The h Bar

Slereah

19:00

Although...

It's only timelike for small enough $\tau_0$

So it's probably not as trivial as looking at the diagram

0celouvskyopoulo7

Well the small enough $t_0$ means you're chosing a small normal neighborhood

you need to use continuity of the derivative of $\eta$ there

It's clearly timelike for $\tau=0$, so it's timelike in some neighborhood

you need your $\tau_0$ small enough so you're in there

MathematicalPhysicist

Can anyone guide me through this question in Ashcroft and Mermin: physicsforums.com/threads/…

Slereah

19:22

What measurements can you perform on the metric, anyway

Given some interferometer, can you measure every component of the metric?

Sounds like a thing that would be in MTW

0celouvskyopoulo7

:/

Slereah

"Eötvös, Pekar and Fekete checked to an accuracy of 5 parts in $10^9$ that the earth imparts the same acceleration to wood, platinium, copper, asbestos, water, magnalium (90% Al, 10% Mg), copper sulphate and tallow. Renner checked ammonium fluoride, and an alloy of 30% Mg, 70% Cu."

GR experiments involve a lot of finding objects to throw

peterh

@Slereah How do you type in "ö"?

Slereah

With my keyboard

There's a ¨ key

AccidentalFourierTransform

19:41

huh, I thought you were German...

dunno why

that wardrobe pin thing reminds me of american beauty

peterh

@AccidentalFourierTransform I not, I am from .hu but I live in .de . Slereah I don't know, I've thought he is from .us .

AccidentalFourierTransform

he's from France

peterh

@AccidentalFourierTransform hu-HU and de-DE both contains "ö" but in different places :-) But, en-US doesn't. fr, I don't know.

AccidentalFourierTransform

close enough though :-P

0celouvskyopoulo7

Whät?

Of cöurse we have umlauts

AccidentalFourierTransform

19:47

in English you sometimes use umlauts in poetry, right?

Avantgarde

ö

Bernardo Meurer

@AccidentalFourierTransform I'll show you my umlaut

0celouvskyopoulo7

@AccidentalFourierTransform Not that I've seen, but we use them for rock bands apparently.

AccidentalFourierTransform

Apr 20 at 17:38, by AccidentalFourierTransform

Metal umlaut

A metal umlaut (also known as röck döts) is a diacritic that is sometimes used gratuitously or decoratively over letters in the names of hard rock or heavy metal bands—for example those of Blue Öyster Cult, Queensrÿche, Motörhead, The Accüsed and Mötley Crüe. Among English speakers, the use of umlaut marks and other diacritics with a blackletter style typeface is a form of foreign branding intended to give a band's logo a Teutonic quality—connoting stereotypes of boldness and brutality presumably associated with Germanic and Nordic cultures. Its use has also been attributed to a desire for a "gothic...

I thought that umlauts were used like "hey, I know that this word doesn't quite fit here, but if you stretch the pronunciation a bit, the metrics kinda work"

nbro

Hi

AccidentalFourierTransform

19:52

sup

nbro

Wikipedia defines proper acceleration as the acceleration measured by an accelerometer; at the same time, an accelerometer is defined as a device that measures proper acceleration. From what I understood, proper acceleration is the acceleration not due to gravity, that is not caused by gravity. But are we talking about Newton's gravity or Einstein's?

AccidentalFourierTransform

good question

0celouvskyopoulo7

@AccidentalFourierTransform A slant rhyme?

AccidentalFourierTransform

hmm i dont know

you should know about these things, not me

but I thought that umlauts were about the metric, not the rhyme

we need @JohnRennie

0celouvskyopoulo7

Oh, well then I don't know

I never took advanced classes like that

Avantgarde

19:58

@nbro yes, it's the acceleration by a force (not gravity)

nbro

@Avantgarde Does it mean that we're in the Einstein's context of gravity, since gravity in Newton's one would be a force?

