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4:01 PM
Chapter 8 of Reed 1 does seem important
 
@0celo7 did you see what i pinged you with
 
what with the unitary operators theorems
 
the three papers
 
Yeah
@Slereah wot
 
He uses it a lot to define the QFT operators $P_\mu$
 
4:05 PM
@Slereah does Eric contain info about Noether’s theorem in SR? I think I’ll be doing the first GR seminar talk on Noether
 
If you have some unitary operator $U$ then you have some operator $U = e^{ikP}$
@0celo7 haven't seen one so far
check this paper, mb
Well I guess this one is more focused on Poincaré invariance
I dunno where to get a good description of Noether's theorem, really
I'm sure there's one that's like bla bla bla principal bundle bla bla bla jet manifold bla bla bla differential graded algebra
 
that's Christodoulou
I really just want Noether's theorem for a free particle
 
So just Poincaré invariance?
It's probably doable with just the "classical" way, really
Just do some Gateaux derivative of the Lagrangian with respect to the symmetry transformation and all that
 
mhm
 
IIRC the original Noether paper is basically done the physics way
With infinitesimal transformations
 
4:16 PM
super-graded cohomological jet bundles or bust
 
I don't think they used bundles back in her days
 
@Slereah I should get his ADM book
 
Who
 
Gourgoulhon
it's too expensive though
 
o
that is what Christmas is for
 
4:18 PM
Noether died in 1935, when Whitney defined sphere bundles
3
 
@BalarkaSen Coincidence?
 
sphere bundles are awful
 
Which Christodoulou thing has Noether's theorem
 
Action Principle and PDE
 
thx
 
4:20 PM
@Slereah p. 360 of SRGF
 
ah yes, it is there
I'm only up to page 69 (nice)
 
nice, this has everything I need
what a great book
truly underrated
 
It does seem to be pretty much the only good SR book
everything you need about SR except for quantum stuff
 
vzn
@0celo7 so you travelled for holidays? SF? still there? how is it?
 
@Slereah what on Earth are boosts again?
 
4:24 PM
The Lorentz transforms that aren't rotations
ie speeding up coordinates
of constant speed
 
so what is the quantity associated to a boost?
 
It's part of the spin tensor, I think?
 
that is not helpful at all
@ACuriousMind
 
I don't recall the name for it
I've never really seen it used
 
vzn
@Slereah lol o_O where the heck did that come from? did you make it up? didnt see it on the lubos pg cfd earlier
 
4:26 PM
I mean I guess it's just like angular momentum, but I don't really think it pops up a lot
@vzn who knows what goes on in Lubos
 
god bless him, he's watched so much Rick and Morty we mere mortals can no longer understand him
 
^
 
@ACuriousMind thx
 
vzn
wonders what year lubos last had paying job o_O
 
4:29 PM
are you making _v a g u e i m p l i c a t i o n s _
 
@vzn hopefully the trump admin will hire him as the sectretary of the department of energy
 
Hello there, how to find the relative velocity of rain respect to a moving object while air is flowing?
 
vzn
@Phase aieee hanging offense o_O
 
@ffahim that seems a bit vague
 
vzn
@0celo7 hes like a real life physics quixote tilting at many different windmills...
 
4:31 PM
>defining mean curvature as an average
what is wrong with physicists
 
lubos can be like the lysenko of physics
 
vzn
@Phase lol maybe you have lubos/ BaS mixed up there :P
 
@0celo7 It does have mean in the name
 
barium sulfide does not watch rick and morty
 
@Slereah everyone knows that's just there for confusion
 
4:32 PM
it has no IQ
 
@Slereah do you have Poisson's book?
 
@BalarkaSen are you being elitist?
that's Not Nice
 
@BalarkaSen The fuck you hating non barium sulphide for
 
Poisson of the Poisson distribution?
 
no
 
4:33 PM
@phase suppose rain is falling at 6ms-1, wind is flowing at 5ms-1 North of East and a car is moving at 2ms-1 eastward , at which angle and velocity rain will hit on the car?
 
vzn
@0celo7 so you travel ½ country and still have no comment? sheesh o_O
 
I do not have any Poisson book, no
 
barium sulfide is a dumbass
there
watchoo gonna do to me
 
@BalarkaSen flag (that's a joke a joke a joke - I have not flagged it - a mere joke)
 
4:35 PM
@0celo7 I hope you like constraint hamiltonian mechanics
 
@CooperCape You're not allowed to flag inoffensive statements [unless 0celo7 made them]
 
@Slereah the constraint equations in GR are great
 
The unwritten rule here is to flag everything 0celo7 says
 
@CooperCape Get rekt by mods who come here after the flag is cast
 
half my message if me clarifying
 
4:36 PM
@CooperCape please do not use that word
 
clarifying?
 
