A clockwork solar system

[PhoenixPhyre]

What would you see if the planets actually moved around the star on brass (appearance, not material) rails? Don’t worry about the practicality, but the appearance. Each satellite is embedded in a geared ring so it rotates on its own axis as it moves.

I’m contemplating using this as the visual motif for my setting’s solar system. It’s all kept in motion by a celestial mechanism and embedded in a crystal sphere set in the infinite dark.

That, or going truly geocentric with no vacuum between planets (and much smaller distances). Basically a fake solar system about 1 million miles across.

[brian 333]

A super orrery with people inside?

Assume a solar system designed around a geocentric model:

Venus and, on rare occasions, Mercury, seem to be moons of the Sun. The orbital rings around Earth would be The Moon, The Sun, (with Mercury and Venus in their orbits,) Mars, (with Phobos and Deimos,) Jupiter, (whose moons are not visible to the naked eye,) and Saturn.

Comets and meteorites, then, would indeed be signs from the gods.

Relative size and distance would be vastly different. Assuming Earth-Luna remain at their real world dimensions, The Sun would be about the same size as Earth. Of course, planetary size could be altered and the whole thing might shift. For example, a nearer Jupiter might be smaller and denser while a more distant Jupiter might be ,larger and less dense, or perhaps even hollow...

[jqavins]

If the solar system is heliocentric, then there'd be no reason to see anything different from the real one, except for seeing the tracks. Until you look closely enough to notice that each planet's axial rotation period (its day) is in some exact rational proportion to it's orbital period (its year). This is because the axial rings (by which I assume you mean gimbals of some sort) are geared to the tracks, and meshed gears always rotate in exact rational ratios.

What about the Moon and the moons of the other planets? Are they also in track's and gimbals? If so, then the planet's gimbal would have to be big enough to enclose all the moons so that the bits don't bump into each other. Which is fine, just keep it in mind.

Relative size and distance would be vastly different. Assuming Earth-Luna remain at their real world dimensions, The Sun would be about the same size as Earth.

I don't see how this follows. What am I missing?

[PhoenixPhyre]

A super orrery with people inside?

Assume a solar system designed around a geocentric model:

Venus and, on rare occasions, Mercury, seem to be moons of the Sun. The orbital rings around Earth would be The Moon, The Sun, (with Mercury and Venus in their orbits,) Mars, (with Phobos and Deimos,) Jupiter, (whose moons are not visible to the naked eye,) and Saturn.

Comets and meteorites, then, would indeed be signs from the gods.

Relative size and distance would be vastly different. Assuming Earth-Luna remain at their real world dimensions, The Sun would be about the same size as Earth. Of course, planetary size could be altered and the whole thing might shift. For example, a nearer Jupiter might be smaller and denser while a more distant Jupiter might be ,larger and less dense, or perhaps even hollow...

I think I was confusing--the geocentric, compressed model was an alternative to the clockwork one. Although they could be blended together. For that option, I'd probably work on conserving apparent angular size.

I'm not actually using the real solar system--there are (right now) 8 planets. The main world (Earth-equivalent) occupies the 3rd orbital slot but is the 4th planet (the 2nd and 3rd are a double planet system). Since the creator of this system was all about powers of 2, the orbital distances are as follows (heliocentric):

Orbital slot: distance (arbitrary units)
1 (Primus) : 1
2 (Secundus and Tertius) : 2
3 (Quartus) : 4

The outer four I haven't actually fleshed out, and may drop entirely. The only important idea is that the main planet is the 4th planet. Because 4 is perfect.

For the squished geocentric model, I was thinking of having only those 4 planets, with the sun being the furthest out thing. And yes, comets/falling stars are usually a sign of something going on with the angels (whose job it is to keep the Outside outside). I'm willing to totally discard Newtonian gravity here, so the sizes of these planets can be completely arbitrary as long as they don't bump into each other and have the right angular size (the innermost one should be about the apparent angular size of Mercury, the twins about the angular size of Venus)

If the solar system is heliocentric, then there'd be no reason to see anything different from the real one, except for seeing the tracks. Until you look closely enough to notice that each planet's axial rotation period (its day) is in some exact rational proportion to it's orbital period (its year). This is because the axial rings (by which I assume you mean gimbals of some sort) are geared to the tracks, and meshed gears always rotate in exact rational ratios.

What about the Moon and the moons of the other planets? Are they also in track's and gimbals? If so, then the planet's gimbal would have to be big enough to enclose all the moons so that the bits don't bump into each other. Which is fine, just keep it in mind.

But what would the tracks look like? How much would be visible? Would they scatter appreciable sunlight during the night-time (leaving glowing tracks across the sky)?