0celouvskyopoulo7

oh no

who gives a shit if gravity is a force or not

Avantgarde

@nbro yes.

nbro

@0celouvskyopoulo7 what? it's very important to know and understand the nature of gravity, I would say...

0celouvskyopoulo7

what what?

"Force" is a made-up human word.

Force is not even defined in the context of general relativity, so applying "force" in that context is rather pointless.

Whether gravity is a force or not has zero to do with the "nature of gravity"

Although that's a made-up phrase as well, so who knows.

Slereah

20:03

Some old physics textbooks have umlauts

in "coördinates"

0celouvskyopoulo7

why physics?

all people used to write like that

Slereah

Yeah

Lovecraft writes like that, too

Like Aëroport

ACuriousMind

@Slereah that's a diairesis, not an umlaut

AccidentalFourierTransform

rôle

0celouvskyopoulo7

> There is a constant $C=C(n,p,q,\delta,C_1,\lambda)$

Slereah

20:04

that's not constant at all!

AccidentalFourierTransform

well, $\frac{\partial}{\partial \mathfrak h}C=0$, so it is a constant

nbro

@0celouvskyopoulo7 well, the point was to distinguish between being in the context of Einstein's theories or Newton's one of gravity

0celouvskyopoulo7

@nbro And they are completely different. To quibble about gravity being a force or not is stupid, what even is a force?

AccidentalFourierTransform

the covariant derivative along the path?

Slereah

@0celouvskyopoulo7 an influence that deviates an object from going on a geodesic

nbro

20:06

@0celouvskyopoulo7 Stupid? Last time I studied physics was in the second year of high school

0celouvskyopoulo7

@Slereah That definition fails for extended objects.

Slereah

@0celouvskyopoulo7 does it

AccidentalFourierTransform

whats the force acting on yo mamma

0celouvskyopoulo7

They don't exactly travel on geodesics.

Slereah

well yes

nbro

20:07

@0celouvskyopoulo7 force often appears in Newton's formulas, so a vague idea of it at least exists...

Slereah

Due to

i n t e r n a l f o r c e s

AccidentalFourierTransform

whatever happened to @BenNiehoff? havent seen him in a while

Phase

@nbro are you asking about whether force is a pseudoforce or real force?

Bernardo Meurer

His addiction to proprietary malware got the best of him

Phase

Because if General relativity is correct, then it's a pseudoforce. But if you consider non-inertial frames of reference, then it's absolutely a force that exists.

0celouvskyopoulo7

20:11

lol, what's a pseudoforce now

nbro

@Phase my only question, right now, is this: chat.stackexchange.com/transcript/message/37394829#37394829

Phase

A force that vanishes with co-ordinate transformation

like centrifugal

Well, not transformation

just choice of frame

"In relativity theory, proper acceleration[1] is the physical acceleration (i.e., measurable acceleration as by an accelerometer) experienced by an object. It is thus acceleration relative to a free-fall, or inertial, observer who is momentarily at rest relative to the object being measured. Gravitation therefore does not cause proper acceleration, since gravity acts upon the inertial observer that any proper acceleration must depart from (accelerate from).

A corollary is that all inertial observers always have a proper acceleration of zero."

-Wiki

Bip bam boom there you go

Slereah

Mister Wiki Pedia, physicist

Phase

@Slereah that's Dr to you

Pedia is his middle name, his last name is Felia

0celouvskyopoulo7

Guess it works.

@Phase Inappropriate.

@Slereah what's an ultraspherical function?

Slereah

20:14

Insisting on the "doctor" tends to be a bit gauche I find

I do not know

Phase

@0celouvskyopoulo7 I can't tell when you're joking or not so I'm just gonna ignore it

Slereah

A very spherical function, I assume

0celouvskyopoulo7

I never joke.

Phase

@Slereah Oh I see. Would you like a can of Mr Pepper?

Slereah

Apparently they are related to Gegenbauer Polynomial

@Phase Mister Pibb only, please

You know who's the classiest supervillain?

Phase

20:15

@Slereah is that some kind of sub-european drink?

