The h Bar

0celo7

2:02 PM

@Slereah I really do

Slereah

what was the book you wanted?

Modern canonical quantum gravity?

Emilio Pisanty

yo folks

can somebody explain how the hell this link

   arxiv.org/pdf/0807.0929%20%22photosynthesis%22.

manages to work?

0celo7

@Slereah indeed

I’ll pick it up at the lib today if you want to read it

Slereah

it doesn't seem to be on libgen

cds.cern.ch/record/1111397/files/9780521842631_TOC.pdf

that one?

oh it's just the index

arxiv.org/pdf/gr-qc/0110034.pdf

this one mb

0celo7

That doesn’t look long enough

This is one of those giant books

Slereah

2:15 PM

is it available somewhere

I think I have it at home?

But it doesn't seem to be in genlib right now

ACuriousMind

@EmilioPisanty Why wouldn't it work?

Slereah

Oh wait

I do find it if I search the author's name

Emilio Pisanty

@ACuriousMind arXiv:0807.0929/YouCanAddWhateverTextYouWantToTheEndOfAnArXivURLAfterASolidusAn‌dItWillWork

Slereah

Oh it's "quantum general relativity", not "quantum gravity"

0celo7

Oh, right

It’s a GR man’s Quantum gravity book

Perfect for us

Also quite rigorous for physics

ACuriousMind

2:17 PM

@EmilioPisanty Also works with most SE pages: physics.stackexchange.com/users/8563/…

Slereah

I hope it's not as obtuse as Rovelli

Emilio Pisanty

@ACuriousMind no, that's just SE being really smart about redirects

Slereah

that man lays on the math thick

Emilio Pisanty

notice that your link will always end up at a single canonical url

now go here and save the pdf to your disk, and tell me what document name it defaults to

heh

0celo7

@Slereah should I pick up Rovelli too?

Slereah

2:19 PM

I dunno

it's an interesting book

Plus it's free on the internet

You can give it a look

There's a lot of epistemology in the first chapters, though

0celo7

I can pick it up from the library

Slereah

Might not be your style

0celo7

I love epistemology

I have epistemological crises all the time

I've just decided that I don't understand physics

3

Emilio Pisanty

here's e.g. what happens at APS journals.aps.org/prx/pdf/10.1103/PhysRevX.7.041059/…;

0celo7

@EmilioPisanty 404

Slereah

2:22 PM

it's one of the rare GR-ish book to talk about the hole argument and such

0celo7

Alright I’ll pick it up

Emilio Pisanty

@0celo7 precisely

Slereah

there's also a lot of rambling about what TIME is

ACuriousMind

@EmilioPisanty Hm, you're right arXiv is not redirecting

Emilio Pisanty

@ACuriousMind toldja

so you can do things like arxiv.org/pdf/1709.00397/"ThisIsTheBestPaperEver";

Slereah

2:27 PM

Oh no

First chapter of Modern bla bla bla

category theory!!

Fortunately it's the AQFT madness

Which I know a little about

0celo7

Oh dear lord

I went on a rant about category theory during my seminar last night

Slereah

"it is also unclear whether the procedure leads to (unitarily) equivalent results when using backgrounds which are physically different, such as two Schwarzschild spacetimes with different mass (the corresponding spacetimes are not isometric)."

Oh no

Secret

After 5 days, I conclude I still don't understand open covers on the rationals and irrationals

Slereah

also Thiemann uses <> instead of \langle \rangle

0celo7

Yeah that’s pretty awful

But he uses the right metric signature

Slereah

2:40 PM

QG books love their heuristic arguments and epistemology man

0celo7

@Slereah what does he do

Slereah

" According to [49] there exist at least 10^4 consistent, distinct Calabi–Yau compactifications"

10,000 isn't that much

@0celo7 The usual

Arguments about quantum energies generating black holes

Metric fluctuations at very small scale

the usual QG stuff

lots of handwaving

But that's typical intro stuff

The math usually butts in at chapter 2

0celo7

Ok

Slereah

Basically it's the "This is why I believe that this theory is the best"

"Much better than all other QG theories"

and then the next 20 chapters are math and the conclusion is "I don't actually have any prediction to offer from this but trust me"

0celo7

2:55 PM

@ACuriousMind what is the correct definition for complex analyticity in many variables?

Slereah

Well, if it's a really good theory, they'll tell you "From this we can derive classical general relativity"

Balarka Sen

@0celo7 The "correct" definition is obviously that at each point your function admits a multivariable Taylor series. The "incorrect" definition is obviously that your function is holomorphic on each complex coordinate individually.

Fact: The correct and the incorrect definitions are equivalent

Slereah

:D

If they're equivalent is it really incorrect

Balarka Sen

No, which is why I put it in scare quotes :)

Slereah

"The Poincaré group is a group of symmetries of asymptotically flat spacetimes while the diffeomorphisms, which are asymptotically trivial by definition, are gauge transformations."

