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…
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<queqiao-> ⟨lpg⟩ decoupling the fairings at the same time as the rocket was pretty much asking for trouble
<queqiao-> ⟨PrinceZola⟩ then its a skill issue from me qwq
<queqiao-> ⟨PrinceZola⟩ ⟪lpg⟫ decoupling the fairings at the same […] ⮪ i did it separately and... well... when i decoupled, same result xP
<queqiao-> ⟨Al₂Me₆⟩ (This has entered #rp1-career-help territory...)
<queqiao-> ⟨PrinceZola⟩ i guess... the precession seems weird but i will move my talks to rp-1 career help
<queqiao-> ⟨egg⟩ ⟪Al₂Me₆⟫ (This has entered #rp1-career-help […] ⮪ To be fair, you won’t get precession on a single-part ship without Principia, because PhysX has not heard of physics.
<queqiao-> ⟨egg⟩ (But yes, the remedies are better explored over there.)
<queqiao-> ⟨Quadrupole⟩ Also cylindrically symmetric objects don't have an intermediate axis
<queqiao-> ⟨Al₂Me₆⟩ ⟪egg⟫ To be fair, you won’t get precession on […] ⮪ Point taken, but the ship has three parts 😛
<queqiao-> ⟨PrinceZola⟩ ⟪Quadrupole⟫ Also cylindrically symmetric objects […] ⮪ before it had when it was the cyllinder + 2 spin motors
<queqiao-> ⟨egg⟩ I’m not sure things are that clean for […] ⮪ Somewhat unsurprisingly using the barycentre of the inner system as the primary changes absolutely nothing to the picture.
<queqiao-> ⟨egg⟩ The equipotentials of Neptune do look a bit odd, given the plethora of trojans it has. I guess while heavily perturbed at any given time it averages out over the centuries as the inner system does its thing.
<queqiao-> ⟨egg⟩ … wait no, I forgot to reread the file
<queqiao-> ⟨egg⟩ … it does something ? ? ?
<queqiao-> ⟨egg⟩ how
<queqiao-> ⟨egg⟩ left to right:
<queqiao-> 1. rotating-pulsating reference frames fixing the Sun and Neptune;
<queqiao-> 2. the Sun and the Neptune-Triton barycentre;
<queqiao-> 3. the barycentres of the Sun and the planets up to Uranus (including the Moon but not the other moons, I could not be bothered), and the Neptune-Triton barycentre.
<queqiao-> ⟨egg⟩ * barycentre
<queqiao-> ⟨egg⟩ So I guess we _do_ want to take the solar system up to Herschel as the primary and the Le Verrier system as the secondary, with no fixed bodies.
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<queqiao-> ⟨badgermasher⟩ I'm a little mystified as to the dimensions and rotations here. Am I to assume the axes in 3 are units of the mean seaparation of the two barycentres? And the orientation is presumably X being along that mean separation? Hence what looks to be the equivalent of L1/L2 on the right?
<queqiao-> ⟨egg⟩ ⟪badgermasher⟫ I'm a little mystified as to the […] ⮪ The units in all three are the distances between the two fixed points. The origin is at the overall barycentre, and the fixed points lie on the X axis. Note that the length 1 is _not_ the mean, it is the _constant_ distance in that reference frame between the fixed points (the reference frame pulsates to keep that distance constant).
<queqiao-> ⟨egg⟩ L1 and L2 are indeed on the right.
<queqiao-> ⟨badgermasher⟩ So what is going on with 2? Is it just the choice of contour levels/difficulty of finding the right contour levels to be generated? Doesn't 2 seem to indicate that the L4 equipotential is displaced away from the fixed Neptune/Triton barycentre? But that one explicitly doesn't include the influence of the inner planets? Or do all three of these include influence of the inner planets and it's just that in 3 you are adjusting the...
<queqiao-> ... frame of reference to account for them?
<queqiao-> ⟨egg⟩ All of those include all the gravitational potentials. The sole difference is the centrifugal potential, which depends on the definition of the reference frame.
<queqiao-> ⟨badgermasher⟩ Alright, well I won't pretend to an intuitive understanding but that makes a bit more sense then.
<queqiao-> ⟨egg⟩ So, adding the inner solar system to the primary (so 2 to 3 in the figure) changes the direction of the angular velocity by 1′20″, and its magnitude by 1,6 ‱.
<_whitenotifier-1adf> [actions] pleroy opened pull request #4: Actions for building and testing Principia - https://github.com/mockingbirdnest/actions/pull/4
<_whitenotifier-1adf> [actions] pleroy closed pull request #4: Actions for building and testing Principia - https://github.com/mockingbirdnest/actions/pull/4
<_whitenotifier-1adf> [Principia] pleroy opened pull request #3644: A workflow to build and test Principia - https://github.com/mockingbirdnest/Principia/pull/3644
<_whitenotifier-1adf> [Principia] pleroy closed pull request #3644: A workflow to build and test Principia - https://github.com/mockingbirdnest/Principia/pull/3644
<_whitenotifier-1adf> [Principia] pleroy opened pull request #3645: Try to make the linker happy - https://github.com/mockingbirdnest/Principia/pull/3645
<_whitenotifier-1adf> [Principia] eggrobin closed pull request #3645: Try to make the linker happy - https://github.com/mockingbirdnest/Principia/pull/3645
<queqiao-> ⟨PrinceZola⟩ why changing max history length doesnt alter my orbital prediction?
<queqiao-> ⟨Al₂Me₆⟩ I do believe the answer is in your question: namely, you are configuring the _history_ while looking at the _prediction_…
<queqiao-> ⟨Al₂Me₆⟩ You want increase either the max step count or the tolerance under the aptly named “prediction” section instead
<queqiao-> ⟨PrinceZola⟩ excuse my stupidity
<queqiao-> ⟨PrinceZola⟩ thanks
<queqiao-> ⟨PrinceZola⟩ hmmm looks fairly stable surprisingly
<queqiao-> ⟨PrinceZola⟩ next principia update: atmospheric drag up until geo-stationary orbit :)))
<_whitenotifier-1adf> [Principia] eggrobin opened pull request #3646: [Not for ابن الهيثم] Multiple primaries - https://github.com/mockingbirdnest/Principia/pull/3646