^^^^
Ok, I'm going to cut it out
I don't want any real flags to any of the unreal jokes here
 
@CooperCape You're not gonna find me disagreeing on any cultural or moral note, especially with "bb", but you're probably gonna run into trouble on SE using the __bba word here
 
::turns attention to the chatroom::
 
@Phase Considering it was a word created to not cause offense...
 
4:38 PM
@ACuriousMind "Nibba" is a well known meme. Substitute "bb" with "gg".
 
::sighs::
 
It is properly done with the B emoji.
 
@CooperCape idk about that, it's just a word that evolved because of the B emoji as far as I'm aware
 
Insulting barium sulfate, tsk tsk tsk.
 
4:39 PM
Welp I can't remove it anymore
sozz
 
Ban CooperCape.
 
Cooper I'm not saying it's offensive to me or 0celo7
I'm saying be wise: don't get suspended over dumb crud
 
I'm offended by everything.
 
vzn
attn wanders around cyberspace due to 3+ stooges dialog
 
[redacted]
 
4:39 PM
@Slereah Apparently the ADM mass is just the GR Hamiltonian evaluated in special coordinates.
There's a bit of a meme going on because mass =/= energy but everyone pretends it is.
 
Makes sense I s'ppose
"You have already voted, but the voting has been cleared by a moderator"
@ACuriousMind you fascist
 
vzn
huh, physicists find solar cosmic ray link to cloud formation/ climate, recently published in nature. o_O motls.blogspot.com/2017/12/…
 
You really need to understand the constraints for this to work
the full GR Hamiltonian is awful
 
@0celo7 Refreshing my page n' I'm still here - soz habibi
 
"We will show that this can be done on a dense set of especially nice vectors"
Better than the set of Nice Functions is the set of Especially Nice functions
 
4:42 PM
@Slereah What can I say, I rule with an iron fist :P
@0celo7 GR is awful :P
 
$$H=-\int_{\Sigma_t^\text{int}}(NC_0-2\beta^iC_i)\sqrt{\gamma}\, d^3x-2\int_{S_t}[N(\kappa-\kappa_0)+\beta_i(K_{ij}-K\gamma_{ij})s^j]\sqrt q \,d^2y$$
 
@ACuriousMind ok Kyros
 
vzn
@BalarkaSen am trying to find a nonoffensive nickname for you, maybe you would like to pick one yourself, you deserve one as longtime chat room regular... or not :|
 
@0celo7 do you also have to Hamiltonize the York term
 
My nama Jeff
 
4:43 PM
Balarka please
 
@Slereah I think that's the second term
 
Don't just bring things back from the dead
It's disrespectful to my religion
 
You gotta appreciate a man who pops in, says "My nama Jeff", then pops back out again...
 
@Phase <death growl> SATAN, SATAN, SATAN, ... did I mention SATAN?? </death growl>
 
Gourgoulhon's 3+1 book is pretty noice
 
4:45 PM
@BalarkaSen I didn't realise html had that feature for headings...
 
vzn
thinking BaS may become standup comedian or youtube celebrity if the math thing doesnt work out
 
Barium sulfide has too low an IQ to do math, comon son
math requires Rick and Morty level IQ
 
@BalarkaSen what did ted tell you about comments like that
 
How about BaSe...
 
vzn
rick and morty pinky and the brain :P
 
4:47 PM
Barium Selenide
 
Bases are cool (chemistry... not vectors eww)
 
@BalarkaSen Isn't the R&M high-IQ joke a bit old by now? :P
 
chemisty is a bastard subject
 
@0celo7 ...
 
"Not only (P1,P2,P3) behaves as the components of a linear form"
wot
 
vzn
4:48 PM
huh? a running joke expiring in this room? whats next, the mod-as-AI joke might get frowned on, unthinkable o_O
 
Nah inorganic/phsyical is cool. Organic can burn.
 
@ACuriousMind Apparently not.
 
w i t h o u t\ e n o u g h\ o x y g e n
 
@0celo7 It can't be worse than math.
Math sucks bro
2
It's total trash
 
vzn
@CooperCape has a nice ring to it! thx! :)
 
4:49 PM
@BalarkaSen any part touched by gromov sucks for sure
pure functional analysis is objectively beautiful
 
I don't see a Banach space in the night sky
what's the point?
there's none
it's trash
cry
.
 
