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.
<egg> !wpn
* Qboid gives egg a berkelium ?
* egg is transconjugated
* egg is sad that English doesn't have the word "transconjugate" for "conjugate transpose"
<egg> bofh: it doesn't, right
<egg> (French has transconjuguée)
<bofh> egg: it does not
<bofh> tho I usually use "Hermitian conjugate" for that.
<bofh> Huh, TIL too
<whitequark> !wpn egg
* Qboid gives egg an Agile mechanism
<egg> D:
<egg> whitequark: have you eaten more moths
<whitequark> egg: yes
<whitequark> small ones
<egg> whitequark: has котя understood gearboxes
<whitequark> egg: dunno
<whitequark> not sure how to check
<whitequark> also we definitely should give the cat more stimulants
<whitequark> today she was torn between "want to sit on an awning and staaaaaare at everything from above" and "the kitten i adopted is meowing"
<whitequark> you could see her flipping between these choices every second sometimes
<whitequark> like an oscillator
<egg> whitequark: hm, were those toxicology studies acute or chronic though
<whitequark> she's extremely bored in our apartment i think
<whitequark> egg: acute, i looked at tox to see the ballpark therapeutic range
<whitequark> and it's at least 60
<whitequark> s/range/index/
<Qboid> whitequark meant to say: egg: acute, i looked at tox to see the ballpark therapeutic index
* egg wonders whether there are any studies of the effects of long-term treatment with stimulants on cats
<whitequark> it doesn't act as a stimulant though
<whitequark> like, it's subthreshold and would do nothing in an animal that doesn't have an attention deficiency
* egg now wonders whether whitequark's findings could be published
<kmath> <DrPizza> @whitequark I now have the perfect excuse to persuade my wife to get more cats. We need... control cats.
<egg> hm, it's 2:31
<egg> wasn't I planning to sleep at some point
egg is now known as egg|zzz|egg
<egg|zzz|egg> now I can keep chatting while having zzz in my nick I guess
<whitequark> egg|zzz|egg: like. the cat *loves* to sleep under eph. i do, likewise, though under a different stimulant
<whitequark> and she's less restless and more focused
<whitequark> this isn't indicative of *arousal*
<egg|zzz|egg> whitequark: largely unrelated, have you seen Sarbian's n-body nyancats
<whitequark> lol
<egg|zzz|egg> a later iteration https://i.imgur.com/hCTDIST.png
<egg|zzz|egg> (unfortunately Sarbian's integrator is bad and clearly at some point this should just call the principia integration libraries https://imgur.com/NOLs61p)
<bofh> whitequark: yeah it's 100% safe at those doses
<bofh> whitequark: I'm actually fairly certain all it'd do for a non-attention-deficit cat is keep them awake slightly longer.
<bofh> LOL THE CODE
<bofh> "we are orbiting cats on a loading screen, so I guess I can live with it"
<egg|zzz|egg> bofh: but Sarbian knows that bad numerics will invoke the wrath of the egg
<bofh> Indeed, apparently!
* bofh is thankful their numerics code is well-written
<bofh> I propose that "pants decomposition" get added as a wpn
<egg|zzz|egg> is pair of pants already a wpn
<egg|zzz|egg> bofh: also is it called a pair of trousers in en-GB
<bofh> LOL I wonder, not sure tbh
<egg|zzz|egg> also I like how it shows how to construct a surface with >= 2 holes and constant negative curvature with right-angled hexagons
* egg|zzz|egg <3 right-angled hexagons
<bofh> Nice.
<egg|zzz|egg> (cut 4g-4 right-angled hexagons out of a hyperbolic plane, sew them pairwise to get 2g-2 pairs of pants, sew that to get your surface; at every corner four right angles meet, so you do indeed have a surface of genus g with constant negative curvature)
<bofh> rofl my mind immediately interpolated in "cut 4g-4 right-angled corners out of a 4-cornered simultaneous time cube...")
<bofh> s/)//
<kmath> <fullbright> when the art team won't make u a chandelier so u just gotta make it out of BSP https://t.co/b9KWnEiIBE
<bofh> goddamnit I wish LinnDrums weren't so expensive. FS1Rs too.
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<kmath> <ProbFact> In high dimensional spheres, nearly all the area is near the equator. Not really "the" equator: it doesn't matter which equator you pick!
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<egg|zzz|egg> hm, that makes sense
<egg|zzz|egg> (though it's hard to visualize spheres beyond S3, and S3 already involves bending one's mind with the Hopf fibration)
* UmbralRaptor assumes that it's something like cos³(θ) bringing down the area far from the equator.
