egg changed the topic of #principia to: Logs: https://esper.irclog.whitequark.org/principia | <scott_manley> anyone that doubts the wisdom of retrograde bop needs to get the hell out | https://xkcd.com/323/ | <egg> calculating the influence of lamont on Pluto is a bit silly…
<queqiao->
⟨PrinceZola ùwú⟩ do sun sychronous orbits work on principia?
<queqiao->
⟨Al2Me6⟩ Yes, of course.
<queqiao->
⟨PrinceZola ùwú⟩ thats coool
<queqiao->
⟨PrinceZola ùwú⟩ however
<queqiao->
⟨PrinceZola ùwú⟩ i should buy a ram stick before tbh
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<queqiao->
⟨sciencecompliance⟩ Question: is Principia purely a passion project, or are the people involved in it invested in some way beyond simply desire (e.g. college thesis, etc...)?
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<queqiao->
⟨Damien⟩ ⟪sciencecompliance⟫ Question: is Principia purely a passion […] ⮪ I asked a similar question a while ago and it's basically a passion project
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<queqiao->
⟨theeo⟩ although it would be a legendary college thesis, etc… if it was made for that
<queqiao->
⟨Butcher⟩ I think most of the people involved already have degrees or doctorates.
<queqiao->
⟨theeo⟩ exactly
<UmbralRaptop>
egg "only" has an MSc. No idea with PHL
<queqiao->
⟨Butcher⟩ More than I have. :-p
<queqiao->
⟨PrinceZola ùwú⟩ Hey if I want to discuss astrodynamics just in general may i do it on this chat?
<raptop>
sure, I think
<queqiao->
⟨PrinceZola ùwú⟩ Bot
<raptop>
kjfl;asdewoiiiiiiiiikdge
<queqiao->
⟨PrinceZola ùwú⟩ How
<queqiao->
⟨PrinceZola ùwú⟩ Like where does that vis-viva eq comes from?
<queqiao->
⟨Quadrupole⟩ The bot is a relay
<raptop>
ゾラ姫、どうして？
<queqiao->
⟨Vlood⟩ ⟪PrinceZola ùwú⟫ Hey if I want to discuss astrodynamics […] ⮪ #principia is here for two reasons: orbital mechanics discussions and cat pictures
<raptop>
Anyway, you can get vis-viva from conservation of energy IIRC
<queqiao->
⟨PrinceZola ùwú⟩ I was trying to do it pen and paper with just newton's gravitational force thingy and well... I got way lost
<raptop>
Oh, yeah. Energy in potential + kinetic vs energy as semi-major axis
<queqiao->
⟨PrinceZola ùwú⟩ And how newton's gravity = elliptical shaped orbits?
<queqiao->
⟨Vlood⟩ ⟪PrinceZola ùwú⟫ And how newton's gravity = elliptical […] ⮪ Kepler
* raptop
is going to laugh if egg suggests lagrangian over newtonian mechanics
<queqiao->
⟨Quadrupole⟩ There are four ways to prove that. Here is a very intuitive way (but hard to construct ab initio!)
<queqiao->
⟨Quadrupole⟩ You can also do it via first integrals. First prove that angular momentum and eccentricity are conserved, then gradually work out the rest. See Richard Battin's _An introduction to the mathematics and methods of astrodynamics_.
<queqiao->
Finally, you can directly integrate angular velocity and eliminate time.
<queqiao->
The key to any derivation of Keplerian orbit is that you need to know the final orbit has the form of "r \propto 1/(1+e\cos(\theta))", and work backwards if you are unsure.
<queqiao->
⟨PrinceZola ùwú⟩ In my brain i was like, ok we have two bodies (one fixed) with a force relationship between them, then I just had to choose an initial position, with a initial velocity and see how the force would change that vector and following that see what path would arise from it
<queqiao->
⟨PrinceZola ùwú⟩ Só yeah I was trying to do the integrals and stuff but I... Got lost xP
<queqiao->
⟨Quadrupole⟩ Here is the standard method you can […] ⮪ Use this method. No integral needed.
<queqiao->
⟨Quadrupole⟩ Just some clever substitutions.
<queqiao->
⟨Quadrupole⟩ ⟪PrinceZola ùwú⟫ In my brain i was like, ok we have two […] ⮪ Also you should not assume one body is fixed. Both bodies moves; it's just that one often moves only slightly. You need to apply conservation of momentum and get a _reduced_ mass and an _effective_ potential. The latter is fixed.
