The h Bar

user218912

01:46

@0celo7 I changed it back.

vzn

03:43

@JohnDuffield lol an illustration to go along with DSs recent reported travails.... also reminiscent of thesis defense mentioned by others around here.... also reminds me of this, maybe saw it in this chat room, dont recall mcsweeneys.net/articles/…

Sir Cumference

03:58

Ugh, Trump is against net neutrality

He's scaring me

knzhou

04:44

Anybody know if there's an equivalent to the HEP rumor mill for other subfields of physics? Or some kind of stats for # professorships / # postdocs / # grad students per year by subfield?

user54412

06:22

@knzhou Astro rumor mill -- complete for postdocs/profs in the US, less so outside, though there's very little astro outside the US anyway.

Mast

07:01

@ChrisWhite ASTRON doesn't count? They're internationally quite active.

John Duffield

@vzn : It's by Nick Kim, an environmental chemist in New Zealand. See Wikipedia and Science and Ink.

Re Einstein, see Clifford M Will’s The Confrontation between General Relativity and Experiment. On page 4 he refers to a period of GR hibernation between 1920 and 1960. On page 9 he says SR only became mainstream in the late 1920s.

Also see the Wikipedia History of General Relativity article. It says Kip Thorne “identifies the ‘golden age of general relativity’ as the period roughly from 1960 to 1975 during which the study of general relativity, which had previously been regarded as something of a curiosity, entered the mainstream of theoretical physics”.

@DanielSank : but you can't explain what's wrong with my downvoted answers, can you? Because there isn't anything wrong. Because they aren't nonsense. Because they refer to Einstein and the evidence. What is nonsense, is the bad attitude exhibited by many self-appointed "experts" here at physics stack exchange, which is giving physics a bad name.

Danu

07:17

Lol, 7 upvotes but no deletion...

John Rennie

well, having a gold badge in the [homework-and-exercises] tag can be useful after all:

0

Q: Find out the dielectric constant of the slab in the sum:

5) Two similar point charges $q_1$ and $q_2$ are placed at a distance r apart in air. If a dielectric slab of thickness t and dielectric constant k is placed between the charges, calculate the force of repulsion between them. Also if the thickness of the slab covers half the distance between cha...

Danu

:)

How are you doing @JohnRennie?

John Rennie

07:33

@Danu I always hate it when someone asks how are you because the answer is usually same as always but that sounds so downbeat :-) I feel like I should have something amazing to say.

Danu

@JohnRennie Oh, no worries haha

John Rennie

Mid-summer is always a slightly surreal time. Everything seems to slow down. The IT stuff I do has settled into a low level trickle and the PSE has got a bit uninspired recently. I guess when the students go back things will pick up.

Danu

07:57

@JohnRennie Yeah, I guess so. Good times to do some self-studying ;)

Secret

08:45

en.m.wikipedia.org/wiki/Gauge_theory At first it is mostly comprehensible, and then exterior algebra started to pop up and I lost track on what it is saying

Will get to differential geometry later after finish revising Quantum

bodokaiser

09:00

@JohnRennie Hi John, physics.stackexchange.com/questions/272699/…

John Rennie

@bodokaiser Hi.

Give me a moment to do a quick sketch of the cone ...

bodokaiser

No problem :D

John Rennie

OK I think this is what the cone is supposed to look like. Does this make sense?

bodokaiser

yes

John Rennie

Ok, consider the ring of charge at the distance $x$. The radius of the ring is $x/\sqrt{2}$ so the area is $2\pi x/\sqrt{2} dx$, and the charge is $\sigma$ times this. OK so far?

bodokaiser

09:08

yes

John Rennie

So the potential is $kQ/x$ where $Q$ is the charge we just calculated. Now just integrate from $x = 0$ to $x = h\sqrt{2}$ and you're done.

bodokaiser

I understand this approach

but I do not understand what was wrong with my initial approach

so if I would integrate over dz (or dr)

John Rennie

To be honest I didn't follow your approach.

bodokaiser

my approach follows directly from the definition

I posted

where you integrate over the area times area charge

John Rennie

I think your area element is out by a factor of $\sqrt{2}$ i.e. $da = 2\pi z (\sqrt{2}dz)$

You've assumed the area element is $2\pi z dz$

bodokaiser

09:21

but why is this assumption wrong?

or better: how would I derive the correct area element

John Rennie

Well, if you integrate your $da$ to get the area of the cone it gives the wrong result ...

bodokaiser

okay I see

thank you!

Secret

12:14

33

Q: Hamilton's Principle

Hamilton's principle states that a dynamic system always follows a path such that its action integral is stationary (that is, maximum or minimum). Why should the action integral be stationary? On what basis did Hamilton state this principle?

quantum-mechanics lagrangian-formalism variational-principle action

38

Q: Why the Principle of Least Action?

I'll be generous and say it might be reasonable to assume that nature would tend to minimize, or maybe even maximize, the integral over time of $T-V$. Okay, fine. You write down the action functional, require that it be a minimum (or maximum), and arrive at the Euler-Lagrange equations. Great....

classical-mechanics lagrangian-formalism variational-principle action

5

Q: Why are D'Alembert's Principle and the Principle of Least Action Related?

