The h Bar

barrycarter

00:00

Mods are beings of pure light who touch the earth lightly and leave behind only happiness.

0celo7

Or Stalin.

ArtOfCode

@barrycarter Actually wasn't, spur of the moment. I'm proud of myself.

skill patrol

@barrycarter the black hole of productivity

0celo7

I think either one works.

@skillpatrol This is true.

Riemannian geometry is a close second.

barrycarter

@kaiser Nice double intentional error there: rotate vs revolve and reverse the heliocentric system

0celo7

00:01

If only @ACuriousMind helped me all the time, it would be much easier!

barrycarter

I, too, blame @ACuriousMind

0celo7

Me three.

barrycarter

Wait, you were also one.

0celo7

Oh

barrycarter

You can't be both one and three.

0celo7

00:01

I can't count. Brain damage, remember?

barrycarter

I mean, yes, we need a scapegoat, but don't get overly enthusiastic.

ArtOfCode

I'm seven. Seven what I don't know. Ducks, perhaps.

barrycarter

@0celo7 I can't remember. Brain damage.

ACuriousMind

@kaiser Well...technically, it depends on the arbitrarily chosen frame what revolves around what...I think the "modern" perspective is neither geo- nor heliocentric

0celo7

@ArtOfCode Certainly not inches.

barrycarter

00:02

Relativity is a geometric theory.

0celo7

Centimeters, maybe.

ArtOfCode

u hurt my feels veri bad

0celo7

@ArtOfCode I'm sorry.

skill patrol

Aaah

0celo7

@ACuriousMind Do you even know what an inch is?

kaiser

00:03

@ACuriousMind I wrote something wrong to make an example of wrong. I did not ever ask for how right-ish it could be. But thank you.

ACuriousMind

@0celo7 It's Zoll in German

barrycarter

@ACuriousMind You're not one of those filthy foreigners, are you?

ArtOfCode

@0celo7 I'd make a joke about mothers, if I wasn't trying to be some sort of moderator.

barrycarter

GASP!

@ACuriousMind You're German like @BernardMeurer ?

ArtOfCode

@barrycarter Nope

barrycarter

00:04

Bad auto-complete

ACuriousMind

@barrycarter No, I'm an actual German. :P

barrycarter

@ACuriousMind I never knew. You seemed so helpful and nice.

ArtOfCode

Brit born and bred. I spell things correctly. ;)

barrycarter

@ArtOfCode Colour me impressed.

ArtOfCode

@barrycarter What colour's that? Reddish-purple?

skill patrol

00:06

green

barrycarter

@ArtOfCode It's the colour of almonium

skill patrol

like envy

0celo7

@ACuriousMind >:(

barrycarter

Or armour.

0celo7

I. Speak. German.

ArtOfCode

00:06

@barrycarter gah, bad barry

0celo7

Why does no one believe me?

ArtOfCode

@0celo7 Ja

barrycarter

@0celo7 Sprechen sie duetsch?

0celo7

@ArtOfCode Ja dei Mutti

barrycarter

Yes, I love the Dog God?

0celo7

00:07

@barrycarter What?

@barrycarter Manchmal.

barrycarter

dei = god, mutti = mutt = dog

ArtOfCode

ich kann spreche keine deutsch

0celo7

@barrycarter Uhhhh

@ArtOfCode Go for it.

I won't flag you.

barrycarter

I speak the Swiss version of German.. it's full of holes.

0celo7

Swiss German is an abomination.

ArtOfCode

00:08

@0celo7 What would my comrades think? I'll refrain.

barrycarter

Do not mock the Swiss.

ArtOfCode

for they have cheese

0celo7

@ArtOfCode What comrades?

I don't even like Swiss cheese.

ArtOfCode

@0celo7 Blue ones.

barrycarter

Do you know where Swiss cheese comes from? Holey cows! ha ha

0celo7

00:09

It's good on Cuban sandwiches, and that's about it.

@ArtOfCode Please elaborate.

