The h Bar

Relativisticcucumber

00:02

@HerrFeinmann I have mixed feelings about this sentiment. I don't like the idea "because someone doesn't have xyz education, they 'fall' for statements that are false and they are being done wrong in this case." I feel this borders on patronizing. Imo one doesn't need a formal education to have sense along the lines of "trust but verify". I think people in every realm of society can be found trying to trick others, so as humans we ought to develop some degree of sense.

@ACuriousMind i should have known

ACuriousMind

@Relativisticcucumber Most beliefs - regardless of what they are about - do not only affect the life of the person who holds that belief, but also those who they interact with. They teach it to their children or anyone else who will listen, they make decisions that affect others based on it, etc. and ultimately if that other person holds power over you (in whatever sense), they will affect you.

This is not an argument to "police" other people's beliefs - with whatever threat of violence that phrasing implies - but it is an argument to at least care about them.

Allie

Mew yeah i dont want to live in a world full of astrology believers

But only so that people wont keep asking me what my sign is when they meet me (jk…. There are worse things than that)

ACuriousMind

00:18

And unless you subscribe to some form of complete relativism or determinism where there is either no choice or completely arbitrary choice involved in determining what you believe in, every worldview has to tell a story of why other people hold different views but you should keep your own - what notion makes keeping your views preferable to adopting those of others?

Allie

Because astrology makes 0 sense and has 0 evidence :P

(I know it was rhetorical)

ACuriousMind

So why did you feel the need to answer it :P (no, really, this ties into what I just said: why do you feel compelled to say something like that when it has also 0 chance when phrased like that to convince anyone who believes otherwise?)

Allie

Because im not trying to convince anyone

Im in a chatroom where I assume the people are well informed enough to understand that

And that everyone would agree

As for why I felt compelled to say it, i suppose a venting of frustration to people who would hopefully understand where im coming from

But i did know you were going to say that

ACuriousMind

And that's the social aspect: Because beliefs inform how we act, you want to be reassured that you are among people who share at least some of the beliefs you hold as important, and will therefore act as you would like them to act with respect to them. (This isn't criticism, I'm just being very explicit about why we generally care about what other people think)

Relativisticcucumber

@ACuriousMind but i think this is an important distinction -- because i don't believe that someone has a right to harm someone because of their beliefs, just that every person has a right to believe what they decide to believe / want to believe. in my opinion, we interact with the world, and ideas are presented to us, but we have to bear the responsibility of how we interact with those ideas, [...]

[...] at least that is what i think. i don't think it makes sense to be mad at an idea for existing. but the question was how to cope with pseudoscience, no? i might be missing the q by taking it too literally

ACuriousMind

00:36

@Relativisticcucumber Yeah, I think you're making a literal distinction where at least I don't see a practical one: You cannot separate a belief from the effects it has on the world - if you "believe" in something but then refrain completely from affecting anything but your own life (if there even is such a thing as an action that only affects your own life) because of it, in what sense do you believe it?

Relativisticcucumber

i mean i suppose my stance would be to be upset with people who believe things that are ridiculous AND act on these beliefs in harmful ways. even tho i dont believe in free will, i believe we should at least act like there is free will (because what else can we do), so that's where i would place my frustration if i were to be frustrated about this topic

im not sure i connected the dots well there but hopefully you get what im meaning to say :PP

@ACuriousMind that's an interesting point. i witnessed a debate on this one time regarding the question of "is it morally right for christians to actively try and convert people", i lived in oklahoma for a few years, and this was a hot topic :P.

ACuriousMind

Sure - but I mean it in a much less overt way: Most beliefs about the world are neither those that affect nothing nor those that make you into a zealous missionary, but they still influence your actions. You tell them to others, you decide to associate with people with similar beliefs, you might vote for someone with the same belief if you happen to live in a democracy or you might be oppressed because of it, etc.

All your beliefs shape who you are, and who you are determines how you act, and your actions almost always affect something more than just "yourself".

