Worldbuilding: torus-earth

Tue, 2014-02-04 17:44

#2

bibliophile20 bibliophile20's picture

ooooh... *steals for

ooooh... *steals for Gatecrashing campaign*

—

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Wed, 2014-02-05 06:01

#3

thezombiekat thezombiekat's picture

so when i launch the sat net

so when i launch the sat net in a can how quickly will they crash, the mechanics of trying to orbit that thing look nontrivial.

Wed, 2014-02-05 10:12

#4

thezombiekat thezombiekat's picture

Ok, a bit more serious

Ok, a bit more serious thought. At the beginning you mention a potential for “bead instability” leading to breakup into a small number of co orbiting bodies. When you talk about moons and tidal forces you don’t come back to this. With tidal forces from a moon causing a bulge large enough to gravitationally effect the orbit of the moon I worry that it will be enough to act on the rest of the planet and precipitate bead instability. If this is correct then a toroid plant cannot have a moon large/close enough to cause even minor tides (which probably precludes interesting ones). One thing I am curious about is how obvious it would be that you are standing on donut or hoop (as a gate crasher). Obviously if you arrive on the pole or hubward areas you can just look and see the weirdness. If your Rimward of the equator. You’re going to measure gravity, the angular speed of stars and take a look at the horizon (which you know could be perturbed by mountains). Is there enough information available to realise you’re not on the usual basically round rock.

Wed, 2014-02-05 11:48

#5

Arenamontanus Arenamontanus's picture

Satnet in a can: I assume the

Satnet in a can: I assume the standard software just assumes a roughly spherical body and is not smart enough to compensate. So a few hours after launch, it has all crashed. Reprogramming it to actually work likely requires a bit of Academics [Physics] - not hard for a transhuman with EP-level software, but you actually need to work for it.

thezombiekat wrote:
Ok, a bit more serious thought. At the beginning you mention a potential for “bead instability” leading to breakup into a small number of co orbiting bodies. When you talk about moons and tidal forces you don’t come back to this. With tidal forces from a moon causing a bulge large enough to gravitationally effect the orbit of the moon I worry that it will be enough to act on the rest of the planet and precipitate bead instability. If this is correct then a toroid plant cannot have a moon large/close enough to cause even minor tides (which probably precludes interesting ones).

Well, it depends on the size of the moon. Luna is causing appreciable tides on Earth, about 55 cm at the equator. This is enough of a bulge to cause the slow displacement of the moon, but it doesn't seem to be correlated to earthquakes of any other geological phenomena (statistical runs are pretty inconclusive). So that kind of tides is pretty unlikely to cause any beading. Especially since rotation will move the bulge around far faster than material can flow towards it. Now, a heavier moon closer to the torus might be another thing. Especially an internal orbit that is resonant with the rotation speed might help pull in a bulge that actually starts attracting more mantle material. But it depends a lot on the internal physics of the planet what it can handle.

Quote:
One thing I am curious about is how obvious it would be that you are standing on donut or hoop (as a gate crasher). Obviously if you arrive on the pole or hubward areas you can just look and see the weirdness. If your Rimward of the equator. You’re going to measure gravity, the angular speed of stars and take a look at the horizon (which you know could be perturbed by mountains). Is there enough information available to realise you’re not on the usual basically round rock.

"Jim, we are close to the equator based on the sun's trajectory. And we know the day is 3 hours long. And that the gravity is 0.3 G. What is the radius of the planet?" "Professor, that is simple. The surface acceleration is GM/R^2-4pi^2R/T=g. M=4pi rho R^3/3. So 4pi(rho G/3 - pi/T^2)R = g, or R=g / 4pi(rho G/3 - pi/T^2). Putting in g=2.94 m/s^2, T=10000 s, and assuming rho to be earth-like 5520 kg/m^3 I get R=2561 kilometres." "What would the oblateness of such a planet be? "The formula is (r_equator - r_pole)/r_equator = omega^2*R^3/2GM=3 pi/2 G rho T^2. 0.12 in this case." "Fine. Wouldn't you say that volcanic rock to the north is a tad further away than 10 km?" "Yes. The laser measurement says 11.49 km." "And what is the horizon distance?" "d=sqrt(h*(2R+h)). For an observer two meter above the ground like me it is 3.2 km. Or, for the polar radius, 3.0 km." "How can you see it?" "Optical distortion? No, then the horizon would be looking bent... OK, maybe I assumed a too high density. If the density is 1000 kg/m^2 I get a planetary radius of -25,500 km." "Do you often get negative distances?" "Ah, of course, the density must be higher... for a osmium core I get 496 km... OK, I can get *any* radius I like by having a density get closer to 1,412 kg/m^3. We need to determine the composition of the planet." "With all due respect, Jim, but this is why I think you artificial intelligences need to get out more." In short, the absurdly short day is hard to reconcile with the gravity, a reasonable density and the horizon distance. It is not super-obvious, but once you do the physics things don't add up.

