user228700

Ah, you've read the transcript, I see :-)

Emilio Pisanty

@ACuriousMind yeah, that one is pretty close

any more candidate dupes?

user228700

No ricey dinner tonight. Had two delicious grilled cheese sandwiches (with corn and tomato and ...some other stuff).

The Dark Side

@ACuriousMind - Please deal with this. I deem it unnecessary, but maybe I'm an edit-reject machine.

Danu

@ACuriousMind if it's actually about just G_2 I know some stuff... But you probably mean more complicated things

John Rennie

16:33

@Kaumudi.H I can see the argument for getting someone to do the clothes shopping, though I jealously guard my food shopping.

user228700

Ah :-) I was trying to shop for a wallet.

John Rennie

@Kaumudi.H: but then I deal with clothes shopping by buying all my clothes from ebay or Amazon :-)

ACuriousMind

@TheDarkSide Well, if you deem it unnecessary, then reject it has "no improvement whatsoever2

Abcd

@TheDarkSide Are they hc/2000 and hc/6000

user228700

@JohnRennie Right, but I was beginning to hate even online shopping!

Abcd

16:34

What to do next?

ACuriousMind

@EmilioPisanty None I can find right now

@Danu Ah, not about $G_2$-the-group and more about the stuff he did in that paper from a few months ago

John Rennie

@Kaumudi.H I have to confess that I like online shopping more than is probably healthy. Especially online shopping for laptops.

The Dark Side

@ACuriousMind But it has certainly improved the post. Sorry, but I am unable to see the line.

@Abcd with all humility, I suggest you better think over it for a while.

ACuriousMind

@TheDarkSide IF it has improved the post, then don't reject it.

The Dark Side

@ACuriousMind Hahaha...

Abcd

16:36

@TheDarkSide I failed to understand the question.

ACuriousMind

You don't reject edits for being "too little improvement". If they improve it, in whatever small way, then approve them. If they don't, then reject them.

2

user228700

@JohnRennie Lol :-P

Emilio Pisanty

@ACuriousMind that's a debatable viewpoint

John Rennie

@Abcd: C is the lowest energy state. Yes?

Abcd

@JohnRennie Yes

ACuriousMind

16:37

@EmilioPisanty I'm pretty certain that's the official stance since the abolition of the "too minor" reject reason

Mithrandir24601

@Abcd Have you read over what @JohnRennie said earlier?

Danu

@ACuriousMind that's what I figured

Abcd

@Mithrandir24601 Yes

user228700

@JohnR: I'm gonna go to to the Anna Centenary Library tomorrow!

The Dark Side

@ACuriousMind Let me make it clear that I'm not protesting against this, and this is certainly not a fight. But I honestly do not understand the line of demarcation, with respect to certain recent examples.

user228700

16:38

Might spend all day there. They even have a cafe so...

Emilio Pisanty

@ACuriousMind you're looking for this:

13

A: The new edit rejection message for "no improvement whatsoever" sounds too hostile

Update Per Kyle Kanos's / episanty's suggestion, "fails" has been replaced with "does not": It's a hostile action. You're rejecting someone's edit, something they spent time writing, asserting that it was utterly pointless. Sadly, that's sometimes necessary - for whatever reason, folks su...

John Rennie

@Abcd For the B to C transition $\lambda = 6 \times 10^{-7}$, and we know that the wavelength is related to the energy by $hc/\lambda = E_B - E_C$.

ACuriousMind

@TheDarkSide The line of demarckation between "little, but visible improvement" and "no improvement whatsoever" is a bit of a judgement call.

Emilio Pisanty

to paraphrase the "official" answer

Kiarash

Hey everyone. Does anyone know a good reference on the kinetic theory of hydrodynamics? I have to calculate the eigenmodes of a fluid using the kinetic theory.

The Dark Side

16:39

@ACuriousMind Exactly.

Emilio Pisanty

> we're sympathetic to the fact that minor edits clutter the front page in sites with a smaller turnover than SO and MSE, but we just don't care that much

John Rennie

@Abcd: likewise you can calculate $E_A - E_C$.

The Dark Side

@ACuriousMind So, was my requirement of expecting that people earn their stripes too strict?

