I am like the wild eyed man in the horror movie

Trying to warn you about the evils that lurk beyond

BUT YOU DID NOT LISTEN

Like the foreign dude from The Thing

@yuggib : I'm telling you about the bona-fide physics. I'm not making it up. Don't accuse me of spamming when I'm merely correcting your popscience misunderstanding.

@Slereah :-D you are indeed overreacting

...or The Blob?

@JohnDuffield You are making up an interpretation. Not acknowledging that, and continuing to change subject is an intellectually dishonest behavior. I never made a statement different from asking you about your interpretations. Since you are not addressing such question, in my opinion you are just spamming.

Curious to see the opinion of others, maybe less involved in this "argument", about that.

^this is me

Anyways, much to @Slereah pleasure, I will not comment further on the matter, frankly because I believe there are better things to do.

@0celo7 I don't know what "turning up" is supposed to mean there.

@ACuriousMind perhaps it is similar to "tuning out?"

Better things like doing research! :) a small enquiry: would you (as physicists) be interested in a rigorous derivation of classical electrodynamics from quantum electrodynamics (for extended charges interacting with the EM field)? Or is it something that, even if it has never been satisfactorily proved, you simply assume to be true and do not care?

@ACuriousMind ::sigh::

get drunk and party

Wouldn't that be somewhat trivial

@Slereah Define trivial

Just take the limit $\hbar \rightarrow 0$

expected, of course; trivial, not exactly

In the case of the path integral, it would be pretty trivial

@yuggib I'm...not sure what that would involve, actually. Taking the classical limit explicitly and showing it is what everyone expects?

@Huy I met an alumnus of yours today

Denzler is...an interesting fellow

@0celo7 Ah. Yes, I did that :D

He's what I imagine ACM to be in 30 years

@Slereah I thought it was pretty clear I was talking about rigorous stuff

taught us all about linear and Bernoulli equations

Well QFT isn't that rigorous :p

went on a nice German rant about people memorizing stuff

What would you use to do it rigorously

DISTRIBUTIONS

Algebraic QFT?

@yuggib path integral is rigorous

you mathy people are meme tier sometimes

@yuggib Thinking about it, I think I'd be interested in that because I'm not even sure what it would look like

@ACuriousMind What is the explicit limit? the limit of the evolution operator?

@0celo7 : for free particles they're okay

Interacting, not so sure

@Slereah For extended charges, you have rigorous dynamics ;-)

they're okay for everything

in the Fock space

@yuggib Yeah, I realized I'm not sure what exactly the "classical limit" really consists of.

Then why is Lorentzian gravity so shit

@0celo7 We clearly have different definitions of rigor

$$\int\mathrm{e}^{-S[\phi]}\,\mathcal{D}\phi$$

done.

rigorous

I don't see the issue

@0celo7 they can "rant" all they want, but when it comes to exam time you better have it down pat.

maybe this is why I can't do analysis

@Rigor no shit, I can do derivations and memorize

idk why these profs think it's one or the other

What's a "German rant", anyway?

rant with a German accent

like Adolf :P

it's an extra level of intellectual rigor

Adolf wasn't German

He was Austrian

yes, master

@ACuriousMind Well, nice to know it would be interesting ;-) The limit consists on associating classical states to quantum states in the limit; the classical non-linear evolution to the quantum one; and most importantly to show that the evaluation of observables converge.

Austria $\cong$ Germany

@0celo7 You know what I'm gonna ask you, right?

@ACuriousMind no

@0celo7 In what category?

@ACuriousMind I did not see that coming

what does that mean, pray tell

You're trolling me, right?

@Slereah They are sometimes ok, but only in euclidean time (and rotating back is not always possible)

I don't know the theory of categories

"sometimes okay" is p. mild

@0celo7 But...we had this discussion at least twice before when you used the $\cong$ sign!

What's the conditions for wick rotations, anywa

y

it depends on the interaction

Do you not remember the discussions about the morphisms of animals?

No

Is it about werewolves

don't know exactly, however it involves knowing some a priori positivity

@Slereah Not you, @0celo7

@ACuriousMind I think the discussion with JD killed a few brain cells

ok, I'll pick a category

I seem to recall that one of the reason why path integral of gravity is complicated is that the action can be arbitrarily negative

$\mathrm{category}=\{\mathrm{categories}-\text{categories such that this is not true}\}$

@Slereah Mathematically for gravity is a mess...very complicated coupling

i.e. it's true in all categories in which it is true

even for QM systems

@0celo7 That is not properly written, and getting access to the "set (or category) of all categories" to substract things from it is a bit difficult

@Slereah I recall Wald mentioning that the meaning of the path integral for gravity is not even clear

@ACuriousMind difficult for you

not difficult for me, I just did it

@ACuriousMind The collection of all categories is definitely not a set

even the collection of small categories is a class

you mathematicians are all so nitpicky

just wave your hands, it'll all turn out great

@yuggib That's why there's scare quotes around it

why can't I have a set of categories

what even is a category

what is a set

what is life

@0celo7 for the same reason you can't have the set of all sets

it's called vicious circle

@yuggib why not

read my comment ^^

@ACuriousMind I was expecting a picture of Shrek

it would have to be in itself

but that works too

you may also call it Russel's paradox

@yuggib I don't care

I'll just make a bigger set

...why a picture of Shrek?