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Wed, 2014-02-05 12:19

#6

bibliophile20 bibliophile20's picture

Arenamontanus wrote:Satnet in

Arenamontanus wrote:
Satnet in a can: I assume the standard software just assumes a roughly spherical body and is not smart enough to compensate. So a few hours after launch, it has all crashed. Reprogramming it to actually work likely requires a bit of Academics [Physics] - not hard for a transhuman with EP-level software, but you actually need to work for it.
thezombiekat wrote:
Ok, a bit more serious thought. At the beginning you mention a potential for “bead instability” leading to breakup into a small number of co orbiting bodies. When you talk about moons and tidal forces you don’t come back to this. With tidal forces from a moon causing a bulge large enough to gravitationally effect the orbit of the moon I worry that it will be enough to act on the rest of the planet and precipitate bead instability. If this is correct then a toroid plant cannot have a moon large/close enough to cause even minor tides (which probably precludes interesting ones).
Well, it depends on the size of the moon. Luna is causing appreciable tides on Earth, about 55 cm at the equator. This is enough of a bulge to cause the slow displacement of the moon, but it doesn't seem to be correlated to earthquakes of any other geological phenomena (statistical runs are pretty inconclusive). So that kind of tides is pretty unlikely to cause any beading. Especially since rotation will move the bulge around far faster than material can flow towards it. Now, a heavier moon closer to the torus might be another thing. Especially an internal orbit that is resonant with the rotation speed might help pull in a bulge that actually starts attracting more mantle material. But it depends a lot on the internal physics of the planet what it can handle.
Quote:
One thing I am curious about is how obvious it would be that you are standing on donut or hoop (as a gate crasher). Obviously if you arrive on the pole or hubward areas you can just look and see the weirdness. If your Rimward of the equator. You’re going to measure gravity, the angular speed of stars and take a look at the horizon (which you know could be perturbed by mountains). Is there enough information available to realise you’re not on the usual basically round rock.
"Jim, we are close to the equator based on the sun's trajectory. And we know the day is 3 hours long. And that the gravity is 0.3 G. What is the radius of the planet?" "Professor, that is simple. The surface acceleration is GM/R^2-4pi^2R/T=g. M=4pi rho R^3/3. So 4pi(rho G/3 - pi/T^2)R = g, or R=g / 4pi(rho G/3 - pi/T^2). Putting in g=2.94 m/s^2, T=10000 s, and assuming rho to be earth-like 5520 kg/m^3 I get R=2561 kilometres." "What would the oblateness of such a planet be? "The formula is (r_equator - r_pole)/r_equator = omega^2*R^3/2GM=3 pi/2 G rho T^2. 0.12 in this case." "Fine. Wouldn't you say that volcanic rock to the north is a tad further away than 10 km?" "Yes. The laser measurement says 11.49 km." "And what is the horizon distance?" "d=sqrt(h*(2R+h)). For an observer two meter above the ground like me it is 3.2 km. Or, for the polar radius, 3.0 km." "How can you see it?" "Optical distortion? No, then the horizon would be looking bent... OK, maybe I assumed a too high density. If the density is 1000 kg/m^2 I get a planetary radius of -25,500 km." "Do you often get negative distances?" "Ah, of course, the density must be higher... for a osmium core I get 496 km... OK, I can get *any* radius I like by having a density get closer to 1,412 kg/m^3. We need to determine the composition of the planet." "With all due respect, Jim, but this is why I think you artificial intelligences need to get out more." In short, the absurdly short day is hard to reconcile with the gravity, a reasonable density and the horizon distance. It is not super-obvious, but once you do the physics things don't add up.