<egg|work|egg> UmbralRaptor: yeah, just compare a circle and a 2-sphere
Thomas|AWAY is now known as Thomas
<egg|work|egg> !wpn Thomas and Iskierka
* Qboid gives Thomas and Iskierka a Euclidean polarimeter
<egg|zzz|egg> !wpn whitequark
* Qboid gives whitequark an umbral category which vaguely resembles a manifold
<egg|zzz|egg> !wpn UmbralRaptor
* Qboid gives UmbralRaptor a zinc wyvern
<egg|zzz|egg> !wpn котя
* Qboid gives котя a metal oxide constant
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<egg|zzz|egg> !wpn regex
* Qboid gives regex a Hermite mutually intelligible factor
<egg|zzz|egg> wait, why am I zzz
<regex> lol
<egg|zzz|egg> regex: um, do you still have you link to that principia-compatible subset of RSS expanded? :-p
egg|zzz|egg is now known as egg
<egg> thanks :-)
<regex> no worries
<egg> trying to set up an RSS/RO save that works to test the upcoming Cayley release
<regex> Speaking of which, I should check on procedural parts.
<egg> it's a bit odd that starwaster can't reproduce the issue
<bofh> egg: yaey hopf fibration
<lamont> regex: would it make sense to fork RSS expanded and bring it into the KSP-RO github org?
<Qboid> lamont: KevinStarwaster left a message for you in #RO [18.07.2017 08:04:49]: ""coasting to circularization burn" <--- on a sub-orbital failed injection burn... :)"
<egg> lamont: I believe Pap just wants to add the relevant bodies to RSS
<egg> and has a branch with that
<egg> hasn't been merged though, try to poke Pap with the output of !wpn?
<bofh> !wpn egg
* Qboid gives egg a lead approximation
<bofh> Oh, so Po-212?
<bofh> It approximates Pb-208 given a few million years :P
<egg> lamont: is there a build of your """PEG""" on a MechJeb targeting 1.2.2?
<egg> (or is RSS/RO secretly 1.3-compatible)
<regex> lamont, uh, maybe? The real problem is that Principia only supports a subsection of everything it covers.
<regex> I install it for Ceres and Vesta though.
<regex> which really need to be in RSS, IMO
<egg> and anyway Pap wants to add eggsactly the things that principia supports
<lamont> all my testing builds are 1.2.2
<egg> lamont: but where are they :-p
<egg> (Ceres, Vesta, the moons of Uranus, Iapetus I think)
<egg> lamont: ah thanks
<regex> sounds about right
<egg> that doc may be out of date though
<lamont> we need IX for late game missions
<bofh> Iapetus is a pain in the arse orbitally iirc
<lamont> egg: i’ve got principia in my main install now, so i’ve been testing that continuosly with principia
<egg> \o/
<lamont> also dug up papers/books on how to to properly calculate translunar return trajectories
<egg> lamont: still high energy though right
<lamont> which should also vastly improve all of mechjeb’s transfer orbit planning
<lamont> high energy! spicy!
<lamont> can clearly use that to plan transfers to lagrange points, but once the ship gets there you’re on your own…
<egg> yeah, and even there it's not necessarily the best way to get there
<lamont> right, flinging it out to the edge of Earth’s SOI and letting the Sun pull on it
<lamont> can’t plan that
<egg> I mean, going to Lagrange points is fun, but a lot of the really useful stuff you can get from Principia is WSB transfers, rather than actually going to a Lagrange point
<egg> the GRAIL trajectories are a lot of fun :-p
<lamont> right now mechjeb simply needs to catch up with late-60s trajectory planning
<egg> yeah
<egg> I think for 2010s we should get it implemented in principia and then if sarbian is interested we can expose a small entry point so it can be used from MechJeb
<egg> but esp. since we have our own idea of manoeuvres and flight plans this would be tricky to do outside principia
<lamont> how is the flight planner currently implemented?
<lamont> and where i’m going with this, is how do i ask principia for a property trajectory integration from c# code?
<egg> fairly thin UI layer talks via the P/Invoke interface (generated from protos for journalling) to the C++ Plugin and the FlightPlan of the Vessel, interface likely to change all the time because so close to the UI
<egg> lamont: it's really not designed in a way that makes it easy, and we don't really want to commit to exposing a stable API at this point (because we keep shuffling things around quite a bit)
<egg> the underlying C++ libs are way more stable
<lamont> yeah
<lamont> if you can stabilize that it makes it easier to do flight planning from c#
<egg> yeah, but I don't really think it's a good idea to have the guidance going from one to the other at that level anyway
<egg> I'd say write an optimization/guidance in C++ on the principia libs, and have the C# ask for its results
<lamont> its not really guidance, its just flight planning and trajectory integration
<lamont> really just the latter
<egg> yes except then you have to know what to optimize on the trajectory
<egg> and returning a trajectory is going to be costly too, whereas if you can just look at it where it lives things are simpler
<lamont> hrm
<lamont> i guess i’ll have to see it
<egg> whatever you return through this interface is going to have very little structure
<egg> so you want it to be small
<lamont> what i want is something like an Orbit class
<egg> yeah that's not going to happen
<lamont> well hang on
<lamont> its not going to look exactly like an orbit, but fundamentally it starts with position + velocity vectors in a reference frame, probably with a precision for the integrator, and then be able to ask it questions like “in the next X seconds” where and when is the closest approach to the moon”?
