12 comments

  • VikingCoder 36 minutes ago

    This is nice.

    I did laugh at how the Gravity built the Earth, with a tiny North America and all, and then as more mass was accumulated, North America got to get bigger and bigger and bigger!

  • Iolaum 18 minutes ago

    My physics bias would like to see earth forming while it's constituents were orbiting around the sun.

    In any case, nice visualization.

    • ck2 3 minutes ago

      that probably happened a few times as well we "stolen" planets or mass from other star systems in the same baby nursery as our sun

      there is also likely a planet that passed through and yanked away a lot of debris, most of the simulations for tilt etc. don't work without the mystery missing planet

      I could watch PBS Space Time all day for that kind of stuff, often do letting it play in the background on repeat, so much better than the news

      * https://www.youtube.com/@pbsspacetime/search?query=planets

      Dr. Becky is also awesome

      * https://www.youtube.com/@DrBecky/videos

  • BigTuna 33 minutes ago

    Great job! 14 is misleading though - while the context is one day, the animation depicts axial precession which takes place over ~26,000 years

  • genpfault 42 minutes ago

    > Einstein

    How are you handling relativistic effects in the N-body simulation?

    • qunabu 33 minutes ago

      Not in the sim right now — it's purely Newtonian (symplectic leapfrog, classical gravity). I show the concept on the last slide ("Einstein: gravity is curved spacetime") — a curve in space wrapping around a star/planet that pulls nearby objects into the well. The quantitative case, Mercury's ~43″/century perihelion precession, I'd add next as a 1PN correction — haven't gotten to it yet. Will try to figure it out how to show this

  • Brendinooo an hour ago

    Super fun! I might show it to my kids later today. Thanks for making it!

  • stevenalowe an hour ago

    Looks great but on mobile the popover covers a quarter of the screen, obscuring the sun

    • qunabu an hour ago

      I should have mentioned that its not mobile friendly so far. I will try to fix this.

      • qunabu an hour ago

        It should be better now

        • iainmerrick 22 minutes ago

          It works pretty well on iPhone, except the descriptive text fills most of the bottom half of the screen, overlapping the sim which is centered on the screen.

          If the sim were instead centered on the free space (the top half of the screen) it’d be perfect.

          • qunabu 17 minutes ago

            There a toggle button to show hide description if you missed it