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 bofh
* Qboid
gives bofh a Selenian pump
<SnoopJeDi>
I didn't reach much of scrollback, but at the bits about capitalism, I started reading a bit of NSC-68 after re-listening to Carlin, and *wow* some of the front matter would be considered straight-up socialist propaganda today
<SnoopJeDi>
"Where the despot holds absolute power...all other wills must be subjugated in an act of willing submission, a degradation willed by the individual upon himself under the compulsion of a perverted faith. It is the first article of this faith that he finds and can only find the meaning of his existence in serving the ends of the system. The system becomes God, and submission to the will of God becomes submission to the will of the system."
<SnoopJeDi>
bofh, rofl
<SnoopJeDi>
may be the most relevant tweet you've sent me
<SnoopJeDi>
(not to besmirch any others!)
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<Ellied>
Bus displays with weird shit on them are the greatest thing
<SnoopJeDi>
me_2017.png
<bofh>
SnoopJeDi: rofl. nice.
<SnoopJeDi>
which thing bofh? :P
<bofh>
...actually half the relevant tweet bit and half the "WWI bomb?" tweet
<SnoopJeDi>
ah I thought maybe you meant NSC-68
<SnoopJeDi>
I love the question mark on that image though
<SnoopJeDi>
WWI bomb? v0v
<bofh>
I'm fairly unfamiliar with NSC-68.
<SnoopJeDi>
as am I truthfully but Carlin mentions it specifically as a genesis of the modern "police state" foreign policy of the US
<SnoopJeDi>
so I thought it might be worth reading for historical context, but I was *not* expecting to read borderline warmongering stuff from the 60s and think "huh, this is close to sedition"
<SnoopJeDi>
every now and then the US political pendulum sneaks up behind you and slams into the back of your head I guess
<SnoopJeDi>
(maybe it's a double pendulum?)
<bofh>
Probably is a double pendulum, honestly.
* egg
throws a symplectic integrator at the pendulum
<bofh>
lmao
<SnoopJeDi>
Still my canonical example of integrating ODEs and making animations in scipy ¯\_(ツ)_/¯
<kmath>
<bofh453> Wow, far outer solar system space science pre-Voyager was... wow. (black underline original, red underline mine). https://t.co/JlDLMW5DPJ
<SnoopJeDi>
it is!
<bofh>
Like there was actually a sizable debate whether the Uranian magnetic field was intrinsic to the planet or induced due to interactions with the solar wind like the Venusian one.
<bofh>
And we had *no idea* until the Voyager 2 flyby.
* egg
pets the Voyagers
<bofh>
Just think, had the Voyager 1 Titan flyby failed and Voyager 2 diverted, we *still probably wouldn't have any idea today*.
<SnoopJeDi>
bofh, so the one of these that *personally* fills me with true joy
<SnoopJeDi>
is the hexagon
<SnoopJeDi>
because I LIVED IT.
<Ellied>
World War (1±1.5) bomb?
<SnoopJeDi>
found the lab scientist
<Ellied>
ah yes, the infamous World War -0.2
<SnoopJeDi>
but yea, the fact that we just had NO IDEA and "holy shit is that a hexagon?" when we flew by
<Ellied>
omg the hexagon
<bofh>
oh gods the hexagon is so amazing
<SnoopJeDi>
it makes me feel guilty about how simplified my mental picture of the gas giants are
<bofh>
like I imagine that was confusing as *fuck* when everyone first saw it.
<SnoopJeDi>
Despite *knowing* my sense of scale/discrimination sucks, I think of them as dull, flat spheres
<Ellied>
I told my mom about it at some point (after it had made it into the mainstream news) and her reaction was "waaaaait a minute"
<SnoopJeDi>
So that I imagine just...egads, what if everyone was stuck in that trap, and we decided to never look, assuming it was all the dull same?!
<SnoopJeDi>
bofh, I remember there being quite a bit of excitement when n-gons were replicated in the lab!
<Ellied>
I forget, did we ever figure out what was up with the Great Dark Spot?
<SnoopJeDi>
although I don't have that paper in my endnote library, hmmm....
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<bofh>
SnoopJeDi: oh, now I'm curious, what's the relevant fluid/gas dynamics that would lead to that anyhow?
<bofh>
Ellied: I think it was just a cyclonic storm, at least that's what the speculation was.
* SnoopJeDi
spooky hands
<SnoopJeDi>
"fluuuuid meechaaaaaanics"
<bofh>
like for starters we still don't know why the hell Neptune radiates much more radiation than it gets from the sun.
