The h Bar

CooperCape

18:00

Gabriel your lack of picture is messing with my mind

Sir Cumference

@GabrielRomon Sometimes I feel like some people here are in 5th grade...

Probably gonna get banned for saying that

CooperCape

Okay just checked online it's okay I am not in 5th grade equiv

Sir Cumference

@CooperCape "some people" :P

CooperCape

I was just confirming to see what age range we're talking about here really

It seems like you take uk and minus q

1*

12th grade is last year of highscool?

John Rennie

The problem is that a flag notification goes out to all 10K users in all the chat rooms, and it only takes two of them to agree with the flag for the automatic suspension to take effect. Sadly not all 10K users read the post properly before deciding.

Sir Cumference

18:03

@JohnRennie Sigh, and mods can't vote to unban someone?

John Rennie

Mods can.

As a humble room owner I can't

Please stop the random starring

Gabriel Romon

Can someone tell me why physicists sometimes use Lie groups theory ?

John Rennie

The star board is intended to draw attention to posts that other chat room members will find interesting or entertaining.

Slereah

@GabrielRomon many cool things are Lie groups

Sir Cumference

@JohnRennie They probably know and just get a kick out of this.

Slereah

18:05

Mostly spacetime symmetries and gauge groups

Gabriel Romon

@Slereah ok, thx

Sir Cumference

Whatever happened to Kenshin?

dmckee

@JohnRennie Yeah, but ... a gentleman wouldn't admit to the last one in polite society.

CooperCape

And so the javascript hate continues... ;p

Sir Cumference

Poor JS...it's looked down upon despite being the single most used programming language on the planet.

CooperCape

18:20

At least there's no one saying "Just use jQuery" all over the place;

Sir Cumference

(by "used", I mean it has an affect on literally everyone on the internet)

CooperCape

Not like every html <Script> tag uses it or anything...

That might and probably is wrong idk

Sir Cumference

@CooperCape Relevant:

CooperCape

sighs;

Sir Cumference

(don't worry, it's a joke pic. Still funny tho)

Found it on SO's meta

CooperCape

18:21

I wouldn't be surprised if "You should definitely use jquery..." got upvoted by 22 users;

probably not marked as answer;

unless the OP is one with the meme;

Sir Cumference

To be fair, jQuery is undoubtably useful

Unless you enjoy changing the DOM entirely through vanilla JS

In which case you're a masochist

CooperCape

Oh yeah definitely...

(There is a certain pleasure in vanilla-ing through life, though)

well... depends on how arduous that makes the task

Sir Cumference

@CooperCape Well yeah, though most of the time your solution to a problem won't be as efficient and probably more buggy compared to doing it with jQuery

At least, for people with only a few years of experience like me

CooperCape

Definitely... could be a fun challenge though

Sir Cumference

@CooperCape True

CooperCape

18:25

Heh I'm running on a few months

Sir Cumference

I might get around to learning AngularJS. Dunno if it's any better

CooperCape

I do still have horribel flashbacks of something I wrote a few months ago where I had waaayy too many setInterval(function() ({'s going on... and they wouldn't consistently turn off so remnants would flash in every so often

I don't really know that much about AngularJS

Sir Cumference

@CooperCape Why would you need that many?

0celo7

Jeez

Why do people like to flag me?

CooperCape

Well I was being a "Hah I don't need the internet I can do it in my own janky style" kinda guy...

Sir Cumference

18:28

@CooperCape Ah

0celo7

@Slereah how do you feel about using mathfrak u for a distribution

CooperCape

@0celo7 Maybe someone's 'momma' was actually jesus...

Sir Cumference

You know, it's mind boggling that SO gets more than twice as much traffic than the rest of the SE network combined

Slereah

@0celo7 poorly

CooperCape

Does it actually?

Slereah

18:29

I usually use $\phi$

CooperCape

That's kinda mad...

Slereah

$\phi[f]$ for the product of a distribution and a test function

Sir Cumference

@CooperCape Yup. 50th or so most popular website in the world

CooperCape

Holy moly... that's quite popular huh...

Sir Cumference

Calling it the "most popular SE site" is an understatement

Slereah

18:30

Well, I don't know about "popular" :p

CooperCape

Then again I certainly have more coding problems than anything else problems (currently... ;p)

Slereah

Certainly useful

Sir Cumference

@CooperCape Well think about it, 99% of the programming questions I have are answered on SO

Slereah

Most people don't code

Sir Cumference

List of most popular websites

This is a list of the most popular websites worldwide according to the top 100 lists published by Alexa Internet, as of April 3, 2017, and SimilarWeb, as of May 2017. == Ranking measures == Alexa ranks websites based on a combined measure of page views and unique site users, and creates a list of most popular websites based on this ranking time-averaged over three-month periods. Only the site's highest-level domain is recorded, aggregating any subdomains. SimilarWeb ranks websites based on a panel of millions of Internet users, International/U.S. internet service providers, direct measurement of...