Slereah

Mister Freeze has an actual doctorate, and unlike most, he goes by Mister

@Phase It's an American one

Phase

Him and Mister Fantastic can stroke each others humbleness'

America sucks

Slereah

Mister Pibb is one of the better known bottom of the barrel cola in the US

Phase

UK rules

fight me

0celouvskyopoulo7

Wy even get discount coke

it's not like coke is expensive

Phase

20:17

Over here we call that "diet coke"

anyone who likes diet coke honestly can't be human

Slereah

I think the scale is like

Coke, Pepsi, Dr Pepper, Mister Pibb

Phase

Coke zero, fine. Diet coke? To the other side of the wall

Slereah

Hm, what else in between

Phase

Excuse me what? Dr Pepper is top tier.

It goes like this

0celouvskyopoulo7

@Phase I like Diet Coke.

@Slereah Pepper is not a Coke ripoff...

Phase

20:18

Dr Pepepr, Pepsi, Co- @0celouvskyopoulo7 no you don't

0celouvskyopoulo7

Yeah I do.

Phase

no one likes diet coke

0celouvskyopoulo7

Prove me wrong?

Phase

that's a lie

0celouvskyopoulo7

I like it.

Slereah

20:18

Phase

dr Bob

Slereah

All the various Dr Pepper knock offs

Dr. Choice sounds like an abortionist

AccidentalFourierTransform

dr perky :D

Phase

What bijective correspondence maps Dr. K to Dr. pepper?

Slereah

Dr. Perfect is probably a character on some soap opera

Phase

20:19

"Real Dr." is quite ironic

0celouvskyopoulo7

@AccidentalFourierTransform he's a pastic surgeon

AccidentalFourierTransform

and there was an actual Dr. Becker, right?

Becker (TV series)

Becker is an American sitcom that ran from 1998 to 2004 on CBS. Set in the New York City borough of The Bronx, the show starred Ted Danson as John Becker, a misanthropic doctor who operates a small practice and is constantly annoyed by his patients, co-workers, friends, and practically everything and everybody else in his world. Despite everything, his patients and friends are loyal because Becker genuinely cares about them. The series was produced by Paramount Network Television. == PremiseEdit == The show revolved around Becker and the things that annoyed him, although the supporting cast also...

Phase

Dr. Shaw sounds like one of those american TV shows where people go on air to talk about dramatic trailer trash drama with a 'professional'

Slereah

In France we have Breizh Cola

It's a breton cola

Phase

Breton

Slereah

20:21

I remember seeing "human cola" in the store, which I assume is some kind of Soylent Green thing

AccidentalFourierTransform

dr chill prescribes certain plants for his treatments

Slereah

Dr. Right is my future husband

Phase

Ok so, this is a chat full of bright intellectuals and people like me, so I'm sure we can solve this conundrum: Pick 3 fizzy drinks, [top tier, middle, worst]

Slereah

While Dr. A+ is what all asian dads want their sons to be

AccidentalFourierTransform

The Beatles - Doctor Robert

►

Phase

20:23

@Slereah and if their kids fail, they regress into Dr. Choice

nbro

So, let me see if I understood correctly what proper acceleration actually is. We're first of all in Einstein's context. We have frames of reference (inertial and non). Proper acceleration is measured by an observer in free-fall or by an observer in an inertial frame, i.e. a frame of reference which is not accelerating. Proper acceleration is not due to gravity, because gravity acts upon the inertial observer as well as upon the objects being measured...

AccidentalFourierTransform

soft drinks taste like shit to me tbh

0celouvskyopoulo7

$$|x-y|^{2-n}=|x|^{2-n}\sum_{j\ge 0}P_j^\lambda\left(\frac{x\cdot y}{|x||y|}\right)\left(\frac{|y|}{|x|}\right)^j$$

wot

Bernardo Meurer

maa.org/external_archive/devlin/LockhartsLament.pdf

AccidentalFourierTransform

the americans torrent

Slereah

20:24

Also the question is

What do you call carbonated soft drinks

0celouvskyopoulo7

haha

Slereah

Cola, soda or pop

nbro

Any serious person here?