As for the gimbals, I was imagining a gear (teeth facing out) attached to the surface of the planet around the equator, maybe by giant pylons anchored in the crust. And yes, the year is an integer number of days (and the formal seasons are exactly 1/4 of the year each. The creator was a bit order-obsessed...

There are two moons which appear equal in angular size, but both one is bigger/further than the other. Both are smaller/closer than Luna is to Earth. The further one out is about half the size and half the distance, with an orbital period of 32 days. The inner one is about half that size (so 1/4 Luna's size) and closer, with a period of 16 days. Yes, this doesn't fit Kepler's laws, but Newtonian gravity really isn't a thing here, so no big deal. I haven't considered orbital planes, however.

There was a third, much smaller moon (~Phobos), but that was broken out of orbit in the early part of history and brought crashing down (to much destruction).

[jqavins]

But what would the tracks look like? How much would be visible? Would they scatter appreciable sunlight during the night-time (leaving glowing tracks across the sky)?

I don't see any way to answer this. What do you want it to look like? You're the one making it up, you're the one saying Newtonian physics don't matter, you're the one who's already said that the tracks are brass-like in color but not actually made of brass. It's all quite arbitrary, and you can arbitrarily decide on any appearance you'd like.

If you want an answer to "Would they scatter appreciable sunlight during the night-time (leaving glowing tracks across the sky)?" then first you have to tell us their size and reflectivity, at a minimum. Are the tracks hair-fine filiments of unimaginable strength? Then they're not visible. Are they as tall as the planets they support, with a lightly frosted metallic luster? Then they are visibly huge and bright.

Likewise, any other question you'd like answered with what "would" happen will require you to provide the conditions under which the question is to be considered.

[PhoenixPhyre]

I don't see any way to answer this. What do you want it to look like? You're the one making it up, you're the one saying Newtonian physics don't matter, you're the one who's already said that the tracks are brass-like in color but not actually made of brass. It's all quite arbitrary, and you can arbitrarily decide on any appearance you'd like.

If you want an answer to "Would they scatter appreciable sunlight during the night-time (leaving glowing tracks across the sky)?" then first you have to tell us their size and reflectivity, at a minimum. Are the tracks hair-fine filiments of unimaginable strength? Then they're not visible. Are they as tall as the planets they support, with a lightly frosted metallic luster? Then they are visibly huge and bright.

Likewise, any other question you'd like answered with what "would" happen will require you to provide the conditions under which the question is to be considered.

That's mainly it. I'm looking for inspiration here more than anything. I can make the numbers work.

My mental picture is of an something shiny (brass just to fit with the clockwork theme) and non-negligible thickness.

Rough parameters--
Radius of planet (r0) = 4000 miles

Reflectivity: about that of a polished metal, probably in an yellow color.
Width: approximately half of the diameter of the planet (so about r0, 6400 km wide).
Closest approach distance to planet's surface of orbital ring: ~30r0 (120,000 miles)

There would be smaller rings for the two moons:
closer ring (500 miles wide) at about 15 r0
further ring (~1000 miles wide) at about 30 r0

Not sure on how they're supported/attached to the planets' surfaces.

Does that help? None of those numbers are fixed at this point (especially the width). I'd want something noticeable with the naked eye, but not dominating the sky.

[jqavins]

Then you've answered your own question. It's "noticeable with the naked eye, but not dominating the sky," brassy yellow in color, and shiney. I'm afraid I still don't understand what help you're asking for.

[Mechalich]

This idea has been done (not especially well in my opinion, but it's out there).

[brian 333]

Are Secundus and Tertius a twin planet like Earth-Moon? Or do they share an orbit from opposite sides of their sun?

I can see an ocean world/desert world dichotomy between them and if they are close enough, avian creatures might traverse ghe distance between. For example, a birdlike creature which feeds on the ocean world but nests in desert cliffs.

[PhoenixPhyre]

Are Secundus and Tertius a twin planet like Earth-Moon? Or do they share an orbit from opposite sides of their sun?

I can see an ocean world/desert world dichotomy between them and if they are close enough, avian creatures might traverse ghe distance between. For example, a birdlike creature which feeds on the ocean world but nests in desert cliffs.

Orbiting around a common center, very close. I haven't figured out anything more than that for sure, but I'm leaning toward putting them very close together, with some kind of fountain/whirlwind/something connecting them and allowing flying things travel between them.

[jqavins]

If they're that close, their mutual gravitational attraction will make them tear-drop shaped, and net gravity will get interesting on their near sides. Have a look at this, and bear in mind that the author was a physicist who wrote with high plausibility.

[PhoenixPhyre]

If they're that close, their mutual gravitational attraction will make them tear-drop shaped, and net gravity will get interesting on their near sides. Have a look at this, and bear in mind that the author was a physicist who wrote with high plausibility.