Slereah

18:31

They just ask SO to do the coding

Sir Cumference

#49

Slereah

this is #1 : itisamystery.com

Sir Cumference

In terms of traffic

0celo7

Phi is universally used as a test function in math

CooperCape

how on earth is itisamystery.com the sight with the most traffic?

Sir Cumference

18:32

@Slereah SO has pretty much devolved into "answer the most basic questions about the most popular programming languages, if you want rep"

CooperCape

If someone replies it's a mystery...

I'll... grrrrr

Sir Cumference

@CooperCape Pretty sure he's kidding

Slereah

hint : I am lying

CooperCape

That's quite a big hint.

Sir Cumference

#1 is Google :P

CooperCape

18:32

Don't make crossowrds.

Slereah

I do that sometimes

They call me the father of all lies

0celo7

I would make a joke about a mother and some salacious material on a certain website containing a word sounding like “corn”, but I won’t.

Sir Cumference

@CooperCape This

stackexchange.com/about

Pageviews: 7.9B (5.7 billion of them on Stack Overflow)

CooperCape

That's a mighty amount

Sir Cumference

The other 2.2B is the rest of SE combined...

CooperCape

18:34

wowzers

Sir Cumference

Oh hey, SE's main site got the new topbar

CooperCape

Oh wow... This question is basically asking what I was asked at a uni interview...

Well... before the interview... we were discussing it as a group with a lecturer

Actually it might not be asking that

eh.

Sir Cumference

You were asked a physics question in an interview? >_>

CooperCape

Dunno if that's sarcasm... uhhhh

yeah?

Sir Cumference

@CooperCape To get in?

Never happened to me

CooperCape

18:40

Yeah...

I mean for a physics course..

Was in both the interviews I've had... (so far...)

Sir Cumference

GRAH

stepped on a lego brick

CooperCape

ooooououuuuuuuhhhhhhhhhhhhoooooooowwwwwwwwww

Anyone know why JSLint is saying it expected '===' in if (inpt.charAt(j) == "x") {? I thought equivalence in these things was denoted '=='...

ACuriousMind

@CooperCape SO is your friend: stackoverflow.com/q/359494/3929857

CooperCape

Ahhh thanks :p I don't usually look up these things because it's not causing an issue...

ACuriousMind

Well, but it pays off to understand the language you're using even if it has not yet wrought terrible havoc on one of your projects, no? ;)

CooperCape

18:49

Oh yes... definitely...

I need... just about all the understanding I can get ;p

To be honest give it three days I'll have probably annoyed you all with my silly lil' q's...

Slereah

19:10

I wonder what's the metric of a spacetime with like

A ring-like singularity

But non-rotating

I'm guessing it would be some weird conical singularity stuff

Oh wait I guess it would just collapse to a black hole

Constantine Black

Hi. Is there any "first order" definition to what we mean when we say phenomenology in physics? Thanks.

Slereah

Not really, no

"phenomenology" is usually code for "there's no math in that talk"

or very basic math

CooperCape

19:26

Do you mean something like empirical research?

ACuriousMind

@ConstantineBlack In QFT and string theory, "phenomenology" means that one is primarily concerned with the "detectable" effects like number of particle species and their properties like mess, charges, etc.

Conversely, if someone is doing pheno, they're likely not primarily concerned with mathematical rigor or inventing new formalisms

Constantine Black

Ok, thanks. The question (@CooperCape) comes from the fact that I have seen the term used similary for the old nucleon-nucleon potentials derived from phase shifts and also on the effective model of low energy QCD, ChiralPT(@ACuriousMind).

ACuriousMind

@ConstantineBlack Ah, in that case it also often means that the "phenomenological" model is fitted to observations instead of being derived from first principles of some sort

CooperCape

Yeah I'm out as soon as any non-highschool phys comes up

ACuriousMind

E.g. Fermi's theory of $\beta$-decay with the four-fermion vertex was first motivated because it fit observations and only later folks realized one could obtain it as an effective theory from the weak interaction by "integrating out" the bosons

Constantine Black

19:32

@ACuriousMind Exactly(and I was also just thinking Weak Interactions)- but ChPT comes from first principles more than the old models I mentioned. So there seems to be an "evolution" if I may say to the way phenomenology is being understood.

ACuriousMind

Indeed. What's "pheno" about ChPT is that ChPT actually tries to predict what we observe in the non-HEP regime, I'd say, instead of searching for analytical solutions or deep insights

Occasionally, I think "pheno" is wielded as a sort of ideological label - are you an ivory tower theorist or a down-to-earth phenomenologist? :P

Slereah

Is chiral PT the whole sigma model stuff?