0celouvskyopoulo7

they're in Abramowitz

Bernardo Meurer

Yep, that was on my clipboard before lel

0celouvskyopoulo7

20:25

@Slereah soda

Bernardo Meurer

@nbro Nope

Slereah

@0celouvskyopoulo7 all functions are in Abramowitz

AccidentalFourierTransform

piracy is wrong mofo

nbro

@BernardoMeurer you can't actually answer for everyone

Bernardo Meurer

@nbro You'd be surprised

nbro

20:26

ok

0celouvskyopoulo7

He's right though

nbro

bye

0celouvskyopoulo7

@nbro bye

AccidentalFourierTransform

thats the generating function of the Legendre (Gegenbauer?) polynomials, right?

Slereah

though really

None of that really matters

I don't like any of the colas

Phase

20:27

@nbro I'm serious

Slereah

I'm more of a fruit dranks guy

Phase

about soda

Slereah

@Phase got a Pepper doctorate in sodas

AccidentalFourierTransform

the best drink is pizza

Phase

@Slereah could you help me with this topology thing? It's about the Axiom of Dr. Choice

Slereah

20:28

I can try

0celouvskyopoulo7

@AccidentalFourierTransform Gegenbauer

They're like Legendre but worse

where do you know them from?

Phase

It's about if you're given a set of Dr. pepper derivatives, that you can choose any of them, but they all taste like garbage

AccidentalFourierTransform

is Dr Choice equivalent to Zevia's Lemma?

@0celouvskyopoulo7 i needed them for my master thesis

Slereah

Only Zorn's lemon drink

Phase

You just had to hijack my joke

and make it far better than mine

AccidentalFourierTransform

20:30

@0celouvskyopoulo7 I was playing around with higher dimensional spherical harmonics

Phase

Btw

@nbro

You're wrong about what an inertial frame of reference is

A freely falling frame in a gravitational field is AFAIK an inertial frame

0celouvskyopoulo7

@AccidentalFourierTransform hmm, well they show up in integral kernels for elliptic operators on weighted Sobolev spaces...

So same reason why spherical harmonics show up in for regular PDE, I guess

who knows

AccidentalFourierTransform

if the wight is the measure on $S^n$, then I guess it is a natural object to use

0celouvskyopoulo7

uhhhhh

it's not

it's $1+r^2$ with some crazy exponent

AccidentalFourierTransform

then no idea

Bernardo Meurer

20:42

@dmckee Are you around?

ArtOfCode

crickets

Slereah

is there general relativistic chemistry

AccidentalFourierTransform

@0celo did you manage to fix MMA in the end?

dmckee

@Slereah Often but not always. See nytimes.com/2014/11/02/opinion/sunday/… for an important alternate perspective.

Being a while guy with enough physical presence to settle a room I've never felt the need to insist on a title even in the classroom, but that a sign of my having it easy.

Slereah

"But they are mostly men, and almost all white, and they have that luxury."

wew

Phase

20:53

Oh god

I couldn't hear you over all my Dr Choice privilege

dmckee

Being pushy about titles outside the context where they matter is often a sign of some kind of personal insecurity or neediness.

Slereah

Especially if you're german

Germans have tons of titles

Phase

I had a secondary school teacher who used to get really shitty when they wouldn't call them "dr"

dmckee

That said, my school is a place where most students use titles for their instructors most of the time.

Phase

despite the fact they only just got their doctorate and kids forget

0celouvskyopoulo7

20:54

@AccidentalFourierTransform mostly

@dmckee I had a professor who ended emails with "Dr. B"

he wrote out his name, of course

I've had two professors who did that, at least

Slereah

I only have a master degree

Feel free to call me master Lereah

Sanya

@Slereah Prof. Dr. habil. Dr. h.c. mult. ? :D

Phase

@Slereah I'm not into S&M thanks

Slereah

@Sanya that kind of stuff, yes

dmckee

We have a couple of professors here with difficult (for rural Americans) names from other parts of the world. One goes by "Dr [firstname]", and the other by is often "Dr. [initial]", though I have heard that he doesn't like that very much.

