The h Bar

0celo7

00:07

@Semiclassical "The Lagrangian $L$ is a section of $\pi^*_{\mathcal C\times_M \mathcal V,M}\Lambda_n M$"

::closes book::

time to do something else

Semiclassical

00:18

...yeah, i'm with you

how'd your fluids midterm go?

swimmingly? :)

0celo7

@Semiclassical very easy

Semiclassical

good

0celo7

find integral curves of a flow, compute a contour integral, check the CR equations for an analytic flow, and show a certain L^2 norm is conserved along the flow

Semiclassical

yeah, that seems simple enough

0celo7

@Semiclassical there was a time when I liked bundles, but how I just really want to know on what space my thing lives and what space it maps into

physicists have the right idea there

rob

02:29

@EmilioPisanty Yes, you post a link to the comment in chat and then other people also vote on it.

Also: d'awww, shucks

0celo7

03:34

7

A: In Search of a Soulmate

Husk, 4 bytes εṠ-u Try it online! Explanation εṠ-u Implicit input. u Unique elements. Ṡ- Delete them from input, counting multiplicities. ε Is the result a singleton list?

@BernardoMeurer explain

what the heck is this language

@Semiclassical i was reading the Bernoulli eqn wiki and found something interesting

if lift was due to the bernoulii principle, then blowing on the bottom of a piece of paper should make it go down

Bernardo Meurer

03:59

@0celo7 Don't go on PCG

It will scar you

0celo7

@BernardoMeurer I just got an email from you

why to that address?

Bernardo Meurer

@ACuriousMind The essay is under review on GDrive, hit me an email from the address you'd like it shared with :)

0celo7

how do you even have it

Bernardo Meurer

I typed Ryan on my google docs share thing and that one showed up

@JohnRennie Morning John

:)

0celo7

I don't think that one is connected to google...

John Rennie

04:01

Morning :-)

Bernardo Meurer

@JohnRennie I wrote a bombass essay on DRM and Intellectual Property

0celo7

Hmm, if a pipe flow empties into a chamber, am I supposed to assume that the velocity is zero

John Rennie

@BernardoMeurer the one quoting from the bill of rights, or whatever the document was?

Bernardo Meurer

@JohnRennie Ah, that was just a meme for one quoting exercise

This is a real essay

I can share the GDoc with you, what email?

Done

Feel free to comment as you please

0celo7

@BernardoMeurer A colleague asked me to read a paper of his. I'm tempted to point out the typographical faux-pas (plural?)

Bernardo Meurer

04:10

Pointing out typographical errors is helpful IMHO

0celo7

like he writes $Cl(\Omega)$ for the closure

like why not $\mathrm{cl}(\Omega)$

Bernardo Meurer

Dunno

John Rennie

I've grabbed a copy as a PDF. I'll have a read once I've checked my servers are all alive and well. It's Windows update week so things are a little tense.

0celo7

windows is the greatest OS

name one better

Bernardo Meurer

@JohnRennie Thanks! Let me know your thoughts :)

John Rennie

04:15

@EmilioPisanty It's odd that it took so long, but the update can sometimes be very slow. Oh well, it's working now :-)

0celo7

@JohnRennie Is Windows update why my PC had to be SW reset when I came home?

it was completely unresponsive

did I break it?

John Rennie

@0celo7 Bernardo isn't going to agree, but Windows has a basically nice architecture. The fact you can run a full Ubuntu system, downloaded from the Ubuntu servers, without a VM or docker demonstrates this.

0celo7

Ubuntu is awful

3

it can't even connect to the internet

John Rennie

But MS have to sell to the general public and they like everything to be pretty, so MS have loaded down what is a basically nice kernel with a shit ton of dross.

Bernardo Meurer

@JohnRennie I put that credit more in Open Source software than in Windows. If Ubuntu was closed source that couldn't happen well

Ubuntu is awful

3

Look at Linux+Wine for example of attempting to reverse a closed API

John Rennie

04:19

Right, but the thing about running Ubuntu on Windows is that it isn't an emulator. Windows has supported OS subsystems since day one (in 1994 I think) and the Ubuntu apps are running ina subsystem not an emulation.

