egg|nomz|egg 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> egg|nomz|egg: generally if your eyes are dewing over, that's not the weather. | <ferram4> I shall beat my problems to death with an engineer.
<egg>
whitequark: any news from котя?
<egg>
bofh: and yes, the BIPM nautical mile is 1852 m, whereas the UK admiralty one was 6080 feet. The UK admiralty mile is deprecated, and you are apparently now supposed to count it as 1853 m (http://www.legislation.gov.uk/uksi/1995/1804/schedule/made)
<whitequark>
nah
<bofh>
1852m is what I've always used as "a nautical mile" (& before you ask, yes, I've had to use that IRL... I spent a year working for oceanographers).
<egg>
bofh: yeah, that has been standard for a while; the BIPM says:
<egg>
The conventional value given here was adopted by the First International Extraordinary
<egg>
Hydrographic Conference, Monaco 1929, under the name “International nautical
<egg>
mile”. As yet there is no internationally agreed symbol, but the symbols M, NM, Nm, and nmi
<egg>
are all used; in the table the symbol M is used.
<bofh>
"Nm" is annoying since I can't help but read that as "Newton-meters"; I personally used nmi.
<bofh>
also saw NM occasionally.
<UmbralRaptor>
Also nm gets used?
<bofh>
I fucking hope not.
<soundnfury>
I think I've seen nm, yeah
<soundnfury>
but nmi is clearly the sane one
<egg>
well, Principia will gladly accept nm in its quantity parser, but that's a very short nautical mile >_>
<UmbralRaptor>
Useful if you're using bacteriophages as landing vehicles.
<soundnfury>
Admiral Ångstrom, commander of the Bitish Navy
<bofh>
Wouldn't it make more sense for him to be the commander of the Norwegian navy?
<soundnfury>
but how do I pun Norwegian to mean smal?
<kmath>
<bofh453> I had mp3s with CP1251 in the tags. Winamp 2 only displayed UCS-2 properly. Cue the world's most buggy ID3 tag rewr… https://t.co/2hgL3jNIFP
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<egg|cell|egg>
Meow
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<egg|cell|egg>
ఠ్ఠా telugu input methods are fun
<awang>
!u ఠ్ఠా
<Qboid>
U+0C20 TELUGU LETTER TTHA (ఠ)
<Qboid>
U+0C4D TELUGU SIGN VIRAMA (◌్)
<Qboid>
U+0C20 TELUGU LETTER TTHA (ఠ)
<Qboid>
U+0C3E TELUGU VOWEL SIGN AA (◌ా)
<awang>
!wpn -add:wpnn meow
<Qboid>
awang: Invalid type
<awang>
!wpn -add:wpn meow
<Qboid>
awang: Weapon already added!
<bofh>
egg|cell|egg: hand-fuzzing CoreText?
<egg|cell|egg>
Don't add a 200c there probably
<egg|cell|egg>
Bofh: nah is the week end
<egg|cell|egg>
But I had never tried the Indic input methods
<egg|cell|egg>
జ్ఞా
<egg|cell|egg>
!u র্য
<Qboid>
U+09B0 BENGALI LETTER RA (র)
<Qboid>
U+200D ZERO WIDTH JOINER ()
<Qboid>
U+09CD BENGALI SIGN VIRAMA (◌্)
<Qboid>
U+09AF BENGALI LETTER YA (য)
<egg|cell|egg>
Okay maybe I shouldn't play with the bengali one too much
<kmath>
<tuxnani> @diodelass @rams2226 That's జ్ఞా in Telugu. Pronounced as given in https://t.co/aj42mF1Fbe
<egg>
Ellied: it has something visually indistinguishable from the most popular of those cursed consonant clusters, but it does not have the (no-op) ZWNJ
<UmbralRaptor>
Ellied: Yay, poster presentations.
<UmbralRaptor>
egg: ZWNJ sounds like a joke, rather than an actual character.
<kmath>
<anfael_> ancillary thought that 'dizzying complexity' is probably not inherent to one script or another, rather that unicode… https://t.co/qvhbzV85kB
<egg>
!wpn Ellied
* Qboid
gives Ellied a tesseral capybara
<egg>
!wpn whitequark
* Qboid
gives whitequark a thermionic 雪風
<egg>
!wpn iximeow
* Qboid
gives iximeow a contravariant hypothetical токамак
<egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a geodesic
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<egg>
s/nano/micro
<Qboid>
egg meant to say: bofh: so the (TAI|UTC|UT1) to TT conversions of Principia are not suitable if you need microsecond resolution
<bofh>
egg: I need second resolution. Maybe 100 millisecond resolution at best.
<egg>
bofh: 100 microsecond would be iffy without TT(BIPM) ftp://ftp2.bipm.org/pub/tai/ttbipm/TTBIPM.17
<egg>
bofh: 100 millisecond is looong
<egg>
bofh: so, it seems this person has found a bug but I'm getting rather tired of their attitude https://forum.kerbalspaceprogram.com/index.php?/topic/162200-wip122-131-principia%E2%80%94version-cohen-released-2018-02-15%E2%80%94n-body-and-extended-body-gravitation-axial-tilt/&page=39&tab=comments#comment-3298250
<egg>
bofh: stabbity open source stab
<bofh>
ah right, BIPM is neat tho.
<bofh>
ahh, the worst part of open source: dealing w/jerks.
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<e_14159>
bofh: s/open source/life
<Qboid>
e_14159 thinks bofh meant to say: ahh, the worst part of life: dealing w/jerks.
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<egg>
bofh: well hopefully phl's reply will bring things back to sanity
<bofh>
e_14159: agreed.