ACuriousMind

@EmilioPisanty A worry that doesn't really apply in this specific case since the question was bumped by community recently, anyway

Abcd

@JohnRennie then?

Emilio Pisanty

16:41

@ACuriousMind sure. But saying "any edit goes, regardless of its bumpingness" is not a policy I would consider productive.

John Rennie

@Abcd To answer the question you need to know $E_A - E_B$, and it's just equal to $(E_A - E_C) - (E_B - E_C)$, both of which you can calculate from the supplied wavelengths.

Abcd

@JohnRennie Thanks.I was editing my previous message to add that btw

The Dark Side

@Kiarash There was a post about that IIRC. You can use the top search bar of the site, or look for the classical book reco question.

ACuriousMind

@TheDarkSide The thing we talked about yesterday? Yeah, 2 rep points are really not that much. Don't reject things for being too little improvement to be "worth" 2 rep, just reject them if you reallly think the post gains nothing from the edit (or if one of the other reject reasons applies)

Emilio Pisanty

I am closing this question as a duplicate, because the essentials ("how do we know QM isn't just a hidden-variable theory?") are so much of a well-trod ground on this site that this question should not go on the Hot Network Questions sidebar - it's just not constructive enough to be representative of this site, and to the extent that the topic is worthy of further discussion, this question is simply not couched in sufficient nuance to really advance that conversation. I'm reluctant to answer-then-close, but this one really doesn't deserve the spotlight. — Emilio Pisanty 17 secs ago

ACuriousMind

16:43

@EmilioPisanty I would say that for any individual edit, that's indeed what I'm saying. If there are five or ten such bumpy edits on the same post, or by the same editor in quick succession, that's something else, but that's a concern on the level of patterns, not individual edits.

John Rennie

@EmilioPisanty Harsh :-)

Emilio Pisanty

@JohnRennie a bit, yeah

ACuriousMind

@EmilioPisanty It sounds a bit as if you wouldn't have voted to close if the question hadn't gone HNQ

Emilio Pisanty

but I do want to note that closing that goes directly against my self-interest

@ACuriousMind it sounds like that because it's true

Jaime Gallego

@JohnRennie It's 37 degrees here. Taking shelter right now in an ice cream shop...

John Rennie

16:45

@EmilioPisanty Closing a question because it made the HNQ seems a but unfair ...

Emilio Pisanty

I think HNQ is a pest when it does these self-amplifying shenanigans

ACuriousMind

@EmilioPisanty Well, but I mean it either is a duplicate or it isn't - it's HNQ status shouldn't have anything to do with it.

Emilio Pisanty

It was on the fence

Kiarash

@TheDarkSide thank you :)

The Dark Side

@ACuriousMind I concur. But e.g. the example quoted above. Even if the deBroglie wasn't thrusted in, the post wouldn't lose anything. With that added, there is certainly some "improvement", but who asked for it? Not the OP certainly (else they would have inserted them themselves). So, it is a case of optional info insertion.

John Rennie

16:46

@JaimeGallego about 25C in Chester. But then my comment was just a poor attempt at a joke rather than any serious comment on the weather :-)

The Dark Side

On the basis of this argument, a lot of posts can be "improved" @ACuriousMind.

ACuriousMind

@TheDarkSide Does anyone need to request additional information for it to be useful? The judgement you have to make is whether the info added is useful or not in the context of the question asked.

John Rennie

0

Q: Can gravitational waves be explained by the interactions between photons?

What the question really amount to asking is, if (as LIGO said) the gravitational waves emitted from the black hole collision were emitted as 'pure energy' this surely means that they were emitted as photons. If this is the right interpretation does it therefore mean that when the waves interacte...

general-relativity black-holes photons gravitational-waves

Eh?

ACuriousMind

@TheDarkSide And they should! Recall that the lofty ideal goal is to have a searchable library of canonical answers, not a bunch of forum threads where individuals ask and answer the same questions over and over again in different variations.

Mithrandir24601

@TheDarkSide Someone once did something very similar to one of my answers (on Worldbuilding) once and I approved the edit, as it did add a tiny bit to the answer, but I really didn't appreciate it and I almost rejected it

ACuriousMind

16:49

I think that adding additional information is a perfectly fine use of the edit button, as long as "goes against the original intent of the post/author" does not apply

Emilio Pisanty

Anyways, @ACuriousMind @JohnRennie if you think that question should be left open, y're welcome to reopen it - just please make sure that it doesn't get it back onto the HNQ list.