Why do we get the same differential equations from both principles? Surely there is a fundamental connection between them? When written out, the two seem to have nothing in common. $$\sum _i ( \mathbf F _i - \dot{\mathbf p}_i) \cdot \delta \mathbf r _i = 0$$ $$S[q(t)] = \int ^{t_2} _{t_1} \mat...

newtonian-mechanics lagrangian-formalism variational-principle action constrained-dynamics

Hmm, if I understood correctly, the reason that a stationary action corresponds to classical equations of motions is because (classical mechanics) virtual work of the system is minimise as it is in some sort of equlibirum and (quantum mechanics) paths with high amplitude are those that corresponds to stationary action

Might have to go read mroe classical mech stuff before pondering again why stationary action of any process must always lead to physically realisable phenomenon

0celo7

14:06

Can someone give a tl;dr on solitons?

Slereah

14:17

Solitons are solutions of non-linear equations that do not degrade

they stay the same shape as they propagate

Rogue wave

Rogue waves (also known as freak waves, monster waves, episodic waves, killer waves, extreme waves, and abnormal waves) are large and spontaneous surface waves that can be extremely dangerous, even to large ships such as ocean liners. Rogue waves present considerable danger for several reasons: they are rare, unpredictable, may appear suddenly or without warning, and can impact with tremendous force. A 12-metre (39 ft) wave in the usual "linear" model would have a breaking force of 6 metric tons per square metre [t/m2] (8.5 psi). Although modern ships are designed to tolerate a breaking wave of...

^example of soliton

Slereah

14:54

What are some Important Theorems on Hilbert spaces needed for QFT?

0celo7

Riesz

Slereah

true

"The next theorem is a non-archimedean version of the well-known Riesz representation
theorem"

yesss

John Rennie

15:32

@EmilioPisanty: wow, a lot of work went into that meta post! Thanks for your efforts and a +1 from me. We haven't had an official moderatorial response though ...

0celo7

@Slereah What is a 1-form?

@JohnRennie I've got "Timmy-Timmy-Timmy Turner" stuck in my head

Secret

A one form is any linear map that takes in one vector and return a scalar

0celo7

@JohnRennie Apparently that song is freestyle

@Secret what's the intuition

Slereah

@0celo7 I am

0celo7

THAT EXPLAINS EVERYTHING

@Slereah Do you know anything about quotient bundles

Slereah

15:41

I do not

0celo7

I'mma need you to send me Steenrod

I'll pay

Slereah

One million dollars

Secret

One intuition in $\mathbb{R}^n$ is the standard dot product between vectors, where the one form has the representation as a row vector and the vector as a column vector

0celo7

no you lunatic

@Secret i haven't seen a row vector in the night sky

Secret

Pictorically a one form can be drawn as a directed stack of hyperplanes and the dot product can be understood as how many planes the vector penetrates through. However this picture can be quite misleading except for $\mathbb{R}^n$ with the standard dot product of vectors (which requires the vector space of one form to be dual to that of the vector space of vectors)

to explain further requires some understanding of dual spaces, which I still trying to wrap my head around the formalism

John Rennie

15:46

@Slereah: could you cast your eye over this. I've stuck my neck out a bit since this is based on what (I think) you and ACM told me a few days ago and it's way beyond what I'm confident about.

2

Q: How do the wave and particle approximations of light arise from the underlying (I assume, more fundamental) quantum field description?

I was informed by this answer from John Rennie that the particle and wave behavior of light are both approximations to the more fundamental description of light as an excitation in a quantum field. How would one, starting with the quantum field description of light, derive/predict the particle a...

quantum-electrodynamics wave-particle-duality

Secret

one of the physical examples of a one form is the gradient function, which one will make use of when deriving various things using the levi citva connection in GR

0celo7

> I was informed by this answer from John Rennie

CALLED OUT

John Rennie

@0celo7 I do like the track. Some Googling tells me there's an album The Life of Desiigner. Have you got it?

0celo7

whaaaaat

not on iTunes

Oh

That was the unofficial pre-release name

The actual album is called New English

It's not that good

John Rennie

@0celo7 oh ...

0celo7

15:49

I gave it a listen

I might give it another

But in general I prefer Future

John Duffield

@0celo7 : in the clear night sky.

John Rennie

According to Wikipedia New English is the mixtape but there is also an album called The Life of Desiigner.

0celo7

embracing the meme?

@JohnRennie hmm, well it hasn't been released then

John Rennie

soundcloud.com/lifeofdesiigner

Oh no, forget that. I don't think that's the album.

0celo7

that's what confused me

the songs there are from New English

WE LEAVE THIS FOR THE READER TO PROVE

AHHHHH

@JohnRennie Also stuck in my head "This that 63 AMG ghost music"

John Rennie

16:01

I've been trying to think of tracks you might like, but the stuff I listen to is all spacerock and psychedelia and I suspect it would bore your pants off ...

0celo7

maybe with a sufficient amount of drugs that I will never take

John Rennie

Oh well. Anyhow I've grabbed a copy of the mixtape and I'll listen now. It's weird about that album. Google finds loads of stuff saying it was released on June 26th, but Amazon has no trace of it.

