UmbralRaptor changed the topic of #kspacademia to: https://gist.github.com/pdn4kd/164b9b85435d87afbec0c3a7e69d3e6d | Dogs are cats. Spiders are cat interferometers. | Космизм сегодня! | Document well, for tomorrow you may get mauled by a ネコバス. | <UmbralRaptor> … one of the other grad students just compared me to nomal O_o | <ferram4> I shall beat my problems to death with an engineer.
<Ellied>
jesus fuck, one of the admins at IIT responsible for sending out emails to everyone on academic probation (which includes me, since I took one class there and failed it) just did so, university-wide, without using BCC.
<Ellied>
I could not possibly have decided to quit this place too soon.
<Ellied>
perhaps this particularly admin will be following me out the door.
<UmbralRaptor>
o_O
<UmbralRaptor>
I, er, have to ask -- why the class at ITT?
<UmbralRaptor>
(And what class?)
<Ellied>
circuit analysis I. turns out, in my research prof's words, it's very hard to get me to do the same thing twice.
<UmbralRaptor>
Ack. Tevenin and norton circuits everywhere.
<Ellied>
predictably, it was Laplace transforms that killed me
<Ellied>
after going over and over kirchoff's laws (that I already new backwards, forwards, intoxicated, and sleep-deprived) it was very hard to suddenly jump into something I actually had to apply differential equations to work out
<Ellied>
this in a class of like 200 people, with no office hours to speak of? yeah, no.
<UmbralRaptor>
eep
<Ellied>
so yeah, I fucked that up, but I also learned that I don't really want to be a EE anyway. Physics is more my thing.
<UmbralRaptor>
I think SnoopJeDi and I are obligated to celebrate that.
<UmbralRaptor>
Still, on an academic probation list for a school you're not even attending is amusing. Email spam aside.
<UmbralRaptor>
22:22:39 < Didactylos> I tried to put coffee in my coffee.
egg|cell|egg has quit [Read error: Connection reset by peer]
egg|cell|egg has joined #kspacademia
egg|phone|egg has quit [Read error: -0x1: UNKNOWN ERROR CODE (0001)]
egg|zzz|egg is now known as egg|afk|egg
egg|phone|egg has joined #kspacademia
egg|cell|egg has quit [Ping timeout: 204 seconds]
egg|cell|egg has joined #kspacademia
egg|phone|egg has quit [Read error: Connection reset by peer]
egg|phone|egg has joined #kspacademia
egg|cell|egg has quit [Read error: Connection reset by peer]
egg|cell|egg has joined #kspacademia
egg|phone|egg has quit [Read error: Connection reset by peer]
egg|cell|egg has quit [Client Quit]
* egg|work|egg
stabs the mobile egg in the joinspam
<egg|work|egg>
!wpn bofh, Fiora, et al.
* Qboid
gives bofh, Fiora, et al. an entangled чертовщина
egg|work|egg has quit [Ping timeout: 180 seconds]
egg|work|egg has joined #kspacademia
ferram4 has quit [Ping timeout: 204 seconds]
<egg|work|egg>
bofh: if you have a Hamiltonian that's quest kinetic energy + some potential (q), can you get something with Noether from the invariance (which isn't quite an invariance, the Hamiltonian changes, but feels like one) under adding the same thing to all velocities?
<bofh>
this sounds literally like just doing a Lorentz boost but I could be misunderstanding you. anyway I, erm, think that does follow if you write out the PDE for conserved currents under that Hamiltonian and bash some computations, I'll look at it more latsr.
<bofh>
what is the actual problem you're trying to apply this result to anyhow?
<egg|work|egg>
bofh: I'm not trying to solve a problem, I'm trying to figure out how Noether's theorem works :-p
<egg|work|egg>
bofh: and I wasn't talking about a Lorentz boost, just about a rigid change in velocity in eggstremely boring classical mechanics
<bofh>
well okay the usual formulation of Noether's Theorem applies to symmetries of the Lagrangian, but it's possible to transform between that and the Hamiltonian picture (just tedious). hmm.
<bofh>
like for instance if you have a Langrangian that's invariant under spatial displacement you get conservation of linear momentum (and the same for conservation of angular momentum if the system Lagrangian is rotationally symmetric)
egg|phone|egg has joined #kspacademia
<egg|phone|egg>
Bofh: yeah but I never touched a Lagrangian, and translation->total momentum is three lines to prove with the Hamiltonian anyway
<egg|phone|egg>
Bofh: Also with the Hamiltonian time->energy conservation verges on tautology :-p
<bofh>
like the Hamiltonian and Lagrangian pictures are easily transformed between and a lot of these simple examples border on tautology there too :P it's just Noether's Thm applies to any general symmetry.