0celo7

Day 1?

Bernardo Meurer

Wine isn't emulation either

0celo7

Windows was only around since '94?

Bernardo Meurer

It's a reimplementation of the API

(AFAIK, maybe I'm wrong)

John Rennie

The subsystem could easily be extended to support any of the distros, but Ubuntu is the biggest so market forces dictate it's done first.

0celo7

04:20

@BernardoMeurer is a commie

he doesn't believe in the market

Bernardo Meurer

I just wrote an essay defending Lockean property rights

How on earth can I be a communist

0celo7

a mild commie then

Bernardo Meurer

Your logic is beyond me

0celo7

@BernardoMeurer are you coming to VA for thanksgiving?

Bernardo Meurer

@0celo7 I thought it was going to be in H-TX?

0celo7

04:27

Did Michelle say that?

Bernardo Meurer

Nope

She doesn't say anything

She's busy

I asked Kat a bit ago and she said it hadn't been decided yet

0celo7

She uses that as a cover to avoid familial contact

Kat is going to VA

that's been known for months

She just told me to find out where you're going

You can come to VA, now how you get there is an issue

Bernardo Meurer

Alrighty then

When's thanksgiving, I'll check planez

0celo7

google

last thursday of Nov

or is it the fourth Thurs?

Bernardo Meurer

Unless Michelle wants to drive to VA lol

0celo7

04:30

idk, I'm not American

*Ron is forced to drive to VA

Bernardo Meurer

23rd of November

@0celo7 Lol

To I fly to DC or to where?

0celo7

Dulles

Bernardo Meurer

$500

No way

0celo7

@JohnRennie it's pronounced Yea btw

rob

05:28

@0celo7 It's the fourth Thursday. One year I had a calendar that used the wrong "last Thursday" rule, and I planned for Thanksgiving on the fifth Thursday. That was a very expensive calendar.

Bernardo Meurer

Lol

@rob Will you drive me to VA?

rob

@BernardoMeurer From where?

Bernardo Meurer

California

rob

Both of those places are kind of out of my way

Bernardo Meurer

I promise not to ramble about POSIX on the car

rob

05:32

@BernardoMeurer That's standard

Bernardo Meurer

Or to complain about the usage of alloca()

rob

man alloca

oooh, garbage collection

Bernardo Meurer

::begins complaining::

rob

free(complaint)

Bernardo Meurer

See, when you're serious you don't rely on garbage collection

rob

05:37

I get garbage collection on Tuesdays. It's quite reliable.

(Next week it's Wednesday due to the holiday.)

Bernardo Meurer

What holiday?

rob

opm.gov/policy-data-oversight/snow-dismissal-procedures/…

Bernardo Meurer

I'm not sure when I get garbage collection here tbh

I should, my house stinks of garbage

That page has no holidays on next week?

John Rennie

alloca is fine as long as you don't try and allocate huge chunks of memory. It's no different to declaring a local array.

rob

@BernardoMeurer Oh, you're right. Columbus day was this week.

My university is off Monday and Tuesday. I got confused.

Bernardo Meurer

05:40

I didn't get this holiday! Not fair!

@JohnRennie Why not just declare a local array at that point?

@rob If I apply to your university and get in will you wine me and dine me?

rob

@BernardoMeurer We don't wine and dine the undergraduates --- usually not legal.

Bernardo Meurer

@rob Will you Mountain Dew me and dine me then?

rob

But if you showed up here I'd totally take you out to dinner.

Bernardo Meurer

How far are you?

I'm kind of hungry right now

rob

I'm far out, man.

Bernardo Meurer

05:44

Are you at least of this coast?

rob

@BernardoMeurer I'm a long way from California.