Relativisticcucumber

i guess though, i might say there's two ways to combat ignorance, 1) one can try to respectfully engage with the individual and see if they are interested in discussion 2) one can choose to disengage if this is not so. to me there are the only options, and frustration is not one of them. i think pseudoscience proponents can be treated similarly if this frustrates someone. [...]

[...] but i feel like a lot of times people want to believe something, and they aren't interested in hearing what i feel like might be the reality, so what can one do other than accept that

whoops i typed this before your message btw

naturallyInconsistent

@SillyGoose this is the default position of Chinese. Literally handed down as ancient wisdom

Allie

hi yall

i picked up a book from the biblioteca

ACuriousMind

00:48

@Relativisticcucumber I don't think anyone proposes frustration as a productive response to disagreement :P

Allie

Lecture Notes in Physics: Density Functional Theory

ACuriousMind

I'm just trying to explain my understanding of why that frustration is natural, and why "what do you care what other people think?" is not a good response to it - the only way to not care what other people think is to not care about anything that happens

Allie

and the first chapter is written by Levy on the constrained search formalism :3

i also picked up solid state physics by Kittel

naturallyInconsistent

@Relativisticcucumber Feynman said that it is still useful; you'll get to attack a wide variety of problems just by trying what others had tried, but in a new area, but at the same time, new Nobel level discoveries require completely new thought patterns, and so cannot be approached by this memorisation trick.

Relativisticcucumber

@ACuriousMind hmm oh my

ACuriousMind

00:50

@Allie biblioteca?

naturallyInconsistent

@Allie I think that book will be confusing to you

Relativisticcucumber

i feel that your logic tries to break down all of the coping strategies i have built up in the past few years xD this has happened more than once xD

Allie

okay, well i have to return it in a week, if i dont like it thats okay

Relativisticcucumber

i mean ok so the q is "how do you cope with this" right, so that is my answer i think i just have to tell myself that what other people think is not smth i can control, but what i can do is be willing to discuss and be willing to adjust my surroundings. maybe this isn't logically sound, but it works for me

Allie

why is that? is there something you recommend before that?

Relativisticcucumber

00:52

bc if we dont enforce this boundary then i think life can easily become miserable :PPPP

ACuriousMind

@Relativisticcucumber congratulations, you're a stoic :P

Relativisticcucumber

NO lol most definitely not i have stoicism

naturallyInconsistent

@Allie Kittel SSP is well known to skip all the BS and go straight to the topic, but that also means that it is quite unintuitive and difficult to read at the start. Midway through, it is very good, though.

Allie

hm

Relativisticcucumber

wait a minute smth bad has happened. i used to HATE stoicism so it's ingrained in me. but now i go back and look at what it is and it doesn't seem so bad....... BAH

what do you think is a good mentality on this topic (if i may ask) @ACuriousMind

i have betrayed myself, hope it's not for nothing :PPP

Allie

00:56

hohenberg kohn yay

@naturallyInconsistent so should I not even bother?

Relativisticcucumber

whoops i meant hate not have

qwerty

i've read the stoics and it annoyed the hell out of me

xD

Relativisticcucumber

i am suddenly insecure

ACuriousMind

01:19

@Relativisticcucumber I...don't really know how to answer that question without sounding even more pretentious that I usually do :P (and I rewrote the following message several times)

But I ultimately always come back to the Kantian idea that we are not separate from one another - we are all creatures endowed with reason, and it is our duty to help one another out of the various immaturities we inflict on ourselves.

To close yourself off from the beliefs of others - to say they don't matter to you - is to deny that universal bond, it is to treat them as irrelevant rather than ends in themselves, and by treating others as irrelevant, we implicitly treat ourselves as irrelevant.

@Relativisticcucumber and here I thought you were saying "I don't have stoicism" like someone would say "I don't have fleas" :P

naturallyInconsistent

01:39

@Allie well, miao miao dunno how much background you had, and could absorb, so you should decide if you wanna try

Allie

i do wnna try :3

Relativisticcucumber

@ACuriousMind but don't you encounter people who don't want help out? so how do you engage with this?