0celo7

Did you buy it?

Or is it free

I get all my music through Apple music, so I dunno what's free and what's not

John Rennie

No comment :-)

0celo7

I see

What the hell is a quotient bundle

@JohnRennie Somehow I can't imagine a 50-yo British man listening to Desiigner

John Rennie

16:10

@0celo7 I'm not convinced people (well, mainly males) ever really grow up. If you think your parents were serious that's probably because they were already serious when they were your age.

You have to bear in mind I grew up a few miles from Glastonbury (where the notorious festival is) and stoned hippes were everywhere. It's hard to take life too seriously under those circumstances.

But I have to confess the Desiigner mixtape isn't really my thing. I liked Timmy Turner because it's trippy, but the mixtape isn't really doing anything for me.

John Duffield

@JohnRennie : but we have now had an answer. Doubtless EmilioPisanty will declare that it so completely incorrect that it is actively harmful to the site and its standing, [and] should be removed from the site.

John Rennie

If you get free music through Apple try the album Censored by Hawklords. That's one of my current favourites. Be warned though, you'll probably hate it :-)

Cor there's a lot of swearing in Da Day

DanielSank

16:26

@DavidZ I got a jury summons and it might prevent me from attending the AMA for which I'm scheduled to the be guest.

Can we find another time?

peterh

Answer of new HQ user was - probably accidentally - flagged as LQ, please try to not expel him:

1

A: Can neutrons detect the diamagnetic effects of superconductivity?

Have a look at this publication https://kops.uni-konstanz.de/bitstream/handle/123456789/5359/322_physicaB_1998.pdf The neutrons will see the exponential decay of an external magnetic field into a superconductor and also scatter on the chemical (nonmagnetic) structure. I believe you are correc...

I suggest this time the attutide like this: "sorry we think you gave enough info for your answer to be not considered as link-only". And not this: "the rule say ..., so we deleted your question, good bye".

DanielSank

@peterh How is the "quality" of the user relevant to whether or not the answer gets flagged?

Dude, there is no reason to care about who posted an answer when we vote to close. We only look at the post itself and judge it by its own merits.

peterh

@DanielSank It is a link to an answer, not to a question. The answer was posted by a Phd & neutron scattering researcher. He doesn't know the link rotting problem, and he expects (imho, correctly) that anyone reads his post, reads also the reference before flags.

@DanielSank Yes, there is a reason: if you handle him as usual, he will go away. If he gets a friendly treatment, he will later probably improve the site with a lot of HQ answers.

DanielSank

16:42

@peterh His (incorrect) assumption is incorrect.

dmckee

@peterh That expectation is wrong. Anyone can link to anything and anyone can claim to be a researcher. It is easy to copy the relevant parts of the abstract and conclusions into the post, and doing so (a) improves the value of the post as an answer and (b) lets anyone who might be interested in reading the paper a chance to decide if it is worth their time.

DanielSank

@peterh Why do you think going by well established and carefully examined site rules is not friendly?

Wouldn't it be even less friendly to enforce the rules without consistency?

That's a very, very good point.

Actually I hadn't thought of things that way. @peterh please consider what @dmckee just said very, very carefully.

John Rennie

@dmckee you tell the user what jerks we are - that's not really fair. Peter's comment wasn't that bad.

peterh

@dmckee I didn't tell anything to the user, John Rennie answered him in a relative cooperative tone and I don't think it would be appropriate to extend that.

DanielSank

@JohnRennie Well, peterh has been spending a lot of time saying how we treat people un-friendly, violate ethics, etc.

peterh

16:51

@DanielSank Yes, enforcing rules ignoring every other is consistent, but unfriendly.

DanielSank

@peterh Really?

I find the physics stack exchange rules rather friendly.

There are designed in a way that actually teaches people to ask questions better.

This is a very important skill.

John Rennie

IIUC all Peter is saying is be nice and polite when we enforce the rules. And that seems fair enough to me.

DanielSank

I am grateful for the way Stack Exchange has helped me improve my self-research and question asking skills.

@JohnRennie I agree 100%.

John Rennie

Then we all agree. Good :-)

DanielSank

Show me something impolite here.

David Z

16:54

Incidentally I took a look at that answer. It's not a link-only answer - not even close.

dmckee

@JohnRennie @peterh Yes. I reacted to a general feeling that some complaintants have been attacking the culture of the site recently rather than to the specific comment on this post.

I apologize and will delete the above.

DanielSank

@DavidZ Even before the edit?

David Z

@DanielSank the way things are going, we could actually move your AMA up to this coming Tuesday (the 12th I think?) and push what I had planned for that day back to the 26th. Or if the 12th is too soon, we can just put it off to the next chat session after your jury duty ends.

John Rennie

I have to say I feel the culture has got a bit, well, if not impolite then at least rather curt.

DanielSank

@DavidZ Either one works for me.

peterh

16:55

@DanielSank No, posting the links as comment is not wanted. Instead, the site policy is that the most essential parts of the link target must be copied into the answer.

DanielSank

@JohnRennie From my own perspective it's because I'm becoming more of a type 4.