0celouvskyopoulo7

20:57

@dmckee Yeah, one prof has one of those awful polish names so I can understand

dmckee

@Slereah My school has a non-trivalal population of instructors without terminal degrees. They are called "Prof. [so-and-so]", which kinda inverts the usual sense that professor is more senior than a mere doctor.

Slereah

Fascists!

0celouvskyopoulo7

What happened??

Phase

I guess

Dr Choice doesn't visit the h bar

Bernardo Meurer

@dmckee ::pokes::

dmckee

21:07

::squirms:: Quit that!

I'm grading so you only get half my attention.

Grades are due on Monday morning.

Bernardo Meurer

Jee

Papa bless

D. What do I do when a professor hates my guts?

ArtOfCode

for (var paper in papers) {
    paper.grade = random.choice('A', 'B', 'C', 'D', 'E', 'F');
}

Bernardo Meurer

And I mean that, he mocks me to my face, and not in a friendly way

Slereah

"Another series of experiments, called "ether-drift experiments", places stringent limits on any unknown, long-range vector field that couples directly to mass energy."

dmckee

@ArtOfCode I think you have to import stairs for that.

Slereah

21:09

What theory even has a vector field directly couples to mass energy?

ArtOfCode

@dmckee that'd be a new one for JavaScript

Bernardo Meurer

Javascript is a mess

Slereah

what would it even be, $D(V_\mu) = f(T_{\mu\nu})$?

ArtOfCode

Mostly, yeah

dmckee

@BernardoMeurer The first thing is to try to avoid him. The second is to bring it to the attention of the department head. Or if it is the department head someone from the office of academic affairs.

They may also be an official grievance policy in the student handbook.

Bernardo Meurer

21:10

@dmckee Avoiding isn't possible, he's my lab professor, he personally reviews my work every week

dmckee

@ArtOfCode I just assume that all simplified code was meant to by python and proceed on that assumption.

Bernardo Meurer

I guess I can talk to the head guy, he's weird though, we see

Slereah

"Among all bodies of physical law none have ever been found that is simpler or more beautiful than Einstein's geometric theory of gravity."

How does one measure beauty

ArtOfCode

@dmckee well in that case

dmckee

@BernardoMeurer On that front all you can try to do is be so good he has to admit it.

No fun, but it will help you in the long run.

ArtOfCode

21:12

for paper in papers:
    paper.grade = random.choice('A', 'B', 'C', 'D', 'E', 'F')

Bernardo Meurer

@dmckee He took points away from me because I used getline() in a way so that all the arrays are allocated automatically to the perfect size, instead of doing some realloc() brouhaha (which is what he expected us to do)

I mean expect as in, thought we were going to, not explicitely told us to

ArtOfCode

@BernardoMeurer hint, from what I'm finding at university: try to do what professors expect, even if you know it's not the right way. They like taking marks away for not doing exactly what the spec says.

And sometimes even for what the spec doesn't say.

0celouvskyopoulo7

@Slereah what are u reading?

Phase

@Slereah With a IFLS article that claims everything in physics is beautiful

dmckee

Hmmm ... getline isn't part of the standard c library (and hasn't been part of the POSIX standard for terrible long ... maybe a decade now), so he may feel that it is cheating in some way.

Bernardo Meurer

21:14

I'm trying! But the guy takes points from me for anything! I implemented a way to do ops on a linked list without ever needed to go over the whole list by using a nicer struct and he took points from me because it wasn't "like everyone else did it"

dmckee

Of course, I love getline.

Slereah

@0celouvskyopoulo7 MTW

dmckee

You could always code your own implementation and use that.