Bernardo Meurer

Hmmm

Okay, maybe I need to buy dinner tonight then

John Rennie

@BernardoMeurer you might want to dynamically declare structs or objects and you might not know how many you want. Honestly, I don't see the problem.

Bernardo Meurer

@JohnRennie ::begins complaining::

John Rennie

I guess the trouble is that there's no way to be sure alloca won't overflow the stack and crash your app since it doesn't return void on an allocation failure, but the same is true of using recurson.

user84215

05:51

Why are there only three possible curvature tensors with constant curvature?

Bernardo Meurer

06:04

@JohnRennie You can easily limit recursion depth

John Rennie

@BernardoMeurer but you don't know how much stack free space is left, so you never know when to limit recursion.

Bernardo Meurer

@JohnRennie That is true, but usually you can use a heuristic such as "if we're recurring 10 million times then something is wrong and we should halt"

Sure, sometimes that's not possible and then may god's love be with you

John Rennie

And the same is true of alloca. You can use a heuristic like don't use alloca to allocate a 1GB array.

Bernardo Meurer

@JohnRennie Yes, but a beginner sees alloca as ez_malloc() and uses it as such

Which is no gouda

I also don't see why alloca() is needed

Just use m/calloc and free

John Rennie

Since when has C been a warm cuddly environment for beginners? :-)

Bernardo Meurer

06:08

Since never, but that doesn't mean I shouldn't hate on things. What else would you have me spend my time doing??

John Rennie

Hugging trees? :-)

(red black trees of course)

Bernardo Meurer

Bah! I'm no tree hugger!

John Rennie

The grinch is alive and well and writing documents about DRM!

Bernardo Meurer

Hahahahaha

Bernardo Meurer

06:52

@JohnRennie Have you got about 300GB to spare for a couple days?

John Rennie

@BernardoMeurer My internet connection isn't fast enough to be shuttling 300GB to and fro. Sorry.

Bernardo Meurer

Dangit

Thanks anyway :)

I need to change the filesystem on my backup drive

John Rennie

You take an awfully long time to conclude that DRM is bad because (a) it doesn't have a copyright expiry date and (b) it doesn't allow fair use ...

Bernardo Meurer

Well, the important point is to show that it's anti-copyright

That's what takes forever

Those are just examples of how it is anti-copyright

But explaining why not allowing fair-use is a bad thing, or why public domain is rightful is complicated

John Rennie

When something goes out of copyright that doesn't mean I have a right to copy it, it just means the author cannot stop me copying it. Likewise fair use.

Bernardo Meurer

07:05

How is the author not having a right to stop you from copying different than you having the right of copying?

John Rennie

You only have a right if someone else has an obligation to you to enforce that right.

Bernardo Meurer

Things with expired copyrights fall under the public domain, at which point they are "common to the public", and everyone has rights of usage on them

John Rennie

But suppose the author buys up all copies and shreds them

Bernardo Meurer

The government has the obligation to enforce the access of the public to the common to allow the community to thrive

It's pretty much the only reason government exists IMHO

John Rennie

No-one has the obligation to force the author to share their (out of copyright) work.

Bernardo Meurer

07:07

But he is not doing that on claims of being the author. He's just a madman burning books

John Rennie

@BernardoMeurer morally possibly - legally not.

Bernardo Meurer

Yes, legally not, and that's part of the problem; that we establish property in a Lockean sense and yet we don't enforce it as such throughout

John Rennie

I'm not saying I approve of or support the current state of affairs, but that's the way it is. We have no right to copy material that is out of copyright.

And neither do we have any right to fair use.

Bernardo Meurer

According to Lockean property rights we do

John Rennie

Legally speaking that is.

Bernardo Meurer

07:10

Yes, fair use is just a doctrine

That was more of an example of DRM, something an individual makes, trumping the interpretation of legality of the legislature which ought not to happen IMHO

Emilio Pisanty

@rob ah, see? It worked!

Bernardo Meurer

@EmilioPisanty If you want to review the paper too I can share it with you :P

I'm kind of proud because I like my points and that never happens

Emilio Pisanty

@BernardoMeurer what paper?