John Rennie

@EmilioPisanty Sadly closing a question as a dupe does not remove it from the HNQ. Your work has been in vain :-)

Emilio Pisanty

@JohnRennie wait, what?

ACuriousMind

@EmilioPisanty Well, I think it should be closed as a dupe - but regardless of its HNQ status.

@JohnRennie caching

@EmilioPisanty Also, believe me, if I had a means to not let questions get on the HNQ list, you would'Ve seen me use it ;)

The Dark Side

@ACuriousMind Well, stuff has prerequisites. And all answers are written at some level or the other. No one begins from the alphabets. If the OP is asking a question with the [tag: wave-particle duality] , it is safe to assume that they know the deBroglie relation.

Anyways, I'll drop the argument. We seem to be getting into rough waters.

@Kiarash :)

ACuriousMind

16:53

@TheDarkSide Yeah, so read the original question, and the answer. If you think the edit doesn't add something that helps answer the question (such as indeed explaining prerequisites that the asker already knows), then reject it.

As I said, the line is a judgement call

I'm not sure what you want from me - just make an honest decision, click the corresponding button in the review queue, and move on ;)

The Dark Side

@ACuriousMind Alright.

ACuriousMind

You won't be tarred and feathered for making a wrong review decision once in a while, if that's what you're afraid of

Review bans are very rare on physics.SE and you won't incur one by voting your conscience.

The Dark Side

@ACuriousMind Alright.

@ACuriousMind Its not about that.

Qmechanic

FYI: Around Tuesday June 13th, 2017, Phys.SE passed another milestone: 100.000 question! Congratulations!

4

Abcd

@JohnRennie I obtained Ea - Eb = 2999hc/6000

I dont think it's correct

John Rennie

17:00

@Abcd $E_A - E_C = \frac{hc}{2 \times 10^{-7}}$ and $E_B-E_C = \frac{hc}{6 \times 10^{-7}}$, so $E_A - E_B = \frac{hc}{2 \times 10^{-7}} - \frac{hc}{6 \times 10^{-7}}$. Yes?

Abcd

@JohnRennie Yes. I got the same

John Rennie

@Abcd and the wavelength for the $A$ to $B$ transition is just $$\frac{hc}{\lambda_{AB}} = E_A - E_B$$

Abcd

@JohnRennie Ohh...The problem was that I was working with Angstrom instead of metres

John Rennie

@Abcd Pro tip: always use SI units

Abcd

@JohnRennie Yes. I got the right answer this time. TYSM.

@JohnRennie sure

John Rennie

17:06

@Abcd $\lambda_{AB} = 3 \times 10^{-7}$ m ?

Abcd

@JohnRennie Yes.

John Rennie

That's what I get too.

@EmilioPisanty: you're in a grumpy mood today :-)

Balarka Sen

17:22

that op though

dmckee

That's because I already know the answer :) — Sam Cottle 8 mins ago

Ugh.

John Rennie

@dmckee definite trollesque tendencies there. Though he has accepted my answer, so he can't be all bad :-)

Secret

My impression when I read that:

but yeah, experience told me you gotta be calm in explaining exactly why and what it is

most people are rational as long one keep their cool

Abcd

17:38

@JohnRennie while calculating ionization energy why do we subtract $E_{ground state} from E_ (infinity)$

Phase

Hi Folks

Abcd

if anyone else knows the answer. please answer

Phase

Abcd because that's the energy that has to be supplied to an electron to lift it from that state to being ionised

it's just like any other potential

if you wanna lift something from Earth to the edge of the gravitational field, it's the same deal

Abcd

@Phase Didn't get you.

Phase

Hm

The electron is in a potential right?

The electromagnetic force from the Proton

Abcd

17:42

@Phase WHich has higher energy state - ground or infinity

Phase

Well, infinity is ionisation

at which point it's not in an energy state as such

it's a free electron

As you go up through the energy states, you get to higher energy levels

Like lifting them up to a higher shelf in a gravitational field

And eventually, you'll get to a shelf so high that if the shelf came off the wall, it wouldn't fall down to earth

Abcd

I want an explanation that fits this definition: If an electron comes from energy level E2 to Energy level E1, then the difference may be expressed in terms of energy of photon as E2- E1 = delta E = hv @Phase . Is such an explanation possible?

