The h Bar

Sir Cumference

12:00 AM

This has to be the most annoying thing I've ever listened to

Star Size Comparison HD

►

The song is obnoxious.

0celo7

tfw you don't have a straightedge or anything to make right angles with

user218912

@0celo7 I just use 2 credit cards.

0celo7

not all of us have rich parents who give us credit cards @bloo

Sir Cumference

I'd say two pieces of paper

or index cards

user218912

@0celo7 your parents are probably richer than mine just sayin.

user218912

12:09 AM

but by credit card I meant any plastic card.

user218912

I only have 1 credit card.

0celo7

@bloo what?

I grew up in the slums of DC

user218912

@0celo7 you said your dad has an engineering firm.

0celo7

I never said that

user218912

May 28 '15 at 2:28, by 0celo7

if I could convince my father and uncle to sell Unger Engineering, I'd be set

user218912

12:11 AM

???

0celo7

I was lying

Sir Cumference

Why tho

user218912

@0celo7 this is new to me.

user218912

you said you were raised in deutschland and then I also remember you saying you live in virginia.

user218912

I only now realized how stupid what I said was. lol

0celo7

12:19 AM

the slums of DC are in VA

user218912

I realized.

user218912

so maybe you're right.

user218912

sorry.

Sir Cumference

@0celo7 Not to sound like an idiot, but how does that work?

user218912

but why did you lie about the engineering firm?

user218912

12:20 AM

@SirCumference there is more than one dc.

Sir Cumference

Sigh...

Well, I feel stupid

0celo7

@SirCumference what?

Washington DC is right next to VA

step one foot outside of "DC proper" and you're in VA or MD

user218912

I just realized "bloo" is an actual thing.

user218912

from a t.v. show

user218912

that I used to watch but had no idea.

0celo7

12:23 AM

@bloo what does that mean?

user218912

@0celo7 there is more than one place named dc in the usa.

user218912

user218912

that's bloo

user218912

this made me laugh

user218912

12:26 AM

best 3d model ever.

0celo7

oh that show

user218912

yep

0celo7

something something monsters orphans?

hot girl?

user218912

fosters home for imaginary friends or something like that.

user218912

yes.

0celo7

12:27 AM

dude with horrible haircut that I emulated for 14 years?

user218912

@0celo7 you had long hair?

user218912

@0celo7 if you mean mac, that's how my hair looks... except not split in the middle.

0celo7

yes

user218912

I am offended.

0celo7

Your hair is offending me

user218912

12:29 AM

I should flag that.

user218912

@0celo7 it's longer now though, goes fully past my eyes.

user218912

but same shape.

0celo7

@bloo get a hair cut

user218912

I think I look cool.

0celo7

good

user218912

2:08 AM

I'm gonna buy some games for my ps vita.

user218912

haven't touched it for a long time.

Sir Cumference

What happened to @bloo?

user218912

well I didn't want to be mixed up with that blue ghost imaginary char named bloo from fosters home for imaginary friends so I changed the oo's to 00's.

user218912

I hope 0celo7 will not forget who I am.

Sir Cumference

or you could just make it bleu or something

Why not IceLord?

user218912

2:20 AM

that sounds too childish

user218912

I used that name in online games when I was a kid.

Sir Cumference

bloo sounds manly?

0celo7

bl00 isn't childish?

user218912

@0celo7 no.

Sir Cumference

It's a child's way of spelling blue tho

0celo7

2:20 AM

^

says the "man" whose name is a pun

Sir Cumference

Says the man whose name is...

Wait what does your name even mean?

user218912

revolver ocelot.

0celo7

Wrong.

user218912

then what?

0celo7

Once again, you've fallen victim to my alter ego's lies

@heather Isn't it your bed time :P

Sir Cumference

2:22 AM

So then what does 0celo7 mean?

What happened to 0celo1-6?

0celo7

I play the cello @SirCumference

the numbers are just there

heather

@0celo7, yup =)

Sir Cumference

@0celo7 Okay, I don't know whether to believe you.

0celo7

that's what Xbox live suggested back in the day

@SirCumference Have I ever lied?

Sir Cumference

2 hours ago, by 0celo7

I was lying

Oct 4 at 19:13, by 0celo7

I lied

Sep 22 at 21:26, by 0celo7

i lied

Aug 30 at 18:05, by 0celo7

I lied. I'll be playing the new Pokemon games

Jul 8 at 1:00, by 0celo7

I lied, it works.

0celo7

2:24 AM

I'll have you shot for libel

Sir Cumference

I think I'll stop there

user218912

@SirCumference wrong guy.

Sir Cumference

Oh crap

0celo7

lol

user218912

May 25 '15 at 2:23, by 0celo7

Get it: my name is a reference to a certain revolver-wielding person.