I have one AGI PC that I can see having that exact conversation with the rest of the party... He has "Modified Behavior: Data Analysis, Enhanced". (Or, as he has it written on his character sheet, "DATADATADATA") Just swap out "Talib" for "Jim"... Now I need to do this, just for the lulz. :D Now, what kind of wind-speeds would you have along the rim-equator, assuming normal or slightly above normal Earth-atmospheric pressures and that pretty potent Coriolis force? It would certainly depend on the local topography, but I have the distinct feeling that we're talking something along the lines of trade winds on steroids. Add in the ITCZ factor that you mentioned in the article, and you could easily get away with hiding the truth about the world's shape behind some pretty impressive storm activity and cloud cover, at least for a little while.

—

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Wed, 2014-02-05 12:47

#7

thezombiekat thezombiekat's picture

the document mentions trade

the document mentions trade winds, doldrums, impressive Coriolis driven storms and tight but impressively powerful tornadoes, all on the rimward side. so what would you like the weather to be doing. this place could be fun

Wed, 2014-02-05 13:43

#8

Killebrew

So, I only understand enough

So, I only understand enough to grasp the basic idea of the physics of the planet. (Who knew that a clinical background didn't come with total understanding of physics eh? Haha) Perhaps someone with more knowledge can answer this for me. With this type of planet, how difficult would it be to set up a series of space elevators and a space station at the central point? And if so, how would you stabilize it in the lagrange point?

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Wed, 2014-02-05 14:43

#9

thezombiekat thezombiekat's picture

Cool idea.

Cool idea. I am seeing 3 or more elevators in different directions to stabilise the stations position. Would be difficult to get everything into position (doubt you can just lay the cable around the hubward equator and then winch it into place) Also not the most useful spot to put it because it can’t fulfil the jumping of point function of a space elevator if you try to move in the plain of the solar system you hit the planet and if you go north or south you still have to fight most of the planets gravity. That said, it would make a great resort and anybody that could build a toroid planet probably isn’t going to say 3 space elevators is too much resources for a hotel

Wed, 2014-02-05 14:45

#10

Chernoborg Chernoborg's picture

Somebody get Magrathea on the

Somebody get Magrathea on the phone,we've got a special order!

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Current Status: Highly Distracted building Gatecrashing systems in Universe Sandbox!

Wed, 2014-02-05 15:23

#11

Killebrew

Hmm, hadn't thought of the

Hmm, hadn't thought of the gravity issue. The resort idea would be amazing. And then I could also see it being made into a fairly secure laboratory for things you wouldn't want spreading. Not as good a hab specifically designed for it in the middle of nowhere, but you have access to a much easier supply route. Perhaps the whole thing, planet and station, are built by the TITANS or even some other entity for some reason? That would make for an interesting gatecrashing plot. Come through the gate into the station, abandoned and perhaps partly non-functional due to internal/external damage and the few systems still working indicate they were monitoring something on the planet.

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Wed, 2014-02-05 16:52

#12

Arenamontanus Arenamontanus's picture

Windspeeds: this is something

Windspeeds: this is something I have not yet managed to get good formulas for. Coriolis forces act to turn winds into circles, but does not change the overall speed. The real driver is temperature differences. The fast days mean that you don't get any effects from daily heating (like seawinds driven by daily land-ocean temperature differences), but the big differences in insolation across seasons would give plenty of power to wind. My suspicion is that the winds would be not just stronger, but also shift more over the seasons. So the visitors might be lucky/unlucky and find the environment in a calm season, and then get a nasty surprise when something like a monsoon on steroids arrives on top of a storm season.

Killebrew wrote:
So, I only understand enough to grasp the basic idea of the physics of the planet. (Who knew that a clinical background didn't come with total understanding of physics eh? Haha) Perhaps someone with more knowledge can answer this for me. With this type of planet, how difficult would it be to set up a series of space elevators and a space station at the central point? And if so, how would you stabilize it in the lagrange point?

Central space elevators anchored to each other across the hole might work: at the surface ends they are subject to a downwards pull that could keep tension in the cable, despite it being weightless at the centre. One nice thing is that the overall distance and force is smaller than on Earth. An outside space elevator is even better: geosynchronous orbit is really low (2,000 km on Donut rather than 35,000 km), so you could make it fairly easily. Again, lower gravity means less intense forces on the cable. And the fast rotation would mean you could use the end with the counterweight mass a really effective launcher of space cargo.