@ACuriousMind hm this is true. but i have found that, with the exception of a few people, interacting with others always leaves me extremely sad. so i feel like irrelevant is better than depressed. so do you not feel sad from human interactions?

@ACuriousMind missed opportunity ;,(

ACuriousMind

@Relativisticcucumber Depends very much on the context. Sometimes disengaging is the right choice, but not because I believe that I in general can't affect them, but because the specific circumstances make it unlikely. I don't mean to imply you should expend infinite effort to influence everyone you meet - just that the default shouldn't be "I can't/shouldn't even try"

Relativisticcucumber

btw what is the origin of the rather small limit on characters in the chat here?

@ACuriousMind oh, yeah i do think i tend to give it a shot. but usually only one.

ACuriousMind

02:01

@Relativisticcucumber I often feel exhausted by interaction in general - in this I match the usual description of an introvert - but not sad, no. Frustration or rage, the term Mr. F used, matches the result of bad interactions much better, hence me jumping in to defend the validity of that feeling :P

qwerty

yet you volunteer much time to moderating hbar? :/

ACuriousMind

@qwerty exhaustion in and of itself is not necessarily a bad feeling, as my friends who love exercise keep telling me :P

qwerty

hahaha, touche.

Relativisticcucumber

Hm that is interesting. I wonder what the root of this sad vs. angry feeling is @ACuriousMind

Allie

meow

qwerty

02:07

@Relativisticcucumber internalising vs externalising?

actually it reminds me a bit of a discussion i had with another phd student at some point during my studies

when i didn't understand a either complicated or badly written paper, I mentioned that I would tend to internalise it a lot. i'd feel stupid or upset, and sad.

I showed this fellow student this same paper I couldn't understand, and he actually raged at it

he threw on the table in actual frustration

i was shocked :p

Silly Goose

does "Canonical form" of a density operator have a specific meaning in the context of statistical mechanics? my guess is it means one of the canonical equilibrium distributions...but i am uncertain.

the hamiltonian here is purely sums of tensor products of pauli Xs, which is why I think "canonical form" is meaning some distribution $\rho \sim \exp(H)$ as this would be consistent with expanding a density matrix in terms of sums of tensor products of paulis

@naturallyInconsistent where is my ancient wisdom

ACuriousMind

@Relativisticcucumber I don't know why we're jumping all over the place tonight but sadness is directed inward, while anger is directed outward. This makes anger - for good and for bad - a productive force: It posits that the world should be a different place, and so let's get to work and smash the bits that prevent it from being different.

> Genuine anger was one of the world's greatest creative forces. But you had to learn how to control it. That didn't mean you let it trickle away. It meant you dammed it, carefully, let it develop a working head, let it drown whole valleys of the mind and then, just when the whole structure was about to collapse, opened a tiny pipeline at the base and let the iron-hard stream of wrath power the turbines of revenge.

2

(Terry Pratchett, Wyrd Sisters)

naturallyInconsistent

@SillyGoose try asking Jensen Huang

ACuriousMind

@SillyGoose Without further context I would interpret this as the density matrix for a canonical ensemble, yes

Relativisticcucumber

But I feel like I lack the confidence to be angry. To be angry you should be confident the thing you are angry at is wrong, not yourself

I mean don’t get me wrong I’ve get anger but it’s just not my go to

Felt* kill the mobile version I have large thumbs

ACuriousMind

02:23

@Relativisticcucumber Yes, that's the difficult part :)

Silly Goose

@Relativisticcucumber i see anger here

Relativisticcucumber

LOL

naturallyInconsistent

02:38

@SillyGoose no, it is correct

@SillyGoose your implication is wrong

Silly Goose

hm i wasn't able to prove the correct implication, but i proved the wanted statement an alternate way

Allie

MEOW!!!!

naturallyInconsistent

M E O W ~

@Relativisticcucumber I think it is only sensible to link those stuff to the histories involved. These days we have plenty of nice youtube videos explaining certain histories on the map, which is sooooo much easier to understand than what people before had to work with

Allie

i like to meow.

naturallyInconsistent

02:54

@HerrFeinmann you know meow meow hath almost no tolerance for them. Too many lives lost, and too much harm. And miao miao's work is supremely close to pseudoscience and so it is extremely important to keep vigilant. Even just taking a fraction of the vast sums they have scammed out, it would have made myow work so much easier with that money.

