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.
<kmath>
<BP_Hutch> Interesting concept art here of a Space Shuttle attaching a TRS booster during a proposed STS Skylab rescue mission… https://t.co/cmzEl63psX
<Qboid>
0d 9h 0m 0s left to event #2: Atlas 5 • TDRS M [at 2017-08-18 14:04:00]. Say '!kountdown 2' for details
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<egg|cell|egg>
!Wpn bofh, Fiora, et al.
* Qboid
gives bofh, Fiora, et al. a primitive kindle with an oscilloscope attachment
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<Qboid>
0d 6h 0m 0s left to event #2: Atlas 5 • TDRS M [at 2017-08-18 14:04:00]. Say '!kountdown 2' for details
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<egg|work|egg>
!wpn bofh
* Qboid
gives bofh a long superpower
<egg|work|egg>
Iskierka: bofh: so I think the average speed ends up being 4a/T?
<egg|work|egg>
Iskierka: so 4/pi times the circular average speed
<Qboid>
0d 4h 0m 0s left to event #2: Atlas 5 • TDRS M [at 2017-08-18 14:04:00]. Say '!kountdown 2' for details
<Qboid>
0d 3h 0m 0s left to event #2: Atlas 5 • TDRS M [at 2017-08-18 14:04:00]. Say '!kountdown 2' for details
<egg|work|egg>
launch window actually opens at 12:03
<Qboid>
egg|work|egg: Description: A United Launch Alliance Atlas 5 rocket, designated AV-074, will launch the TDRS M communications and data relay satellite for NASA.
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<UmbralRaptor>
!kd -edit:2 time 2017-08-18T12:03Z
<Qboid>
UmbralRaptor: Updated event #2: Atlas 5 • TDRS M - A United Launch Alliance Atlas 5 rocket, designated AV-074, will launch the TDRS M communications and data relay satellite for NASA. - 2017-08-18 12:03:00
<egg|work|egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor an analytic fish
* egg|work|egg
blames Poisson
<UmbralRaptor>
<_<
<egg|work|egg>
!wpn bofh
* Qboid
gives bofh a Lambert nitrated e_14159
<Qboid>
0d 1h 1m 0s left to event #2: Atlas 5 • TDRS M [at 2017-08-18 12:03:00]. Say '!kountdown 2' for details
<egg|work|egg>
um
<egg|work|egg>
Thomas: seems that it's still counting down to the old time somehow
<bofh>
> for e near 1, 1-e^2 "only" loses up to half of the precision?
<bofh>
sounds about right
<bofh>
also fun I just discovered a death-dapter.
<bofh>
thankfully it arced and shorted out *before* I plugged my phone into it
<egg|work|egg>
bofh: but x^2-y^2 for x near y can lose all of it, from the graphs I made?
<bofh>
looking at the PCB it's a really terrible shoddy ringing choke switching PSU
<bofh>
tin whisker built up between the very badly electrically isolated low and high voltage sides
<bofh>
anyway does that necessarily hold for *all* x,y or is it dependent on x *and* y being specific values to maximize precision loss?
<egg|work|egg>
bofh: I was looking at x and y that were very close
<egg|work|egg>
bofh: because I'm trying to find cases where x^2-y^2 is catastrophic
<egg|work|egg>
thing is, it appears to be more catastrophic than 1-e^2?
<bofh>
so x=1 is one of the less pathological cases?
<egg|work|egg>
bofh: maybe
<egg|work|egg>
bofh: I looked at them in different ways, the general case with eggsperiments, the special case with scribbling on paper (because I'm at work)
<bofh>
"Never stop stirring a mixture you suspect may contain an interface between a strong oxidizer and an organic compound. (Once stopped, never abruptly start, or you’ll make it runaway more efficiently.)"
<bofh>
oh god I made that mistake once and it similarly ended very poorly.
<whitequark>
key word "once" lol
<bofh>
Indeed.
<bofh>
(also you may want to sci-hub that pdf link)
<whitequark>
the springer page embeds the whole thing
<whitequark>
I think they meant to embed the first and the last page but it only has two
<whitequark>
A+ job
<egg|work|egg>
but if you want you can buy it for about 35 CHF :-p
<bofh>
whitequark: LOL okay I see it after refreshing twice
<bofh>
amazing
<egg|work|egg>
I'm confused by the wording of "Scaling it up quite little was a right thing to do. Scaling it up at all was not."