<SnoopJeDi>
(I have no idea but just consider FD to be literal actual sorcery)
<Ellied>
yeah, I remember seeing something about it being recreated in the lab but the physics was well over my head (no pun intended)
<kmath>
<bofh453> Still giggling at "I Have No Orthogonal Basis And I Must Project".
<SnoopJeDi>
...does that modification alter your toughbook's IPxx rating Ellied?
<Ellied>
Oh, probably
<SnoopJeDi>
lmao bofh
<Ellied>
the protruding connector is almost certainly a weak point
<egg>
bofh: clearly Ellied did that so she can plug MHV into her laptop,
<SnoopJeDi>
relatedly, apparently Ellison held onto that phrase for *years* before he dreamt up AM?
<Ellied>
aaaaaaaaaa
<SnoopJeDi>
Ellied, well what I should have asked instead was did you take measures to retain the toughiness of it, like a seal around it
<Ellied>
oh, I did fill in behind it with superglue
<Ellied>
it should be watertight.
<SnoopJeDi>
shipit.rtf
<Ellied>
actually, the plug wasn't watertight at all before. It relied on a little rubber flap which has since broken off.
<SnoopJeDi>
I've contemplated that magsafe-alike hack, but usually decided I don't care enough to do all that work
<SnoopJeDi>
...particularly because I've used Thinkpads for the last 5 years and *man* thinkpad chargers are just...nice.
<Ellied>
it did end up being a fuckload of work. involved taking a dremel to the magnesium of the housing (aaaaaaa) to make it fit decently.
<bofh>
00:54 <@SnoopJeDi> relatedly, apparently Ellison held onto that phrase for *years* before he dreamt up AM?
<bofh>
huh, cool. didn't know that.
<SnoopJeDi>
Ellied, very nicely done
<bofh>
Ellied: clearly you should use polyurethane expanding foam :P
<bofh>
also MAGNESIUM? damn.
<Ellied>
yeah, that's what all the load-bearing structural parts of a CF-30 are made of, it turns out.
<Ellied>
it had me fooled because it's textured and anodized, but it bleeds shiny when you cut it.
<Ellied>
it's got this giant monolithic magnesium plate-thing that holds all the little fiddly bits in place inside. I couldn't figure out how to get it free, so I had to work around it.
<bofh>
That sounds like a pain in the arse to handle/cut thru.
<Ellied>
aye.
<Ellied>
but I suppose you almost get your money's worth with these things.
<bofh>
if I saw it I'd prolly be tempted to connect antenna feedline to it.
<SnoopJeDi>
(I got my first "anybody got a USB-C connector?" the other day)
<Ellied>
we have so many BNC-to-whatever-the-fuck adapters lying about and various devices that produce power that can be connected to BNC, finding an alternate way to charge my laptop in the absence of the brick is all but trivial
<bofh>
Thankfully all the high-power HF feeds I'm used to use N-type so you're prolly safe.
<Ellied>
don't worry, next project is going to be an advanced flexible-input RF rectifier so it can charge off of high-power RF
<Ellied>
SnoopJeDi: I asked that of my friends on our trip to see the eclipse if they had USB-C, and got a bunch of looks like I'd just come from Jupiter
<Ellied>
also we have N-type to BNC adapters in plentiful supply
Technicalfool is now known as TechnicallySleeping
<bofh>
Ellied: true, but needing an adapter would likely give me pause to think before hooking up, say, the output of a 1kW linamp to a random connector.
<bofh>
(also that linamp is terrifying. pair of 3CX400A7 tubes and can in theory be replaced with a pair of 3CX800A7 tubes)
<bofh>
(I love how if you leave it in storage for too long it's recommended to run the heaters overnight before applying any plate current, since there may be uneven deposition of oxides that could lead to thermal runaway and well I hope you like breathing Beryllium Oxide dust)
<Ellied>
aaaa
<bofh>
also now I'm reminded of the second strangest feeling I've ever felt, which was when I keyed down 150W SSB (SSB-LC, actually) into a dipole antenna about 15cm away from my head.
* whitequark
peeks in
* whitequark
is terrified
<bofh>
can't describe it at all beyond "it was incredibly weird and hard to describe". also the solution was to take a step back and retry. thank you inverse-square law.