@Allie so do many of us mewwww

@HerrFeinmann that the bible is not being interpreted literally is 1) extremely recent invention that had never been the norm in history, 2) not true today, still happening in some places, and frankly not surprising when people are just finding whatever is convenient for their political stances

Allie

its sad were stuck on this stuff lol

but its ok

Silly Goose

is this a typo?

Allie

little things make me happy :3 (unfortunately, little things also make me sad)

Silly Goose

$\text{tr}_2 (\exp(K_1 \sigma_x^{(1)} \otimes \sigma_x^{(2)})) = \text{tr}_2 (\mathbb{I} \otimes \mathbb{I} \cosh(K_1) + \sigma_x^{(1)} \otimes \sigma_x^{(2)} \sinh(K_1)) = 2\cosh(K_1)$

where the $\sinh$ term vanishes since paulis are traceless

man the notation in old papers is really quite something else...

how can you even come up with something so unreadable

naturallyInconsistent

03:11

@SillyGoose They didnt have ways to typeset easily. But it seems like you found your answer?

naturallyInconsistent

03:39

@Allie did you read myow myow's restatement of Tobias's thingy?

Allie

i did but im tired, im going to read it again tomorrow

i read some notes from Levy about the constrained search that helped me understand i think

i have a question but i should work on this tomorrow when im rejuvenated

thanks for your help today

naturallyInconsistent

mew mew~

Allie

meow

im learning

i AM capable i think

naturallyInconsistent

03:55

yeah~

Ryder Rude

06:39

hi

Herr Feinmann

07:02

@Relativisticcucumber beware that I didn't state it as a law, just that there is nonzero correlation

@Relativisticcucumber because deep inside I do not see science as something one can choose to accept or not

I mean, if I were given a choice, I would not care and mind my own business. That's why I asked :P

@naturallyInconsistent oh, sure, but I mean: science as we intend it today was not the norm in history either. I'm just saying that I genuinely think that at least in principle religions can coexist with science, in the sense that a scientist may embrace both and that would not undermine their credibility. I do not, but I think that is possible.

On the other hand, I wouldn't trust with my life a n astrophysicist who believes in astrology

Herr Feinmann

07:39

@ACuriousMind this reminded me of Evangelion :P

Ryder Rude

08:17

@HerrFeinmann one big difference between metaphysics and pseudoscience that I have characterised is that pseudoscience claims to make predictions while metaphysics doesn't claim to make predictions

e.g. if I say stars cause people to be angry, i am making an empirical statement without basing it on reliable experimentation

DIRAC1930

08:34

It seems so strange that physicists didn't know about matrices before and around the time matrix mechanics was invented

Doing random linear transformations must have been so exausting in the old days

ACuriousMind

08:53

@DIRAC1930 Who would have been doing "linear transformations" :P The modern formulation of linear algebra in terms of vector spaces was itself only 30 years old - Peano only wrote down a recognizably modern definition of a vector space in 1888.