@BalarkaSen I think the story of three wise men following the Banach space across the sky to Poland was overtaken by the other one a few thousand years ago...
 
physics is annoying because people say stuff that has no meaning
 
@0celo7 According to Gromov the Cheetah runs because it wants to reduce entropy.
 
@BalarkaSen I have no idea what that's supposed to mean
 
4:54 PM
it's bIoLoGy
Gromov is a biologist now
 
@BalarkaSen why do you study maths and physics then?
 
Balarka studies physics?
 
@Abcd I like to do trash things
 
@BalarkaSen lol
 
@Abcd Balarka studies my mind
 
4:57 PM
@Slereah what's the free particle Hamiltonian in SR?
 
@0celo7 $p^2 / 2m$?
Wait, do you include null particles
 
Not sure
 
@BalarkaSen is Death Growl the furry equivalent of Death Grips?
Culture Shock [featuring the Fursuits]
 
The Polyakov Lagrangian is $$\frac 12 e^{-1}\dot X_\mu \dot X^\mu - m^2 e$$ and the Hamiltonian is $$\frac 12 p^\mu p_\mu + m^2$$
 
SPREAD EAGLE CROSS THE BLBLBLOCK
Featuring such stellar bars as "I ---- the music I make it ----"
 
5:08 PM
errr
$$\frac 12 e (p^\mu p_\mu + m^2)$$
That way the EoM are just $\dot p = 0$, $\dot q = p$, $\dot p_e = - (p^2 + m^2) $ and $\dot e = 0$
 
@JohnRennie You've probably been asked this umpteen times before, but would you recommend a Dell Latitude laptop (I was looking at the 5580) for someone who'd be using it for relatively basic applications (needs noticeably more processing power than the likes of Microsoft Office but nothing like gaming or video editing, so the specs look reasonable) for ~10 hours a day, 5 or 6 days a week?
 
Hi, everybody.
@Mithrandir24601 Can you list what you want to do with it?
 
@Mithrandir24601 there are no bad laptops these days. You could pretty much toss a coin (or whatever random selection method you favour) and get a good laptop.
Were you planning to buy new?
 
@JohnRennie You say that, but I'll never forget the time that we went through a laptop in less than half a year...
 
I wouldn't quite say there are no bad laptops...
 
5:16 PM
But since the action has no $\dot e$ term, $p_e$ is a conserved quantity
Hence $p^2 + m^2$ is a constant of the motion
 
@Mithrandir24601 Really? What happened?
 
@JohnRennie yeah, most likely - so much use tends to wear them down quite quickly
 
vzn
tries to follow mysterious BaSe ramblings on gromov eg biology + entropy youtube.com/watch?v=j2LTRE6sX2o ihes.fr/~gromov/PDF/structre-serch-entropy-july5-2012.pdf
 
I use my laptop at that sort of level and have never had a laptop fail
 
Sid
@Mithrandir24601 Dell Latitude is good. My friend uses it and he seemed pretty satisfied.
 
5:18 PM
@Mithrandir24601 you gotta pay attention to stuff like the keyboard.
 
@JohnRennie Essentially, it was a useless laptop with a bad screen with a processor (or something) that just couldn't quite cut it
@DanielSank That's exactly why I'm asking
 
Do you want to buy new, or would you buy second hand on eBay?
 
@Mithrandir24601 if you can supply a price limit a few important target applications, and some general description of what kind of hardware (keyboard, trackpad, screen) you like, I can help.
 
@DanielSank Essentially, lots and lots of typing on excel, word and random specialist (tax) software
 
@Mithrandir24601 That doesn't sound like a heavy load ...
 
5:19 PM
@Mithrandir24601 If you're a keyboard afficionado get a Thinkpad
 
@Mithrandir24601 Does it have to be Excel and Word or would a cloud-based spreadsheet and Word processing option be ok?
 
Their screens aren't the best though
 
@DanielSank It's for my parents, so... Excel and word, otherwise they'll get confused...
 
I will say that in my own personal opinion Thinkpads have some of the worst keyboards I have ever used. Keyboards are a point of personal taste though.
 
(also, legal requirements dictate things have to be encrypted)
 
5:20 PM
@Mithrandir24601 go it. That's an important piece of information.
 
@DanielSank You're just such a heretic
 
@Mithrandir24601 What sort of budget?
 
@BernardoMeurer Thinkpads have mushy keys. Some people like that. I don't.
@Mithrandir24601 Uhhhhhh, ok... so your parents encrypt their hard drives?
 
@DanielSank You just love to hate everything I love
 
@BernardoMeurer I love Linux. Stop whining.
 