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Wed, 2014-02-05 20:49

#13

Chernoborg Chernoborg's picture

Internally, this is going to

Internally, this is going to be complicated. On one hand the high rotational velocity will translate to a powerful magnetic field to deflect solar wind. At the same time, the increased surface to mass ratio would cause the planet to lose heat faster than Earth. This leads to to a thicker crust and eventually a weaker field with less volcanism to replenish the atmosphere lost to the solar wind. Plate tectonics must be pretty terrifying too with continents having to wrap around different curves as they move. Perhaps this would lead to more subcontinental landmasses . This could interfere with the formation of a Pangaea style supercontinent and keep the torus in balance! At least until the crust froze from heat loss.

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Wed, 2014-02-05 21:47

#14

thezombiekat thezombiekat's picture

If this is an artificially

If this is an artificially constructed planet is there any compelling reason for it to have a liquid core. The temperature issue can be solved by moving a little towards the star. You arrange the oceans deliberately provide maximum heat flow between summer and winter sides mitigating temperature extremes. It means you don’t get plate tectonics messing up your carefully designed oceans. And the increased rigidity reduces the risk of bead instability.

Thu, 2014-02-06 06:48

#15

Arenamontanus Arenamontanus's picture

Chernoborg wrote:Internally,

Chernoborg wrote:
Internally, this is going to be complicated. On one hand the high rotational velocity will translate to a powerful magnetic field to deflect solar wind. At the same time, the increased surface to mass ratio would cause the planet to lose heat faster than Earth. This leads to to a thicker crust and eventually a weaker field with less volcanism to replenish the atmosphere lost to the solar wind.

I have not run the heat diffusion equation for this case, but I suspect the effect is not super-large: torus worlds cool off faster, but it is still in the range of billions of years. Note that if there is some tidal flexing then the rotation will heat up things. In fact, I suspect this is going to dominate over radioactive decay for heating. If there is too much, the world might actually melt.

Quote:
Plate tectonics must be pretty terrifying too with continents having to wrap around different curves as they move. Perhaps this would lead to more subcontinental landmasses . This could interfere with the formation of a Pangaea style supercontinent and keep the torus in balance! At least until the crust froze from heat loss.

The different curvature is not a problem: the crust is essentially a liquid on this scale. It is the area changes forced by rimward and hubward movement that will really fold things. I think you are right about the subcontinental shapes. A supercontinent cycle on a torus? It is not clear it would be an attractor like on Earth. That would be really interesting to model!

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Thu, 2014-02-06 13:25

#16

bibliophile20 bibliophile20's picture

There would be serious

There would be serious subduction zones, as well as highly crumpled terrain, around the hubward equator. You'd end up with serious amounts of continental cratons accumulating there, due to their resistance to subduction, as well as fairly serious mountainous terrain, especially due to the lower gravity. Hmm... Placing the divergent plate boundaries and upwelling zones is more difficult, as they're governed by internal convection currents within the core and mantle. Due to the spin acting as a centrifuge, I'd expect that you'd see a greater number of hotspots and divergent plate boundaries towards the hubward zones as a general rule. Not that the rim wouldn't have any, and they'd both have substantially more hot spots than the polar regions. Hmm... At the same time, the spin would encourage material to migrate towards either equator and not towards the polar regions... Thinking about it, I'd think that the divergent plate zones would tend towards the equators, and the subduction zones would be towards the polar regions, and you'd find your biggest continents aggregating there from craton accumulation, as a general rule of thumb. Now, the rifting you would get from plates formed at the hubward equator having to stretch out as they move rimward would be interesting. Lots of volcanic arcs, lots of rift valleys, big volcanic cones from the lower gravity. Probably island chains that put the Caribbean and Indonesia to shame. After even further thought, in direct contradiction to my first paragraph, I don't think that you'd see subduction zones too close to the hubward equator. It would happen, but it would be atypical and would shift over time. The lower gravity of the equators makes upwelling from below easier, and the higher gravity of the poles makes subduction easier. Now, this is partially counteracted by the egg-shaped cross-sections of the toruses, with a greater distance between the core and the crust at the equators and shorter distances between the core and crust at the poles, but convection currents don't care about distance so much as they do about path of least resistance, and lower gravity is path of least resistance. And, again, this is all on geological time scales; there's nothing stopping a spreading divergent zone from showing up and rifting a continent on the poles, or a continental plate to start subducting under the equators, but, over the lifespan of the planet, that's where I think they'd be more statistically likely to appear. (yay, putting those geo-sciences classes to work!)