I mean people were mucking around with matrices etc. a bit before that but really the whole modern way of doing math is not that much older than the 20th century physics that uses it

Ryder Rude

Peano randomly formalises a vector space and just 30 years later it has found use in a new theory that no saw coming

@DIRAC1930 Maxwell had to write 12 equations in his Maxwell equations paper because people didn't use vectors

i have been thinking hard about the unreasonable effectiveness of mathematics

if anyone wants to discuss their thoughts, ping me

Slereah

09:11

There was no formal notion of vector space til Grassmann in 1844

qwerty

09:21

i've always thought that we call them matrices etymologically is just very strange

etymonline.com/word/matrix

Slereah

It means mother

This was before Freud and they had yet to resolve their Oedipus complex

qwerty

lol

ACuriousMind

@Slereah Arguably it's only until the second version of the Ausdehnungslehre because the first is not yet a math book :P

while the second version looks like a slightly old-timey version of a linear algebra textbook

Slereah

@ACuriousMind also I'm assuming that nobody knew what the hell he was talking about in the first version

Ryder Rude

people back then weren't familiar with formalism and abstraction

Slereah

09:25

Really one of the biggest evolution in science through the ages has been an evolution in pedagogy

ACuriousMind

@Slereah I certainly don't!

Slereah

Ancient people were terrible at conveying ideas

also pagesetting

Ryder Rude

if u just randomly defined a structure, people wouldn't understand it unless u related it to the real world

Slereah

I don't know if this is because paper was so expensive but boy I don't like looking at ancient books

Ryder Rude

not only people wouldn't understand it, people would think it is nonsense

Slereah

09:26

Euclid didn't know about paragraphs

Let the text breathe

Hell they didn't even know about spaces

qwerty

@Slereah don't you think this was partly by design? i mean people used to be sooo secretive about their work and knowledge

Slereah

@qwerty Hard to say really

Ryder Rude

@qwerty there used to be math duels to decide who gets to hold the math position

Slereah

I know that some books were meant to be understood

qwerty

its like people nowadays who do coding and they dont wanna write comments

Slereah

09:27

like we have some 6th century textbook

meant to edify the youths

archive.org/details/denuptiisphilolo00martuoft

ACuriousMind

@qwerty that's mostly laziness/failure to empathize with people (including future selves) who no longer remember the full context of a piece of code, not secretiveness

Slereah

This book is reasonably fun to read I guess?

@ACuriousMind Also if we judged things by that metric, we'd think many modern physicists were also engaging in secretive esoteric tradition

instead of just thinking that what they say is very obvious

ACuriousMind

@Slereah But that's just general orthography back then not specific to writing on paper/parchment

Tobias Fünke

@Allie nice :)

Slereah

@ACuriousMind still, tough read!

ACuriousMind

09:30

the inscriptions on stone from the time look the same - all caps, no spaces - even if there had been space to write it differently

Ryder Rude

i think ancient people did not necessarily think that what they say was obvious, but more that they were themselves confused about what they were saying

Tobias Fünke

@ACuriousMind Community is such a gem. I love it

Slereah

People did have some notions of word separations

like Egyptian had determinatives and cartouches

Ryder Rude

a lot of mathematical ideas used to be communicated using philosophy and metaphysics ideas, and the conveyer had to be confused about their metaphyscs

Slereah

but like everything pagesetting is a technology

ACuriousMind

09:31

so I don't think it's (only) an economic reason, it (bizarrely to modern sensibilities) just wasn't considered important to separate the elements of speech in the same way we do in modern orthography

Slereah

Sometimes we just have to find it out first

We still carry around a lot of counterproductive things in orthography really :p

Ryder Rude

e.g. Newton writes a lot about absolute space and tries to mix physics with metaphysics. he probably couldn't make the ideas well defined if pressed on it

Slereah

@RyderRude Have you read it

Ryder Rude

it was supposed to be understood based on vibes

@Slereah not the original text, but other sources like wiki

Slereah

You will get a degree in wikipedia reading

2

Ryder Rude

09:34

Descartes also didn't have a rigorous definition of the continuum when he first introduced it. he probably had metaphysical motivations, which are bound to confuse both the author and the reader

only when physics/math became separated from metaphysics did the ideas become less confusing for everyone

@Slereah lol

qwerty

@ACuriousMind i dunno maybe people joke but i have definitely heard "job security" as an answer to "why isn't this code documented"

