Engineering the Ultimate Solar System
March 1, 2018 8:02 AM Subscribe
How many stable planetary orbits could exist around one star? And how many planets could be packed into the Goldilocks zone (where liquid water can exist)? Let's use physics simulations to find out!
This is pretty neat, but I also suspect that at least part of the motivation was to come up with a solar system in which Firefly would make sense. No matter. I'm digging the ninja moves.
posted by Halloween Jack at 9:03 AM on March 1, 2018 [4 favorites]
posted by Halloween Jack at 9:03 AM on March 1, 2018 [4 favorites]
If it's any consolation, the author doesn't simulate with applets; the simulations are done offline and are summarized with pictures and the occasional video.
posted by a snickering nuthatch at 9:09 AM on March 1, 2018 [1 favorite]
posted by a snickering nuthatch at 9:09 AM on March 1, 2018 [1 favorite]
It's interesting, the ringworld has long been thought to be the ultimate space construction for species looking for legroom, but this (final) concentric construction seems to be both materially easier as well as create more space. I think the overwhelming problem here would be distributing heat to the outer planets, though--light doesn't pass through all your dozens of inner planets, so most of your outer rings would be in perpetual shadow. I guess it depends on if your stellar-building civilization had energy needs any longer.
posted by TypographicalError at 9:18 AM on March 1, 2018 [1 favorite]
posted by TypographicalError at 9:18 AM on March 1, 2018 [1 favorite]
If you had that much traffic wouldn't that impinge on how much energy any one planet could receive? There's going to be increasing amounts of eclipse action going on if you're not in the first ring.
posted by anazgnos at 9:21 AM on March 1, 2018
posted by anazgnos at 9:21 AM on March 1, 2018
most of your outer rings would be in perpetual shadow
I don't think so. The planets are still very small compared to the size of their orbits.
posted by paper chromatographologist at 9:21 AM on March 1, 2018 [1 favorite]
I don't think so. The planets are still very small compared to the size of their orbits.
posted by paper chromatographologist at 9:21 AM on March 1, 2018 [1 favorite]
If you had that much traffic wouldn't that impinge on how much energy any one planet could receive?
Is there a reason why the orbits need to be coplanar? The author is willing to accept coplanar orbits in opposite directions. I haven't seen anything in the links about why being coplanar would be necessary for stability, and orbits that are not in the same plane would have the advantage of not blocking each others' light.
Two dimensional thinking?
posted by justsomebodythatyouusedtoknow at 9:28 AM on March 1, 2018 [2 favorites]
Is there a reason why the orbits need to be coplanar? The author is willing to accept coplanar orbits in opposite directions. I haven't seen anything in the links about why being coplanar would be necessary for stability, and orbits that are not in the same plane would have the advantage of not blocking each others' light.
Two dimensional thinking?
posted by justsomebodythatyouusedtoknow at 9:28 AM on March 1, 2018 [2 favorites]
I think most of the eclipse action for each planet is going to come from its binary partner. Which is not necessarily trivial! Since the planets are tidally locked with their binary partners, only one side of each planet (the side facing away from the binary partner) is going to get real sun.
posted by a snickering nuthatch at 9:29 AM on March 1, 2018
posted by a snickering nuthatch at 9:29 AM on March 1, 2018
Earth has a diameter of about 12,700 km. Its orbital circumference around the Sun is roughly 470,000,000 km. That's a ratio of 0.000027.
Even with 42 planets in an inner ring, climate-changing eclipses are unlikely.
posted by explosion at 9:32 AM on March 1, 2018 [3 favorites]
Even with 42 planets in an inner ring, climate-changing eclipses are unlikely.
posted by explosion at 9:32 AM on March 1, 2018 [3 favorites]
Is there a reason why the orbits need to be coplanar? The author is willing to accept coplanar orbits in opposite directions. I haven't seen anything in the links about why being coplanar would be necessary for stability, and orbits that are not in the same plane would have the advantage of not blocking each others' light.
Two planets that start off orbiting in different planes will still attract each other gravitationally. The net effect of this is that Planet A will pull Planet B towards Planet A's orbital plane, and vice versa. So eventually they end up orbiting in the pretty much the same plane anyhow.
posted by Johnny Assay at 9:46 AM on March 1, 2018 [5 favorites]
Two planets that start off orbiting in different planes will still attract each other gravitationally. The net effect of this is that Planet A will pull Planet B towards Planet A's orbital plane, and vice versa. So eventually they end up orbiting in the pretty much the same plane anyhow.
posted by Johnny Assay at 9:46 AM on March 1, 2018 [5 favorites]
Buried in Part 5 there a link to Super Planet Crash, a super game in which you try to not crash planets.
posted by Kabanos at 10:26 AM on March 1, 2018 [3 favorites]
posted by Kabanos at 10:26 AM on March 1, 2018 [3 favorites]
Actually, I just realized that maybe the binary pairs of planets might orbit each other in a way that allows them not to eclipse one another; they just need to orbit one another in a plane other than that which they orbit their star. If those two planes are perpendicular, then one pole of each planet gets roasted and the other pole freezes, while their equators hang in perpetual evening.
posted by a snickering nuthatch at 10:44 AM on March 1, 2018
posted by a snickering nuthatch at 10:44 AM on March 1, 2018
the ringworld has long been thought to be the ultimate space construction for species looking for legroom
Haha, but ISTR that someone figured out that orbitals are more efficient?
posted by GCU Sweet and Full of Grace at 10:45 AM on March 1, 2018 [2 favorites]
Haha, but ISTR that someone figured out that orbitals are more efficient?
posted by GCU Sweet and Full of Grace at 10:45 AM on March 1, 2018 [2 favorites]
paper chromatographologist: "most of your outer rings would be in perpetual shadow
I don't think so. The planets are still very small compared to the size of their orbits."