<egg> but your guidance on complex trajectories may want to optimize for different things, e.g. the integral over the trajectory of the difference from the actual trajectory
<lamont> the algorithm i want to implement doesn’t care
<egg> lamont: the algorithms you're looking at at the moment are for high-energy orbits, so there you don't care about principia anyway
<lamont> you integrate, figure out the delta in miss in the periapsis, adjust your guess, then re-shoot
<egg> we're talking about different problems
<lamont> yeah, but i want to get it precise beyond just patchy conics
<egg> and also, if I make an API, I want it to support fancier algorithms, not just what you're writing now
<lamont> sure
<egg> since anyway getting that API together will take months
<lamont> but if you have a public interface to c# it opens up the API to a broader audience, you can do more with c++ but its less accessible
<egg> lamont: also there's the more fundamental question that we also have our own manoeuvres, that are independent from the stock manoeuvres
<egg> lamont: yes but at the moment the last thing I want is to have everybody depending on code that I constantly reshuffle and yelling at me that I broke their mods :-p
<lamont> well yeah
<egg> at some point I'd probably be interested in guidance for the principia manoeuvres
<egg> and that would obviously be part of principia
<egg> once that exists, it can be forwarded wherever as a high-level API maybe
<lamont> heh, well i need to get the MJ code levelled up to 3D and implement apollo-era IGM at least
<lamont> and extract that into a library for more than just ascents
<lamont> then could translate that to C++
<egg> possibly; in the meantime I guess I could try getting the principia flight plan to be usable from the ground up in some manner, so you can plan missions without being in a parking orbit
<egg> but I'm not sure how that would work from a UI point of view
<lamont> hrm
<egg> I guess you could have a disembodied flight plan in the tracking station, start it from some combination of altitude/flight path angle/inclination/speed/etc... seems tricky :-p
<lamont> yeah
<lamont> i mean it’d be cool if you could figure that out
<lamont> “summon a parking orbit to plan an injection burn"
<egg> it would be necessary to plan things like ccar.colorado.edu/asen5050/projects/projects_2012/truesdale/img/grail.jpg
<egg> and clearly we want cute trajectories like that
UmbralRaptor is now known as NomalRaptor
<egg> !wpn NomalRaptor
* Qboid gives NomalRaptor a just-in-time Glamdring
* NomalRaptor promptly stabs things.
<NomalRaptor> Apartment application status: ㄟ(ツ)ㄏ
<egg> !u ㄟㄏ
<Qboid> U+311F BOPOMOFO LETTER EI (ㄟ)
<Qboid> U+310F BOPOMOFO LETTER H (ㄏ)
<NomalRaptor> Moving company at least now has a date for when they'll do the estimate.
<NomalRaptor> But I could be looking at being pushed from August 1st to 14th for move in.
* NomalRaptor stares at the EPRV III conference (August 14-17)
<NomalRaptor> On an unrelated note, I accept pull requests for the /topic gist.
<NomalRaptor> https://twitter.com/rygorous/status/887392621156474881 <-- rapidly expanding foam?
<kmath> <rygorous> @FioraAeterna parts A and B of polyurethane foam for A Great Prank That Will Get You In So Much Trouble.
<Fiora> NomalRaptor: he may be referring to expanding foam, which is a *fabulous* tool in general
<Fiora> it expands roughly 30x from its original volume. a large drum of it could cause phenomenal havoc.
<Fiora> it's also useful as a fairly cheap source of arbitrary amounts of foam (which can be carved into shapes) or just in general a way to hold things in place via pressure.
<NomalRaptor> ah
<bofh> goddamnit the You Spin Me Right Round percussion track is astoundingly complicated (try following along clap, cowbell & hihat at the same time! it's great fun!)
<bofh> a lot of this is doing a wonderful job reminding me I have zero useful perception of rhythm or timekeeping.
<bofh> Which isn't *surprising*, but still aggravating.
<kmath> <PAYOLETTER> @DrMRFrancis i do appreciate that phobos is falling apart due to stress bc same
<NomalRaptor> Same
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<egg> lamont: your PEG is nice btw :-p
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<bofh> polyethylene glycol?
<bofh> PEG?
<Qboid> bofh: [PEG] => Powered Explicit Guidance
<bofh> ahh.
<egg> bofh: sometimes the discussions here have to do with either KSP or academia, surprisingly
<egg> though admittedly it's catpics most of the time
<bofh> "Like its components, UH 25 is flammable, toxic (carcinogenic) and corrosive." why am I not surprised
<bofh> I like that parenthetical tho.