David Z

@DanielSank Hm, OK, in that case I'd go for putting it on the 12th. Someone should update the meta post accordingly. cc @vzn

DanielSank

@DavidZ I'm on it.

David Z

@peterh well... as far as I can remember, site policy is simply that an answer should qualify as an answer without considering external resources. If someone posts an answer that doesn't meet that criterion, I don't believe there's a set policy on what must be done with it. If someone can edit it into shape, that's probably better than deleting it or converting it to a comment in most cases, but any outcome is possible.

DanielSank

@DavidZ Would you mind stickying a note in the chat room about the date change?

...since it's short notice?

Secret

16:59

0

Q: Would a Quantum Physicist with a Chemistry B.S. be qualified to teach a class like Physical Chemistry?

I'm a chemistry and physics double major soon to graduate, and I'm looking toward a Ph.D. in quantum physics. So obviously I love quantum mechanics. I've just learned that I prefer to study the world from the perspective of a physicist rather than a chemist. Without going into too much unnecessa...

physical-chemistry

DanielSank

Date change: DanielSank AMA now August 12

4

David Z

no problem

DanielSank

thanks

peterh

@DanielSank Don't be type4, if you don't have time to handle such situations, or you are bored on them, you can simply let them to others. If you go away, it will be a loss to the site, just as if @qbar never posts anything any more.

DanielSank

@peterh Well, I'm not really type 4. That's not quite what I meant. I'm really a type 1.

I'm a type 1 who is starting to get tired of giving the same advice over and over.

However, I do my best to direct people to the help center with links, and explain the rules.

David Z

17:02

@DanielSank yes, before the edit. Actually it hadn't been edited when I posted that chat message (and my comment). When we talk about link-only answers, we really mean link-only.

DanielSank

@DavidZ mmm. ok.

peterh

@DavidZ If I could, I had long copied the relevant parts of the link into his answer. But I can't and won't commit a mistake.

David Z

My rule of thumb for when an answer looks like it might be link-only: mentally remove any links from the post and imagine it had been posted that way. If it would qualify as an answer without the links, then it's not link-only.

DanielSank

@DavidZ certainly

peterh

@DanielSank On HQ user I understand a user, who is capable to write such answers, what you can't find on the internet. Thus, the only way to know what he says if you make a Phd in physics, which is impractical in many cases. It is essentially an abbrevation of this: "an user capable and willing to write many HQ posts".

vzn

17:08

@DavidZ ok (served on a jury once yrs ago, long story)

peterh

@DanielSank I think needless to say, that their existence and proportion is essential for the future and the quality of the PSE.

DanielSank

@peterh Agreed.

However, another important quality in a user is their willingness to read, understand, and follow the rules.

And perhaps above all else, the ability to take feedback from other users and act on it without getting offended or taking it personally.

These are things l learned by hanging around this site (and by working on group software projects).

@peterh Please, please read this

catb.org/esr/faqs/smart-questions.html#intro

vzn

@peterh while not entirely a fan myself, think trying to chg SE culture is a quixotic and/or sisyphean task

dmckee

@DanielSank Speaking of which qqbar has deleted the post and left a testy comment.

DanielSank

@vzn Disagree. I feel like I helped this site accept more applied answers than before.

@dmckee Yes, note that he also mentioned that he's a PhD in the comments. Seems like he was trying to invoke some notion of authority. I find that rather distasteful.

I'm sad that the post was deleted, and I wish the user would feel more welcome, but if a user can't be bothered to learn the site culture and accept some simple impersonal criticism then I'm not sure what else can be done.

dmckee

17:15

@DanielSank If that comment is to be taken seriously, then my attempt to help out was the straw that broke the camels back. ::sigh::

peterh

@vzn No prophet is accepted in his own hometown. Yes, it is possible, but only if you know and accept that you won't ever see a direct result.

DanielSank

@dmckee Well, I do think what just happened indicates that we have a real problem.

While I disagree with @peterh's comments about users in "good standing" and "high quality users" etc., especially as relevant to whether or not a question should be closed, I do think that we should think about how to retain users who, after learning the ropes, could contribute a lot.

vzn

@peterh "prophets" are quite rare historically and also tend to turn into martyrs. there seem to be no cyberspace prophets so far. its a job descr with very high risk.

DanielSank

@vzn lolololol

vzn

@DanielSank another radical pov is that maybe absolutely nothing is wrong with the site :| ... oh to add to sisyphean/ quixotic metaphor, also "boiling the ocean"

DanielSank

17:20

@vzn I think there are problems.

peterh

@DanielSank I read this and I follow this since many years. But now I'am coming from a course which was paid by my company. I learned a technology. Not a very high level thing, essentially a programming framework using the same patterns and solutions as the 5 previous I've learned already. There was a teacher holding my hand and helped to learn. And I learned with around 10 times faster if I would have learned the same from the google, following what is in your link.

DanielSank

We just had a PhD scientist show up, provide useful information, and then eventually delete the post and leave in a huff.

vzn

@DanielSank its a human agglomeration, what is evidence of problems? hurt feelings are not necessarily evidence of "problems". hurt feelings happen in most human group endeavors... agree its ideal to try to minimize them

DanielSank

@peterh I agree. There is nothing as useful as a teacher!