I'd get banned for the explanation

@0celo7 that "bigger" set, is not a set.

so let's leave it at that

@0celo7 This may in fact be why you can't into analysis :P

@yuggib wtf is a set then

god dammit I'm an engineer, just make a bigger set

Didn't we also have that discussion? I'm having deja-vu.

very cool new paper by Maldacena for those interested

::punches @FenderLesPaul ::

an object in the first order language $(\in)$, with some additional axioms

e.g. ZF axioms

I have three events on thursday at exactly the same time

@ACuriousMind no

@0celo7 Time to get your time-turner, then!

no harry potter allowed

What?!

lol I literally just printed out the paper

HP is for nerds

@0celo7 How could you understand topology without knowing what a set is... :-P

and yet now I can't find it on arxiv anymore

@yuggib a set is a collection of things

it's arXiv 1509.03612

"Looking for a bulk point"-Maldacena et al

@0celo7 ...soooooo?

@0celo7 With additional rules

@yuggib those are unnecessary

@FenderLesPaul lol...it seems indeed gone from the arXiv

@ACuriousMind so it's not allowed here

@ACuriousMind very weird lol

because I literally just printed it out

@0celo7 They are necessary indeed, else you would make weird collections like this: $\{ x, x\notin x\}$.

@0celo7 Dude, this is the chat of a physics website. How would being "for nerds" disallow it here?

@yuggib that's a fine set you've got there

@ACuriousMind speaks the truth

@ACuriousMind uh, because we're not nerds?

except for you apparently

Does the set of physics chat users contain the set of all nerds?

@0celo7 Ahahhah, you know the next question, do you? ;-)

@0celo7 Speak for yourself. I am.

you and your RPGs and video games

I ain't a nerd

@yuggib no

@AngusTheMan probably the other way round

there is no next question

Looking up the word "set" in the dictionary is a one way ticket down the rabbit hole...

ask the next question, I can take it

@FenderLesPaul You're a geek, then? ;)

guaranteed

@0celo7 $S=\{x,x\notin x\}$; $S\in S$?

yup

@ACuriousMind actually I'd rather be a nerd than a geek

so I take it back

@Rigor :-D bad idea indeed..

all sets contain themselves

@0celo7 wat

why are you guys so surprised

@0celo7 what about the empty set?

mathematicians don't know math lol

You can't have the empty set contain itself!

of course you can

durr

It has no members

$\emptyset = \{\emptyset\}$

@0celo7 EDIT: $1=\{\emptyset\}$

@ACuriousMind did you read Timaeus' answer to my question

$0=\emptyset$

JD is right, I haven't addressed it, because I don't really get what it's saying

please ELI5

who is ELI5?

$2=\{\emptyset,\{\emptyset\}\}$

oh

@0celo7 no

Not in the mood for that today

@ACuriousMind please do

:(

you're not in the mood for physics

The empty set is the set with no members, otherwise it wouldn't be empty :P

but it contains itself because the empty set is not a true member

it's empty

I seem to be setting off the spam alerts today

stop trolling, then :P

what do you mean by "true"

@ACuriousMind fine

@Rigor you tell me

you said it

(I have no idea what spam alerts you're talking about, though)

"you have to wait 5 seconds to post again"

"you have to wait 6 seconds to post again"

"the empty set is not a true member"

etc.

Ah

Yes, you can't post in rapid succession

I've never had this happen this much

did someone flag me and it's now persecuting me?

@0celo7 that's the punishment for not understanding set theory

^seems legit

that happens automatically, no need of flagging

:-D

ffs can someone please read Timaeus' answer

I don't like that JD has a legitimate argument

I just don't understand what he's saying

@0celo7 I don't like his style, at all.

personally, I think he misunderstands how crazy JD is

sooooo wordy

I think JD is literally saying electrons are photons

he thinks he's too legit to quit

@ACuriousMind and often imprecise. And always judgemental

but it seems like Timaeus is saying JD is just calling electrons + photons the EM field

and that that's legit? I'm not sure

@yuggib Yeah, the wordiness and imprecision go hand in hand because he seems determined to avoid equations as much as possible (although the text indicates he knows them just as well)

are we talking about Timaeus or JD?