<bofh>
the scaleup being only a small scaleup was good. the fact that a scaleup existed was bad
<whitequark>
^
<bofh>
is what I interpreted it as (and agree with)
<whitequark>
sec, an update incoming
<egg|work|egg>
ah, I interpreted the first sentence without conditioning on the second "scaling it up by a factor > 1 not too big is good", and read that way it was contradicting the second sentence "the scale factor should be <= 1", hence confusion
<whitequark>
bofh: F5
<egg|work|egg>
!wpn bofh and whitequark
* Qboid
gives bofh and whitequark an icosahedron
<bofh>
"And a coolant pump. Actually specified at 100% duty cycle, and not just to "well, how hard is it to make a decent water pump"."
<bofh>
apparently the answer for "how hard is it to make a decent 100% duty cycle water pump" is "hard"
<egg|work|egg>
!wpn -add:wpn pump
<Qboid>
egg|work|egg: Weapon added!
<bofh>
yeah, butanediol is somewhat miscible with water but not what I'd call well, I think the oily blobs were indeed the mixture separating out as you wrote
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<Ellied>
Trying to go to a makerfaire with my uni robotics club. It's tomorrow. All the other members of the club just suddenly either backed out or won't return my messages, and I also can't find the actual time of the thing anywhere on the website.
<Ellied>
It has a date, maybe it's just the full 24 hours from midnight to midnight.
<UmbralRaptor>
Ellied: oddly plausible.
<UmbralRaptor>
egg: ah, so much for that.
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<bofh>
Ellied: full 24 hours is quite plausible
<bofh>
UmbralRaptor: I've now got a Julia set of cats myself
<egg>
bofh: yay
<egg>
bofh: hmmm, so if the magnitudes of x and y are close to 1, x^2-y^2 seems to lose ~ halfish the precision, maybe it was losing all the precision because of underflows?
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<X>
Egg can you teach me quantum perturbation theory?
<egg>
probably not, try bofh
<UmbralRaptor>
X: like nth order corrections to annoying equations that are related to ones w/ analytic solutions?
<X>
O_o
<UmbralRaptor>
So instead of a particle in a 1D infinite well, it's in a well w/ a step.
<UmbralRaptor>
Or a delta function in the middle.
<UmbralRaptor>
or…
<bofh>
like I assume X meant what UmbralRaptor said. Like perturbing a known system's Hamiltonian H0 with some perturbation \lambdaV, where H0 is one you know how to solve, etc?
<egg>
bofh: is there any case where x^2-y^2 is better behaved than (x-y)(x+y)?
<egg>
ferram4: nice! though I don't think I'll be simulating that in Principia just yet
<bofh>
egg: sure, I'll do that once done reading this paper
<egg>
tbh when I started, axial tilt was a weird pipe dream, and so was drawing ourselves :-p
<ferram4>
It is focused less on the exact simulation (because very little was known at the time and we're still clueless) and more on, "this guarantees some margin of stability of this type"
<ferram4>
And the ultimate test is still, "run the chamber and set a bomb off in it"
<egg>
hah
<egg>
also cc whitequark, Fiora ^
<ferram4>
There is also a 1995 edition published by AIAA.
<egg>
AIAA?
<Qboid>
egg: [AIAA] => American Institute of Aeronautics and Astronautics
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<ferram4>
Hmm, that makes me wonder.
<ferram4>
NACA?
<Qboid>
ferram4: [NACA] => National Advisory Commitee on Aeronautics
<ferram4>
Ah, good.
<UmbralRaptor>
GMRT?
<Ellied>
bofh: pretty sure not. The guy running it is a prof here, and he finally told me he'd be there at 5:30 AM
<UmbralRaptor>
!acr -add:GMRT Giant Metrewave Radio Telescope
<Qboid>
UmbralRaptor: I added the explanation for this acronym.
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<Qboid>
0d 9h 0m 0s left to event #5: 「みちびき3号機」／H-IIAロケット35号機 [at 2017-08-19 05:29:00]. Say '!kountdown 5' for details
<kmath>
<ObservatoryCats> Hanging out in a Faraday cage to prevent radio emission leakage. https://t.co/OpibU5cTe4
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<soundnfury>
Tonight's project: train char-rnn on a 2.4MB corpus of Linus Torvalds rants
<soundnfury>
preregistration of hypotheses: I predict that the output will be _fricking hilarious_ with p < 0.01
<egg>
bofh: random factoid: if you're looking for a number that squares badly in binary64, you can take (the binary64 closest to) ζ(17), it squares with a 0.4996 ULP error
<Ellied>
what's char-rnn?
<egg>
RNN?