ArtOfCode

@0celo7 Blue ones with diamonds.

0celo7

@ArtOfCode Diamonds?

The...UN?

barrycarter

The Gnomes of Zurich control the world's finances. They're even more powerful than SE mods.

ArtOfCode

Of the moderator variety

0celo7

Jesus Christ this is why we need to be armed.

The Stack Exchange mods are gathering the UN to kill us.

kaiser

00:10

44

A: A guide to moderating chat

What tools are available to regular chat users? You, as a member of the community, have the ability help keep chat a place that is welcoming for everyone. There might be a variety of other users, including moderators and room owners, in chat with you. Users can be distinguished by the way thei...

2

barrycarter

@0celo7 Ooooh, if you're German, that's possibly in bad taste.

ArtOfCode

Yep, that's exactly what's happening. Guys, we've been sussed.

0celo7

@barrycarter Why? I haven't killed any.

ArtOfCode

Let's not even skirt around holocaust jokes

kaiser

@0celo7 You are very close to a permanent ban.

barrycarter

00:11

@0celo7 Yes, but it suggests you approve of the actions of Chancellor Hitler.

0celo7

@kaiser What?

ArtOfCode

One way ticket to banland.

0celo7

@ArtOfCode Oh come on.

ArtOfCode

@0celo7 No

kaiser

@0celo7 Do not make "jokes" about Swiss dialect. Not funny.

0celo7

00:12

@kaiser What?

ArtOfCode

Holocaust, rape, suicide, etc, are not jokes to be made here

0celo7

I can't tell if you're serious.

skill patrol

he is

kaiser

Are you German?

ACuriousMind

@0celo7 finally you have that experience with someone else!

barrycarter

00:13

I think @kaiser is joking but @ArtOfCode may be serious.

0celo7

@ArtOfCode Well where were you when @barrycarter was encouraging my suicide!

barrycarter

@0celo7 Yeah, but you suggested it.

ArtOfCode

@0celo7 In bed, probably.

barrycarter

@0

0celo7

@kaiser Born and raised. Somewhat.

barrycarter

00:13

@0celo7 I only wanted to help you achieve your goals.

0celo7

@barrycarter I can't tell.

I think @ArtOfCode is serious.

kaiser

@0celo7 Don't blame others.

Secret

@Slereah graph theory?

barrycarter

Your comment didn't really offend me, but it did seem a little ... icky.

ArtOfCode

Very serious.

0celo7

00:14

But I'm not sure about @kaiser .

@kaiser What?

Please make sense.

@ArtOfCode I thought we were friends.

barrycarter

Oh come on!

0celo7

Uh-oh.

ArtOfCode

@barry no

0celo7

What did you say @barrycarter ?

barrycarter

Apparently, it got deleted.

ArtOfCode

00:16

There the line is drawn

0celo7

@barrycarter Email me what you said!

ACuriousMind

@0celo7 Especially friends know when they have to be serious with each other.

barrycarter

There isn't even a Swiss language.

0celo7

@ACuriousMind On the internet, no one knows you're a spider!

Or serious or joking!

Or any of that stuff!

@barrycarter I think @kaiser is Swiss.

barrycarter

@0celo7 Apparently. And he maybe a bit nationalistic as well.

ArtOfCode

00:17

On that note, I'm off to bed, so trample on the line if you like. But I'm not responsible for other mods who come here and ban you for it.

0celo7

Are the Swiss allowed to be nationalistic?

@ArtOfCode How long would the ban be?

barrycarter

@0celo7 See, my message got deleted when I said something like that.

0celo7

I don't see what we're doing wrong.

We're having a friendly chat here.

If anything, banning us now would be entrapment. It's the mods who are antagonizing us :(

barrycarter

@0celo7 Yes. Mortal enemies though we be, let us band together as brothers to defeat the hated mods.

Secret

scienceathome.org/games/quantum-moves/game

0celo7

00:19

@barrycarter Why are we mortal enemies?

Secret

Try this game. I love how citizen science became more common nowadays

barrycarter

@0celo7 Weren't we?