Bernardo Meurer

I'm writing about DRM and intellectual property rights

Knowing me you can infer I'm writing against DRM I suppose

Emilio Pisanty

@BernardoMeurer I'm happy to have a look but I can't promise I'll have too much time for it

John Rennie

07:16

@EmilioPisanty it's only 7 pages and a quick read

Bernardo Meurer

@EmilioPisanty What email should I share the Google docs with?

Emilio Pisanty

@JohnRennie what?

@BernardoMeurer icfo email

Dead easy to find

[email protected]

Bernardo Meurer

Coolio

@EmilioPisanty Sent :)

John Rennie

@EmilioPisanty suppose I publish a book, then the day before it's out of copyright I buy back all the existing copies and shred them. You have no legal right to demand me to supply you with the contents of the book.

If you can find a copy of the book I can no longer stop you copying it, but no-one has any obligation to make me share the book with you.

Emilio Pisanty

@JohnRennie I guess it's an issue of precise wording

John Rennie

07:22

It's a misuse of the word right

Emilio Pisanty

We don't have a right to copies of material that's out of copyright

We do have a right to copy material that is out of copyright

@JohnRennie also, that kinda depends on whether the country the work was published has a copyright-library system that makes it compulsory, in principle, to deposit copies of every copyrighted work

If this is the UK and the author did not dodge their legal obligations, I can just walk up to the British Library and ask for a copy

(they will take ages because the main hq is in London but the bulk of the archives are in Yorkshire, which totally makes sense, but still)

John Rennie

This was in the context of Bernardo's assay where he makes the point that unless DRM has an expiry date built in it will continue to prevent copying after the copyright has expired.

Emilio Pisanty

@JohnRennie ah, yeah, that is a trickier matter

I need to think about that more carefully

John Rennie

I'm not disagreeing that DRM is bad (though IMHO useless would be a better description :-) but I'm not sure Bernardo's argument is valid.

Emilio Pisanty

Well, here's a related question

Is it illegal to circumvent DRM that's attempting to enforce an out of date copyright?

John Rennie

07:31

You'd have to ask a lawyer, though I would have guessed not. That is, there is no obligation on anyone to prevent you copying the contents of DRM protected material that is out of copyright.

Anyhow, I have to go check my servers now ...

Bernardo Meurer

@JohnRennie "assay"? Are you trying to be derogatory? :P

John Rennie

Oops! Sorry.

Bernardo Meurer

@EmilioPisanty According to DMCA yes

@EmilioPisanty Precisely

Sir Cumference

08:27

YES

I finally got an answer to an absurdly hard problem

I only had to work until 4:30am to do it...

user129412

09:00

If I am not mistaken, a zero charge boundary condition is quite different from a V = 0 boundary condition (in electrostatics) is it not?

One is no electric fields and the other is grounded?

John Rennie

10:07

@MathematicsAminPhysics ahem

user84215

@JohnRennie You do not like it. Right?

John Rennie

@MathematicsAminPhysics as @ACuriousMind said last time, you should make it clear in the post that this is not an event associated with this room. And you need to put that in the post so that when the post is starred the disclaimer appears on the star board as well.

user84215

@JohnRennie I think nobody will star it. If it may be starred, you can remove stars.

John Rennie

I was asking you politely. If you wish to remain a member of the room please take note of the wishes of the room owners.

user84215

The following workshop will be held in the Physics Workshops room (It has nothing to do with the h Bar room): Covariant Electrodynamics in Different Dimensions, at 9:30 GMT on Sunday, October 15, 2017

John Rennie

10:19

→ 2 messages moved to trash

Thanks.

Physics Meta

10:50

0

Q: Approved/OK form of cross posting

Let us say I have (and I have!) a very technical question related to the (proper) mathematical formulation of physical theories. Should I ask it in one section only (let's say mathematics) and wait for a good/thorough answer there, or should I cross-post it in the physics section, knowing that th...

support

Slereah

11:55

Is there a QFT model of electric conduction

ACuriousMind

@Slereah I think a fermion gas models the average conductor pretty well, no?