@vzn This is a very common comment in the software community, and it's one that I strongly disagree with.

Hurt feelings lead to less productive work.

If the goal of this site is high quality content then like it or not we need to care about people's feelings.

I think there are ways of not hurting people's feelings and keeping the quality standards high.

John Rennie

@DanielSank actually that user comes over as a bit of a tw*t. Saying *I'm the expert and flouncing off isn't a great way to impress people.

DanielSank

17:23

@JohnRennie Indeed not.

0celo7

@JohnRennie I don't think so

DanielSank

@JohnRennie But as DZ mentioned, the post really wasn't so bad.

0celo7

My brother has definitely changed since having kids

vzn

@DanielSank have never liked the SE hold/ close mechanisms myself much & have blogged on exactly that topic but think theres not a lot to do about it...

@DanielSank full sympathies however have you seen that semiclassic SE ceo post on "sand versus pearls"?

Physics Meta

0

Q: What constitutes non-answers?

The flag reason for non-answers is the following: This was posted as an answer, but it does not attempt to answer the question. It should possibly be an edit, a comment, another question, or deleted altogether. Seems clear, doesn't it? So I read this post, and I flagged it as a non-answer,...

discussion flagging

dmckee

17:25

@JohnRennie I've wondered from time to time how much of that is cultural. It's certainly bad form in the circles I grew up in. But is it part of the usual way of doing things elsewhere?

vzn

@DanielSank there are some crank phds in cs who write P != NP papers, another blog topic of mine, and theres a omerta/ code of silence in the community wrt them. think its kind of an issue with academia imported into cyberspace. am all for attracting "quality" phds but even academia does not fully share that goal without "qualifications" (actually involving more than a phd etc)

peterh

How do cutting edge physics researchers communicate? For example, consider an active researcher having a question, what even he can't answer easily. For example, it is in a topic what is not in his focus of interest. What does he?

0celo7

Where is ACM when you need him :/

DanielSank

@vzn nope, link?

dmckee

@peterh They talk to some colleagues. In person, by phone or by email. Lots of that goes on at conferences.

DanielSank

17:33

@dmckee I have no tolerance at all for appeals to authority in science.

None.

0celo7

Aha

DanielSank

@peterh I ask people, email experts if I know any, and post here :-)

0celo7

@ACuriousMind Even in your absence you are a rubber duck

vzn

@DanielSank blog.stackoverflow.com/2011/06/optimizing-for-pearls-not-sand / atwood

DanielSank

It's embarassing, but I rarely read research papers outside my field.

0celo7

17:34

@DanielSank Why should that be embarassing?

You probably don't have time to go browsing arXiv for stuff that doesn't directly affect you

Secret

I read research papers both in and outside my field, but since my mind is an incoherent mess, sometimes the ideas in one paper will jump into another and create mush in the thought process

dmckee

@DanielSank I try hard to read one or two each semester. But the time pressure is intense.

peterh

@vzn If there is a buggy system what you want to fix, your direct power is probably far too few to reach any significant change. This is why you can't hope in a direct result. But if you know this, and don't do anything in this reason, you are using essentially an oversimplified model: you simplify the reality to you, as lone wolf, and to "the System", what is monolithic, big, and it is entirely against you.

Slereah

Math dudes

I don't understand the p-adic valuation

peterh

@vzn Fortunately, the reality is not so sad in most cases, even if you can't hope in a direct result now.

Slereah

17:38

$v_p(t)$ is the unique positive integer such that $t = p^{v_p(t)} q$

What is q

vzn

@peterh SE is indeed much like a monolithic system. many ppl dont realize how little its chgd over the yrs. anyway all human systems tend to look inherently "buggy" and some of its not resolvable. kind of like a mirage: it looks solid/ like it exists but it doesnt really. try reading the link for more insight into the central thinking behind SE design & how youre basically experiencing it...

Secret

@Slereah have you tried the maths chat room, cause ACM and co. are not on today?

@Slereah Related mathoverflow.net/questions/45150/…

dmckee

@vzn I take it you weren't here during the first couple of years. Big things changed, sometimes more than once. But that means the system has moved into a local optimum of sorts, and will take some heavy pressure to move.

peterh

@vzn Do you remember the SO post I citated? This. Look the edit history of the question. It was many times closed by mod power, and then reopened by mod power 10 minutes later. The mods fighted on it behind the walls. Around this time, a new mod election has also happened. Around this time, 2 of most bloody handed mods gone away. Around this time, the newly elected mods became somehow very friendly, cooperative mods, despite

@vzn they were quite militaristic and evil inner circle members earlier. The change was very surprising, although it wasn't ever communicated from the SE side, what they did, I think there was a CM action behind the walls. Before that, I fighted them and I was bullied by them. Now the SO is a peaceful site.

@vzn Remember Gandhi: first they ignore you, then they laugh at you, then they fight you, then you win.

vzn

@dmckee have been on SE ~5yr now. ~1.5yr physics chat. think/ have observed there is a commonly seen SE culture that crosses sites. some on each site dont realize its actually crosscutting. "heavy pressure" in any direction is unlikely at this point. its all starting to congeal so to speak.