0celo7

2:25 AM

wrong guy

there's at least 5 people with my name

you have to check the user numbers

user218912

no.

Sir Cumference

Uh, you could just click the link of the poster

user218912

if you click the name it goes to your profile.

Sir Cumference

Just saying

0celo7

fine

since you all hate me, leave

user218912

2:28 AM

@0celo7 what?

Sir Cumference

so wait

is it read like oh-celo?

0celo7

oh-chello-seven

Sir Cumference

ah-celo?

chello?

user218912

wtf

Sir Cumference

@bl00 But you really don't need to worry about having a childish name here. @MAFIA36790 Literally has "mafia" in his name. @AlfredCentauri mixed his name with a star.

Hell, I have a pun in my name

user218912

2:35 AM

I feel better now.

Sir Cumference

tbh it was a more recognizable name than bloo

I probably just pissed off two users up there.

@bl00 Want to see something cool?

user218912

always.

Sir Cumference

All right, here's a math magic trick

Think of a number, okay?

user218912

ok.

Sir Cumference

Now count the number of letters it takes to spell that number.

user218912

2:43 AM

ok.

Sir Cumference

That's your new number. Now count the number of letters it takes to spell that number.

user218912

ok.

Sir Cumference

Repeat this. You'll always end up at "4" after long enough.

It works with negative numbers, decimals, surreal numbers, imaginary numbers, infinity...

Any number.

Once you get to 4, there's nothing else you can do. 4 has four letters.

user218912

I realized that.

Sir Cumference

Not impressed?

user218912

2:45 AM

yes my mind is blown.

Sir Cumference

:D

user218912

I am dropping condensed matter.

user218912

I will replace it with GR.

user228700

Hello :-) Is anybody familiar with the formula that gives the coordinates of a point externally dividing a line segment. I asked at the Math SE chat, but to no avail...

user218912

@SirCumference want to learn something cool?

Sir Cumference

2:53 AM

Sure

user218912

read tong's notes. xD

Sir Cumference

._.

0celo7

@bl00 do you ever stick with anything?

user218912

@0celo7 no.

user218912

I'm hopping subjects until I finally find something I really like.

0celo7

2:56 AM

it will end up being analysis

or did you drop that?

user218912

dropped it to fit grad stat mech in my schedule.

0celo7

do you not have graduation requirements?

user218912

15 credits.

user218912

in physics and math

user218912

for now I'm thinking my best bet is to do ST because it's cool and can be applied to GR, QFT, CMT, other things etc...

user218912

2:58 AM

so even if I decide to switch to another area of physics from that I won't be lacking or have to start from scratch.

user218912

so right now I'm focusing on GR and QFT, and on the side I'm brushing up my QM and math.

0celo7

@Kaumudi what time is it in your part of the world?

@bl00 what math?

user228700

@0celo7 8:30 AM

user218912

@0celo7 like index notation, tensors, manifolds, lie algebra, (also some basic calculus which apparently I am forgetting).

0celo7

do you know enough topology for manifolds?

user218912

3:05 AM

non-rigorous description of manifolds

user218912

physicist manifolds

0celo7

so you're reading Zee?

@Kaumudi k

user218912

carroll.

0celo7

hmm

does the course follow carroll?

user218912

I don't go to the lectures so idc, the course book is the notes.

user218912

3:07 AM

the lectures for GR are not good.

user218912

just reads off of projected notes and doesn't write anything down on the board.

user218912

it's about carroll level or lower.

0celo7

what are the notes?

lemme see

@bl00 You should read Wald

user218912

any reason?

user218912

I think carroll is really good.

0celo7

3:11 AM

Wald has topology

and basically

1, 2: analysis/geometry, 3: topology, 4-rest: other crappy math

user218912

@0celo7 notes

user218912

@0celo7 is that important for ST?

user218912

and will I understand wald as my first (or semi-first) book?

0celo7

@bl00 no, not really

depends what ST

user218912

like what you were doing

user218912

3:14 AM

to read BBS

0celo7

1 or two semesters?

user218912

all of it.

user218912

you mean gr or st?

0celo7

these notes

1 or 2 semesters?

user218912

1

user218912

3:17 AM

3 months basically

user218912

3 hours / week

user218912

why?

0celo7

> Many discussions of Riemannian geometry in GR textbooks get all mathematical, andthis often turns o physics students. So I will make you a promise right now: I will notintroduce more math than we actually need to get the physics goals of this course achieved

garbage

user218912

xD

0celo7

> Mathematicians in this PHY483F class will generally need to hold their tongues on nitpicking

What's this class?

wait

user218912

3:19 AM

for physicists.