Slereah

Not if you want the band structure!

Though really would it be much harder?

Just replace the Pauli equation with the Dirac equation

Put some potentials

Ah, apparently there's model for it in graphener

Let's see

Slereah

12:28

So I got an answer from that astronautics paper about the missing issues on their site

no electronics version, apparently!

Very sad

they sent me the index, though

I'll ask if I can buy a paper version

It's a very generic journal on astronautics so there's quite a few fun papers

a bunch of stuff about SOVIET SPACECRAFTS

0celo7

@ACuriousMind how do I compute the vertical part of a vector field using only a covariant derivative?

ACuriousMind

12:50

@0celo7 Well, the covariant derivative gives you a connection form, and that is equivalent to an Ehresmann connection in the form of a horizontal subbundles, so in principle you should be able to compute the horizontal (and therefore the vertical) projector from it, but it's not a computation I'd want to actually carry out :P

0celo7

@ACuriousMind Yeah I know it's possible in principle but the result Christodoulou gets seems suspiciously simple

IIRC the covariant derivative is the exterior derivative of the horizontal part. So using it to directly compute the vertical guy seems strange

@ACuriousMind but strangely enough I understand this stuff better on PG bundles, but here I have a vector bundle

ACuriousMind

@0celo7 What is his result?

0celo7

And thinkin about connections in terms of distributions on vector bundles makes my mind hurt.

ACuriousMind

@0celo7 Yeah, at least the curvature - "commutator of covariant derivatives" - is just the connection form applied to the bracket of the horizontal parts of two vectors field. I would agree a simple formula for the vertical part of a vector field seems strange

0celo7

13:05

@ACuriousMind $\mathcal C\times_M \mathcal V$ is just some bundle on $M$

the connection $\Gamma$ on $M$ lifts canonically

0celo7

13:51

@ACuriousMind ?

Skyler

16:19

Hey guys, whats the best primer on AFMs you've come across

DanielSank

@JohnRennie Yep. We use it over MS Word despite all the anguish. What does that tell you about MS Word?

Skyler

@DanielSank oy

DanielSank

yo

Skyler

btw, i live way closer now, had a few busy weeks but that's starting to clear up

DanielSank

k

fite me

Skyler

16:23

ye man

you know when you saw me biking

DanielSank

ya

Skyler

i live now like 2 blocks from there

DanielSank

dope

@BernardoMeurer Nooooooooooo. Don't drink that swill!

Skyler

btw, know anybody i should bug here for AFM questions

DanielSank

Jason Seifter, but he doesn't use this site.

ACuriousMind

16:29

@0celo7 I don't understand that equation: If $(q,v)$ is a coordinate tuple for the bundle, then why can we feed $q$ and $v$ separately to $f_{t\ast}$? Also, I suspect this expression not somehow general, but depends on how this field $X_\ast$ is lifted and what sort of bundle the $\mathcal{C}\times_M \mathcal{V}$ thingy is.

@Skyler What's "AFM"?

Skyler

atomic force microscope

@DanielSank so i just need to beat him at smash next time i see him

0celo7

@ACuriousMind Ok, so $\mathcal C\times_M\mathcal V$ is roughly $S_2M\times_M \mathrm{Hom}(TM,S_2M)$

ACuriousMind

What's $S_2M$?

DanielSank

@Skyler yep

0celo7

@ACuriousMind symmetric 2-tensors

and the $\times_M$ just means product the fibers in the natural way over the base

DanielSank

16:34

@ACuriousMind: Writes things like $\mathcal{C} \times_M \mathcal{V}$, but doesn't know what AFM means.

0celo7

@DanielSank I have no idea what AFM is either

CooperCape

Can I join the 'I don't know what AFM means' club please?

