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This is really speculative- let's say that in the far future we develop really sophisticated technology and are able to move/manipulate planets/moons and asteroids at will. How many Earth's could be made from the raw materials of the solar system? How many Earth's could you get from the Jupiter system alone? 1? 100's? or more?
Banned
Isn't one Earth bad enough!?
Actually, I'm not too willing to try speculating on this one just yet... But I would ask for a bit of clarification....
Are you asking about making Perfect Clones of Earth (such as each and every element in their exact proportions) or reasonably, functionally close facsimiles of Earth?
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Quite a few no doubt - if we have the engineering capabilities.Originally Posted by banquo's_bumble_puppy
However there is not enough room to slot any more earths into the habitable zone.
It may be alot easier terraform Mercury, Venus, Mars and the gas giant moons - especially if we had the capability you require for system wide planetary mining and construction.
Loads of living space in the solar system already.
Banned
I'm not sure I agree with this... According to one model I saw, there's enough room for up to 24 of 'em.
If these 'abilities' cover being able to move planets around, they can just as easily be used to control orbits as well.
Balancing an Earth on the opposite side of the sun in the same orbit -up to 24 Earths total. Like Lug nuts.
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Hmm...if you could transmute hydrogen and helium into heavier elements, then you could theoretically cannibalize the gas giants and make hundreds of Earths. It gets better...the mass of metals (that is, elements heavier than hydrogen and helium) in the Sun alone far exceeds the current mass of the Solar System outside of it.
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not perfect clones....but close ones....shirt sleeve enviroment/or not....maybe each world could be different to suit the tastes of the inhabitants....how about a mostly water world? (melt Europa....provided that there's no pre-existing life)....or an ice world similar to Andoria of Trek mythos....
Order of Kilopi
Your post (and the OP) reminded me that I've always wanted to know how many lug nuts could be manufactured from all the iron ore of an Earth-sized planet?
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It would be quite a feat to pull rocky material out of the gas giants.
Baring that, you have to make do with the other rocky planets and moons as source material. My guess is, you could make only one or two more Earths given the objects we know of. I'm not sure how much extra stuff you could get from the kuiper belt or oort cloud.
For example, consider this - looking at mass alone (I know the problem is slightly more complicated than this)
Mass of Earth = 5.97x10^24
Mass of Mercury + Venus + Mars + every object in the asteroid belt = 5.84x10^24
So there, using all the stuff from the inner solar system, you almost but not quite have an object of the same mass as Earth, and Venus alone gave you 90% of that. Taking all the moons of the outer planets and every comet we know of, I doubt you build a third object of this mass.
And keep in mind, composition is important too. To really have "Earth" you need a large metallic core and lots of silicates and water on the crust. For the long term, a nice big moon wouldn't hurt either. Without taking apart the gas giants (which would be a bigger project than building a planet) I don't think there's enough mass in the solar system to do it.
It would be *so* much easier to build giant rotating habitats a-la Rama than to build a planet.
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I thought there was a careful equilibrium at play in the ecliptic plane and adding another earth size mass would knock the whole shebang into a chaotic state.
But I suppose if we had the power to actually make new earths then we could also do something about orbit stability etc...
Established Member
how's about a Dyson sphere?
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The surface area of a sphere is 4pi*r^2 so if you had a dyson sphere that extended out to the orbit of Earth, the volume of material you'd need would be 2.8123E+17 square kilometers. So if your dyson sphere was only 1 kilometer thick, you'd need a volume of material equal to that many cubic kilometers.
The total volume of the Earth is 1.0832073E+12 km^3. That's only 1/100,000th of the material you need. Of course, if we're making things up then we can say that you build the dyson sphere only one atom thick, in which case, sure, you've got enough material. In reality, the whole thing would have to be made out of something stronger than diamonds. You would certainly need the equivalent of millions of Earth-sized planets to build such a structure.
It's easy to forget how empty space really is. Here's a little experiment that you can do. Take a marble. When I did this, the marble I used was 2cm in diameter. That marble represents Earth. Go to a long straight road or something and stand next to a tree or your car or whatever. That will represent the Sun. Now start walking. You'll have to walk 225 meters, or 737 feet to get to the orbital distance of the Earth. You should really try this. It's awesome to stand there with that little marble in your hand and realize how much empty space there is between us and the Sun.
Try to imagine a sphere with a radius as big as you just walked. That's a pretty freaking big sphere! How many marbles would it take to build something like that?
By the way, the Sun would be about 2 meters in diameter on this scale. And if you really want to completely blow your mind, Betelgeuse is actually larger than our planned dyson sphere - and there are stars even larger than that!
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A quick back of the envelope calculation says you need the mass of earth in carbon nanotubes to make a 1AU radius Dyson Sphere that is just under one-centimetre thick (one third of an inch). How thick does it need to be?
I suspect you need a much smaller star for the Dyson Sphere trick.
Banned
Are you, by chance, related to Bender Bending Rodriguez?
Banned
Emphasis mine.
Isn't that the real problem? Sooner or later we'll meet up with life elsewhere, likely to include bacteria that may solve this world's problems by wiping us out(+/- other life forms here) Think AIDS, SARS, smallpox in the New World, syphilis in Europe, bubonic plague all over the Old World, etc. All admittedly not totally fatal, but almost, to many communities.
Banned
All those ailments you listed evolved right here on Earth.
Why would an alien germ be compatable with our software?
Established Member
I agree, an M star with little flaring would require much less material for a Dyson sphere. I think the Dyson concept could be scaled as small as Io, which produces considerable internal heat, because of being quite close to Jupiter's strong gravity. A sphere completely surrounding Io with a radius of about 2000 kilometers could reflect most of the escaping IR = infrared back at the surface, heating the surface to the desired temperature. It would still be about 100 degrees k outside the sphere, so energy could be extracted quite efficiently. Neil
Established Member
The Io sphere would also be affected by tidal pull, don't forget that.
If you want to harvest the energy of tidal forces, it might actually be better/cheaper/easier to build a lattice of large masses connected by pistons or something. Put that into the right orbit and as it's stretched by the tides, the pistons will be actuated. So in other words, forget about using Io as a middle man and just get the energy directly.
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