Slereah

@qwerty I wish that was true but instead companies will just hire people and then have them not understand the code base

ACuriousMind

^agreed, the company doesn't care, they don't understand what programmers do anyway :P

qwerty

lol >.>

@Slereah i'm guessing you'd hate reading arabic

knowing you you've probably tried some ancient text too

Slereah

09:52

@qwerty also Chinese and Japanese :p

Just looking at a chinese text makes my head hurt

Tobias Fünke

@Allie you can ping me if needed (and if you want to) :) it is good for me to go back to the basics and think through them

qwerty

@Slereah you need to be trained like a small child at chinese school. none of this complaining about headaches, you will have 100 characters copied out every day

Slereah

@qwerty Just reform the entire language imo

It can be done

Ryder Rude

how much would you agree with the statement "modern physics, in principle, explains all of human observation"?

"all" meaning "most". "most" meaning : excluding the unknown physics

Slereah

I know Chinese has been reformed several times but obviously they were not being serious about it

Ryder Rude

10:03

and before we can address this question, what do we mean by explaining all observation?

qwerty

@Slereah you can become dictator of china after you finish your homework, nice try

Slereah

Is language reform part of Xi jiping Thought

I have not read the whole program

qwerty

i think it depends on what you mean by language reform. im not an expert

Slereah

Anything that will get the script under 100 characters at minimum I'd say :p

qwerty

Bopomofo

Bopomofo, also called Zhuyin Fuhao ( joo-YIN foo-HOW; 注音符號; Zhùyīn fúhào; 'phonetic symbols'), or simply Zhuyin, is a transliteration system for Standard Chinese and other Sinitic languages. It is the principal method of teaching Chinese Mandarin pronunciation in Taiwan. It consists of 37 characters and five tone marks, which together can transcribe all possible sounds in Mandarin Chinese. Bopomofo was first introduced in China during the 1910s by the Beiyang government, where it was used alongside Wade–Giles, a romanization system which used a modified Latin alphabet. Today, Bopomofo is more...

Slereah

10:07

Get the bopomofo in I say

qwerty

i'm sure nI will know more, it's a TW keyboard thing if i understand correctly

Slereah

also to maximize intuition in all visualization, all data should be expressed using Chernoff faces

Chernoff face

Chernoff faces, invented by applied mathematician, statistician, and physicist Herman Chernoff in 1973, display multivariate data in the shape of a human face. The individual parts, such as eyes, ears, mouth, and nose represent values of the variables by their shape, size, placement, and orientation. The idea behind using faces is that humans easily recognize faces and notice small changes without difficulty. Chernoff faces handle each variable differently. Because the features of the faces vary in perceived importance, the way in which variables are mapped to the features should be carefully chosen...

2

qwerty

omfg what this is amazing

Slereah

Perfect method

qwerty

there's missing labels >=(

Slereah

10:16

Exactly the face you make on ketamine coincidentally

mister nobody

that's interesting

Slereah

It's an intriguing notion but on a personal level I am skeptical about whether it's better at conveying information

Although maybe good at propaganda

You don't want the statistics to get to the ANGRY FACE do you

Herr Feinmann

10:35

Do quasiparticles have zero chemical potential?

mister nobody

@Slereah i just like that it represents data in new ways

could anyone help me see where the formula here comes from ? en.wikipedia.org/wiki/…

it's quite simple, a differential form for heat, but idk where it comes from

Slereah

Data representation is important

qwerty

10:51

your profile pic

Slereah

that it is

qwerty

what is it?

Slereah

It is pages from the Codex Seraphinianus

An encyclopedia of a world that doesn't exist

naturallyInconsistent

11:09

@qwerty it is actually quite connected to modern Korean

@HerrFeinmann definitely not the usual situation.

@misternobody you need to be much clearer about what your question is

Herr Feinmann

11:29

@naturallyInconsistent Do you happen to know why FD distributions is used for quasifermions with dispersion relation $E_k=\sqrt{(\varepsilon_k-\mu)^2+|\Delta|^2}$ in the form $\frac{1}{1+\mathrm{e}^{\beta E_k}}$?