0celo7

@ACuriousMind So those $f_{t\star}$s are the lifts of $f_t$ to those bundles

he's using $f_{t\star}$ for the lift of $f_t$ to three different bundles, but the idea is the same in all cases.

ACuriousMind

@DanielSank In physics outside my specialty I often don't know the English technical terms - had Skyler written "REM" I'd have known what it is :P

0celo7

I don't know what REM is either

ACuriousMind

16:36

@0celo7 Rasterelektronenmikroskop

0celo7

Oh, atomic force microscopy

ACuriousMind

Ah, wait, atomic force is RKM - Rasterkraftmikroskop

0celo7

You're thinking SEM = scanning electron microscopy

@ACuriousMind So somehow the vertical part of the generator is the covariant derivative of the flow

that seems backwards

@ACuriousMind And it relies on everything being tensor bundles so the covariant derivative of the flow makes sense

ACuriousMind

So, uh, $f_{t\ast}$ is a tensor field along the curve $t\mapsto f_t(x)$, and the claim is that the covariant derivative of that tensor field is the vertical part of the generator of $f_{t\ast}$

Fixed ;)

0celo7

Yes, I think that's it.

ACuriousMind

16:45

So, in general this statement would not make sense because you couldn't take the covariant derivative of the flow for an arbitrary bundle with connection (well, you wouldn't get a flow $f_{t\ast}$ on the bundle that's non-trivial on the fibers to begin with, I guess)

I'm afraid I'm not good at Riemannian geometry, as you know :P

0celo7

The notation $f_{t*}$ is intentionally suggestive, the action is by pushforward through $f_t\in\mathrm{Diff}(M)$

ACuriousMind

So, no idea where that statement comes from

0celo7

@ACuriousMind this has nothing to do with Riemannian geometry

it's field theory

literally, I'm trying to understand the construction of Noether currents for bundles

@ACuriousMind I will review the construction of the splitting $TE=H\oplus V$ for vector bundles given a covariant derivative.

That might explain the mystery

It's not a common topic

@ACuriousMind Do you remember the story for $PG$-bundles?

ACuriousMind

@0celo7 Yes, given the connection form $\omega$ and the orbit map $O$, the horizontal space is the kernel of $\mathrm{d}O\circ \omega$.

0celo7

Orbit map?

Where is Kobayashi and Nomizu when you need it...

ACuriousMind

16:51

@0celo7 The map that applies the group action, $(p,g)\mapsto pg$.

0celo7

Oh, the right action

most people call that $R$...

oh god, Kobayashi and Nomizu omit the $d$ on derivatives

@ACuriousMind So they just say that $\ker\omega$ is the horz. space

where does the right action come in?

ACuriousMind

Yes, it just identifies the Lie algebra (which is the target of $\omega$) with the vertical tangent space.

Depending on how you define $\omega$, you may omit it - it's "morally" $\ker(\omega)$, yes.

Should be $O_p$ up there, btw - I only want to take the derivative in $g$.

0celo7

Well, so if the horizontal part of the bundle is the kernel of the connection, then the vertical part should be something involving the connection, perhaps

@ACuriousMind Ah

So yeah, a diffeo when you fix $p$

ACuriousMind

@0celo7 Sure - $\omega$ (or $\mathrm{d}O_p \circ \omega$) is surjective onto the vertical space

0celo7

Kob-No write $Q_u=\{X\in T_uP:\omega(X)=0\}$

ACuriousMind

16:57

Yeah, the more I think about it, the more superfluous is the $\mathrm{d}O_p$

It's $\ker(\omega)$.

0celo7

@ACuriousMind Germanism, the "is" should be at the end ;)

This vertical/horizontal nonsense is too complicated

ACuriousMind

So, wait - at a point, the connection form is just the vertical projection, $\omega_p = \mathrm{d}O_p^{-1}\circ \pi_V$

0celo7

What is $V$?

ACuriousMind

$\pi_V$ is what I call the vertical projection $TP\to VP$

0celo7

What you just wrote looks canonical. The connection isn't.