0celo7

I read that wrong

>If you are intensely interested in the mathy aspects of GR, the Mathematics Departmenthas a nice APM course for you

APM?

user218912

applied math.

user218912

I know that course

user218912

want to see the notes for it?

0celo7

yes

user218912

3:20 AM

here

user218912

he's a new prof at my university, teaching the course based off another course he taught, using the same notes.

user218912

it looks hardcore.

user218912

I don't think I'm ready to take that course, it's in the winter though.

0celo7

it's still for physicists

user218912

really?

0celo7

3:23 AM

if you have to define homeomorphism in your notes, it's not for mathematicians

user218912

any other reason?

0celo7

2. on page 82 is new to me.

Huh.

user218912

I think you would love this course.

0celo7

nvm they don't define homeomorphism

@bl00 probably

user218912

so do you agree it's way too advanced for me?

0celo7

3:27 AM

Hmm, how would I prove that? An immersed compact manifold has a nonempty boundary...

user218912

I should stick to my carroll.

0celo7

Right, one should show it's clopen in $M$

Closed because it's compact Hausdorff.

user218912

@0celo7 is the stuff in that course useful for reading BBS?

0celo7

Not at all

Ah, sure, cover by balls. So it's open in $M$

The contradiction is that you can't cover by balls

Yeah, neat result. I'm sure I knew that at one point.

user218912

alright, thanks. I will stick to carroll and use eschrig/nakahara for geometry background for bbs.

user218912

3:30 AM

also

user218912

when can I begin BBS?

0celo7

eschrig?

user218912

After QFT I?

0celo7

@bl00 Never

BBS is terrible

user218912

what do you recommend then?

0celo7

3:30 AM

maybe after you've read Polchinski

Polchinski

@ACuriousMind 's notes too

user218912

so it's more advanced than polchinski? :O

user218912

@0celo7 similar book to nakahara, google it if you want.

0celo7

@bl00 yes

it's also harder because it's terrible

user218912

so when can I begin ST?

user218912

right after qft 1 and gr 1?

user218912

3:32 AM

or do I need qft 2

user218912

we don't do path integrals in qft 1

0celo7

@bl00 ah that's a good book

@bl00 you need both QFTs, definitely.

user218912

@0celo7 how come you said you don't know all of the stuff in qft 2 but you went quite far into st?

0celo7

it was a mistake

superficially I knew everything in QFT2

user218912

ok, then I'll begin st in april, don't want to rush.

user218912

3:35 AM

hopefully nakahara 3rd edition will be out by then.

user218912

it's been delayed by a year.

0celo7

Lee's preparing a second edition of Riem geo

you should get it when it comes out

user218912

but will I need it?

user218912

I want to do physicists string theory for now.

user218912

and I am bored of math for some reason.

0celo7

3:36 AM

I'll get it and give it a quick read (probably nothing new in it for me)

@bl00 no

user218912

oh right when is your birthday again?

user218912

oct 27?

0celo7

10 days.

user218912

oh

user218912

I still owe you lee xD

user218912

3:37 AM

how will I send it to you?

0celo7

I can give you my address on skype

user218912

how long does it take to ship?

0celo7

not sure...

from Amazon presumably?

user218912

I have free prime.

user218912

yes

0celo7

3:38 AM

yeah me too

2 days, always

user218912

okay so I'll buy it for you in a week.

0celo7

cool :)

user218912

but in return can you please help me out on my trivial-obvious questions for qft and gr?

user218912

assuming it's within your domain.

user218912

not stuff like calculate this integral for me like before, more like conceptual questions.

user218912

3:41 AM

the rest I'll figure out myself.

0celo7

ok

user228700

5:25 AM

Where is everybody? :/

Sir Cumference

@Kaumudi Sleeping probably

user116211

Damn; I had question for 0celo7 ;/

user116211

He went off early today.

user116211

5:44 AM

Does anyone know what singlular Lagrangian is?

user116211

This is a new term; I googled but what came were bunch of papers beyond my scope now.

user228700

@SirCumference Huh.

user228700

@MAFIA36790 Are u allowed to study today?

user116211

@Kaumudi What?

user228700

@MAFIA36790 On account of Durga puja and all, I mean.

user116211

5:52 AM

@Kaumudi ohh.

user116211

All days are indifferent to me.

user228700

Right :-)

Secret

O wait, so they have finally managed to made one?? Breaking time translation symmetry?

user116211

@Secret Time translation symmetry isn't rigid, is it?

Secret

Well, since that 2012 proposal about time crystals, there are a couple of papers followed that showed you cannot have a nonstationary ground state. The paragraph about the 2016 paper is rather new, thus I am not sure how they can overcome those previosu findings

This paper talks about systems with broken time translation symmetry

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