Yes, you're right--perpetual shadow is overstating it by quite a lot. But there should be interesting effects nonetheless that reduce the side of the goldilocks zone.
posted by TypographicalError at 10:46 AM on March 1, 2018 [1 favorite]
I don't think so. The planets are still very small compared to the size of their orbits."
Yes, you're right--perpetual shadow is overstating it by quite a lot. But there should be interesting effects nonetheless that reduce the side of the goldilocks zone.
posted by TypographicalError at 10:46 AM on March 1, 2018 [1 favorite]
This would be much safer than the ringworld, which would crash into its Sun in a very short time if its thrusters failed.
Both constructs are detectable from a distance. It’s like putting up a “tasty brains here!” sign to any hostile aliens.
posted by monotreme at 1:06 PM on March 1, 2018 [1 favorite]
Both constructs are detectable from a distance. It’s like putting up a “tasty brains here!” sign to any hostile aliens.
posted by monotreme at 1:06 PM on March 1, 2018 [1 favorite]
I think most of the eclipse action for each planet is going to come from its binary partner. Which is not necessarily trivial! Since the planets are tidally locked with their binary partners, only one side of each planet (the side facing away from the binary partner) is going to get real sun.
Remember that binary planets are still very far away from one another! If you lived on the middle of the side facing the other planet, you'd have a brief "night" when the other planet eclipsed the sun, but then back to day as soon as it passed.
Solar eclipses only last about 7 minutes out of our 24 hour day. Even if it were an hour long (bigger moon/binary planet), we'd still get a lot of "real sun."
I think the bigger question is how fast can a binary system revolve, and what does life look like when the "day" cycle is closer to 24 days than 24 hours.
posted by explosion at 1:58 PM on March 1, 2018 [1 favorite]
Remember that binary planets are still very far away from one another! If you lived on the middle of the side facing the other planet, you'd have a brief "night" when the other planet eclipsed the sun, but then back to day as soon as it passed.
Solar eclipses only last about 7 minutes out of our 24 hour day. Even if it were an hour long (bigger moon/binary planet), we'd still get a lot of "real sun."
I think the bigger question is how fast can a binary system revolve, and what does life look like when the "day" cycle is closer to 24 days than 24 hours.
posted by explosion at 1:58 PM on March 1, 2018 [1 favorite]
Quite interesting, in this context, to think about the long-term stability of Saturn's rings, which is a matter of some debate but it's quite possible that they only formed in the Cretaceous and may not have a very long lifespan in planetary terms. There's a respectable case that the evolution of complex life needs more than just Goldilocks, but a system capable of sustaining long-term stable environmental niches, and that may get rarer the more gravitational masses you have sprinkled around the place.
Once you've evolved to the point where you can move planets around, though, sure. Knock yourselves out.
posted by Devonian at 1:59 PM on March 1, 2018
Once you've evolved to the point where you can move planets around, though, sure. Knock yourselves out.
posted by Devonian at 1:59 PM on March 1, 2018
Both constructs are detectable from a distance. It’s like putting up a “tasty brains here!” sign to any hostile aliens.
I think it's much more a "yes, there's intelligent life here, and no, you don't want to fuck with a civilization that can move planets" sign.
posted by a snickering nuthatch at 2:01 PM on March 1, 2018 [1 favorite]
I think it's much more a "yes, there's intelligent life here, and no, you don't want to fuck with a civilization that can move planets" sign.
posted by a snickering nuthatch at 2:01 PM on March 1, 2018 [1 favorite]
How big would the universe have to be before one of these systems formed by chance?
posted by straight at 10:28 PM on March 1, 2018
posted by straight at 10:28 PM on March 1, 2018
straight: "How big would the universe have to be before one of these systems formed by chance?"
Current theories on solar system formation point to these being impossible to form naturally. Or at least the ultimate pack.
posted by Mitheral at 1:38 PM on March 2, 2018
Current theories on solar system formation point to these being impossible to form naturally. Or at least the ultimate pack.
posted by Mitheral at 1:38 PM on March 2, 2018
TypographicalError: "It's interesting, the ringworld has long been thought to be the ultimate space construction for species looking for legroom"
You can easily go larger than a ringworld. Various varieties of Dyson sphere or an Alderson disk, for example.
posted by Chrysostom at 10:20 PM on March 2, 2018
You can easily go larger than a ringworld. Various varieties of Dyson sphere or an Alderson disk, for example.
posted by Chrysostom at 10:20 PM on March 2, 2018
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I admit I may have a problem that needs some counseling.
posted by RolandOfEld at 8:24 AM on March 1, 2018 [5 favorites]