Phase

Well, i feel like you're not really paying attention but ok I'll try putting it in terms of that

Yes.

Well, explanation?

Abcd

@Phase so please explain

I don't mean a detailed explanation

Just a brief one

Idk what's the word I am looking for in lieu of explanation

Phase

let me just try the analogy one more time

You're confused why the energy of ionisation is the difference between the ground state and an infinitely high E state right

Abcd

17:47

@Phase I understood your shelf analogy

@Phase yes

Phase

Ok, so let me finish the analogy

Eventually you'll get to a shelf so high that if the shelf came off the wall, the ball wouldn't fall down because g is so weak / zero

But you've used energy getting the ball to that point

Abcd

yes

Phase

and that energy is gpe ground state [bottom shelf] gpe infinity [top shelf]

the difference between them I mean

It's exactly the same principle with electrons

Abcd

@Phase gpe?

Phase

gravitational potential energy

Abcd

17:48

@Phase Why not the other way round?

Phase

What do you mean

Abcd

why not gpe infinity - gpe ground state or why not gpe groundstate - gpe infinity

Phase

Well, I said the difference

Which implies that sign isn't important

Abcd

@Phase It is important.

Phase

not really

Abcd

17:50

@Phase While dealing with IE, negative sign changes to positive

as we subtract from 0

E infinity = 0

Phase

Im confused

The ground state isn't Zero eV

Also, the energies are negative because they're inside a potential well

Abcd

@Phase The infinite sate is not the ground state

Phase

So a smaller negative minus a larger negative gives you a positive

Well yeah it's not

But the infinite state isn't zero either

Abcd

@Phase My book says so :(

Phase

Oh right sorry my brain malfunctioned

In terms of the potential well yeah it's zero

because the ground state is negative, and the potential well is essentially flat at E = 0

Abcd

17:53

@Phase Can you explain using the terms I gave you initially

Phase

Sure I guess

Abcd

Ok. Please do so then..

Phase

For an electron to go from $E_0$ to $E_\infinity$ it would need an energy change of $E_0 - E_\infinity$. Since it's positive, it's not an emission of a photon needed but an absorption of one with suitable $E = hf$.

Abcd

@Phase infty instead of infinity

Phase

Fair, still new with a lot of MathJax

Abcd

17:56

Same here...

Phase

Anyway, did that help?

Abcd

not much though... sorry

Phase

What confuses you? I'm not really understanding

is it why the difference is positive? Or why we take the difference?

Abcd

why not Einfinity - E0 ? Why E0 - Einfinity

Phase

Ah shit

that was a typo

Meant to be E infin - E 0

Abcd

18:00

@Phase I know it was a typo. But why not the other way round?

Phase

Sorry, you have to understand I haven't done Physics in a while and I've been spending the last few months rotting my brain playing games

Abcd

It's okay. Thanks.

Phase

Oh

i see what you mean

Try drawing a diagram of the energy levels and thinking about it from there

i gotta go eat, came back home recently and parents doing a BBQ : p

Phase

18:32

Ok back, if you still haven't got it then it's just because energy changes are always the E final - E initial, and the energies of bound states are negative so it results in positive

Abcd

18:48

@Phase Alright. thanks. :)

0celouvskyopoulo7

19:14

Bernardo Meurer

@0celouvskyopoulo7 Welcome back :)

0celouvskyopoulo7

Long time no talk

Bernardo Meurer

True dat

0celouvskyopoulo7

@BernardoMeurer when is your calculus exam

also I'm going to Kevin's next weekend, remind me to skype you

or facetime

Bernardo Meurer

July 03

@0celouvskyopoulo7 I will

0celouvskyopoulo7

19:25

er, not next weekend

Bernardo Meurer

Called Kat the other day

0celouvskyopoulo7

two weeks

I talk to kevin most lately

haven't talked to Michelle since last year

Bernardo Meurer

Lol

I talked to her last week

And to Ron this week

He invited me out wine tasting once I move :P

0celouvskyopoulo7

you're not 21

Bernardo Meurer

And Ron gives a fuck since when?