<queqiao->
⟨sciencecompliance⟩ ⟪PrinceZola ùwú⟫ In my brain i was like, ok we have two […] ⮪ Yeah, this is essentially it. Much more complicated in practice, though, but you can construct a simple model with point masses and just loop over each body with the vector sum of the forces on each body updating the velocity vector and hence the position at each time step. It's fun to play around with if you know a little programming.
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<queqiao->
⟨lamont⟩ the real question nobody asks: prin-kip-ia or prin-sip-ia?
<queqiao->
⟨Quadrupole⟩ Hard k. It's Latin.
<queqiao->
⟨lamont⟩ but we're mostly conversing in english here and we're not latin
<queqiao->
⟨Vlood⟩ ⟪Quadrupole⟫ Hard k. It's Latin. ⮪ Depends on the latin
<queqiao->
⟨Stonesmile⟩ Original work was written in latin though
<queqiao->
⟨Soviet Onion⟩ ⟪Vlood⟫ Clearly it's prin-chip-ia ⮪ it is rather prin/ship/ia 😏
<queqiao->
⟨Vlood⟩ ⟪Stonesmile⟫ Original work was written in latin […] ⮪ my gut tells me that ecclesiastical latin superseded classical latin by that point
<queqiao->
⟨Quadrupole⟩ > New Latin had no single pronunciation, but a host of local variants or dialects, all distinct both from each other and from the historical pronunciation of Latin at the time of the Roman Republic and Roman Empire. As a rule, the local pronunciation of Latin used sounds identical to those of the dominant local language; the result of a concurrently evolving pronunciation in the living languages and the corresponding spoken...
<queqiao->
... dialects of Latin.
<queqiao->
⟨Quadrupole⟩ Wikipedia says it's probably s
<queqiao->
⟨Quadrupole⟩ Not going to stop me from pronuncing every Latin loan word clasically though.
<queqiao->
⟨Quadrupole⟩ * classically
<queqiao->
⟨Vlood⟩ ⟪Quadrupole⟫ Wikipedia says it's probably s ⮪ i'll still instinctively pronounce it as "ch"
<queqiao->
⟨Quadrupole⟩ That's probably because you live in a"generic eastern Europe country" though. Wikipedia says Romanians may have pronunced c as tʃ , or ch.
<queqiao->
⟨Quadrupole⟩ * a "generic
<queqiao->
⟨KTL Rob Powell⟩ having studied Latin at school I say it as if it is a K but I feel other variations are fine in modern English and American English
<queqiao->
⟨KTL Rob Powell⟩ let alone non native English speakers trying to pronounce it
<paculino>
Are you saying that American English is not modern English? 🤔
<raptop>
I was hoping to make a joke about modernism, but apparently that was a tradition in too many countries
<queqiao->
⟨vevladdd 🇺🇦⟩ The best is with rrrr, ci as tsy and a as ya
<raptop>
Anyway, the fun version of en-US involves mostly speaking in acronyms
<raptop>
(en-NASA and en-DOD are surprisingly enough mutually intelligible)
<queqiao->
⟨vevladdd 🇺🇦⟩ 🇬🇧 Traditional
<queqiao->
🇺🇸 Simplified
<raptop>
Yeah, seeing how wacky traditional CN gets, this is definitely an argument for simplified characters/spelling reform
<queqiao->
⟨Soviet Onion⟩ ⟪paculino⟫ Are you saying that American English is […] ⮪ English is mostly French, followed by Latin 😏
<queqiao->
⟨Soviet Onion⟩ +various other languages like
<queqiao->
⟨KTL Rob Powell⟩ with a bit of Germanic too boot!
<raptop>
Yeah, words like skosh and tokamak aren't from anything romance or germanic
<queqiao->
⟨Soviet Onion⟩ ⟪raptop⟫ Yeah, words like skosh and tokamak […] ⮪ there are a few other words taken from asian languages too, like chutney or juggernaut
<raptop>
cot also, right?
<queqiao->
⟨egg⟩ ⟪raptop⟫ is going to laugh if egg suggests […] ⮪ Hamiltonian probably
<queqiao->
⟨egg⟩ ⟪lamont⟫ the real question nobody asks: […] ⮪ [pʁɛ̃sipja]