ACuriousMind

17:01

What do you mean by canonical?

Xsnac

Hello guys, just posted a question if you would like to give it a minute of your life I would very much appreciate it. physics.stackexchange.com/questions/362668/…

0celo7

There's multiple connections but you just wrote a formula without mentioning a connection.

Do you mean $\pi_H$?

ACuriousMind

@0celo7 No, the connection vanishes on horizontals, after all.

@0celo7 What I wrote there is the connection form associated to a principal Ehresmann connection (i.e a splitting $T=V+H$ with projections $\pi_V,\pi_H$).

0celo7

Oh ok, I guess projecting onto the vertical requires one to separate out the horizontal first.

So that's where the connection is

@ACuriousMind Ok, so what about that formula?

ACuriousMind

Well, $\pi_V(X) = \Gamma(X)$. Now $(\nabla_X F)^k = (X^j F^i \Gamma^k_{ij} + V(F^k))$.

Ugh

Anyway, I got to go, sorry I wasn't of that much help

0celo7

17:17

@ACuriousMind np I've got class anyway

DanielSank

17:48

@ACuriousMind Random Eye Movement.

It's a stage of sleep.

Emilio Pisanty

19:02

@JohnRennie poor OP seems to have gone unheard

0

Q: What is the meaning of pp-wave (plane-fronted wave) in the gravitational theory?

What is the meaning of the pp-wave (plane-fronted wave)? How can I understand this concept? Whether there is a image can help me to learn its physical meaning at the first sight. I know that there are many theories about gravity, such as Einstein field equations and the gauge theory. Whether the ...

general-relativity differential-geometry gravitational-waves

this is just the same old plane waves from EM, right?

just with a wonky tensor-valued polarization or something

Slereah

pretty much

pp-waves are just generic plane waves in GR

They can be EM, scalar or gravitational waves

Emilio Pisanty

why pp tho

Slereah

Not sure

Maybe related to p-waves of classical mechanics

where the p stands for pressure (and which are for longitudinal waves)

Which pp-waves are

Or maybe the p denotes the momentum

or p for plane

Emilio Pisanty

weird

I mean, y'all could just have said "plane wave" like normal people do

Slereah

19:19

Maybe because it sounds like "peepee"

Emilio Pisanty

19:35

what, like a Star Wars blaster?

I mean, 'cause it'd be terrible practice if y'all hid a dick joke in your physics or something

Semiclassical

lol

@EmilioPisanty i'm trying to think if there'd be a way to hide a comment in a pdf file uploaded to arxiv

like you can hide comments in html pages that you won't ever see unless you dive into it

Emilio Pisanty

@Semiclassical no, I like it the way it is, without explicit marks

Semiclassical

fair enough

Emilio Pisanty

kinda like the paper we used for inspiration (by my PhD supervisor), tandfonline.com/doi/abs/10.1080/0950034042000275360 Fig. 5

Bernardo Meurer

20:23

@ACuriousMind hi

Hans

@BernardoMeurer: You are not greeting me but rather @ACuriousMind, are you?

Bernardo Meurer

@Hans Correct, I do not know you

0celo7

@BalarkaSen r/vaporwaveaesthetics

Balarka Sen

20:43

already know that one

i'm a big vaporhead

0celo7

@BalarkaSen is that the same as being an airhead?

$\jj$

hm.

$\jmath$

Physics Meta

-2

Q: Why did my question become off-topic?

I have a question about my Physics Stack Exchange post: Kepler's Third Law Why did my question become off-topic? I just wanted to get a formula and said that I will solve it myself. Why aren't formula questions allowed? As far as i know, the formulas are in conceptual physics. Then, I'm ask...

support homework specific-question close-reasons

0celo7

@BalarkaSen My advisor dumped surgery papers on me. What is surgery?

Semiclassical

20:58

something something Ricci flow?

0celo7

@Semiclassical this isn't in a Ricci flow context

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