0celouvskyopoulo7

19:26

sigh

they won't let you in the doors, genius

Bernardo Meurer

@0celouvskyopoulo7 ::shrugs::

Balarka Sen

dump wine, get coke

0celouvskyopoulo7

don't make me call the DEA

Balarka Sen

fine, get yellow bugpowder

0celouvskyopoulo7

yellowcake?

Balarka Sen

19:30

you probably wouldn't want to inject yellowcake into your veins

0celouvskyopoulo7

@BalarkaSen where u at in do Carmo/GHL?

Balarka Sen

Riemann curvature tensor. I haven't progressed fantastically since we last talked

been procrastinating and doing other stuff

SevenSidedDie

Not a good conversation to be having on your first day back @0celouvskyopoulo7. @BernardoMeurer, not a good conversation to be encouraging either.

0celouvskyopoulo7

....

what?

SevenSidedDie

@BalarkaSen too

Balarka Sen

19:34

lolwat

SevenSidedDie

@0celouvskyopoulo7 You get off topic and then you start into inappropriate conversations. You're already walking towards a conversation about illegal activities. Please get a clue.

0celouvskyopoulo7

If this is how it is, I think I won't last a week

lol

SevenSidedDie

@0celouvskyopoulo7 That's on you.

Balarka Sen

If yellow bugpowder is inappropriate, that's something I guess

0celouvskyopoulo7

Isn't cocaine descriminalized in Portugal?

And @BernardoMeurer is Portugese

Balarka Sen

19:36

It's a well recognized drug in Bill Burroughs' groundbreaking novel Naked Lunch, by the way

Bernardo Meurer

All drugs are decriminalized here

SevenSidedDie

@0celouvskyopoulo7 You got chatbanned last time for trying to argue that you technically don't have to listen to a mod because [reasons]. Don't start.

Bernardo Meurer

This is a degenerate country

SevenSidedDie

The conversation about drugs ends here.

0celouvskyopoulo7

Ayy

@BernardoMeurer chill

SevenSidedDie

19:37

@0celouvskyopoulo7 He's chilled for 30 minutes.

0celouvskyopoulo7

I saw

Balarka Sen

shrug

0celouvskyopoulo7

@SevenSidedDie If I ask questions, will I be banned?

SevenSidedDie

You two have a problem in that you feed off each other. On your own you're mostly okay. Think about how you can break that feedback loop, and maybe mods won't have to get involved in this room so much.

0celouvskyopoulo7

I am genuinely curious

SevenSidedDie

19:38

@0celouvskyopoulo7 Depends on the content, of course, as always. If you don't know what you can be chatbanned for, you haven't been paying attention.

Here's a suggestion: talk about physics.

0celouvskyopoulo7

I'm not a physicist, why would I do that?

Balarka Sen

I have talked about drugs numerous times here and none of the room mods has warned me. I diverted the actual reference to actual drugs to a fictionalized drug like after one message.

0celouvskyopoulo7

^

SevenSidedDie

@0celouvskyopoulo7 Then talk about analysis, calculus, etc. Stay on topic.

Balarka Sen

I do not think this is a particularly intelligent discussion from your part. The general conscience about topic in hbar is varied, and not restricted to physics and mathematics.

0celouvskyopoulo7

19:40

@SevenSidedDie Honestly, the policies a quite variable. I don't know how I'm supposed to know what is appropriate.

SevenSidedDie

@BalarkaSen Well, now you've been warned.

0celouvskyopoulo7

There's no fixed topic here

Never has been

Balarka Sen

@SevenSidedDie Ok, but I do not see a rational reason behind the warning. I will take it, though.

SevenSidedDie

@0celouvskyopoulo7 That wasn't a rule, that was a suggestion for how to stay out of trouble. Don't be obtuse when responding to mods telling you to chill, it's what you generally get chatbanned for.

@BalarkaSen Here's another warning: don't encourage 0celot.

0celouvskyopoulo7

Ok, I said nothing about drugs.

Why am I getting in trouble here?

SevenSidedDie

19:42

@0celouvskyopoulo7 You're not in trouble yet. You're being warned to stay away from your usual trouble.

0celouvskyopoulo7

I don't know what that means, but ok.