I mean, no chemical potential is used $\beta(E_k-\mu')$

I can imagine it's somehow included because $E_k$ includes the chemical potential of the "real" particles

But it's not in a "linear" way

bolbteppa

12:10

@Slereah Was Euclid the n-lab of his day

The Crisis in String Theory is Worse Than You Think | Leonard Susskind

►

Devastating

Slereah

@bolbteppa probably the platonic academy, I guess?

That was the Big Project of gathering the Knowledge

Of which Euclid was part

Also Aristotle was probably the insane guy trying to make a compendium of all knowledge in that context :p

His books are very wide ranging

But Euclid was also a compilation of a lot of older sources yeah

bolbteppa

@Slereah As is the lab no :p

Ryder Rude

@bolbteppa i think Susskind says we need to abandon supersymmetry and develop a theory for De Sitter while borrowing some ideas from the current string theory

@bolbteppa nvm u had linked a timestamp about the other theories :P

bolbteppa

12:29

Woit Theories

User1865345

@Slereah I have seen mentions of Chernoff faces in applied multivariate texts (mostly in passing by). Apart from that, I have not seen its serious usage anywhere else.

bolbteppa

String Theory's Biggest Critic Debates String Theorist...

►

@RyderRude have you listened to any of these

Ryder Rude

@bolbteppa i think i started listening to it but it was boring

just looking at the timestamps, it is mostly just about academia politics

which is probably why i stopped watching it

i am interested in technical debates about the theories themselves

mister nobody

12:47

@naturallyInconsistent the question is why they expand dq = dU/dT + dU/dp + p(dV/dT + dV/dp) the d are partials.

Slereah

@User1865345 they are too scary to use

mister nobody

im told this is due to the phase rule, but I wonder if that's a good answer, and really explains it completely, and why isn't mentioned at all at wikipedia then..

Slereah

github.com/jdrem/chernoff-faces

Terrifying

mister nobody

where is the tiny head

Slereah

on your shoulders

mister nobody

12:50

down your hips

ACuriousMind

@misternobody I mean, that's just how differential forms work, no? If you have a function $f$ that depends on $n$ variables $x_1,\dots, x_n$, then $\mathrm{d}f = \sum_i \frac{\partial f}{\partial x_i} \mathrm{d}x_i$. Here they just took $U$ and $V$ to depend as $U = U(T,p)$ and $V= V(T,p)$ and plugged that in

mister nobody

You can just assume that U(V,P) as well or U(V,T); that is the question: does 2 suffice and why those, and not say the entropy $S$ ?

ACuriousMind

I'm not really sure what your starting point here is from which you want to answer that question

To me, it's more or less an assumption in thermodynamics that the variables that specify your system are $T,p,V$ and only two of those are independent because they're related by an equation of state (e.g. the ideal gas law).

User1865345

@Slereah well true. Night marish.

mister nobody

@ACuriousMind maybe, i was just confused because that isn't mentioned in wikipedia

ACuriousMind

13:03

@misternobody I mean, they did say "at constant pressure", so stuff depending on $p$ here wouldn't make any sense to begin with

I'm not really sure what you expect Wiki to say here, it's not a textbook that builds the physical theory from the ground up in every article

mister nobody

they did not say that, what you wrote is a general expression, not for constant pressure.

all i expected is that they cite if there is an important underlying assumption, like the phase rule or an equation of state relating T,P,V

ACuriousMind

ah, right, sorry, that didn't make much sense. My second point stands, though - the goal of the Wiki article on heat capacity is not to teach the whole of thermodynamics leading up to it

mister nobody

yeah i agree, i tend to use wikipedia the wrong way

Slereah

13:39

Kinda want to see Chernoff faces for emergencies tho

Imagine if you saw some emergency indicator like that in your car

For your oil needing a change

and its face is getting more evil

🙂😐🙁☹️😮😦😧😨😰😫

Allie

@TobiasFünke thank you so much :)

mister nobody

it's got the risk that it'll be used for everything, like a little face and a cloud (cloudy days), a little face in the sun (sunny days); and in the case you write i'll leave people without a useful mapping symbol.