Secret

17:45

@slereah an illustrative example here math.stackexchange.com/questions/1174254/…

So in that case, q is the quotient while $p^{v_p(t)}$ is the divisor and t is the divident

vzn

@peterh lol. that exact quote is on my blog along with other subversive-sounding/ antiestablishment ones etc. enjoy great quotes esp on that topic. but think they must be applied with great care wrt situation. do you want to be gandhi? vzn1.wordpress.com/quotes

@peterh repeat: sand, does that word mean something to you?

peterh

@vzn Of course it wasn't my effect there, but my fights on the meta SO played also a little role in it. No, I won't be ever a "Gandhi", I am only a lone wolf on the internet loving physics and the programming :-) And I don't think that I will ever reach any direct positive result, I don't this for that. Btw, @qqbar deleted his answer, what means we lost not few good answer what he could have written, if we let him to do. :-(

vzn

@peterh there may be some systematic chgs to SE or individual sites that could improve it in some modest ways, but havent figured any out myself after years of looking. there are many constraints involved. anyway if you look at the meta posts youll probably find years of material related to your objections.

peterh

@vzn Btw, the current state of the PSE is much more friendly as it was a year ago and now I don't see a reason for direct partisan fight.

vzn

@peterh yay

@peterh do you have some physics training?

peterh

17:58

@vzn Yes, the sand is what is capable to skive the sharp splinters in the desert to roundish ones. The poor little sand grains, not knowing that they are too small to reach anything.

@vzn Few.

vzn

@peterh what? undergraduate classes? selftaught? etc

peterh

@vzn Undergrad classes + many selflearn. But I am still far from a grad level.

vzn

@peterh see youre a particle-physics fan, me too

peterh

@vzn Yes yes! Now I have a nice idea, but it requires a lot of QFT to learn, so I am on it now. :-)

vzn

@peterh cool am reading a new bio of feynman at moment (literally bought at caltech bookstore!)

peterh

18:03

@vzn :-) I've also read a good book from Feymann. goodreads.com/book/show/45776.Feynman_s_Rainbow How the symmetries saved a life :) :) :)

vzn

@peterh cool saw that one years ago. really like the 2 books he wrote himself, read em as teenager

peterh

@DanielSank He interpreted the feedback of the site in a way that we won't read his reference, but we want to delete his posts, because we are jerks. From his viewpoint, based on what he has seen from the site, it wasn't an unreasonable interpretation.

Sanya

18:21

why can't I flag for a transfer to chemistry stackexchange?

peterh

@Sanya :-) :-) :-) What do you think? :-)

Sanya

because the system is evil @peterh

peterh

@Sanya :-) :-) Do you want more details?

Sanya

always, I enjoy analysing cruelty that I'm powerless against :) @peterh

0celo7

Augmented double complex cohomology is kill

peterh

18:31

@Sanya 1) The SE intentionally makes it hard, because it would create territorial conflicts between the mods. 2) On the same reason, also the mods are very careful before a migration. 3) (2) is strengthened by the fact that the mods having mostly a strongly conflict-avoiding personality, so were they selected. 4) Migrated posts mean in most cases also a reputation transfer, which excites the subhuman urges of the militaristic inner circle members.

0celo7

I mean what even is this

peterh

@Sanya 5) Many migrated question would also result the transfer of the visitors from the SE sites. It would strengthen (1) and (4).

Sanya

@peterh I found it rather funny to have rep on math SE despite never having been there :D but sounds mainly like a personal problem, to be honest ... :O well, let's just have another off-topic question around, won't matter much anymore :D

@0celo7 it's wrong because the axes don't have unit length ticks

0celo7

what

Sanya

don't take me seriously ^^"

0celo7

18:36

@ACuriousMind OH MY GOD ČECH COHOMOLOGY

...wow

peterh

@Sanya 6) Some "intermediate site", only to handle migrations, could solve the problem, but it would mean that the SE needs to develop its software. They won't develop, or change anything. They are in winning position, any change of it would result more chance to negative effect for them as positive. They need very strong reasons for a sw change, and it seems the pure rationality isn't one of them.

Sanya

@peterh well ... then I guess I'll just live with that

peterh

@Sanya No, it is not enough. If you find anybody in the future asking why are the question migrations de facto impossible, explain them that the decision makers of the SE aren't really on the top.

Sanya

@peterh yep, now I can - I was just wondering whether I was lacking rep before

peterh

18:52

@Sanya Yet another reason: the top of the SE pyramids looks as this: there are the site mods, they are theoretically elected by the community, practically the SE has also a significant influence to their selection. They are the kings of the sites. Over them, there are the CMs (community managers). They are SE employee. There are around 10 of them, for the around 140 SE sites.

@Sanya -> they have the monopoly of the inter-site relations. If large-scale inter-site relations would exist, with inter-site community initiatives, it would endanger their controlling abilities, even their positions.

@Sanya --> No, they don't want that the site communities are talking eachother and synchronize their wishes and initiatives.