—

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Thu, 2014-02-06 22:56

#17

Chernoborg Chernoborg's picture

Curiously,my geological

Curiously,my geological speculation came from thinking about the auroras on this world. Before reviewing the article I had thought it would be fun to fly a morph across the gap ( sadly not possible) and how the auroras could light up the shadowed parts of the interior. A quick check on toroidal magnetic fields has me now thinking that there may be -some- lights along the interior surface but more importantly, that a significant radiation belt may occupy that space as well! The same mechanism that funnels charged particles from the solar wind into the earths atmosphere to produce auroras would exist here, but with no planet to run into they could just bob around for a while before escaping. Not a big deal I admit, but something to keep in mind. All of this has been assuming we're sticking to as earthlike a model as possible. Makes sense since that's what we're most familiar with. Suppose we go with a more Titan-like model of planet. A glacial terrestrial ( I don't like ice dwarf as a descriptor ,I'm not silicate biased) could have all the same conditions applied with similar results. Heck, Haumea is almost there already!

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Fri, 2014-02-07 06:19

#18

thezombiekat thezombiekat's picture

Chernoborg wrote: interior

Chernoborg wrote:
interior surface but more importantly, that a significant radiation belt may occupy that space as well! The same mechanism that funnels charged particles from the solar wind into the earths atmosphere to produce auroras would exist here, but with no planet to run into they could just bob around for a while before escaping. Not a big deal I admit, but something to keep in mind.

:( but my hotel :(

Fri, 2014-02-07 08:35

#19

nick012000 nick012000's picture

Chernoborg wrote:Curiously,my

Chernoborg wrote:
Curiously,my geological speculation came from thinking about the auroras on this world. Before reviewing the article I had thought it would be fun to fly a morph across the gap ( sadly not possible) and how the auroras could light up the shadowed parts of the interior. A quick check on toroidal magnetic fields has me now thinking that there may be -some- lights along the interior surface but more importantly, that a significant radiation belt may occupy that space as well! The same mechanism that funnels charged particles from the solar wind into the earths atmosphere to produce auroras would exist here, but with no planet to run into they could just bob around for a while before escaping. Not a big deal I admit, but something to keep in mind.

But what if there's a moon occupying part of the space in the center of the torus? Obviously, the surface would likely be uninhabitable, given the high amounts of radiation that it would be exposed to, but would it produce auroras instead?

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+1 r-Rep , +1 @-rep

Fri, 2014-02-07 09:10

#20

Arenamontanus Arenamontanus's picture

nick012000 wrote:But what if

nick012000 wrote:
But what if there's a moon occupying part of the space in the center of the torus? Obviously, the surface would likely be uninhabitable, given the high amounts of radiation that it would be exposed to, but would it produce auroras instead?

Depends on whether it has enough of an atmosphere. Plausible moons have to be pretty small, or tidal forces will cause them to crash. But imagine something like a captured comet outgassing a bit: that would likely produce amazing auroras.

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Fri, 2014-02-07 17:50

#21

Chernoborg Chernoborg's picture

Oh dear! Ummm...I invoke

Oh dear! Ummm...I invoke "Space Whales are Cool" get-out-of-science free card! everyone knows hugs from space whales protect you from radiation *SMOKE BOMB!!*

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Current Status: Highly Distracted building Gatecrashing systems in Universe Sandbox!

Fri, 2014-02-07 21:10

#22

Arenamontanus Arenamontanus's picture

Chernoborg wrote:*SMOKE BOMB!

Chernoborg wrote:
*SMOKE BOMB!!*

"Look at the auroras in that smoke cloud!" "Hmm... must be ionized gas." "Do you think we could detect where he went using the ion trail?" "Nah. Let's look at the space whales instead."

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Fri, 2014-02-07 22:06

#23

Chernoborg Chernoborg's picture

Having your hotel and auroras too

Now THERE'S an idea! Build the space elevators and in the center place a cometary nucleus. Then turn the comet into a beehive habitat like the ice hotels that get built in the arctic countries. Throw in some space whales surfing through the auroras of the sublimating comet and you'll have the oligarchs and gerontocrats beating a path to your gate address!