<egg|phone|egg>
Yes, but is boosting really a symmetry
<bofh>
Well translation in space is one of the generators of the inhomogeneous Galilean group so...
TechnicallySleeping is now known as Technicalfool
egg|cell|egg has joined #kspacademia
egg|phone|egg has quit [Read error: Connection reset by peer]
egg|phone|egg has joined #kspacademia
<egg|afk|egg>
bofh: but I'm not talking about translation in space, I'm talking about adding the same Δv to all velocities; this doesn't conserve the Hamiltonian (assume it's a Hamiltonian for a nice physical system), but somehow it feels like it's a thing that doesn't do much
egg|cell|egg has quit [Ping timeout: 183 seconds]
egg|afk|egg is now known as egg
<egg>
!wpn bofh
* Qboid
gives bofh a turbo ladder
<bofh>
egg: oh. you're talking about literally doing a velocity boost. that's trickier.
<bofh>
offhand it still feels non-conserving except for certain hamiltonians
<bofh>
but let me think about that and crack open a classical mechanics text
<egg>
bofh: yeah it definitely doesn't conserve the Hamiltonian (e.g. if it's kinetic + V(q), V doesn't change and kinetic energy increases), but can we still get something out of it :-p
<bofh>
yeah that's what I'm not at all sure about. in general, I'm going with no, but under which cases can we is more complicated :P
<bofh>
goddamnit I have 99 Luftballoons stuck in my head
<UmbralRaptor>
The war machine springs to life, opens up one eager eye...
Technicalfool has quit [Remote host closed the connection]
SilverFox has quit [Excess Flood]
SilverFox has joined #kspacademia
TonyC1 is now known as TonyC
<bofh>
SnoopJeDi: heh, it's kind of mesmerizing
<SnoopJeDi>
my research scientist is being a real asshole about the interpolation he used so I'm stuck reverse engineering is fortran today
<bofh>
that's always a "fun" time
<bofh>
like I've been putting off doing the same for the past week, should prolly get it done since supervisor needs fixes to it in by tomorrow.
<SnoopJeDi>
it's just really frustrating that I burnt up 2 or 3 months because the data he said he was using are totally not the data he was using
<UmbralRaptor>
SnoopJeDi: Code not available upon request, but upon swearing an oath of fealty?
<bofh>
SnoopJeDi: jesus fuck
<SnoopJeDi>
I mean I assume he started from those data at least
<bofh>
SnoopJeDi: what an outright asshole
<UmbralRaptor>
Also, stabbity.
<SnoopJeDi>
but 1-5% variation from a naive trilinear fit seems abnormal to me
<SnoopJeDi>
and yea electric fields can be misbehaved sometimes but this data is smooth as butter so a naive strategy should be just fine
<bofh>
yeah I somehow doubt some of this
<SnoopJeDi>
I'm not really giving him a fair treatment in how I'm telling it, but I'm frustrated with him
<bofh>
Like if I lost two months of work b/c of piss-poor communication I'd be pissed off too.
<SnoopJeDi>
anyway I think what he's actually using is a bicubic interpolation
<bofh>
Heck, losing half a day of NHFML magnet time earned someone a very snarky tirade for about 30 mins
<SnoopJeDi>
which sure whatever I guess that's not an abnormal choice if you can live on the plane but this data has to be extended to 3D pretty soon and that seems like asking for trouble if the naive off-the-shelf-scipy-tool interpolation will do
<bofh>
and that wasn't even a total loss thankfully, he only mostly bungled up the experiment setup but not totally.
<SnoopJeDi>
in the end my grudge shakes out as something like 0.5° of RF phase so it's probably not actually that big a deal but I'm pegging an 11/10 on the petty meter today
<bofh>
SnoopJeDi: yeah bicubic isn't my choice if I need to immediately scale up a dimension, and tricubic is nasty.
<SnoopJeDi>
yea it looks pretty hairy
<SnoopJeDi>
part of it's a cultural problem. To me, this looks literally insane: `Vres=a0+rx*(a1+rx*(a2+rx*a3))`
<SnoopJeDi>
as if Fortran didn't have an exponentiation operator for legibility's sake
<bofh>
SnoopJeDi: so you do want to use Horner's Scheme for polynomial evaluation because: A) it is better behaved numerically, B) it requires fewer arithmetic steps than the naive approach.
