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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<_whitenotifier-979b> [Principia] astro-angelfish opened issue #4227: Principia fails to load even library has been set up correctly - https://github.com/mockingbirdnest/Principia/issues/4227
<queqiao--> <e​zs​na​ck​> Is there a formula to go from c3 to pe speed at a certain altitude?
<raptop> This feels like a patched conics question, though I suppose that's good enough with a sufficiently hyperbolic orbit?
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<queqiao--> Reply to "e​zs​na​ck​: Is there a formula to go from c3 to pe speed at a certain altitude?"
<queqiao--> <N​az​fi​b> Assuming a simple Keplerian orbit:
<queqiao--> <N​az​fi​b> v² = v_esc² + v_inf² = 2μ/r + C₃, where
<queqiao--> <N​az​fi​b> v is the speed at radius r;
<queqiao--> <N​az​fi​b> v_esc is the escape velocity at radius r;
<queqiao--> <N​az​fi​b> v_inf is the hyperbolic excess velocity;
<queqiao--> <N​az​fi​b> μ is the gravitational parameter;
<queqiao--> <N​az​fi​b> C₃ is the characteristic energy.This holds at any position along the orbit, not just at periapis.
<raptop> ...I think you need to explain to him how to take better selfies
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<queqiao--> <B​en​ji​> Nono, those are the best selfies. Only cats and 4yo can do it perfectly.
<queqiao--> <s​ii​ma​v> Boris is just hinting at how empty that tummy is :hangrybeale: https://cdn.discordapp.com/emojis/1090008580054339776.png
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