<Ellied>
θ_Θ
<bofh>
(turns out accidentally TMS'ing yourself with the Space Jam theme SSB-modulated to 20 meters leads to some weird effects. not trying that again)
<SnoopJeDi>
"Has anyone here had Prof. X for Analytical Mechanics?"
<SnoopJeDi>
"Yes. 10/10 would recommend."
<SnoopJeDi>
"Yes, a full hammer outta sickle. My favorite class here."
<SnoopJeDi>
(prof X. is quite Russian and a student-of-a-student of Landau)
<Ellied>
my research prof's name is Landahl, but the department chair (who has known him for decades I think?) sometimes calls him Landau
<Ellied>
Landahl, meanwhile, refers to the department chair as "my chair"
<SnoopJeDi>
hell of a promotion
<SnoopJeDi>
also I'm not sure why I censored the prof's name, because his notes are actually super relevant to recommend here.
<kmath>
<MississippiDOT> MDOT crews are removing 1K+ pumpkins from HWY 90 in @passchristianms that were blown onto the road due to… https://t.co/RrLlSKk221
<Ellied>
the pumpkins are attacking
<Ellied>
insert joke about ṁ
<UmbralRaptor>
dMississippi/dt
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<Qboid>
0d 18h 0m 0s left to event #11: 「みちびき4号機」／H-IIAロケット36号機 [at 2017-10-09 22:00:00]. Say '!kountdown 11' for details
<UmbralRaptor>
"Mathematics is an experimental science, and definitions do not come first, but later on." - Oliver Heaviside
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<egg>
!wpn whitequark
* Qboid
gives whitequark a radioactive summation-like platypus
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<Qboid>
0d 12h 0m 0s left to event #11: 「みちびき4号機」／H-IIAロケット36号機 [at 2017-10-09 22:00:00]. Say '!kountdown 11' for details
<Iskierka>
tbf @ thinkpad chargers I believe they did change it for the T*20 -> T*30 jump, they just kept it the same since there. I have seen some exceptionally old ones using a different design
<Iskierka>
battery also changed around the same point but since then they should be interchangeable. Hopefully that might be introducing SBS management and they intend to keep current design?
<kmath>
<astronomolly> Shoutout to colleagues who "if I work on wknd I wait til Monday to send email bc I don't want to set bad example or… https://t.co/Gtt2JIjQM8
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* Qboid
gives UmbralRaptor an antimony rotary heptagon
<UmbralRaptor>
!wpn egg|work|egg
* Qboid
gives egg|work|egg an abelian tensor with a Laplacian attachment
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<APlayer>
Hi!
<UmbralRaptor>
¡lo
<APlayer>
Question on my low TWR simulator: It was initially envisioned to help plan ejection burns. Now, the thing is, this spiralling behaviour is less efficient than a point burn. Is it reasonable to continue the burn until the desired orbital energy is achieved, rather than until the planned dv is expended?
<APlayer>
(Orbital energy being, I believe, kinetic energy + potential energy)
<UmbralRaptor>
I suspect so, but not sure that orbital energy will get you quite on the desired trajectory?
<APlayer>
Why not?
<APlayer>
I think I care about relative energy and movement direction only?
<APlayer>
At least approximately well enough, that is.
<APlayer>
(What will classical mechanics master egg say to this question?)
<UmbralRaptor>
I might break misunderstanding the problem. Is it for changing orbit around a single body, or eg: Earth ↣ Mars?
<APlayer>
It is for interplanetary travel, basically to work in company with alexmun's trajectory planner
<APlayer>
Where his tool does the launch windows (and point burns, as an estimate for the actual burns) and mine corrects the point-burn approximation
<APlayer>
Which can be a nightmare for ion powered ships
<APlayer>
Also, I need a way to calculate the final ejection angle... I guess that's the periapsis?
<APlayer>
That is, the periapsis is at the ejection angle if the burn went properly
<Iskierka>
... that point I don't follow at all
<APlayer>
Iskierka: which point?
* APlayer
is confused for confusing people
<Iskierka>
how the periapsis would be an an ejection angle
<APlayer>
Well, I have my final elliptic, parabolic or hyperbolic orbit. And I need to know the ejection angle
<APlayer>
So I can know at what anomaly to start my burn for real#
<APlayer>
At what angle to pro-/retrograde, rather
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<APlayer>
Why is the specific orbital energy in many examples negative?