Sanya

@peterh it is fascinating how much of human interaction is simply based on the illusion of power and controll

peterh

@Sanya Yeah. Well, reason 8) Most of the money of the SE is coming from the SO. It is mainly from the ads, and from the jobs SO (the are essentially headhunting IT jobs for US & EU companies. They are willing to pay a lot for them, because a really high level programmer can make 10*, 100* money for them. The overall hit rate of the whole stackexchange network is around on the level of the stackoverflow, but they money what it makes it far from it.

@Sanya So, the SE Inc develops the SO as it can, and ignores the smaller SE sites. This is why there is a lot of imporvements on the SO which exist exclusively there (+2 review queues, jobs, documentation). And this is why are any programming related questions forbidden on the other SE sites. i.e. if you want to ask a question about android programming, you can't do it on the Android SE, they will close it and direct you to the SO.

@Sanya Now if a migration would be practically existing, and it would be common, it would result that the SO loses more questions as it gets.

@Sanya Theoretically here you can migrate only if there are 5 3k+ users voting to close a question, but 3 of them need to vote for migration, and to the same site. (On the SO, this limit is 4!!!) The list of these sites are quite limited with bullshit reasoning. The real reason is that the SE doesn't bother the SE network, only the SO is for them important.

Sanya

while it would be easy to just exclude SO from the migration process

but well, they are in the end financing the servers and stuff, so ... :D

peterh

19:08

Or to convert it to a network of many smaller sites. I've read some posts from an SE leader, it seemed to me as if it would be hard for him to remain polite while they denied any possibility of "dividing the SO".

@Sanya I think, they are only in one of the many possible minimal potentials of a Higgs mexican hat. I can't see the masters of the "community management" in their decisions, in my opinion they seem more like primitive exprogrammers totally incapable to see out of his narrow world view.

Sanya

doesn't make me too mad to be honest - they're running the site the best way their mindset allows them to and it's not too full of real feature-missing in my experience so far

peterh

@Sanya You are right, it could be really much more worse.

David Z

@Sanya you can

I don't know what @peterh is going on about

2

Just flag for moderator attention with something like "off topic; might be suitable for Chemistry"

Sanya

@DavidZ I didn't see the option - I just saw "move to math SE or meta physics SE"

dmckee

@peterh The reason there are few migration paths and it is difficult to get another one allowed is because even when there were only four sites in the network it became obvious that most users are not conversant enough with the rules on sites they don't frequent to judge what would be on-topic elsewhere.

peterh

19:20

@Sanya Since 1-2 years there are significant positive changes in the "community behavior". This is not the normal way, in most cases the internet communities tends to be ruled by a psychotic inner circle. I suspect, they got too many feedback about the organized bullying (remark: PSE was absolutely not the worst in this case), and they pressured the CMs to do something.

dmckee

Sever Fault and Super User complained at length about the amount of utter crap that was getting dumped on them from Stack Overflow.

And Programmers got it even worse: they were used as a trash bin for months.

Even with the understood rule being "don't migrate crap" and a very limited number of targets, a large fraction of migrations are closed on the target site.

peterh

@Sanya The result was, that somehow, around in some months, most of the SE sites had been somehow much-much more friendly... well, this had been totally unimaginable on the internet, only here on the SE was possible.

Sanya

even though a flag for migration shouldn't just automigrate, so I would've thought it would mainly need to be the mods who need to somehow now the other SEs @dmckee

David Z

@Sanya yeah, that's how it works. When you flag for moderator attention to ask for a migration, we check with the people on the other site to see if it would be a good migration.

dmckee

@Sanya The standard work-flow for moderator migration is to ask the mods on the potential target site if they want a question. We have a all-mods chat room where such discussion can occur.

David Z

19:24

If you choose Math, then the question is automatically migrated (assuming 4 people vote for it), and we have that option because people on this site have demonstrated that they know the scope of Math SE well enough to be trusted to know what will fit there.

We don't have enough data to do that for any other site.

peterh

@dmckee Yes, yes, I know. But I am also an user, an avid user on many SE sites, and I have an experience. This experience shows, that the questions aren't migrated and it doesn't matter how well are they matching the remote site topic. I investigated in this topic years long.

Sanya

ah ... well, it would help to have a kind of "if you think it should be migrated somewhere else, please flag it for moderator attention" because I just assumed there were only the displayed options at all :D @DavidZ @dmckee

peterh

@dmckee I think, the complaints of the SF were mainly (1) and (4). The complaints of the SU were probably more realistic.

Sanya

anyway, thank you three :) I didn't want to occupy you too much with a simple question @DavidZ @dmckee @peterh

David Z

@Sanya It's probably listed somewhere, but generally, if you have anything that needs to be dealt with in any way that's not covered by the standard flag, use the flag for mod attention.

peterh

19:27

What do you think about an intermediate site? I am thinking some like a meta site, which would be an intermediary between the site migrations.

Sanya

@DavidZ I've been discouraged from that flag by misusing it :D

peterh

Anything closed as offtopic (but maybe ontopic on other sites), would go there. On this site, people could vote, if they want to see that question on their site or not. If a question is not needed on any site, it would be deleted. It would solve the whole problem.

David Z

@Sanya what do you mean?