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Current Status: Highly Distracted building Gatecrashing systems in Universe Sandbox!

Sat, 2014-02-08 18:33

#24

ORCACommander ORCACommander's picture

You'll have to replace the

You'll have to replace the comet every now and then though :P

Sun, 2014-02-09 00:34

#25

bibliophile20 bibliophile20's picture

So, I'm going to give this

So, I'm going to give this (specifically Hoop) to my PCs tomorrow; I've stranded them deep in the Gate network at the moment (one of the asyncs kinda redirected the Gate link to a TITAN experiment... but it's okay, she found where her mother is. ^_^ ), and this'll give them a nice place to stage out of, looking for a way home, especially if I place multiple gates on it (I'm thinking six, placed in such a way that indicate that they originally were placed at 120 degrees apart on the inner and outer equators... once you compensate for ~900 million years of continental drift). So I'll give a full report on the reactions. *evil grin* But, first, aside from getting odd errors such as negative distances when trying to reconcile the day length, density, gravity and horizon distance, what other fun and odd-ball physics anomalies and nonsensical math results can I throw at them? (Assuming that I start them near the rimward equator, to maximize the surprise).

—

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Sun, 2014-02-09 23:40

#26

bibliophile20 bibliophile20's picture

...My players are usually

...My players are usually mature. Not tonight! So, things went fine at first. Connected to the gate; PCs were pleased to find a place to use as base camp and refugee settlement from the TITAN experiment, but anomalies immediately began to accumulate. First, there was the density anomaly. Talib noticed that the rotational speed, measured horizon distance and gravity could not be made to function for a spherical world. The immediate assumption was the the world was hollow and filled with a gas or something. That got disregarded quickly as impossible. Then, once they noticed that the north-south and east-west horizons were of different distances, they assumed that they were on the rim of a highly oblate but still topologically spherical planet. So they reprogrammed their SatNet In A Can with that assumption and launched it. They lost about a third of the satnet to the weird geometry, but managed to have enough survive to take up geosync and the vase-orbits through the hole (long term). The immediate reaction was "that's cool!" when I described the far rim of the torus coming into view out beyond the close arc. So they began launching more satnets and now have full coverage of the entire torus. In their analysis of the data, they found the other five gates, and are now planning on establishing a colony here, using the population from the TITAN experiment that I mentioned, while they try and dial an address home. The maturity, however, failed when it came time to name the planet... Donut, was of course, immediately suggested, but eventually shifted in favor of Bagel (the local animal and plant life are already been theme named around pastries and bagel toppings). The immature members of the group, however, made motion to call it after various anatomical features that incorporate rings of muscle. Sphincter is the most technical and mature of any of the suggestions that resulted. I facepalmed repeatedly... *sigh* Fortunately, I have veto power in the form of having 15 allied NPCs that are working alongside them and can also express their views. However, the names Halo and Hub are fighting a losing, dare I say it, rearguard action against the forces of scatological humor. :p I've made the ring 500-600 million years old, based on continental drift patterns (assuming that they were at 120 degrees around the rim and hub equators, offset by 60 degrees between the two sets), which was an excellent roll from one PC (Talib, the DATADATADATA AGI; he has officially declared that he has the voice of Johnny 5, and repeatedly calls for "More Input!") Further exploration will continue next session.

—

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Mon, 2014-02-10 08:06

#27

ORCACommander ORCACommander's picture

even with the accelerated

even with the accelerated cooling 500-600 years old seems rather young for solid continents granted i am looking at earth's time scale on wikipedia atm this would put the planet around the later bombardment phase <- nice little thing for some excitement maybe? but things should be still relatively inhospitable. Oddly enough i have no problems with complex life being on this planet this early. with 6 gates non intelligent life could of easily hitchhiked or purposefully brought through by other explorers

Mon, 2014-02-10 09:31

#28

bibliophile20 bibliophile20's picture

ORCACommander wrote:even with

ORCACommander wrote:
even with the accelerated cooling 500-600 years old seems rather young for solid continents granted i am looking at earth's time scale on wikipedia atm this would put the planet around the later bombardment phase <- nice little thing for some excitement maybe? but things should be still relatively inhospitable. Oddly enough i have no problems with complex life being on this planet this early. with 6 gates non intelligent life could of easily hitchhiked or purposefully brought through by other explorers

500-600 million years old. Half a billion years. Minimum. You were off by six orders of magnitude :) It predates the Cambrian Explosion. And, yeah, it's an artificial object that had a seeded biosphere that has since undergone half a billion years of evolution.