ACuriousMind

(whether it's a good or bad label depends on whether the theorist or the phenomenologist use it ;) )

Anonymous

@Semiclassical I got Arfken delivered today. It seems to cover a good range of topics. If they had just included a chapter on Differential Geometry and Linear Operators it would be perfect! Anyway, I'm going through the first chapter now :)

Anonymous

The first chapter seems to have trivial topics though

Constantine Black

19:35

It is, maybe, like a more theoretical treatment of observation in the sense that having a series of experimental/pheomenological results one sees "negatively" this results, looking for ways to formulate a model that ask more the question: why the results aren't something else in contrast of asking why they are the way they are- so here comes symmetry as a major catalyst for modern physics.

@Slereah Pretty close, yes.

@ACuriousMind So, from my last paragraph, it' s better from a theorist point of view :) , I guess. But it comes from down to earth results. No?

@ACuriousMind But, there is something "deep" in ChPT in that the pion comes more naturally from Goldstone's theorem.

Or in the Skyrme model, the nucleon as soliton, or in the N_c --> inf limit of QCD. But for the later I'm not sure if it's phenomenology or pure theory?

Slereah

well there's a theory reason behind the various phenomenological models

in the limit of $m_u = m_d = ...$, there's some $SU(N)$ symmetry to QCD

Hence you can just express the theory as a generic $SU(N)$ gauge thing

Constantine Black

@Slereah Ofcourse, that's how ChPT comes. It' s the SU(N) gauge think( I only studied two flavors).

@ACuriousMind May I ask you something irrelevant about Heidelberg university?

bolbteppa

20:15

"That cost of tuition at MIT is technically about $50,000, even though a lot of student’s don’t have to pay it. Under the House Republican’s tax proposal, these graduate students would have to report that tuition forgiveness as income. Ryan Hill, a fourth-year PhD student at MIT, told NPR that he already pays taxes on his $30,000 stipend.

But, adding in the value of his free tuition, he said, would require him to pay taxes as if he made $80,000 a year – a huge difference for him and his wife, who works part time while also caring for their new baby. The House on Thursday, in a 227-205 vote…

2

How exactly is the phd system in the US going to survive?

This would pretty much wipe out a gigantic segment of the phd student population

Sid

@bolbteppa Good luck. The President is going to give loans to people...

bolbteppa

We all know supersymmetry is only done by coastal elites I guess

@Blue Arfken pretty good on Bernoulli numbers and stuff around that chapter

Anonymous

@bolbteppa I see. It's in the analysis chapter!

Anonymous

Arfken goes a bit easy with the proofs it seems

bolbteppa

Arfken is not that good but for a first exposure to a topic it's useful for physics

Anonymous

20:20

In chapter 1 they give a hand-wavy proof of D'Alembert's test.

Anonymous

Anyhow, I'm liking it

bolbteppa

Nice short ways of thinking about topics

'Kathleen Farley, a graduate student in biological sciences, paid $2,824 in taxes on her stipend of $25,969 last year. If President Donald Trump’s tax plan takes effect, she calculates that she’ll have to pay $5,174 — almost double what she’s paying now. The unexpected financial burden might force her to drop out of Rutgers University-Newark. “If you walk away, you have nothing,” she says. “I would have just lost four years.”'

3

That's something else...

0celo7

22:31

@bolbteppa Hopefully it won’t.

Mithrandir24601

I have to admit, right now, I'm exceptionally glad I didn't decide to apply for PhDs in the USA

Abcd

22:48

In free expansion of a gas, $\Delta S_{system}>0$ according to me because entropy is a state function. But the answer key disagrees. Can someone tell me who is correct?

CooperCape

Anyone know anything about integration of MathJax into HTML?

Actually it's okay I got it...

ACuriousMind

23:30

@ConstantineBlack Yes, sure. (Sorry for the late reaction, I was playing cards with some friends)

Semiclassical

23:43

@bolbteppa that matches the zeroth order calculation I had: if you’re doing TA/RA work half-time ie your paid hours = tuition benefit then making the latter taxable amounts to a doubling of the income tax rate on grad students

It’s not as if that tuition benefit goes into your pocket, after all

Which is ridiculous

(Maybe if they were phasing it in over a few years? But as it stands now it’s just immediately be taxes * 2)

ACuriousMind

43

Q: Why can't universities work around the proposed reclassification of tuition remission as taxable income, by not charging tuition?

There has been a lot of press about how the new tax proposals currently being considered by Congress could hurt grad students because one of the plans would treat remitted tuition as taxable income. I understand why this would be bad -- grad students who receive tuition remission would have to p...

@GPhys @Semiclassical ^related to our recent discussion

In unrelated news (but related to another discussion here recently), SMBC on meaning in a meaningless universe.

3

Transcript for