<bofh>
like consider Vres=a0+a1*rx+a2*rx**2+a3*rx**3. That's 0+1+2+3=6 multiplies, whereas your line is 0+1+1+1=3 multiplies. this gets progressively worse for higher orders too.
<egg>
bofh: hm, is it better behaved? iirc Knuth asks the question but doesn't answer (it is faster of course)
<bofh>
(and this is assuming that the compiler turns **2 into rx*rx and not into a function call to f__pow8i4 or w/e
<SnoopJeDi>
Fair enough
<egg>
Casteljau's method is nice too
<bofh>
egg: hm, I swear I saw either Kahan or Gerhard&von zur Gathen explaining why it is in the common case at least, but can't find it offhand.
<SnoopJeDi>
For where this code runs (this isn't in the bulk, it's run-once code) I'd rather it be a bit slower but more explicit
<bofh>
and yes, Casteljau's method is indeed nice.
<SnoopJeDi>
but then, if readability were a concern would it truly be in Fortran at all? ;P
<egg>
SnoopJeDi: so like Horner's method is such a common pattern that I'd be surprised to see a polynomial written the obvious way
<SnoopJeDi>
yea that's kind of what I mean as far as cultural difference
<bofh>
SnoopJeDi: yeah, for run-once code I say go with whatever is clearer (tho for me Horner evaluation of a polynomial is immediately obvious, but that's as a result of working with polynomial approximations to special functions a lot)
<bofh>
yeah, that makes sense.
<SnoopJeDi>
it's also just those clumsy human emotion things getting in the way
<bofh>
like for me seeing explicit polynomial evaluation the naive way would trip me up for a bit, but for someone with less experience with numerical analysis coding styles, it would likely be the opposite, or could at least (as demonstrated)
<SnoopJeDi>
this guy is frankly brilliant and it's a real shame he's hitched his wagon to my advisor's dying star, but he's so sharp that he truly does operate in the man-as-an-island scientific pattern
<egg>
bofh: tbh if I saw a polynomial written without at least Horner (or fancier) I'd want to scrutinize the surrounding code for numerical insanity :-p
<bofh>
yeah, like in general comment the shit out of anything unclear is my policy
<SnoopJeDi>
very rarely is anyone but him working with anything he's built
<bofh>
egg: heh, same.
<egg>
bofh: comments \o/
<egg>
50-line comment blocks about the history of mathematics \o/
<SnoopJeDi>
bofh, my biggest gripe about his Fortran styling is actually just the pattern of cramming as much shit onto one line as possible :P
<bofh>
speaking of which in this code I'm stuck reverse-engineering I am fairly certain that not only did he reimplement RK4 in the init stage instead of using quadpack *but fucked it up*.
<bofh>
I'm not enthused for the fixed-point iterates part of the code.
<bofh>
> 50-line comment blocks about the history of mathematics \o/
<bofh>
people need to do this more often, it's so useful and fun
<egg>
SnoopJeDi: gah, awful modern fortran with long lines and code that starts on the first column
<bofh>
yep, I, how do you fuck up writing naive RK4.
<egg>
FORTRAN IV FOR THE WIN
<bofh>
okay I like Fortran 90 BUT CODE SHOULD NOT START IN THE FIRST LINE
<egg>
C EXCEPT COMMENTS OF COURSE
<bofh>
EXCEPT MAYBE THE FUNCTION/SUBROUTINE DECLARATION AND 'END'
<bofh>
C AND YES, THOSE
<egg>
C AND COMMENTS ARE DENOTED BY A C, NOT AN EXLAMATION MARK
<egg>
C I MEAN WHAT IF YOU DO NOT HAVE AN EXCLAMATION MARK
<bofh>
* APPARENTLY YOU DO WHAT LAPACK DOES AND INEXPLICABLY USE AN ASTERISK
<SnoopJeDi>
I think the only instances of indentation in his code that I've seen are for demarcating loops
<bofh>
SnoopJeDi: *sobs*
<SnoopJeDi>
but I don't get a right to an opinion there because I don't write Fortran
<egg>
C I DON'T WRITE FORTRAN EITHER, BUT MAKING FUN OF IT IS A RECURRING THEME HERE
<SnoopJeDi>
I'm particularly flummoxed by the halfway habits of folks who clearly learned F77 but also kept learning
<bofh>
Oh?