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<egg>
!wpn e_14159
* Qboid
gives e_14159 a Hamiltonian bandersnatch
<egg>
!wpn bofh
* Qboid
gives bofh a Халатников 🐍-like pilcrow
<bofh>
!wpn egg
* Qboid
gives egg a Renesas ladder
<bofh>
egg: iirc you can get most of the way with TT(BIPM) by adding 3 sinusoids to time, I just forget what the periodicities are.
<APlayer>
egg: Does it make sense to move calculations dependent on the altitude into the main integrator loop instead of the function f(t, Y)? The scenario is a rocket launch, so the things that depend on altitude are pressure and gravity
<APlayer>
That way, I save some computation time, but I ignore changes in pressure and/or gravity that happen between different k-constants
<egg>
uh
<egg>
mostly you invalidate any proofs about the error if you randomly mix things like that
<egg>
bofh: pretty sure I'm better off interpolating the BIPM table than writing constexpr trig functions...
<APlayer>
egg: So you advise against that?
<bofh>
egg: oh in your case yes
<egg>
APlayer: yes, just implement the integrator and don't invent your own salad unless you can prove things about it
<bofh>
egg: in my case I'd use them at runtime
<APlayer>
Alright, will do
<egg>
bofh: but why wouldn't you want to have the ability to do those conversions at compile time :-p
<egg>
bofh: context: we want wide quantities, e.g. for the argument of a polynomial evaluation, so we don't unpack the argument for each multiplication; but it should work with the fancy typed geometry :D
<egg>
bofh: it works surprisingly well to have the representation is on top of the type, e.g. DoublePrecision<Instant> or (soon) Wide<Time>, rather than having things like Time<DoubleDouble>
<egg>
s/is /
<Qboid>
egg meant to say: bofh: it works surprisingly well to have the representation on top of the type, e.g. DoublePrecision<Instant> or (soon) Wide<Time>, rather than having things like Time<DoubleDouble>
<egg>
bofh: also, I'm thinking that our Frame::origin should have coordinates -0 rather than +0, so that the +/- origin are really no-ops
<egg>
(the neutral element of addition is -0 :D)
<egg>
otoh you can't win because there's also the - origins
<egg>
oh, apparently clang knows it can turn -0 - x into an xor and -(-0 - x) into a no-op (but MSVC doesn't)
<kmath>
<chordowl> Def.: A sudoku group is a group whose Cayley table is a valid sudoku solution.
<bofh>
egg: same
<egg>
so an n-sudoku group is a group G of order n², equipped with a partition P in subsets of cardinality n, such that for each S and T, in P, ST = G...
<bofh>
LOL
<egg>
note that you just need that, you obviously have the columns and rows
<egg>
first question: does a nontrivial sudoku group exist?
<bofh>
That's actually the exact question I'm trying to determine since I'm honestly leaning no.
<egg>
bofh: so obviously a nontrivial sudoku group cannot be abelian
<egg>
therefore there is no 3-sudoku group
* UmbralRaptor
fails to parse.
UmbralRaptor is now known as EntropicRaptor
<egg>
bofh: so we have to look at least at 4-sudoku groups
<kmath>
<eggleroy> @chordowl Hm. The 3×3 blocks on the diagonal cannot be symmetric and therefore the group cannot be Abelian, ↯ (… https://t.co/aRUj7t2s7v
<bofh>
Iiiiiiinteresting.
<egg>
bofh: the hunt for a 4-sudoku group is on tho
<kmath>
<webmz_> It’s a tremendous bummer to hear academics confess having to hide their activities around inclusion and mentorship… https://t.co/fdOomnWH9K
<kmath>
<Alex_Parker> Just got back from the Kavli Frontiers of Science meeting, where I got to interact with amazing people pushing the… https://t.co/I7yJJNKnhE
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<EntropicRaptor>
!wpn APlayer
* Qboid
gives APlayer a tempered 50Ω Sagan-like corvid
<APlayer>
!wpn EntropicRaptor
* Qboid
gives EntropicRaptor a stabby hash which strongly resembles a PDF
<APlayer>
Other people always get nicer wpns than me, heh
<EntropicRaptor>
A Sagan-like corvid sounds interesting to talk to.
<EntropicRaptor>
But, uh, why are we measuring its resistivity?
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<kmath>
<Alex_Parker> Just got back from the Kavli Frontiers of Science meeting, where I got to interact with amazing people pushing the… https://t.co/I7yJJNKnhE
<kmath>
<chordowl> @eggleroy I don't think that works either (for n>1), since one of the S∈P must contain the identity and then |SS|<|… https://t.co/SNl9lbisre
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<kmath>
<chordbug> mathematicians have cleverly sidestepped the problem of "naming things" by just turning it into a fun relaxing game… https://t.co/d1ZWPD1OKG
<kmath>
<diodelass> The three generations of fermions are "normal-ish things," "heavy things," and "silly-heavy things"
<bofh>
I mean there *are* normal-ish, heavy effective mass and silly with heavy effective mass fermionic (quasi)particles but I think that's a bad hierarchy. For one thing the middle one has very few elements :P
<UmbralRaptor>
bofh: well, it works for quarks also?
<bofh>
True.
<bofh>
I guess it does work for fundamental particles fairly well.
<bofh>
(Just goes to show you how often I work with *those* :P)
<bofh>
(Admittedly, muonium is useful. Never had the opportunity to use it tho).
<UmbralRaptor>
How about positronium?
<bofh>
I mean that's two "normal-ish" class leptons in a bound state, that's perfectly legit :P