0celo7

I'm your mortal enemy, to me you'e some guy on the internet.

barrycarter

Well, I'm disappointed.

0celo7

I have few mortal enemies.

ACuriousMind

00:20

@0celo7 You know, I never had problems with that. It's you, personally, who seems to have a problem to make "jokes" that are perceived as such.

barrycarter

Old white mathematician seeks arch-nemesis. Apply within.

0celo7

@ACuriousMind I don't even know what you're talking about.

I'm saying I don't know if @kaiser really wants to ban me.

And I'm disappointed that @ArtOfCode would ban me for [redacted].

Oh well, the life of the edgy teenager is a hard one.

barrycarter

oooooh!

Or were you referring to yourself?

0celo7

@barrycarter Yes.

I don't think @ArtOfCode is a teenager.

barrycarter

Oh, I thought you were implying @ArtOfCode ... ok

@0celo7 You're a teenage German living in TN?

0celo7

00:23

@barrycarter Well...

@ACuriousMind Is it disingenuous to call myself "German"?

ACuriousMind

Um. I don't really care, but given that you usually portray America as a bastion of civilization in contrast to Europe, it seems a bit inconsistent.

0celo7

@ACuriousMind Certain parts are indeed civilized.

barrycarter

The non-Southern parts.

0celo7

The other parts are full of liberals and young people. Ick.

barrycarter

But you're a young people?

ACuriousMind

00:25

@0celo7 You mean Canada?

0celo7

@ACuriousMind Good one.

barrycarter

Any place that's named after another place: New Orleans, New York, New Mexico, etc.

0celo7

Their fire hydrants freeze over.

No civilization up there.

barrycarter

And the dogs weenies get stuck to them?

0celo7

@barrycarter They eat dogs up there. I think.

barrycarter

00:26

@0celo7 Well, the French ones probably do.

Once you start eating snails and frogs, there's really no lower limit.

0celo7

Snails are damn good.

I've had frogs a few times, nothing special.

A good snail is pretty awesome though.

barrycarter

It's like a big blob of snot.

0celo7

@barrycarter I'm not a cannibal.

barrycarter

You're German.

And you're young.

0celo7

@barrycarter Which sucks.

barrycarter

00:28

Plus, that's not exactly what I meant ;)

Being old ain't no picnic either.

0celo7

Yes, I buy that.

So eating a Frenchie is not cannibalism.

barrycarter

Good point.

0celo7

I wouldn't eat a monkey though.

barrycarter

There are people who eat monkey brains while the monkey is still alive.

0celo7

As my music teacher in Germany used to say, AIDS is a problem because of [redacted] [redacted] monkeys without a [redacted].

He was pretty racist.

Zing!

@barrycarter Don't the Chinese eat live octopus/squid?

I'm pretty sure I've seen gifs of them eating live frogs and fish, too.

barrycarter

00:31

Oh, I've heard they eat live fish, but not octopus or squid?

Live fish, yes.

Dave Barry wrote about it.

0celo7

Eating Live Squid

►

barrycarter

Hey the Klingons eat gah'ck

0celo7

Never watched Star Trek.

barrycarter

Are you SURE you're a mathematician?

0celo7

I'm an engineer. Maybe.

I don't know what I am.

barrycarter

00:32

OK, that explains it. I'll use smaller words.

0celo7

@barrycarter We can talk about differential geometry.

@Slereah Perfect for you:

1

Q: Deriving the Spinor Completeness Relation without using a Representation

To preface, this has taken up 1 entire day and a further 2 afternoons of work so I will just list the most promising attempts rather than clutter half a notebook ! Given the relations for the spinors, $u(\mathbf{p},\pm\tfrac{1}{2})$ and $v(\mathbf{p},\pm\tfrac{1}{2})$ as, $$ (\not p - m)u(\math...

0

Q: When it is acknowledged space is curved, does that mean the lines which add unto each other are curved rather than straight?