5:21 PM
@Mithrandir24601 Don't let them use LUKS2
@DanielSank ::crosses arms::
 
@BernardoMeurer Damn straight, boi.
 
Almost four hours into defragging this HD
 
@JohnRennie Recommend requirements for things like sage are 6GB of RAM and a 2.3GHz multi-core processor, so it's not massive but not really light either
 
@Mithrandir24601 I'm confused, is the laptop for you or for your parents?
 
@DanielSank From April, it'll be a legal requirement, yeah
@BernardoMeurer parents, I'm exceptionally happy with the one I've got :)
 
5:23 PM
@Mithrandir24601 Ah, just give them a Dell
What have you got?
 
@JohnRennie The minimum amount to get a suitable laptop
 
@BernardoMeurer Yes, read the chat log.
 
@BernardoMeurer an Alienware. It's very good
 
Ok, price limit? @Mithrandir24601
 
@DanielSank "Is it for A or for B"; "Yes"
 
5:24 PM
4 mins ago, by Mithrandir24601
@DanielSank It's for my parents, so... Excel and word, otherwise they'll get confused...
 
@Mithrandir24601 Those are nice, how's Linux support?
 
::crosses arms::
 
@BernardoMeurer Still haven't got round to putting Linux on it... ::guilty look::
 
::headbutts daniel::
 
@BernardoMeurer ::blocked by Santa Hat::
 
5:25 PM
@Mithrandir24601 ::frowns aggressively::
 
Sid
@Mithrandir24601 Use Windows...
 
@Sid NOT ON MY CHRISTIAN CHAT
 
@DanielSank Current one costed £650-£700 (forgot exact number), so somewhere around that would be good
 
Back to the main point: @Mithrandir24601 what's the price limit?
ah
 
::frowns so hard forehead and chin mix into one::
 
5:26 PM
@Mithrandir24601 that will get you a pretty powerful laptop.
 
@BernardoMeurer don't make me put on my universe. I'll do it.
 
Have you looked on the Dell site?
 
Yeah that's a lotta money.
 
@DanielSank I don't fear your hats
 
A WHOLE UNIVERSE
 
5:27 PM
@JohnRennie And it must not have a glossy screen
 
Ok I'm doing it...
@Mithrandir24601 Ah.
 
Sid
My parents tend to get confused with anything other than Windows. I don't know about others...
 
This is like pulling teeth...
 
@JohnRennie Yeah, hence asking about the Latitude :P
 
Your universe can't attack me, I'm protected by 4 layers of FREE SOFTWARE VMs
::looks at daniel from FreeBSD inside NetBSD inside OpenBSD inside Arch Linux::
 
5:29 PM
@Mithrandir24601 you won't go wrong with a Latitude. They are a good solid well made business grade laptop. But they are on the expensive side. I would have a browse through the Dell site and see what their prices are like.
 
@JohnRennie a touch over £700
 
@JohnRennie I've been thinking about the XPS lately
But they're still on Gen 7 Intel CPUs
I'm probably waiting for 10nm though
As I have for about 6 years now
 
@Mithrandir24601 Which model? A 5000 series?
 
@JohnRennie Yeah, it's the just-about-to-be-outdated model, so there's almost £500 off
 
Sid
@BernardoMeurer Windows is better than Linux. runs away
 
5:31 PM
I'm just putting this out there as information, it's not really a recommendation for your parents' case: a Chromebook would have insane battery life and access to Google Drive which supports cloud word-processing and and spreadsheets and is encrypted in the cloud storage.
 
@Sid I won't judge you, the same way I don't judge people who like sodomy or BDSM
 
The keyboards are fantastic.
 
@Mithrandir24601 I wouldn't worry about it being yesterdays model. Improvements are incremental these days.
 
And they're extremely affordable.
 
@DanielSank Wait, you like Chromebook keyboards? O.o
 
5:32 PM
Also note that Google spreadsheets and word processing documents can export to their MS equivalents.
@BernardoMeurer The HP one has a fantastic keyboard.
 
Sid
@DanielSank "but"? It can't be all that perfect...
 
You can't run Sage on a Chromebook
 
@JohnRennie yeah, I was just thinking that someone might turn round and say that the keyboard is universally known to be awful or something :P
 
@Sid But it needs internet and doesn't run anything else
@JohnRennie Why do his parents need Sage?
 
@JohnRennie What's Sage? Nobody said Sage was a requirement?
 
