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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

#101

Post by xnx »

lutusp wrote: post #23
jjmarr wrote: post #10

Is this with Gemini 3?

> Is this with Gemini 3? An LLM couldn't provide results for a sim like this, compared to a relatively simple numerical differential equation solver, which is how this sim works. Unless you're asking whether a sim like this could be vibe-coded, if so, the answer is yes, certainly, because the required code is relatively easy to create and test. Apart from a handful of specific solutions, there are no general closed-f…

Part of the Gemini 3 Pro marketing release demonstrated that search results can include interactive UI elements like a simulation of the three body problem https://youtu.be/uYQGrK55gxQ?t=21

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

#103

Post by criddell »

layer8 wrote: post #76
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

Would it be incorrect to say the universe was a single point at one time? That's been my layman's understanding - the universe at the start was infinitesimally small (a point) and has been expanding since.

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

#104

Post by lutusp »

moi2388 wrote: post #31
lutusp wrote: post #27

Earlier quoted context omitted.

> However, some of these were misleading. I had one running for 15 minutes at 5x, and the third body did eventually return. That's not misleading. Real three-body orbital systems show this same behavior. Consider that such a system must obey energy conservation, so only a few extreme edge cases lose one of its members permanently (not impossible, just unlikely). Ironically, because computer simulators are based on nu…

I don’t understand. How would energy not be conserved if one flew away? It’s not in the system, but it’s still out there?

I'm just saying that, because of energy conservation, an escaping member would need to permanently carry away more than 1/3 of the system energy (for equal-mass satellites). This is possible but unlikely.

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

#105

Post by jgchaos »

lutusp wrote: post #21

> Open to suggestions for additional presets or features! Anaglyphic (red/cyan) 3D rendering would be nice. I've created a lot of anaglyphic 3D apps over the years, but they're no longer very popular -- I suspect it's the goofy glasses one must acquire and wear. But a true 3D view of an orbital simulator like this greatly increases its impact and tutorial value.

I do not currently have a set of those glasses so I can't test it, but three.js has this and it's pretty easy to add. There should be an "Anaglyph 3D" checkbox at the bottom of the configuration settings. Let me know if you are able to test it out.

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

#106

Post by lutusp »

adastra22 wrote: post #41
lutusp wrote: post #22

Earlier quoted context omitted.

> 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…

There are stable solutions. See: Earth’s Moon (or any other planetary moon in the solar system).

> There are stable solutions. See: Earth’s Moon (or any other planetary moon in the solar system).

Those are not stable solutions. Remember that Earth's moon only came into existence because of a collision with a protoplanet in the past, and if a large enough body passed close by in the future, we might lose our moon -- all because of the complexity of orbital systems with more than two members.

> (or any other planetary moon in the solar system)

There are any number of examples of planets gaining and/or losing moons because of multi-body orbital complexity.

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

#107

Post by lutusp »

jgchaos wrote: post #105
lutusp wrote: post #21

> Open to suggestions for additional presets or features! Anaglyphic (red/cyan) 3D rendering would be nice. I've created a lot of anaglyphic 3D apps over the years, but they're no longer very popular -- I suspect it's the goofy glasses one must acquire and wear. But a true 3D view of an orbital simulator like this greatly increases its impact and tutorial value.

I do not currently have a set of those glasses so I can't test it, but three.js has this and it's pretty easy to add. There should be an "Anaglyph 3D" checkbox at the bottom of the configuration settings. Let me know if you are able to test it out.

Thanks! I tried the anaglyphic option, but the data being provided to the engine doesn't include third dimension data (so the orbits are essentially flat in the third dimension). Also the orbital colors interfere with the anaglyphic effect (which normally expects white graphic data that it then splits into red and cyan).

I think adding third-dimension data would solve or mitigate the other issues, because full-color anaglyphs are possible, although at a reduced degree of subjective separation between the views.

Thanks for pointing out to me that an anaglyphic option is present, which I managed not to notice the first time.

Anyway, with third-dimension data, the anaglyph option ought to work -- for hard-core, old-fashioned red-blue eyeglass wearers. :)

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

#108

Post by jgchaos »

lutusp wrote: post #107
jgchaos wrote: post #105

Earlier quoted context omitted.

I do not currently have a set of those glasses so I can't test it, but three.js has this and it's pretty easy to add. There should be an "Anaglyph 3D" checkbox at the bottom of the configuration settings. Let me know if you are able to test it out.

Thanks! I tried the anaglyphic option, but the data being provided to the engine doesn't include third dimension data (so the orbits are essentially flat in the third dimension). Also the orbital colors interfere with the anaglyphic effect (which normally expects white graphic data that it then splits into red and cyan). I think adding third-dimension data would solve or mitigate the other issues, because full-color…

I just added that option. It wasn’t there when you initially looked :). Are you using one of the 3D presets/random config or are you using a 2D preset? I'll order a set of glasses so I can test. Not very familiar with this so would be fun to experiment.

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

#109

Post by adastra22 »

lutusp wrote: post #106
adastra22 wrote: post #41

Earlier quoted context omitted.

There are stable solutions. See: Earth’s Moon (or any other planetary moon in the solar system).

> There are stable solutions. See: Earth’s Moon (or any other planetary moon in the solar system). Those are not stable solutions. Remember that Earth's moon only came into existence because of a collision with a protoplanet in the past, and if a large enough body passed close by in the future, we might lose our moon -- all because of the complexity of orbital systems with more than two members. > (or any other plane…

If you are presupposing external perturbations or collisions, it's not an N=3 system... we're talking about the three body problem. A tidally locked system with periodic resonance is permanently stable in the absence of external forces.

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

#110

Post by hermitcrab »

jgchaos wrote: post #97
hermitcrab wrote: post #92

Earlier quoted context omitted.

>'fudge factor' Maybe that is what the 'softening' parameter relates to?

Yes, the softening factor keeps the forces from getting too big when bodies get close together. Better for the visualization but not very accurate to leave it in.

Better than things flying off to infinity or the whole simulation slowing right down.
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