I smell some physicist shenanigans

Balarka Sen

3:02 PM

I smell nothing

my nose is totally blocked from the flu

0celo7

@BalarkaSen Yeah I saw that as a theorem but the incorrect definition seemed better

So I was confus

Balarka Sen

the incorrect one is def easier to work with

I mean this is totally false for mult. smooth functions eg

0celo7

Yes

Slereah

I skipped a bunch of the intro

Onto chapter 1

Balarka Sen

what are u reading

Slereah

3:06 PM

"Classical Hamiltonian formulation of General Relativity"

Oh no

Balarka Sen

is this loop quantum gravity

Slereah

not again!

Balarka Sen

aka bullshit?

Slereah

"Modern canonical quantum general relativity"

so yes

Balarka Sen

mhm

user228700

3:07 PM

@BalarkaSen x'D Wow, nice!

Slereah

As we all know String Theory is the true god

user228700

@JohnRennie Hello! :-) How's it going?

0celo7

@BalarkaSen as of right now it’s as bullshit as string theory

IMO the math is much nicer so it’s the better theory

Balarka Sen

@Kaumudi.H thanks. now, if only i end up getting a secured position in any of the exams of > epsilon importance...

how did your drawing exam go?

the 5th grade drawing exam

crayons and shit

0celo7

@Kaumudi.H oh shit you’re an expert artist now

Slereah

3:09 PM

@0celo7 it has much less topology though

0celo7

Can I commission some stuff?

@Slereah topology is one of the worst maths

Balarka Sen

@0celo7 i see

what does it say

0celo7

Algebraic topology, that is

Balarka Sen

string theory says we are all strings

user228700

@BalarkaSen -.-

Balarka Sen

3:10 PM

what does LQG say?

0celo7

@BalarkaSen no clue. I haven’t picked up the book yet

Balarka Sen

maybe it says we are all loopy

0celo7

We’re all loops

Slereah

LQG says we are all spin-networks

Balarka Sen

see?

i know physics

Slereah

3:11 PM

Although actually LQG is mostly for spacetime

And scalar particles IIRC

It has troubles dealing with fermions

String theory has the benefit of being STRINGS FOR EVERYBODY

No need to wonder about what to put on your spacetime

It's spaghettis every day

user228700

My exam was actually OK, thanks! In the first exam they conducted for it, I managed to fail, somehow, so going into this one, my only prayer was to pass properly, which I think I might just!

Balarka Sen

cool cool

user228700

How's your day going?

Balarka Sen

not bad

user228700

Still miserable?

Balarka Sen

3:18 PM

by definition

user228700

Right.

user228700

@Balarka: Are you in the mood for 41 Dad Jokes in 4 Minutes?

Balarka Sen

jesus no

user228700

x'D

user228700

I will link to it regardless:

user228700

3:21 PM

41 Dad Jokes in 4 Minutes! (with special guest star...)

►

Balarka Sen

I internally died at the 5th joke he made. I can't

I tried

user228700

Check 2:06.

0celo7

@Slereah fermions are nonsense anyway

Slereah

ur made of fermions

You're nothing but nonsense

Balarka Sen

2:23 is a proof worthy theorem

Hank Green clearly doesn't know any math

Sid

3:27 PM

@Kaumudi.H first exam? Internals?

Balarka Sen

he needs to work on his quickmaffs

user228700

x'D

user228700

@Sid Yep.

Slereah

"the famous Gauß equation"

>Gauß

Sid

meh. No one cares about internals

Balarka Sen

3:28 PM

Gaub

Gaubonnet theorem

user228700

@Sid Most everyone here seems to give many, many craps about internals :-/

0celo7

Gauβ

Sid

@Kaumudi.H How is the total semester marks divided in your college?

Slereah

Gauβonnet

user228700

@Sid I don't know the details but this much is clear-the internals don't matter very much.

Balarka Sen

3:31 PM

oh my gau$\beta$

John Rennie

@Kaumudi.H Hi :-)

user228700

Hallo! :-)

Slereah

Chapter 1 is a whole lot of foliation shenanigans

John Rennie

@Kaumudi.H the snow has stopped :-)

Actually most of the snow has already melted. As attempts at a white Christmas go it was a bit premature.

user228700

:-) Ah, that's a shame.

John Rennie

3:38 PM

Oh well. I'm about to eat lunch (in about 5 minutes) so the world looks a bright sunny place right now.

I started watching John Green's dad jokes video, but I'm not sure I can take 4 minutes of that ...

user228700

@JohnRennie *Hank :-)

user228700

You ought to be able to! You are, after all, the quintessential dad of this chat :-)

Balarka Sen

JR's jokes are much, much better

Sid

@JohnRennie At 15:30? That late?

John Rennie

Ah, yes, he started the video with Good morning John, which I obviously misheard as Good morning I'm John or something like that.

@Sid I suppose it's not really lunch. Sort of a lunch dinner hybrid.

@Kaumudi.H my jokes are invariably almost but not quite obscene

user228700

3:41 PM

:-) True.

John Rennie

BTW I'm cooking that chocolate brownie pie for dessert today.

user228700

Ah, lovely! :-) Picture, please!

Slereah

"chocolate brownie pie" sounds like a cake

a chocolate cake

John Rennie

Will do. It takes 35 minutes to cook, so it will be a while.