5:33 PM
@Mithrandir24601 What on earth do they do?
@DanielSank I think he did, it's a Python scientific computing thingy IIRC
 
@DanielSank It's a bit of accounting/tax software
 
11 mins ago, by Mithrandir24601
@JohnRennie Recommend requirements for things like sage are 6GB of RAM and a 2.3GHz multi-core processor, so it's not massive but not really light either
 
Ah, lol
Wrong sage :P
 
I am a sage
v. wise
wait, does that joke work in english
i'm not sure
sage (plural sages)

A wise person or spiritual teacher; a man or woman of gravity and wisdom, especially, a teacher venerable for years, and of sound judgment and prudence; a grave or stoic philosopher.
Yeah it's all good
 
@Mithrandir24601 I've never used a current gen Latitude so I can't give a personnal recommendation. However I've used dozens (literally) of Dell Latitudes of different generations and they have all been great. The firm I work for sells Latitudes to the businesses it supports. I doubt you will go wrong with a Latitude.
 
5:37 PM
You know my thesis advisor once told the class a story
Of the method they used to find officers for the glorious soviet army
They asked the soldiers to read cos x
And if they said cosx
They were not officer material
 
@Mithrandir24601 you would certainly get the same quality laptop cheaper from Acer or Asus, the problem is that I have no idea what their equivalent would be.
 
@JohnRennie I'll have a look, thanks
 
@Mithrandir24601 If you go for a Latitude consider getting a docking station. I use a Latitude as my main workstation, but I have it on a docking station most of the time and use a full size display and keyboard.
 
vzn
did someone say dell? see if this influences your buying decision :P brides.com/story/…
 
@JohnRennie That's a good idea. We'll have a spare monitor lying around anyway....
 
5:42 PM
Damn, Alexa Dell is hot!
Now I'm definitely buying a Dell
 
vzn
uses similar primal id criteria for choosing which expensive machine to buy
 
Uh-oh
something sketch is happening on my defragmentation-compression process
It's suddenly consuming large amounts of disk space
Hm
had 73GB free, now down to 69
67
Maybe I just have to rebalance it afterwards ...
 
@BernardoMeurer I have a food hangover
3000 calorie dinner
 
@vzn Not sure you should be calling people "bimbo"s :P
@0celo7 Nice and healthy
 
vzn
@BernardoMeurer lol if the shoe stiletto fits wear it :P
 
5:50 PM
 
I have 250g of flour left
Just enough to attempt waffles
 
@vzn No, you don't get to insult people even if you think the insult is accurate.
@0celo7 spam?
 
@ACuriousMind You stink
 
@Slereah better than 250 g of fluorine
 
@ACuriousMind what about if you think the insult is accurate
 
5:52 PM
@ACuriousMind getting a random hw message from an Indian isn't spam?
 
@Slereah That's why he didn't delete my message
 
Yeah I also got those random invitations
 
lmao vzn got banned
 
@0celo7 No, spam on the SE network has the very narrow meaning of unwanted advertisement of products or websites.
 
@ACuriousMind ok well interpret it in the (co)generalized sense
 
5:53 PM
Did I ever tell you about the cool refreshing taste of coca cola
 
@BernardoMeurer I know enough people who would disagree :)
 
@ACuriousMind They are advertising their bodies as reward to help
 
ACM doesn't wash his hair every day
 
On the dark web
 
him stinking is factual
 
5:54 PM
They have offered it to me many times
@ACuriousMind Is also a level 4 vegan
 
@ACuriousMind is vegan?
 
@ACuriousMind are you really
 
He doesn't eat anything that casts a shadow
 
5:55 PM
so he eats mushrooms
 
It was part of his contract as being CEO os SAP
 
and dirt?
 
they need it for PR reasons
 
@BernardoMeurer 0celo7 can't get that reference, he never watched the yellow devilpeople :P
 
@ACuriousMind :P
 
5:55 PM
they're all trashy people
why would I watch it
 
@0celo7 I actually do think I should be a vegan for moral reasons but I'm a bad person who sacrifices the moral high ground for tastiness :P
6
 
you're worse than a vegan
 
You are a vegan wannabe
 
@0celo7 Yes, that's what I just said!
 
@ACuriousMind I'm the opposite
I don't discriminate
I think that's the most moral position
@BernardoMeurer M takes forever to get ready
she has to like embalm herself in beauty products
 
5:58 PM
"Mirror Reaper" is damn good
 
@0celo7 She looked good in the video you sent me though
So it's working!
 
she is starting to look fake
 
Where are y'all headed?
 
apple
 
Everyone is fake
Store or Bees?
 
5:59 PM
going to tell them to stop fucking up battery life
 
@BernardoMeurer hq
 
Get me a new iPhone
mine fucking sucks
 
you have the same one I do
 
Yes
And it's crap
 

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