If so, how in the world could Einstein have proved this? Thanks.

general-relativity spacetime curvature geometry space

@ACuriousMind Do you get this?

barrycarter

@0celo7 Hicker-efential geometry?

0celo7

@barrycarter Dunno what that is.

@barrycarter I can tell you about the wonders of Riemannian geometry.

skill patrol

@0celo7 that's not nice

0celo7

Whoa!

@skillpatrol The truth hurts!

skill patrol

00:35

still...

barrycarter

@0celo7 You realize that some Swiss people are French, right?

Ohhhh...

That's gonna get deleted.

skill patrol

just cool it

barrycarter

You have offended Der Kaiser.

0celo7

No.

I deleted it.

skill patrol

good

0celo7

00:37

@skillpatrol You approve of the censorship that goes on here?

skill patrol

no

barrycarter

I think we've found our 2nd scapegoat.

skill patrol

just don't get carried away

barrycarter

Carried away with free speech?

skill patrol

with acting like an animal

0celo7

00:39

Whoa!

skill patrol

1 hour ago, by skill patrol

@barrycarter the process is be nice

enough said.

vzn

01:06

in theory salon, 43 secs ago, by vzn

What is quantum weirdness? Physicists reveal a new explanation that could help build superfast advanced computers / dailymail

0celo7

@skillpatrol Good job.

vzn

@DanielSank idea: use standard terminology for the string, then the QM harmonic oscillator, show both eqns, then point out the analogy and a single unified eqn.

DanielSank

01:37

@vzn In a paper about that correspondence, I'd do that, but in this paper I need to just tell the reader this fact and move on.

It's limited to four pages, which when you include figures is not much space at all.

barrycarter

That... was... annoying.

0celo7

@barrycarter Agreed.

What did they get you for?

barrycarter

@0celo7 Two comments about French people in which I was actually responding to you.

0celo7

Well I got suspended for a French comment.

barrycarter

Something needs to be done here.

0celo7

01:42

We can go straight to the top.

barrycarter

I was thinking that too... who would that be, exactly? The company?

0celo7

The community manager, shog9.

He can ban mods.

barrycarter

That's for the whole of SE?

0celo7

Actually, we weren't banned by mods.

barrycarter

Good point.

Just someone with a chip on their shoulder.

0celo7

01:43

@skillpatrol flagged our comments and the 10k reviewers got us.

barrycarter

I sort of wondered about that. @skillpatrol Did you do that?

Because it seems like someone got annoyed by what I was saying and then searched backwards though my messages to flag something, as though they were just looking for an excuse.

0celo7

@barrycarter Seems like it.

barrycarter

In other words, they flagged me for something that wasn't flaggable by going retroactive.

I don't see @skillpatrol as that sort of guy but I guess he'll answer when he gets back.

0celo7

I don't think he will answer.

He might block us though.

barrycarter

I mean, he didn't seem unhappy about it, but I don't think he actually did it.

I would suspect @kaiser given his dislike of anti-nationalistic sentiment.

0celo7

01:46

Insulting a nation is different than anti-nationalism.

barrycarter

You mean it's more minor?

True.

0celo7

@barrycarter Nations are made up, so insulting a nation is like insulting a fairy.

barrycarter

@0celo7 Hey, you can get banned for that :P ... plus, it was a joke. If you're too thin-skinned to accept jokes about a country, you shouldn't be a mod.

0celo7

I would say the same is true about the [redacted], but I don't want to get banned.

barrycarter

I'm gonna have to start reading up on the appeal/complaints process here.

0celo7

01:48

@barrycarter The best you can do is "email the SE team" and they might get back to you.

AFAIK.

bolbteppa

@0celo7 do you know what a flabby sheaf is?

0celo7

@bolbteppa My stomach?

SevenSidedDie

You've attracted the Eye of Sauron. Hi. @barrycarter and @0celo7, don't treat the network code of conduct like a game where you see how close you can get before a message gets deleted. Both of you can have a day off for repeated and deliberate violations. Ta.