Bernardo Meurer

He didn't even know about getline() and how if you pass it a NULL pointer it allocates for you

0celouvskyopoulo7

@BernardoMeurer How are these freshman classes

ArtOfCode

21:15

@BernardoMeurer also what I've found: think dumb. That sounds kinda harsh, but if your programming abilities are beyond everyone else in your class, try to think as they would and code accordingly

2

0celouvskyopoulo7

This is the equivalent of someone talking about bifunctors on $\infty$ categories

Bernardo Meurer

@ArtOfCode I can do that, sure, but it's hard when what he expects is really vague, so all I do is optimize for speed

@0celouvskyopoulo7 This is basic stuff programming-wise IMO

dmckee

@BernardoMeurer SO, providing your own implementation with a copious documentation comment at the front solves your problem and shows him that you know how to deal with alloc class function.

ArtOfCode

Yep. I guess you've tried asking him to be more specific in his requirements?

Bernardo Meurer

@ArtOfCode ::nods::

Slereah

21:16

"Birkhoff's theory predicts the same redshift, perihelion shift, deflection, and time-delay as general relativity. But it requires that the pressure inside gravitating bodies equal the total density of mass-energy; and as a consequence, it demands that sound waves travel with the speed of light."

This sounds like a major issue

Bernardo Meurer

@dmckee That'll show him!

dmckee

@ArtOfCode And I am afraid that there is something to that. I had a prof like that, too.

Bernardo Meurer

I was on the brink of delivering my assignments in inline assembly just to spite him

Slereah

"Not until the work of Will was it realized that Whitehead's theory predicts a time-dependance for the ebb and flow of ocean tides that is completely contradicted by everyday experience."

ArtOfCode

@dmckee Aye, I've got one at the moment too. Refused to let me use static in a Java assignment a couple months ago because the course hadn't taught it yet.

0celouvskyopoulo7

21:17

my thermo prof took off points for not writing down exactly the equation from the formula sheet

Slereah

ther's a lot of weird gravity theories

0celouvskyopoulo7

Writing down 1st law wasn't good enough, had to write down the whole damn thing, then cross of things

ArtOfCode

Also refused to let me use abstract classes, but to be fair those are year 3 at least.

Bernardo Meurer

@ArtOfCode I had to build a goddamn graphical game without structs lol

0celouvskyopoulo7

@ArtOfCode wait what

how old are you

ArtOfCode

21:18

@0celouvskyopoulo7 5

obviously

Bernardo Meurer

I was doing some serious pointer magic-fuckery to pull that off

ArtOfCode

@BernardoMeurer ouch

Slereah

Sorry this site is forbidden to people under 13

We'll have to ban you

ArtOfCode

@Slereah waaaah, mommy he's being mean to me

0celouvskyopoulo7

@dmckee I'd liket to report an underage user.

ArtOfCode

21:19

/s

Bernardo Meurer

@ArtOfCode I implemented 2048 in SDL2 in pure C without any structs, all in a single file, and with no extra libraries (apart from SDL and standard stuff)

It was hell

SINGLE FILE

We couldn't make our own header files

Slereah

MTW says that outside of Cartan's theory, only metric theories of gravity work

I'm not sure I agree

0celouvskyopoulo7

what was Cartan's theory?

Bernardo Meurer

@dmckee Why are header files in C the way they are? Why do I have a .c and a .h? Why not write all the code in the .h already?

Slereah

@0celouvskyopoulo7 Zero curvature and non-zero torsion

0celouvskyopoulo7

21:21

how does that work?

what's the manifold

dmckee

@BernardoMeurer Compile-time efficiency.

0celouvskyopoulo7

zero curvature is a strong condition on topology

well...maybe not if you're not using LC

Bernardo Meurer

@dmckee ::listens carefully::

dmckee

Keep in mind that c was originally written to run on something with less memory and computational power than things you've run with a potato.

Bernardo Meurer

That's true, I have some tuned potatoes

But I don't get what difference it makes, having a .h and a .c as opposed to just a .h

dmckee

21:22

Compiling is hard work and you didn't want to compile the code for anything more than once if possible. Those the whole separate compilation infrastructure.