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<Iskierka>
because the orbital energy of a closed orbit is negative
<Iskierka>
infinite distance at zero velocity is 0
<APlayer>
Ah, so it's relative
<Iskierka>
everything is relative
<Iskierka>
and there is no other good reference point for orbital energy, so
<APlayer>
Ugh, never start a conversation with physicists :p
<APlayer>
Also, no, the speed of light is not
<Iskierka>
The speed of light is very relative. That's what infuriated michaelson and morley and made einstein famous
<APlayer>
How are you going to explain this?
<Iskierka>
Light is always relative to the observer. That's the point. It has no absolute reference
<APlayer>
The speed of light, not light itself ;-)
<Iskierka>
And everyone's measurement of that is relative to themselves, else movement differences would cause differences in measurement
<APlayer>
God, help me
<APlayer>
Ugh, never start a conversation with physicists
<APlayer>
Anyway, now that you've proven me fundamentally wrong about the laws of the universe... So I can use the orbital energy and ejection angle to make sure I am on nearly exactly the planned trajectory?
<Iskierka>
I'm not a physicist. Though the implications of relativity and causality do matter for distributed systems
<APlayer>
That is, are interplanetary orbits achieved from different burns but with the same ejection angle and potential energy at the escaped planet similar enough for the difference to be negligible?
<APlayer>
s/potential energy/orbital energy/
<Qboid>
APlayer meant to say: That is, are interplanetary orbits achieved from different burns but with the same ejection angle and orbital energy at the escaped planet similar enough for the difference to be negligible?
<Iskierka>
I don't actually know but am going to confidently assume that you need to define "negligible"
<APlayer>
Can arrive at destination with a correction burn of few tens of m/s
<Iskierka>
incomplete answer as you're definitely going to have significant position error more than velocity, assuming it works as intended
<APlayer>
Or rather, can use equivalently in KSP
<APlayer>
And how would I do this otherwise? I mean, it can't be harder than what I did already, can it?
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<APlayer>
!wpn egg's phone
* Qboid
gives egg's phone a Максутов-Cassegrain canon
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<UmbralRaptor>
APlayer: assuming patched conics and the burns finish before switching SOIs, somewhat yes. You get the right magnitude, though will need to be careful with timing for direction.
<APlayer>
I.e. I suspect this is the velocity at infinity, is that true?
<APlayer>
Woops, nevermind that. I did not read far enough
* APlayer
loves sites that actually explain things to people who might actually be idiots, such as me
<APlayer>
What is the vector r in equation (5.37), though? Is that the current position? Seems weird, that would mean solely changing the position changes the result. Or is that rather the periapsis position?
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<UmbralRaptor>
APlayer: looks like current position with respect to earth (r_0 being r at periapsis)
<egg>
!wpn whitequark
* Qboid
gives whitequark a diamagnetic lanthanum rectifier
<egg>
!wpn UmbralRaptor
* Qboid
gives UmbralRaptor a good minion
<UmbralRaptor>
!wpn
* Qboid
gives UmbralRaptor a pythonic iron tombstone
<egg>
!wpn Fiora
* Qboid
gives Fiora a Dirac isochoric zepplin/cone hybrid
* UmbralRaptor
beats the minion to death with a pythonic iron tombstone
<UmbralRaptor>
!wpn egg
* Qboid
gives egg an insulating ship/superuser hybrid
<APlayer>
But then the equation makes no sense?
<APlayer>
I mean, wouldn't that mean that the departure asymptote angle changes with the ship advancing (coasting, that is) along its trajectory?
<APlayer>
Or does "the math work out" this way?
<UmbralRaptor>
I think "the math work out" as in the portion of the velocity that's not parallel to the departure angle goes to zero?
* UmbralRaptor
pokes egg
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<Qboid>
0d 4h 0m 0s left to event #11: 「みちびき4号機」／H-IIAロケット36号機 [at 2017-10-09 22:00:00]. Say '!kountdown 11' for details
<APlayer>
It may or may not be the current position, but I doubt it is, for by changing the position, I believe the departure angle would change as well
<kmath>
<johnregehr> while we're on the subject, why can't my 4-core Macbook Pro running all the latest software play bluetooth music and also browse the web
<egg>
!choose sleep|leekspin|nomal
<Qboid>
egg: Your options are: sleep, leekspin, nomal. My choice: sleep
<egg>
;choose sleep|leekspin|nomal
<kmath>
egg: leekspin
<egg>
raptorchoose sleep|leekspin|nomal
<bofh>
leekspin
<bofh>
why do you posess Alliums with high angular momentum anyhow?
