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Show HN: Browser-based interactive 3D Three-Body problem simulator

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Re: Show HN: Browser-based interactive 3D Three-Body problem simulator

#72

Post by nhatcher »

tetris11 wrote: post #64
nhatcher wrote: post #11

This is amazing! Nicely done! I did something similar, mostly 2D here: https://www.nhatcher.com/three-body-periodic/ (Mine is just unfinished)

what the heck? are those three orbits genuinely symmetrical in 2D or did I misinterpret

I'm not sure which ones are you talking about specifically. But there are some with some heavy symmettrical patterns indeed. To my eyes some are mesmerizing to watch.

The orbits are computed in real time, so yeah what you are seeing (modulo errors in my code is genuine)

There are some caveats though. Some orbits are periodic only in a rotating frame of reference.

EDIT: you can share the URL and I can see which orbits you are talking about

Like: https://www.nhatcher.com/three-body-periodic/?class=bhh_sate...

Re: Show HN: Browser-based interactive 3D Three-Body problem simulator

#73

Post by [deleted] »

lutusp wrote: post #22
kapitanjakc wrote: post #14

No physics expert but isn't this unpredictable (based on what I saw in series) ? Amd this does seem predictable, I saw this for almost a minute

> No physics expert but isn't this unpredictable (based on what I saw in series) ? A three-body orbital problem is an example of a chaotic system, meaning a system extraordinarily sensitive to initial conditions. So no, not unpredictable in the classical sense, because you can always get the same result for the same initial conditions, but it's a system very sensitive to initial settings. > Amd this does seem predict…

[deleted]

Re: Show HN: Browser-based interactive 3D Three-Body problem simulator

#76

Post by layer8 »

ralferoo wrote: post #50

One thing I'd never really considered before is how frequently bodies get ejected at high speed from the simulation, especially as the number of initial bodies is increased. Suddenly made me realise that the "big bang" which previously seemed a bit of a random and magical theory (obvious question is why would the universe be expanding from a single point when gravity would be immense) now seems a lot more plausible w…

The universe didn’t expand from a single point in the Big Bang, that’s a common misconception: https://lweb.cfa.harvard.edu/seuforum/faq.htm#m9

https://lweb.cfa.harvard.edu/seuforum/questions/#:~:text=EVO...

https://ned.ipac.caltech.edu/level5/Peacock/Peacock3_3.html

Re: Show HN: Browser-based interactive 3D Three-Body problem simulator

#77

Post by adastra22 »

hermitcrab wrote: post #57
adastra22 wrote: post #38

Earlier quoted context omitted.

Seriously there was so much wrong with that book.

There was a lot right with it as well IMHO. It was very original (I've only read the first book so far).

To each their own, I suppose.

Re: Show HN: Browser-based interactive 3D Three-Body problem simulator

#79

Post by layer8 »

gorgoiler wrote: post #44

I didn’t realize something until I used this simulation: with three bodies you can eject one body in one direction and the barycentre of the remaining two in another. This means that compared to the original frame of reference you have an orbiting pair that moves . It’s one of those things that seems so obvious and yet actually seeing it is a really important step in understanding.

There are animations of how the solar system as a whole moves through space. (The solar system isn’t stationary within our galaxy.) The planets therein are forming spirals around the trajectory of the sun in a similar fashion.
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