<Qboid>
egg: [RNN] => Recurrent Neural Network
<Ellied>
oh god
<Ellied>
soundnfury: please ping me and let me know how that goes
<soundnfury>
:)
<Ellied>
better yet, start a twitter account to post highlights, and see if you can get him to try to sue you
<soundnfury>
I don't use twitter. But if it's really good some of it might go on G+
<bofh>
egg: jesus christ I wasn't aware that just *squaring* can have that much error.
<kmath>
<erowidlinus> It's the one drug that can keep the nausea down, because it basically hides everything that happens under the dentry->d_lock spinlock.
<Ellied>
'If anyone gave me usable source code for big-endian, I'd go "ahh, all pending pull requests for this, they would seem to be the real world."'
<egg>
bofh: well if you're unlucky :-p
<egg>
ζ(17) is unlucky apparently
<bofh>
I wonder if that has a nice closed form.
<bofh>
OTOH ζ(3) iirc doesn't so no reason why ζ(17) should
<Ellied>
"I'd had around 50-70 shrooms, and I think the changes are result of fleeing on the register allocation." god
<bofh>
that's a *lot* of shrooms
<Ellied>
I'm surprised the uncertainty isn't higher tbh
<Qboid>
0d 6h 0m 0s left to event #5: 「みちびき3号機」／H-IIAロケット35号機 [at 2017-08-19 05:29:00]. Say '!kountdown 5' for details
<Ellied>
"I'd had around -20-50000 shrooms"
<egg>
Ellied: negative amounts of shrooms?
<bofh>
please, it's psilocybe cubensis, not Ambien.
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<Ellied>
egg: yeah, your stomach spontaneously produces complete shrooms, which are ejected from your esophagus
<UmbralRaptor>
egg: Why not? There are cases in the literature of eg: neutrino and eggsoplanet masses with error bars going past 0.
<Ellied>
Effects include improved cognitive function and +5 to detect illusion
<bofh>
Ellied: I swear that's my mental baseline. At least the latter.
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<egg>
!u ℘
<Qboid>
U+2118 SCRIPT CAPITAL P (℘)
<egg>
!u ?
<Qboid>
U+1D4AB MATHEMATICAL SCRIPT CAPITAL P (?)
<egg>
!u ℛ
<Qboid>
U+211B SCRIPT CAPITAL R (ℛ)
<egg>
!u u+1dae
<Qboid>
U+1DAE MODIFIER LETTER SMALL N WITH LEFT HOOK (ᶮ)
<egg>
!u u+1d4ae
<Qboid>
U+1D4AE MATHEMATICAL SCRIPT CAPITAL S (?)
<egg>
!u u+1d4ad
<Qboid>
U+1D4AD (?)
<egg>
bofh: this is fun ^
<egg>
some of the mathematical alphanumerics were already in the BMP, so are unassigned in the corresponding spots of the SMP
<egg>
because SCRIPT CAPITAL P is Weierstrass P, and MATHEMATICAL SCRIPT CAPITAL P is just a script P :D :D :D
<bofh>
Yeah I was curious why the hell script capital P was duplicated when nothing else in the BMP was duplicated in mathematical alphanumerics in the SMP
<bofh>
it's a bit annoying tbh, would prefer that they'd just add the duplicates with a canonical decomp to the BMP entries, since then the blocks are contiguous and you can easily move from A-Z to a mathematical alphanumeric block just by adding a constant offset.
<egg>
bofh: it makes sense not to duplicate things just for the fun of exercising decomposition tbh
<egg>
bofh: that way the duplication is semantic (℘ is not ?)
<bofh>
no no no, make the duplicate resolve canonically to the BMP one, and the BMP one compatibility (Font) decompose to A-Z
<egg>
bofh: iirc canonical decomposition is just for compatibility chars that were distinct in pre-unified encodings, and that's not the case here
<egg>
bofh: also you can't go both ways with those, it only decomposes in one direction and there's no way back
<bofh>
Yeah, never said you'd need to go back.
<bofh>
Tho that's interesting about canonical decomposition, didn't know that but it does explain a lot.
<egg>
bofh: stuff like greek question mark, Angstrom, etc. were in old encodings iirc
<bofh>
hey having Angstrom be distinct from Å is useful I maintain
<bofh>
since there is a semantic difference between those two
<egg>
bofh: well, but I guess the consortium says it's at a higher level (and the standardizing bodies say e.g. that the symbol for Ohm is a capital Omega, not that it's the symbol for Ohm which is not a bird)