<SnoopJeDi>
I mean I get that Fortan will never have the culture of very explicit variable names, but it continues to look like golf in all the code I've seen
<bofh>
C I HAVE WRITTEN A FAIR AMOUNT OF FORTRAN (SADLY?) SO YEAH
<SnoopJeDi>
(which was generally *in* F77 at one point so it's just technical debt I guess?)
<bofh>
before F77 even
<bofh>
my one gripe is people not using "implicit none"
<bofh>
b/c that leads to so many bugs
<SnoopJeDi>
when the variables correspond to formulae it's usually not a big deal anyway
<egg>
uuuuuuh
<SnoopJeDi>
x, xp, xpp, is pretty clear
<egg>
p, q,
<egg>
^ the source of endless bugs
<SnoopJeDi>
but yea, I try not to judge a language I haven't written in, heh
<SnoopJeDi>
(without compromising my healthy allergy to write-only code)
<bofh>
write-only code can go die in a fire imo
<SnoopJeDi>
ta for the pointer to Horner's method though
egg is now known as egg|nomz|egg
<Ellied>
there is a door in the hallway near my lab that is marked "Consumer Fraud Prevention Laboratory"
<Ellied>
what does that even mean
APlayer has joined #kspacademia
* UmbralRaptor
has guesses involving checking products for regulatory compliance. But they're just guesses.
<UmbralRaptor>
SnoopJeDi: ...do I want to know what's going with your advisor's star dying? =\
<APlayer>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a threaded vial of Y-909
<APlayer>
Y-909?
<UmbralRaptor>
!wpn APlayer
* Qboid
gives APlayer a dip pen
<SnoopJeDi>
I'm mostly being a salty unappreciative shit UmbralRaptor
<SnoopJeDi>
I mean not that I'm wrong, his scientific career absolutely did peak ~30 years ago
<UmbralRaptor>
Hm. 30 years ago would have been the design phase of the SSC...
* SnoopJeDi
coughs
<UmbralRaptor>
That can't be good for one's career.
<SnoopJeDi>
but yea, it's mostly just salt: I'm not in a great place right now
<SnoopJeDi>
UmbralRaptor, the failure of the SSC you mean?
<SnoopJeDi>
but particularly considering how wrapped up my advisor was in the magnet drama, it's not what I'd call a point of pride
<SnoopJeDi>
I should be clear that I think he was *right* back then (such as I understand the arguments of the day)
<UmbralRaptor>
hm
<SnoopJeDi>
but people kinda assume SSC is just this black hole that we got nothing out of and that's definitely *not* true
<SnoopJeDi>
I believe Chao's Handbook (which is a very definitive text) uses the design docs as a primary reference in a few critical places
<SnoopJeDi>
The multipole expansion bit in particular comes to mind because I've read it about ten thousand times
<egg|nomz|egg>
bofh: um, about that p.45 thing, it's not going to fit in a tweet, also it's in 16th century french
<egg|nomz|egg>
bofh: "On moys de octobre, ce me semble, ou bien de septembre (affin que je ne erre, car de cela me veulx je curieusement guarder) fut la sepmaine, tant renommée par les annales, qu'on nomme la sepmaine des troys jeudis : car il y en eut troys, à cause des irreguliers bissextes, que le soleil bruncha quelque peu, comme debitoribus, à gauche, et la lune varia de son cours plus de cinq toyzes, et fe
<egg|nomz|egg>
ut manifestement veu le movement de trepidation on firmament dict aplane, tellement que la Pleiade moyene, laissant ses compaignons, declina vers l'Equinoctial, et l'estoille nommé l'Espy laissa la Vierge, se retirant vers la Balance, qui sont cas bien espoventables et matieres tant dures et difficiles que les Astrologues ne y peuvent mordre ; aussy auroient ilz les dens bien longues s'ilz povoient toucher jusques
<egg|nomz|egg>
là.
<egg|nomz|egg>
"
<UmbralRaptor>
egg|nomz|egg: shoot it with your phone?
<egg|nomz|egg>
UmbralRaptor: by virtue of being 16th century I can just copy-paste it from wikisource :-p
<Qboid>
APlayer: Description: A SpaceX Falcon 9 rocket will launch the 14th Dragon spacecraft on the 12th operational cargo delivery mission to the International Space Station.
<egg>
!wpn UmbralRaptor
<egg>
!wpn bofh
<egg>
uh
<egg>
Qboid?
<egg>
!wpn Thomas
<egg>
but wpn seems borked?