Slereah

Well, I don't know if Cartan requires zero curvature

But the metric is independant from the matter content, anyway

dmckee

There are some nice questions about this on programmers and stack overflow (the ones on SO are old, mind you).

@BernardoMeurer The typically header file only requires the compiler to update the symbol table, not actually build a AST and emit code.

Bernardo Meurer

Ah, I see

Cool

0celouvskyopoulo7

8

Q: Mathematica stuck in "running" for every calculation I attempt, kernel error

I downloaded Mathematica this morning to do an implicit polar plot. I attempt to run the code Manipulate[ ContourPlot[ Evaluate@With[{r = Sqrt[x^2 + y^2], \[Theta] = ArcTan[x, y]}, {r Cos[Pi \[Theta]/(Pi - 2 chi)] - Exp[1/(r^2 Sin[Pi \[Theta]/(Pi - 2 chi)]^2- 1)] == 0, r^2 == 1}], {x, -2, 2}...

I'm at +8!

@BernardoMeurer My desk lamp is flickering, what do?

Bernardo Meurer

@0celouvskyopoulo7 More power

That's always the solution

jk

Put a capacitor on it

A bigass one

0celouvskyopoulo7

21:31

what's that

Slereah

0

Q: Why does the world look 3+2 dimensional instead of 2*3+2 dimensional?

In quantum mechanics, it is not obvious (for me) how to deduce the perceived dimensionality of the world from the (mathematical) description by high-dimensional wave functions. To simplify the problem, let us restrict the question to how the world looks like when perceived (only) with the help of...

quantum-mechanics electromagnetic-radiation spacetime frequency fourier-transform

I wanted to comment "what" but apparently you need 15 characters minimum

Bernardo Meurer

@0celouvskyopoulo7 Just plug mains into a potato and then plug the potato on your lamp

0celouvskyopoulo7

@Slereah see my comment.

rob

@Slereah Whaaaaaaaaaaat?

Slereah

Nice ruse

rob

21:33

59

A: Is gravity just electromagnetic attraction?

Short answer: No. Long answer: Nooooooooooooooooooooooooooooooooooooooooooooooooooooo. Moral of the story: Gravity and EM are two very different things that look similar to some people because they both fall off like $\frac{1}{r^2}$. Be careful what you trust. When someone makes a claim like th...

Sha Vuklia

Guys, I don't really understand why they mention a "field of view"? I've seen it in a post* here on Stack, but I still don't understand why we consider this. Why does it matter how much we see?
* https://physics.stackexchange.com/questions/126101/why-the-electric-field-vece-is-constant-position-independent-for-an-infi

Slereah

it refers to solid angles

0celouvskyopoulo7

The moral of my story is to never think you're smart enough to understand PDE

It's an impossible task

Slereah

they are pretty shit

0celouvskyopoulo7

@Slereah Let's write a book on weighted Sobolev spaces

Slereah

21:45

no thx

0celouvskyopoulo7

what better do you have to do

Slereah

The GR book

Another book I had in mind to do was just a big book on spin

Just explain spin from all possible angles

Because it is the worst explained thing

Sha Vuklia

@Slereah oh okay, I've never heard of that before

oh i have actually

didn't know it was called like that

0celouvskyopoulo7

Slereah

@0celouvskyopoulo7 No

0celouvskyopoulo7

21:49

@Slereah It's basic GR

Slereah

is it

0celouvskyopoulo7

no

Thomas Klimpel

@Slereah Since my question is referenced here already, let me just repeat my wish to get an explanation what is wrong with my question:

Why the downvotes? Seriously, it is unclear to me what is wrong with this question. Maybe I will ask on "The h Bar", perhaps somebody is willing to explain it to me. Feel free to also explain it here, then I don't have to ask. I won't take your explanation as indication that you downvoted... — Thomas Klimpel 19 mins ago

0celouvskyopoulo7

@Slereah "The large scale structure of Sobolev-spaces"

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