<Iskierka>
UmbralRaptor, sounds like a driver conflict that I had with linux on old laptop that any bluetooth device, even game controller, would dominate the aerial and allow no wifi bandwidth
<UmbralRaptor>
bofh: I blame Finland.
<Iskierka>
ofc, that's linux, with everything thrown together randomly, so of course that couldn't happen on professionally developed software like that of a Mac /s
<UmbralRaptor>
Iskierka: Okay, that's extra embarassing with Apple.
<UmbralRaptor>
Also, i3 wm is a better GUI than OSX.
<Iskierka>
and it's definitely not being defeated by my thinkpad, which ALSO uses a shared aerial with the exact same problem presented, in linux, and does not exhibit this problem
<UmbralRaptor>
...why does this homework want me to go to a non-inertial reference frame? D:
* UmbralRaptor
basically doesn't use BT >_>;;
<Iskierka>
I didn't until got some BT earphones for treadmill then it turns out they're convenient for uni
<Iskierka>
even if tomorrow I intend to just use them for noise isolation on the train and read instead of listen
<egg>
bofh: I plant them on a spinning planet,
<UmbralRaptor>
bofh: egg hacked the IERS to alter the spin rate to just under 0.04 radians/second.
<bofh>
UmbralRaptor: ahh, clearly.
<bofh>
ahh, I love it when I downmix something to mono and then get surprise phase cancellation. it's AWESOME (note: not actually awesome).
<Ellied>
My classmates/students in the electronics class I took 2 years ago (and I'm effectively TAing now, although I haven't officially been hired because the class is so small) told me I have been more helpful than the prof with the course material.
<Ellied>
That's not necessarily a good thing (I could be giving them too much help and not making them do enough) but I've been trying my best to avoid that.
<Fiora>
Iskierka: oh fate/go is hardly a weird anime game,
<Fiora>
i mean it's just like, normal levels of weird
<Iskierka>
I forget what it was I even saw at the time that was weird
<Iskierka>
oh yeah, massive fourth wall anachronism while flirting about honeymoon with ... I don't evne know. Is she wearing a flower as a corset?
<Ellied>
wow that... that comes out real nice in IRC on a terminal with font AA turned off
<bofh>
Not bad.
<Fiora>
Iskierka: okay so you know how western media loves to have cartoonish-level views of non-western history
* Iskierka
didn't get that one on twitter and it doesn't seem to make more sense off it
<Fiora>
fate/go is that except it's the japanese applying fractured fairy tale logic to the entirety of western history
<Iskierka>
Ah, okay. Still silly, but silly with a point
<Ellied>
Iskierka: in some colored emoji fonts it forms an approximation of an H-R diagram
<Iskierka>
aaah. It fell apart somewhat in tweetdeck but it's not spacing it out the same way as actual twitter so everything was disconnected
<Fiora>
it begins with helping joan of arc defeat her evil twin who teamed up with gilles de rais to annihilate medieval france
<Fiora>
it gets less historically accurate from there.
<Iskierka>
also https://twitter.com/FioraAeterna/status/917349530072260609 blame people first being confused when a 40 minute train journey that was on time would take 38 minutes (or something like that), then blame the US for summer time
<kmath>
<FioraAeterna> Isn’t it messed up that midnight isn’t actually the middle of the night
<Fiora>
the most recently released english section involves helping francise drake defeat blackbeard (who is actually a creepy pedophile), who it turns out is trying to find the ark of the covenant because he's being manipulated by David and Medea.
<Iskierka>
I did check it on twitter and see it working properly :p
<Ellied>
Ah, i wasn't sure if you were having font problems, the coloration of those characters seems like it could easily be arbitrary between platforms
<Iskierka>
!u ?
<Qboid>
U+1F535 LARGE BLUE CIRCLE (?)
<Iskierka>
Probably not?
<Fiora>
why is there a unicode codepoint for "large blue circle"
<Fiora>
are all the other colors in there too.
<Iskierka>
apparently there's also white and red at least
* Qboid
gives Iskierka a zygohistomorphic hypothetical jellyfish
<egg>
!wpn icefire
* Qboid
gives icefire a cyclic nucleotide-gated bustard-like submersion
<egg>
Fiora: yeah emoji in general and those with explicit colours in particular are weird, but that allows for plain text Hertzsprung-Russel diagrams, which is good, right :-p
<egg>
(see also the yellow heart which was a hairy heart on some version of android >_>)