I checked your flag history, your number of declined flags is very small indeed

Sanya

" flags should only be used to make moderators aware of content that requires their intervention" and I thought ... well, apparently I'm not aware of what exactly requires intervention, so I let it drop

David Z

Ah well... the intent was to show that that specific thing was not flag-worthy. Not to discourage you from using custom mod flags entirely.

peterh

19:33

There is a max limit of declined flags in the last times, maybe 2 months. As I can remember, at most 40% of your flags can be declined in the last 2 months (the % and the time interval can be different). If you have more, you can't flag. And, if a mod thinks you are annoying him with flags, he will solve the problem with his powers.

Now the problem is, 1) flags are timeouting 2) undecided flags aren't counted as declined, but they can be declined/disputed if the mod/vote decides so. Thus, it is possible that your flagging permission is multiple time accepted and then revoked again, while you don't do anything.

David Z

@peterh can you point to where that is explained on Meta Stack Exchange or in the documentation?

peterh

@DavidZ As I can remember, it was said to me some years ago from a non-CM, but known SE programmer, either on meta SE or on meta SO.

@DavidZ I could dig for that, if you think it is important.

David Z

Yes, I do

peterh

@DavidZ ...but I can't guarantee that I will find it.

David Z

Not urgent, but it is important to get this right

peterh

19:39

@DavidZ Ok, I am on this.

peterh

20:02

@DavidZ Wow! I found: meta.stackexchange.com/questions/229162/…

@DavidZ That key info is probably lost in the SOmeta-SEmeta split and the retroactively deletions of the years, but Servy user also said some quite similar.

GPhys

ATLAS result: twitter.com/Resonaances/status/761575139234443264

2

0celo7

Hey peeps how do I take the partial of $f(x,g(x))$ wrt. $x$?

GPhys

relevant: twitter.com/smugsmphys

DanielSank

21:31

@GPhys Summary for those of us who don't know particle physics?

Physics Guy

Hey Guys.

GPhys

22:48

@DanielSank There was an observed excess in diphoton decays at 750 GeV in the last LHC run, suggesting new fundamental particle (or other similarly drastic standard model deviances). Clean channel, unlikely to be systematic error, observed in both CMS and ATLAS, 3.9 sigma. Now, 500+ theoretical papers later and with more LHC data, it's gone.

In summary from the HEP community, with love: youtube.com/watch?v=bhNQ9cv5K7Q

dmckee

23:07

@GPhys Reports on wonderfully authoritative sources such as facebook are reporting that talks at International Conference on High Energy Physics say the 750 GeV bump has dsappeared: just statistics after all.

So far I haven't been able to find a science link, but presumably any embargo the collaboration have had on preprints and the like will be lifted now that they've "announced" the thing.

BBC reporting: bbc.com/news/science-environment-36976777

GPhys

@dmckee ATLAS: atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/… CMS: cds.cern.ch/record/2205245?ln=en

dmckee

@GPhys Thanks.

Of course, particle physicists are used to seeing 3 sigma bumps fade into the background as more data comes in, but the coincidence in both general purposes experiments was so tempting.

GPhys

@dmckee At one point there were rumors of a "loose cuts" analysis making it 4.9 sigma

but that ATLAS (apparently wisely) chose not to release it

dmckee

Accusing other users of dishonesty is not going to fly.

Seriously.

John Duffield

Being dishonest isn't going to fly either.

0celo7

23:15

what's happening?

John Duffield

Something about we only judge an answer on its merits.

OK I'm off to bed. Bight all.

DanielSank

23:36

@dmckee Huh?

Helka Homba

23:47

Mind if I plop this in here?

in The Nineteenth Byte, 11 mins ago, by Helka Homba

Famous scientist polls:
favorite - http://www.strawpoll.me/10925229
best name - http://www.strawpoll.me/10925231

dmckee

@HelkaHomba May. I wanted to vote for Ray Davis as my favorite scientist. Now I feel cheated.

0celo7

Who that

dmckee

Though now that I think a little harder, Norman Borlaug has a really good claim on that, too.

Ray Davis was the man behind the homestake mine neutrino experiment. He stood firm against theoretical criticism for thirty years until he was proven right.

Borlaug was "the father of the green revolution".

0celo7

what

dmckee

@0celo7 I'm going to pretend that you're being intentionally obtuse.

0celo7

23:54

Pretend away

I still don't know who/what that is

dmckee

Which one? Mind you, if you chose the "green revolution" I am going to accuse your whole generation of being ignorant and tell you to get off my lawn.

But seriously, google "father of the green revolution".

0celo7

I'm not on your lawn

@dmckee I already did

Never heard of it or the dude

dmckee

He may have saved more lives than anyone else living or dead.

0celo7

Whut

dmckee

Though I suppose he has compentition in that department from the Russian officer who didn't launch the ICBMs.

Helka Homba

23:57

He developed shorter, easier to grow wheat as I recall. But I was just keeping the list short for convenience :I

dmckee

@0celo7 Mass starvation was simple a fact of life in much of the world at the beginning of the 20th century.

0celo7

where is @yuggib when you need him

dmckee

It still happens, but it's rare enough to make it on CNN when it does. He's the person most responsible for that.

0celo7

ok

I wonder what the regularity for parabolic PDE solutions is

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