Sid

@Kaumudi.H Actually, JR is of the same age as my Dad.

user228700

3:43 PM

@Sid Ah, wow, I see. Are you a second or third child?

user228700

@JohnRennie OK :-) I'm having two dosas for dinner, cooked by my grandmum!

John Rennie

user228700

Yep, I remember!

Sid

@Kaumudi.H Second(and youngest) child, yes.

John Rennie

@Kaumudi.H aha you've fled the hostel!

(I would too :-)

user228700

3:44 PM

:-) Almost immediately after my exam got over!

user228700

@Sid I see. My dad turns 50 next year, I think, and I am the eldest child, so yes, that makes sense.

Balarka Sen

ugh parenthesized smilies

(😺)

such a happy kitty

3:47 PM

no. it's trapped

between the parenthesized atrocities

Slereah

Cats enjoy being in boxes

0celo7

It’s being held down by the man

Slereah

Be they parenthetical

Balarka Sen

communism killed the cat

i mean capitalism flick

@Slereah the mouseover text tho

Semiclassical

morning chat

Slereah

4:00 PM

Mroing

user228700

4:17 PM

@JohnR: Picture?

John Rennie

4:28 PM

I broke it getting it out of the disk :-(

Still tastes OK though :-)

user228700

:-) Cool. Mint ice cream?

John Rennie

@Kaumudi.H Yes :-) If I can get the other half out without breaking it I'll take a photo of that ...

user228700

OK :-)

0celo7

@JohnRennie what the heck is that

John Rennie

51 mins ago, by John Rennie

It got a bit mangled though ...

0celo7

4:39 PM

@Slereah got rovelli and tiemann

DanielSank

Hi, everybody.

Sid

@DanielSank Hey! You have survived the burning state?

DanielSank

@Sid I wouldn't say that yet.

user228700

@DanielSank Hello :-) How is you?

0celo7

is you?

are you

DanielSank

4:42 PM

@Kaumudi.H I is good.

0celo7

@Slereah Should I read Rovelli over the break?

user228700

@0celo7 -.- Gosh, I was merely attempting to be a little silly with my words.

user228700

@DanielSank Good to know! :-) Your state is on fire? How come? It's December...

DanielSank

@Kaumudi.H Southern California doesn't care about seasons.

John Rennie

user228700

4:44 PM

Ah, hmm :-/

John Rennie

There, that's better!

Sid

@0celo7 I am waiting for you to tell "Indian English". :P

0celo7

@Sid I've been attacked on this issue before so I'll just be quiet

do know that I'm shaking my fist in the background

user228700

@0celo7 To be clear, you weren't attacked-simply reprimanded for being insensitive :-)

user228700

@JohnRennie :-( You're making me hungry...

0celo7

4:46 PM

@Kaumudi.H tomato, tomato

Sid

@0celo7 yuck

0celo7

@Sid you don't like tomatoes?

Balarka Sen

0celo7's been attacked for mocking indian english?

Sid

@0celo7 Nope. They make things sour...

user228700

@BalarkaSen He has been "attacked" for mocking most things Indian, so I assume so...

0celo7

4:48 PM

Ahem, I do not mock

I just say they're wrong

Well, I do mock indian english

user228700

Tomato, tomato :-)

Balarka Sen

well indian english is pretty shit

0celo7

touche @Kaumudi.H

user228700

@BalarkaSen True.

0celo7

aha!

I'm right!

Balarka Sen

4:49 PM

i can't read most acclaimed works in indian english

user228700

@0celo7 Well, I did agree with you on that front!

John Rennie

I love all the different dialects of English. I think they make the language so much more fun.

0celo7

holy h*ck loop quantum gravity is satanic!!

Balarka Sen

I found the literary content of Magudi Days dry and completely hollow

0celo7

parkinsons level image quality, yikes

Balarka Sen

4:50 PM

@JohnRennie I think British English is pretty bad too.

Irish English is where the fun is

absolutely amazing

user228700

@BalarkaSen :-O

0celo7

American English > German > other

John Rennie

I don't think Indian English is all different from BBC English. Scots English is probably a lot more different.

0celo7

Big Black Curry English?

user228700

Man, R.K.Narayan is one of my favorite authors!

Balarka Sen

4:51 PM

@Kaumudi.H Well, I have never found the appeal in him

I can't actually come up with a name from India who writes in English and the works of whom I really care for

Sid

@BalarkaSen Chetan Bhagat. :P

user228700

Phrases and words such as filter coffee and tumbler give me the feels, which would explain my particular taste for his work.

Balarka Sen

jesus fucking christ @Sid

John Rennie

@BalarkaSen no, I'm pretty certain he wasn't Indian and didn't write in English

Sid

@BalarkaSen Don't use swear words in the Lord's name. :P

0celo7

4:55 PM

@BalarkaSen ok this deserves to be flagged

Balarka Sen

Amitav Ghosh is pretty hip

but I think it's only mildly interesting

user685252

in other news:

Now 529 pages for 19,000 spam profiles. – doppelgreener 2 days ago

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