Part of my difficulty here is overriding what I know from normal physics, as I'm a physicist by training. It's more "will this look cool and fit the aesthetic" with the physics tuned to make it possible. But yeah, that's the kind of thing I'm thinking of for those planets. I'm not sure how much a role they play in anything other than as set-dressing, though. The main planet has lots of unexplored territory yet.

[jqavins]

Part of my difficulty here is overriding what I know from normal physics, as I'm a physicist by training.

Hmm. The author, Robert L. Forward, was also a physicist, and renowned for the accuracy and/or plausibility of the science in his fiction. I haven't worked the equations for this, and I'm not sure that I could, but I've always assumed that Forward did. The idea is that the distance between the two bodies is beyond the Roche limit (hence the name) but just barely.

[brian 333]

If one body is tidally locked but the other not, only the tidally locked planet will be teardrop shaped. Rotating with reference to the other world will create oblate spheroids. If both bodies are tidally locked a dumbell shape of the twin system will result.

Neither is a stable arrangement. The mutual rotation will be disrupted over time by stellar winds and magnetic fields and by the gravitational interferance of other planets in the system. Either they will be flinging away from one another in slow-mo or collapsing into one another. The sharing of an atmosphere will also cause rotational disruption in the same way a figure skater spins faster and slower by extending or retracting her arms. They might eventually achieve stability once they are far enough apart, assuming both are tidally locked. Otherwise, like Earth's Moon, they will continue to be pushed or pulled by tides until they break free of each other, collapse into each other, or become consumed by the expansion of their dying star.

The time required to merge or separate might be days or billions of years. There are simply too many factors to say this or that always happens. Heck, magnetic fields in certain arrangements could stabilize the system, but naturally occurring magnetic fields are notoriously fickle.

[Morphic tide]

*snip*

I presume the whole "clockwork solar system" thing can cover much of the discrepancies...

[Max_Killjoy]

In a system with planets running on clockwork gearing, I'm not sure I'd count on things like solar wind and tidal sheer being issues. We've officially left Kansas.

[PhoenixPhyre]

In a system with planets running on clockwork gearing, I'm not sure I'd count on things like solar wind and tidal sheer being issues. We've officially left Kansas.

And in this case quite intentionally.

I've kind of decided against this idea, as I couldn't make it really work well in my head.

My current plan is more classical--

* purely circular orbits at integer ratios (the designer of this star system had a thing for powers of 2)
* finite-size, separate, co-moving, interacting elemental planes for each planet (interacting in that the planes of planet N might overlap at some points in the orbit with those for planet N-1 or N+1).
* an outer crystal shell/barrier separating this pocket universe from the Dark Beyond.

[Max_Killjoy]

And in this case quite intentionally.

Based on past conversations, I'd figured it was.

I've kind of decided against this idea, as I couldn't make it really work well in my head.

My current plan is more classical--

* purely circular orbits at integer ratios (the designer of this star system had a thing for powers of 2)
* finite-size, separate, co-moving, interacting elemental planes for each planet (interacting in that the planes of planet N might overlap at some points in the orbit with those for planet N-1 or N+1).
* an outer crystal shell/barrier separating this pocket universe from the Dark Beyond.

The tracks and gears could still be metaphysical... or really there in some way, a sort of "clockwork dark matter" that can't be seen or touched normally, but is part of the underlying structure of reality.

(Physics/Fantasy parallels... a bit like how the "deep origin" of the 4th BCE Greco-Sumerian setting I'm working on parallels the concept of a singularity "blowing up" into a universe.)

[brian 333]

Anaxamenes Crystal Spheres comes to mind. Although in thismodel, the gods were lazy because stars break loose and fall every so often, proving how small stars really are because when these fallen stars are found they tend to be the size of a fist.

[PhoenixPhyre]

The tracks and gears could still be metaphysical... or really there in some way, a sort of "clockwork dark matter" that can't be seen or touched normally, but is part of the underlying structure of reality.

(Physics/Fantasy parallels... a bit like how the "deep origin" of the 4th BCE Greco-Sumerian setting I'm working on parallels the concept of a singularity "blowing up" into a universe.)

Seen from Celestial City (home of the angels) on Astral plane, it might very well look that way because you could see the Great Mechanism that distributes energy (the same stuff of which souls, matter, and all other things are made) around the pocket universe. I will have a short adventure set there real soon, so that might be a good aesthetic.

Of course, in another part of the plane, it may look like veins pumping blood or like rivers across the "sky" or something like that. The Astral plane is shaped by perceptions, after all and is without fixed shape.

Technically, the whole setting is the dream of a fragment of reality, but that doesn't come into play much. It's more deep backstory.

And, as to falling stars, those would be interactions between the intermittently-overlapping elemental planes causing crystallization of anima. Or so I'm thinking right now.