@0celo7 the former

@0celo7 seriously, you have to have a firm understanding of what the "empty set" represents

@Rigor dude

I know what the empty set is

and honestly I do not see your issue with his answer. He is just vaguely recalling known facts about QED, or standard model in general. And some Occam's razor stuff.

@0celo7 An engineer never knows. Anything.

@yuggib because JD says I didn't respond

which is true

I don't know how to respond

@0celo7 Well, Timaeus is not sharing the same view as JD; he is simply stating, in a vague form, common lore. I do not see it as a point in favour of JD.

@yuggib what is that supposed to mean

and you asked a question, you are not supposed to answer

> but really Duffield is right.

@0celo7 Just a joke about engineers. In my country are quite popular among physicists/mathematicians.

the mathematicians' ones involve physicists as well; and the opposite is also true

does a lock on my question mean I shouldn't comment on the answers as well?

@0celo7 I would say so

@0celo7 That in my opinion is a poorly phrased sentence, due to non-english native language

he is just making an hypothetic assumption that involves the fact that Duffield would be right

I wonder what will come of this

what would the meta post be about

"bad bad 0celo7"

"Taming the Ocelot" would be a nice post title :D

"Taming the Ocelot with Einstein and The Evidence"

also Feynman

@0celo7 but that breaks the symmetry.... $E\wedge E$

but EFE is also the Einstein equation

besides if $E\in\Omega^\mathrm{odd}$, then $E\wedge E=0$:O

@0celo7 $\wedge$ here is the logical connective... $E\wedge E$ is never zero; it is everything

it was a joke

don't think I'm stupid

mine also

wtf

I know very well you aren't

we've gone too far

let's get back to physics

@ACuriousMind how's BBS

@obe are you reading Wald yet

@0celo7 I'm reading ballentine.

I have a 3 hour qft lecture tomorrow.

rekt right?

@0celo7 Haven't read further

I'm lazy, did I mention that? :D

so you're not doing ST for your master thesis

@FenderLesPaul @ACuriousMind what can you tell me about "monodromy charge"

@ACuriousMind let me know when you get to page 211

@0celo7 Have not heard that specific term, but it's quite obvious that it's a charge incurred by a monodromy ;)

fascinating

astronomer at work

I wish I could see who the star man is

@Danu Aren't you some kind of chat moderator? Should you be going around calling people names?

hi daniel !

Well it is JD

p. justified

@JohnDuffield That's the tamest "carp" I've ever read by CuriousOne.

@Gowtham Hi.

@JohnDuffield First of all, no, I do not know all about this. Not all physicists study quantum field theory. Do you know all about superconducting qubits? Why not? Surely you know all about them. See my point?

He knows everything

Except math apparently

@JohnDuffield You do realize that you are simply insisting on a different point of view in explaining the Evidence shown in the experiments, yes? Because charged particles come out of the interaction, most physicists find it best to think about the process as the electromagnetic field interacting with other charged fields.

Your decision to think of it otherwise is your own business, but I don't really see why one would insist on considering this interaction as direct photon/photon when there isn't a particularly good way to represent that in a theory. We get the Evidence, we make a theory to explain/predict. The theory we have that works well does not have direct photon/photon interaction.

If you can come up with a better one then more people would pay attention to this alternative point of view.

@DanielSank You may take the ticket and wait in the queue for that answer...

You invoked the evidence, @DanielSank, but did you even think about Einstein

there are at least @Danu, @ACuriousMind, @dmckee, @0celo7 waiting...

as well as me, of course ;-)

"Let us consider a quantum system Q with an associated Hilbert space H."

He uses blackboard bold H for the Hilbert space

That man is evil

Which man

Einstein or JD?

Some dude in a paper

^did I not fuck up here

For some reason my latex document pdf's do not load.

I'm having a doubt b/c it has matrices involved

"switching"

The ol' switcharoo

It's a theorem from analysis and you say "switching"

I may also say sometimes "loopdeeloops" when talking about homotopy

but you are correct in any case

but what if the derivatives are

COVARIANT

Well they are not here

Time to head home

@yuggib Hm. well I have time to wait because I'm still waiting for CuriousOne to tell me whether or not he still thinks the DWave machine is as powerful as a coffee maker.

Einstein in Matrix Form is an abomination

@0celo7 wazzat?

geodesic equation in terms of matrices

@0celo7 k

amazon.com/Einstein-Matrix-Form-Derivation-Relativity/dp/…

horrible book

@Slereah Oh snap!

the very idea of it is cringe worthy