Slereah

13:57

@ACuriousMind Any idea what a fracture square is beyond "a pullback"

As far as I can tell it is also sometimes called a "Hasse square"

ACuriousMind

I don't know either of those squares :P

Slereah

Finding a lot of examples but they are kind of wildly different?

they are also a lot of number theory and algebraic geometry which makes things trickier to read for me

apparently the integers are the fiber product fo p-adic integers with rational number

whatever that may mean

Related to the general categorical notion of localization I guess

since you can perform various of those identities by localizing various elements of Z

Ryder Rude

14:14

@Slereah it sounds impressive

i need to learn a few things. please give references

i need to learn the relation between physics and other forms of applied math. i think they are related by "reductionism", but I need precise meanings of these ideas

and I need to learn the meaning of "explanation". when we say that an applied math model explains a phenomenon, what does that mean?

this is all related to the philosophy of applied math

and also, why is physics so focused on predictions? when physics can predict the future, we say physics "explains" things

but physics doesn't explain initial conditions, for instance. it is strange that it is focused on predicting the future

Silly Goose

I’ve get to get myself a copy of the Codex Seraphinianus…

Allie

MEOW!!!!

Slereah

14:31

@SillyGoose it's a nice book

Although a bit big

Relativisticcucumber

@HerrFeinmann hm interesting

Herr Feinmann

@Slereah Gravitation is thick, not big, so that comparison doesn't tell me much :P

Slereah

I'll drop it on you see how big it is

Herr Feinmann

I own a copy

Slereah

Apparently fracturing is the decomposition of an object into simpler objects, roughly speaking

Herr Feinmann

14:43

We can fight to death using it as a weapon, if you will

Slereah

@HerrFeinmann bit unwieldy

Herr Feinmann

May 6, 2023 at 19:54, by ACuriousMind

@Mr.Feynman yes, the killing vector is the tangent to the trajectory of a copy of MTW thrown directly at your head

Allie

@TobiasFünke I do have a question about the constrained search formalism: so if your hamiltonian is $T + V_{ee} + V_{ext}$, I understand that the ground-state wave function $\Psi_0$ for a given density $n(\mathbf{r})$ comes from minimizing $\langle \Psi_0 | T + V_{ee} | \Psi_0 \rangle$, since for a fixed density the contribution from $V_{ext}$ does not change

Slereah

golem.ph.utexas.edu/category/2013/05/…

It is a bit annoying that a lot of the important info to understand nlab is on the blog :p

Silly Goose

@Slereah they should modify it to also be by a noninvertible map

Slereah

14:48

wot

Allie

And so after minimizing the expectation value to get $\Psi_{min}$, Levy obtains a "total multiplicative potential" $V$ which is both $V_{ee} + V_{ext}$. Of course, the electron-electron repulsion operator is not a multiplicative potential, but I'm thinking that since the ground-state wave function is determined uniquely by your choice of density, maybe the multiplicative potential is just defined in terms of how $V_{ee} + V_{ext}$ acts on $\Psi_{min}$? That would make sense to me but im not sure

Slereah

"At this point I feel like I should be saying something about Spec(ℤ). Unfortunately, I don’t know what to say!"

Bit of an anticlimax!

Silly Goose

Doctor my functor keeps forgetting 🤯

Ryder Rude

@Slereah hi. i wrote a book description above. do u know of any such book

Slereah

No.

Allie

14:56

lul

Slereah

Ugh

I don't want to learn about p-adic numbers

also they write it as $\mathbb{Z}_p$, same notation as the cyclic group, which is extra annoying

Allie

Slereah

need to apply that nailpolish more evenly

Allie

smh...

calling me out

the other hand is better

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