Crap like that is why this exists:

296

Q: Toward a philosophy of Chat

TL;DR: The Problem This keeps happening in chat: Surprise at flags on vulgar messages. Language that would invariably get your comments deleted on the main site occasionally gets flagged and deleted in chat. Confusion reigns. Controversial topics leading to bickering and name-calling. Folks b...

discussion chat feedback help

skill patrol

06:51

you maybe interested in this @dmckee?

ArtOfCode

07:02

@0celo7 Wrong :P 'm 18.

skill patrol

srsly?

@ArtOfCode

ramsay

is it verly highly recomended to do differential geometry before GR

yuggib

07:18

@ramsay it depends at which level and how (undergrad level self/university, grad level,...) you plan to study it

anyways there will be many notions of geometry yes

Slereah

Do some curved imbedded manifolds

It is way easier to start with

ramsay

well now i am gonna enter UG university

skill patrol

if you ever want to talk about serious technical mathematics with serious mathematians check out the homotopy theory room at mathoverflow @yuggib

yuggib

@ramsay doing physics?

ramsay

yup

yuggib

07:21

@skillpatrol homotopy??? no thanks... ;-P

ramsay

@Slereah isn't that differential geometry?

Slereah

It is.

Well, part of it

yuggib

@ramsay it depends on your interests; if you want to focus on GR for a thesis, then it may be good to do some diff geo beforehand

Slereah

Not all curved manifolds are imbedded, though

yuggib

if else the concepts that they give you in an introductory GR course would probably suffice

Slereah

07:23

Really it depends on what you do as a thesis

if you do numeric simulations diff. geo. is probably not that useful

yuggib

@skillpatrol that is the problem of mathoverflow: the population of algebraists/geometers is dense

ramsay

my thesis is gonna be Physics

yuggib

you can get some other mathematician only as a limit point

@ramsay with that title? :-D

Slereah

Are there any other groups outside of $\Bbb R^n$ that have the al-jabar $[P^\mu, P^\nu] = 0$

ramsay

@yuggib :-D but i am still a beginner

yuggib

07:27

I understand that

ramsay

but whenever i open a GR book on its introductory pages there is a equation list written "you must know"
some equations are like flat spacetime , schwarzschild geometry.....

yuggib

but you could become an expert on every subject in physics

so at some point you'll have to choose

and only then it is worth to specialize

Slereah

Oh wait I guess any quotient group of it

Torus groups and whatnot

ramsay

@yuggib i think it is gonna be hard

yuggib

@ramsay it always is

and probably you will end up doing something you would have never thought of

look at @Slereah , I'm pretty sure he did not want to be a programmer... :P

skill patrol

07:32

@yuggib isn't that better than being invaded by finitists? ;-P

yuggib

@skillpatrol not sure...the worst would be a combination of both

luckily Zorn is too important in geometry/algebra

ramsay

i think complex analysis is also needed for GR, isn't it?

Slereah

Eh

Not often

It's pretty rare to even have to deal with complex numbers

(well except for wave equations on it)

ramsay

"It's pretty rare to even have to deal with complex numbers" <----- sounds great

what about TOPOLOGY ?

yuggib

why the caps lock?

Slereah

07:39

There is a study of spacetime topology but for the most part it's not common in GR

ramsay

@yuggib it is hard i heard from my seniors

yuggib

however there will be a good deal of topology, but only if you want to be very accurate on the mathematics side

@ramsay it is sometimes counterintuitive, but not that hard

Slereah

Most GR papers are really about studying state equations on some spacetime

They are fluid druids

ramsay

so it implies i should have hard base of 'topology', shouldn't i?

yuggib

@Slereah and then there are the serious guys

Slereah

07:42

That's a long ass paper

ArtOfCode

@skillpatrol srsly

Words Like Jared

If a bunch of comments (but not all) went missing from another user on a Physics.SE question is there another explanation other than themselves manually deleting them? If this is the wrong place to ask this, I apologize.