SevenSidedDie

If you were in trouble, you wouldn't be able to talk right now.

0celouvskyopoulo7

Can we continue our conversation?

SevenSidedDie

@0celouvskyopoulo7 No.

5 mins ago, by SevenSidedDie

The conversation about drugs ends here.

0celouvskyopoulo7

I wasn't talking about drugs.

I don't think you actually read any of my messages.

SevenSidedDie

19:43

@0celouvskyopoulo7 Then it's not continuing, you're returning to a safe topic. Feel free.

Balarka Sen

@SevenSidedDie I do not think you carefully read my criticism of your warning; I simply defended what I said. If 0celo7 interprets that as encouragement, well, that's not a particularly useful argument against me. But once again, I am making a constructive argument here, and not trying to refute your warning.

SevenSidedDie

@BalarkaSen Yet you're still talking about it for some reason. Please tell me what magic words mean “drop the topic” to you, so that I can say them.

bolbteppa

@0celouvskyopoulo7 what do you know about Maurer-Cartan forms

Balarka Sen

You told me to stop talking about drugs, I did. I am making a point about the meta-reason behind your warning to me, which you did not tell me to not do. If you do so, well, I don't have much to say.

0celouvskyopoulo7

@BalarkaSen I have fallen into the rabbit hole of hyperbolic PDE

Also, I wrote something for someone about why we use Sobolev spaces, if you want to read it

Balarka Sen

19:45

I think you are having a logical confusion here about what the discussion is going on about. But oh well.

@0celouvskyopoulo7 I don't know much about those.

bolbteppa

I doubt you motivated Sobolev norms properly

SevenSidedDie

@BalarkaSen Mod calls aren't a subject for litigation, precisely because meta discussions become meta-meta discussion, like this. So, let me cut that one off: drop the topic of a) drugs, b) being asked to drop the topic of drugs, c) any other spin-offs from (a) and (b) and (c).

0celouvskyopoulo7

@bolbteppa Properly? What does that even mean. It makes sense to me.

Lemme upload the thing

dropbox.com/s/r6qy5kdqa6cxc8w/why%20sobolev.pdf?dl=0

This might not answer the question "why," but it perhaps explains a little

Phase

Hey, if anyone could answer my likely-misunderstanding of physics that would be Swell. If different basis states rotate at different speeds under a Unitary transformation e^-iwt, how would you obtain a mixed state that doesn't change w.r.t? How does the transformation drop out? Also, what about if the change is discrete and sudden

Danu

Hi, welcome back @0celouvskyopoulo7

0celouvskyopoulo7

19:50

@Danu Grettings

Danu

@0celouvskyopoulo7 I would like to read that, if you would allow me...

0celouvskyopoulo7

How's the thesis?

@Danu see the dropbox link

Danu

I'm mostly working on finding PhD positions. It fucking sucks :'(

bolbteppa

@0celouvskyopoulo7 typo on page 1 maybe, $||u||_1$ should be $||u||_2$ right?

0celouvskyopoulo7

@bolbteppa it's the $H^1$ norm

Oh no, why doesn't chatjax work?

Danu

19:52

You might need to renew the bookmark

I had to, a few weeks (?) back

0celouvskyopoulo7

k

@Danu thanks

Danu

Btw, isn't it just because Sobolev spaces are the completion of the thing you want to (morally) work with? And you want a Banach space structure

Balarka Sen

@Danu How's your math coming off

0celouvskyopoulo7

@Danu Yes, but in there I outline the general idea of how to solve the problem.

You do need a Banach structure, exactly

Danu

@BalarkaSen Haven't done much of it. See the above.

0celouvskyopoulo7

19:54

But I wanted to explain the whole process for a linear elliptic PDE

Balarka Sen

Ah, Ok

Danu

It's a really terrible thing, this PhD application process

It sort of paralyzes me

Balarka Sen

I can imagine

Danu

The uncertainty or something, I don't know

All I know is I haven't really been able to work/focus for weeks :(

Anonymous

@Danu Where are you applying? In Germany?

Danu

19:57

@bolbteppa You're confusing $L^2$ with $H^1$: $H^n$ means you take the sum of the integrals of the first $n$ derivatives (including the zeroth), treating the whole sum in a sort of $L^2$-like fashion.

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