ultimatecampresource.com/site/camp-activity/…

that reminds my favourite crank theory I read back in physics forums

> As it is with all things, Dark-Suckers don't last forever. Once they are full of dark, they can no longer suck. This is proven by the dark spot on a full Dark-Sucker.

ronapostle.wordpress.com/2011/09/16/…

and then this is a debunk of that

@0celo7 I did not understand the christmas comment

10/10

\

wtf

@BalarkaSen I got some books for free

is it the bible

i have a free bible

One of them is Chrisodoulou and Klainerman

so basically

@BalarkaSen also Hempel

I got Streater and Wightman in the mail

@BalarkaSen Burago, Burago, and Ivanov

Lang, Hungerford

@Slereah if you figure out what edge-of-the-wedge is about would love to know, in there somewhere

Well I found out what the edge of the wedge stuff is

@0celo7 cool

The hard part is relating it to the problem I have

@BalarkaSen spin geometry

I think I'm missing some

I've gotta get the stack on monday but it was def christmas

@BalarkaSen there was this book "diffeology" that I left there

is it interesting?

idk

@BalarkaSen this book has too many words

@BalarkaSen (the metric geometry one)

it's very Russian

whom is the metric geometry book by

burago, burago, and ivanov

i see

@BalarkaSen it's actually quite nice for leisure reading, or at least the intro chapter is

why dont you read gromov

he has a book on metric geometry :3

I might eventually

I'm only learning this crap because one of Gromov's students is a big GR person, but no one actually understands his work besides him and Gromov

lmao

his writing style is impenetrable

you're never sure what's a trivial remark or a deep theorem, where exactly the proofs are, and he hides stuff behind a wall of references

so, Gromov style

truly

@BalarkaSen I'll be getting exercises from this book when I teach analysis, wow

russians may be shit writers, but the exercises are cool

i like the exercises in eliash-misha

@0celo7 oh btw I proved a cool thing a few days ago

If $(M, \omega_M)$ and $(N, \omega_N)$ are closed manifolds with specified volume forms, denote $\text{Diff}_\omega(M, N)$ to be the space of diffeomorphisms $f : M \to N$ such that $f^* \omega_N = \omega_M$, i.e, the volume forms are preserved.

ok

The inclusion $\text{Diff}_\omega(M, N) \hookrightarrow \text{Diff}(M, N)$ is a (weak) homotopy equivalence

why would that be interesting to anyone

This follows from the Moser trick I was telling you about

idk it's cute man

is it in EM?

@BalarkaSen infinite dimensional geometry is very mysterious to me

nah Mike told me to prove it and after some fiddling I did

@0celo7 I think these guys are Frechet manifolds, yes?

I do not know

moi neither

I mean, that sounds right, but meh

Not my area

hm is there a Cartan's magic formula if i want to look at $\mathcal{L}_X T$ where $T$ is symmetric, not antisymmetric?

"Let B denote a unit ball in R^3 with its center removed. Then B can be split into 4 disjoint subsets, which can be rearranged (by means of rotations) so as to form two copies of B."

I think they're just saying Banach-Tarski but that's some bullshit. If you take out points, then your notion of "two copies" is not obvious.

Especially if the maps involved are just rotations.

@BalarkaSen Not that I've seen.

@Slereah yo

reed and simon 4 is impossible to read

is that the one with the QFT construction

Or is that 3

I seem to recall it's the one that has the representation Hilbert space for KG

4 is, among other things, perturbation theory

@BalarkaSen

beautiful

@BalarkaSen every Riemannian length structure on R^n is induced by a map f: R^n --> R^n

p cool

(rarely a smooth map)

no proof though

not even a reference

typical Russian math

maybe its proved in the book

further somewhere

Further, we mention that (though hard to believe and not easy to prove) ...

doesn't seem like they intend to prove it

@EmilioPisanty Milord, I need a TeX CV format

@0celo7 I used this one last time

github.com/posquit0/Awesome-CV

... with some modifications of my own ;-)

\o @EmilioPisanty

@EmilioPisanty any that you'd like to share?

fancy

thanks

specifically them google scholar, orcid and SE buttons

I probably won't steal that part

@0celo7 you can't

you need to pull in a new font

github.com/jpswalsh/academicons

they're not in fontawesome

oh no I'm just saying I don't have publications yet so I don't need google scholar, etc.