yuggib

@Slereah that's a serious paper

Slereah

it is

ArtOfCode

@WordsLikeJared A mod deleting them

Slereah

07:43

Then again

What would be a silly GR paper

Words Like Jared

@ArtOfCode Thank you.

yuggib

@ramsay again, it depends at which "level" you want to study them

Slereah

But from what I've seen, most GR papers are like "Boopidiboo fluid flow on the shiggydiggy metric"

2

yuggib

@Slereah because they're done by physicists :-P

Slereah

The average QFT paper is more "Splork production in $G^\Lambda-V^\aleph$ collision at $s = 530 keV$"

ramsay

07:49

huh...
then is "GR by James b. hartle" good to start for a 15 year old who doesn't know complex analysis, spacetime, diff. geometry and topology ?

Slereah

I usually advise Callahan for a gentle intro to GR

amazon.com/The-Geometry-Spacetime-Introduction-Undergraduate/dp/…

ramsay

thank you Slereah

Slereah

Hm

I found a paper that is both on vixra and arxiv

Doesn't seem too cranky, it's just a classic derivation

Jester Tran

08:10

A and B are matrices, what is this inequality called? ||A+B||_{op} <= ||A||_{op} + ||B||_{op}

Slereah

Cauchy Schwarz inequality?

Oh wait no

Triangle inequality I think

Jester Tran

@Slereah Why isn't it Minkowski's Inequality?

Slereah

Triangle inequality is the generic term for it

Jester Tran

@Slereah I see, thanks

Slereah

For any norm $\|.\|$, the triangle inequality is $\|A + B\| \leq \|A\| + \|B\|$

Jester Tran

08:17

@Slereah Thanks

yuggib

it appears that the triangle inequality for $L^p$ spaces is indeed attributed to Minkowski (and called Minkowski inequality)

however, I know of another inequality on function spaces that is more commonly (as far as I know) called Minkowski and is the following

$\lVert \lVert f(x_1,x_2)\rVert_{L^p_{x_1}}\rVert_{L^q_{x_2}}\leq \lVert \lVert f(x_1,x_2)\rVert_{L^q_{x_2}}\rVert_{L^p_{x_1}}$

i.e. you can exchange the order of taking $L^p$ norms in two different variables

David Z

room topic changed to The h Bar: General chat for Physics Stack Exchange (physics.stackexchange.com). For MathJax see meta.stackexchange.com/a/220976 (no tags)

skill patrol

why?

yuggib

08:37

and more importantly, what is the difference with before? just "see" in place of "use"?

ah ok, no tags

David Z

Oh, for the room topic?

yuggib

yes

David Z

It's a new link. It goes to a list of options for enabling MathJax in chat, rather than just the bookmarklet that we had before.

yuggib

::nods in approval::

even if there will always people asking why they can't see TeX in the chat

T__T

skill patrol

>:'(

Slereah

08:43

Can't the chat just have latex support by default really

David Z

If you click on the link in the new room topic...

42

Q: Any chance of MathJax in chat?

It would be really nice to be able to use MathJaX (math formulas) in chat. Not specially for formulae, but for things like $V_{CC}$ in electronics chat would be very useful.

feature-request status-declined chat mathjax

Slereah

It does not really answer it

It only talks about it for SO

David Z

No, the question is general. (Note that it gives electronics chat as an example)

Slereah

It is implemented on the math chat

Why not here

We use as much latex as them

David Z

@Slereah No it's not... unless I'm missing something huge

Slereah

08:51

"This is implemented on math.stackexchange.com -- you can check it out there. It will never be on Stack Overflow, though, as it is an extremely heavy dependency."

Oh I guess they just mean the main site

skill patrol

yes

skill patrol

09:17

this is what they use in the chatroom

They also have this pinned which maybe inorder here @DavidZ

David Z

We could develop a written chat room etiquette if people want it, sure. Feel free to put that proposal on meta.

But I don't think we have problems with any of those rules in the math post.

skill patrol

that particular post was made by the ex-owner of the room

most of those rules were directed at trying to get rid of me

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