—

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Mon, 2014-02-10 22:06

#29

ORCACommander ORCACommander's picture

easy there i tend to lop off

easy there i tend to lop off things like millions and billions when i am talking in scale with someone. a bad habit i have picked up in eve online i am afraid.

Mon, 2014-02-10 22:16

#30

bibliophile20 bibliophile20's picture

Sorry if my tone was seen as

Sorry if my tone was seen as aggressive. My apologies, but you were making projections and statements on faulty assumptions, so I wanted to do a reset on those before the errors propagated. (also, I tutor science and math, and, speaking as an educator: *wince* That's a bad habit, yeah. Could be worse: at least you have a legit excuse, unlike Young Earth Creationists. ;-p )

—

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Mon, 2014-02-10 23:21

#31

ORCACommander ORCACommander's picture

Oh indeed i don't mind people

Oh indeed i don't mind people pointing out when in error but in your haste to correct me you came off a bit as rubbing my nose in it which i do not take kindly to. But lets move on shall we :) Artificial construction does indeed invalidate my concerns over the feasibility. shame though i like the idea of the pc's running around like chicken little :P ya when talking to others about the market prices or negotiating contracts once we establish whether something is expressed in billions or millions of isk we tend to truncate down to 3 figure numbers for expediency's sake unless we need to graduate in to a higher or lower scale and the when doing final negotiations clarifying the final price of something. I can see how it would annoy outsiders :) Here may be a more general artificial world question but might have some impact on your game: when building a planet/planetoid how would one distribute elemental deposits. the torus/hub world obviously requires balanced mass distribution but that still leaves a lot of leeway. Would precious metals be laid out in patterns for aesthetic or practical reasons. would iron be laid out in bands or perhaps belted like a car tire. would deposits of heavy radioactives be placed at regularly intervals or blended over the entire area. and then there is the more chaotically engineered of lets try and get it as natural as possible and only really respect the mass distribution and getting a dent number of isotypes to keep things warm for a while.

Mon, 2014-02-10 23:58

#32

bibliophile20 bibliophile20's picture

Depends on what purpose you

Depends on what purpose you're laying those formations down in and what the planet/oid is being designed for. Really, it comes down to that. In this case, I'm betting that you'd lay things out so that the torus would be as stable as possible, for as long as possible, and habitable as possible for as long as possible (which, unless you want to bring in tech to take up the slack, means a carbon cycle and an active core/ring). Also, again, apologies on the tone.

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"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin

Tue, 2014-03-11 12:28

#33

Arenamontanus Arenamontanus's picture

Planet design is a mix of

Planet design is a mix of engineering constraints and aesthetics. You can put deposits in any pattern you like, but then gravity and mantle motion will change it. Over a few centuries this does not matter, but over a few hundred million years they will get naturally mixed up. Note that unless your deposits are *huge* they will not affect the stability much. The difference between iron ore (5.9 g/cm^3), igneous rock (2.79 g/cm^3) and anthracite (1.3 g/cm^3) is not big on a planetary scale, and hydrostatic equilibrium will simply move them to a level where they are stable. On Earth the mantle has density 3.3 to 5.7, and the core ramps up from 9.9 to 13 or so. So unless you start putting huge chunks of osmium in some places (they would tend to sink, of course) I doubt you can destabilize the planet by just adding ores. I realized that there will be some fun geophysics because of the different thermal gradients: http://www.aleph.se/andart/archives/2014/02/more_donuts_with_warm_fillin... Basically, continental plates near the equators will be thicker than at the poles, so if they move north or south their undersides will tend to melt. Probably that produces spots of volcanism and other fun stuff. Conversely, north and south pole plates will be thin, so when they migrate they will likely fold more. If the planet is young, there will not be that much sedimentary deposits. So there might be little coal, rock salt and sandstone compared to Earth (still, a hundred million years is nothing to sneeze at - the sandstone making up Great Britain is just 60% of that age). So the designers may want to add extra layers. Complete with fake fossils, including occasional Precambrian rabbits or teapots as Easter eggs.

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