@0celo7 yeah, it's probably not a great idea then

I do intend to fork the awesome-cv repo and github and make those changes available

but that requires some dedicated time which is going to be hard to come by

@EmilioPisanty oh, there's room for an inspirational quote

"The next person to propose a new definition of a connection should be summarily executed." - M. Spivak

@0celo7 I don't know why

@EmilioPisanty I could imagine my advisor asking me "what is this shit" if I sent it to him with a quote

@0celo7 exactly

Leave the quotes for the blog :P

Fuck yeah, "Einstein and the Evidence." - J. Duffield

You got it pal.

btw @Semiclassical here's the modified Pearcey

@0celo7 what is it doing in Reed

I thought perturbation theory was a scam

or is it for QM

exponential decay to the top right, exponential growth where the zeros are

but with some interesting three-fold symmetry going

@Slereah perturbation theory is very real

it's just very, very hard to do correctly

What do the colors mean?

presumably it actually just reduces to the Airy function if you fix the second argument

yeah it's pretty hard to even find a paper that treats it rigorously

@Slereah see kato, Perturbation theory for linear operators

maybe I should re-check with a different sign? presumably the essentials of the Pearcey behaviour are in the change between $y<0$ and $y>0$, right?

@skullpatrol that's a plot of $\log(\tilde P(x,-1))$ for $x$ in the complex plane

where $\tilde P$ is a modification of the Pearcey function as defined in chapter 36 of the DLMF

lines are contours of the phase and the amplitude of $\tilde P(x,-1)$, the colours are the phase

ok, thanks

@Semiclassical Oh, I get it now. The diffraction-catastrophe canonical integrals as defined in §36.2 do admit other linearly-independent contours, corresponding to the other solutions of the $\Phi_K'(\partial_{x_1})$-like differential equations, but those other solutions don't involve the full set of saddle-point dances.

neat

And, since the nontrivial aspects reduce to fewer saddle points, they can just be mapped down to a lower order of catastrophe

so there's no need to report them so they don't

I think

or something along those lines

bloody hell

it's hard replaying games without autosaves

I keep forgetting to save

@Slereah what game?

Escape from Monkey Island

It's one of Those games

Late 90's games that only work on virtual machines

Because you can pretty much only run them on windows 98

lol

there's a few games like that

They're so tied to a specific type of hardware and old windows libraries

It's basically impossible to run them on modern PCs

Got a new battery installed in the phone

It is pretty nice

Having the battery not drop down after a few hours

@BalarkaSen interesting, Goursat's theorem holds even if the function is not holomorphic at a point in the triangle, but still bounded there.

If something holomorphic is bounded near a singularity you can extend over that singularity holomorphically

removable singularity theorem

you can prove it without that

Yes but I mean it's not interesting

per se

@Slereah ugh, those things are a pain

I spell it as Ga-low-ah

Where the "Ga" is spelled as in "gasket"

@BalarkaSen you write Galowah?

what is wrong with you

potato pohtato

It's French dawg

...

s is silent most of the time

also "Darboux" is "Darboo"

Because it indicates a sound that Indians cannot produce but is essential for French

@Blue Why not write "fish" as "ghoti"?

It's the same sound

what

gh of "bough", o of "women" and ti of "nation"

F I SH

@Blue Fuck me, you think Latin letters originated in England?

@Blue lol what. do you think French alphabet originated from English alphabets?

they all have a common root

@Blue You might find it interesting that numerals are not English either...

Swastikas aren't German!

@Blue You don't need to know the history of Western languages. Think about Burmese and Bengali

they have a common origin, that's all.

also Assamese

youre from there so youd see the similarity

yeah

this is why German spelling is good, English is bad, and French is confusing

what about Russian

gulag

blyat

@0celo7 as James Joyce once said "Gee each owe tea eye smells fish"

(ghoti spells fish)

@BalarkaSen do you know how to get Cauchy's integral formula with a $\Re(Re^{i\phi}+z)/(Re^{i\phi}-z)$ thing in it?

hell no

@BalarkaSen not nice

?

@BalarkaSen idk I'm failing at algebra

...is it too late to withdraw?

If

@skullpatrol no, literally failing to add fractions correctly in a complex analysis problem

@Blue Yes. Languages change with time. But spoken language changes faster than written language. So often, if a spelling doesn't match the way a word is said, it's because it matches the way the word was said a few hundred years ago.

There are many other reasons for differences between the way a word is pronounced and the way it's spelt, but this is kind of the main one.