<egg>
!tell egg foo
<egg>
Thomas: Qboid
<UmbralRaptor>
!wpn egg
<UmbralRaptor>
!help
<UmbralRaptor>
;wpn egg
<UmbralRaptor>
<_<
<egg>
but some parts of Qboid work
<egg>
!help kountdown
<egg>
!kountdown 1
<egg>
... does !summonops work
<egg>
wait, it answered APlayer
<egg>
!kountdown 1
egg has left #kspacademia [moo]
<egg>
hm
egg has joined #kspacademia
<APlayer>
!wpn Qboid
<APlayer>
Aww dang
<APlayer>
But it worked just a hour ago? And I don't see Qboid leaving or joining since then?
<Thomas>
That doesn't mean that the bot didn't crash. It's behind a bouncer
<Thomas>
!wpn
<APlayer>
Weird
<Thomas>
Restarting the bouncer, brb
Qboid has left #kspacademia [#kspacademia]
Qboid has joined #kspacademia
<APlayer>
"Turning it off and on again", basically
<APlayer>
!kountdown 1
<APlayer>
Nope
<APlayer>
!wpn egg
Thomas has joined #kspacademia
<APlayer>
Not working, Thomas
<Thomas>
Because I still need to connect the actual bot
<Qboid>
egg: Description: A Japanese H-2A rocket, designated H-2A F35, will launch the Michibiki 3 navigation spacecraft, the third member of Japan’s Quasi-Zenith Satellite System.
<Qboid>
egg: Updated event #0: H-2A • Michibiki 3 - A Japanese H-2A rocket, designated H-2A F35, will launch the Michibiki 3 navigation spacecraft, the third member of Japan’s Quasi-Zenith Satellite System. - 2017-08-12 04:40:00
* UmbralRaptor
stabs things.
<egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a discrete spectrophotometer
<UmbralRaptor>
;8ball Will the couch fit in the new apartment?
<kmath>
UmbralRaptor: Don't count on it
<egg>
!wpn Fiora
* Qboid
gives Fiora an adiabatic interregnum
<UmbralRaptor>
!wpn egg
* Qboid
gives egg a squeezable cell/ion channel hybrid
<egg>
uh
<UmbralRaptor>
You squeeze the cell, and it changes the ion distribution across the membrane.
<kmath>
<DatesInMovies> Aug 10th 1988 - Zero Cool was in the New York Times for crashing 1,507 computer systems #Hackers #HackThePlanet https://t.co/WDyQxSkGZ9
<bofh>
UmbralRaptor: isn't that just an exocrine gland then tho?
<lamont>
RISC architecture is gonna change everything
<bofh>
lamont: it's got a 28.8kbps modem
<SnoopJeDi>
RISCy business?
icefire has quit [Ping timeout: 200 seconds]
<egg>
!wpn bofh
* Qboid
gives bofh a Zener ? which strongly resembles a proof
<egg>
!wpn lamont
* Qboid
gives lamont an americium catbus
<egg>
lamont: quick, document your code!
<lamont>
active matrix, man. a million psychedelic colors.
<bofh>
test: ̂?(x)
lamont has quit [Remote host closed the connection]
<bofh>
yeah most things seem to not render that as I want them to
<SnoopJeDi>
bofh, LaTeX: the sentence
* UmbralRaptor
? Knuth with UTF-8.
<UmbralRaptor>
bofh: I guess. Biology is confusing.
<UmbralRaptor>
"In this paper, we will argue that the Principle of Mediocrity as applied to the reference class of all extant technological species leads to the inference that the typical such species is short-lived and that their demise coincides with the extinction of their global biosphere."
<UmbralRaptor>
A lot of this paper's arguments seem to rest on a normal distribution. I wonder what happens if you assume a log-normal dist for civilization lifetimes?
<bofh>
well for starters that would match reality more closely >_>
<UmbralRaptor>
I like how that line implies that you're an alien or a time traveler.
* UmbralRaptor
pokes travel schedules with a stick.
<UmbralRaptor>
Why can't chicago be, say, 300 km farther south?
<bofh>
heh.
<bofh>
when are you in chicago out of curiosity?
<UmbralRaptor>
Probably not any time soon =\
<UmbralRaptor>
11 - move out of old apt (Springfield MO) 11-13 - travel to Penn State. 14-17 - EPRV III conference. 17-18 - Travel to Fairfax VA. 18 - move in to new apt
<UmbralRaptor>
21 - probably miss the light show celebrating the release of Chebycheff. 28 - classes start