|
|
| View previous topic :: View next topic |
| Author |
Message |
Progress City
Guest
|
 Posted: Thu Jan 03, 2008 7:03 am Post subject: Terraforming Saturn? |
 |
|
Would it be possible to build a nanotube shell around Saturn and
terraform it?
Saturn has approximately 95 times the surface area of Earth, but only
91% of its gravity.
Would a shell several feet thick be strong enough to support an Earth-
like environment and a large population?
[Saturn also has a solid ground (if it exists) of metallic hydrogen buried
under the crushing pressure of a highly toxic atmosphere. Presumeably, one
would want to live outside the atmosphere, thus requiring an inner shell to
stand on and an outer shell to trap the atmosphere, thus inviting second order
questions such as, 'Where might we obtain 45 billlion cubic kilometers of
oxygen?' 'With what source of power might we heat that atmosphere to a liveable
temperature?' and 'How might we stabilize two rotating spheres of diamond which
might weigh on the order of a million metric gigatons so they do not crash into
each other?'
[In short, there would seem to be better ways to live in space. -- Moderator
JSN] |
|
| Back to top |
|
 |
| |
Ads |
Advertising
Sponsor
|
|
Perry E. Metzger
Guest
|
| Posted: Thu Jan 03, 2008 11:27 pm Post subject: Re: [Sci.nanotech] Terraforming Saturn? |
|
|
Progress City <progresscity@gmail.com> writes:
| Quote: |
Would it be possible to build a nanotube shell around Saturn and
terraform it?
Saturn has approximately 95 times the surface area of Earth,
|
According to Wikipedia, its mass is 95 times that of earth. Its
surface area is smaller, about 83 times.
| Quote: |
but only 91% of its gravity.
|
"91% of its gravity" is a very bad way of putting it. What you
probably should say instead is that the acceleration due to gravity
(or perhaps more colloquially but not as accurately, the force due to
gravity) at the top of the atmosphere is .91 of g on earth.
| Quote: |
Would a shell several feet thick be strong enough to support an Earth-
like environment and a large population?
|
Why don't you calculate it?
To start with, figure out roughly what the tangental compressive
forces will be on your shell. You can do a quick calculation by
pretending you have hoop 60,000km in radius being pulled in at all
points by a uniform force. Pick a figure for the radius and density of
the hoop -- try something like 1m and the density of water for
simplicity -- and then figure out the force of compression along the
tangent at on any point.
This is a fairly simple problem -- the only tricky part is that you're
going to have to do one very simple integral over a quarter of the
circle to get the component of the force at each point along one
direction. I won't spoil your fun by setting up the problem for you --
I'm sure you'll enjoy doing it on your own.
| Quote: |
From there, a slightly better calculation over a sphere should be
obvious, but I think you'll quickly decide that you don't need to |
bother with that calculation.
| Quote: |
[In short, there would seem to be better ways to live in space. --
Moderator JSN]
|
Without question.
Perry |
|
| Back to top |
|
|
| |
Ads |
Advertising
Sponsor
|
|
Progress City
Guest
|
| Posted: Sat Jan 05, 2008 10:37 am Post subject: Re: Terraforming Saturn? |
|
|
| Quote: |
'Where might we obtain 45 billlion cubic kilometers of
oxygen?'
|
We make it out of the hydrogen! Stars have the ability to fuse
hydrogen atoms into all the elements that we have around us. Perhaps
we too will be able to do this once we have advanced Nanotechnology.
We could do it today, but it would be far too costly and take too much
time.
[Strictly speaking, nanotechnology at its most sophisticated, Drexlerian vision
is about the intentional positioning of individual atoms. This is a powerful
technique and can achieve many things, but what it cannot do in any obvious or
direct fashion is the intentional positioning of sub-atomic particles, which is
what fusion is. In other words, what you want is a sort of hypothetical
picotechnology-- which no one has ever seriously proposed or even begun to work
out the engineering techniques of. Either that, or you want to use
"conventional" nanotechnology to brute force slam hydrogen atoms together in
quantities we don't even begin to have at our disposal to replicate
"conventional" fusion.
[Nanotechnology is not magic-- Moderator JSN]
| Quote: |
'With what source of power might we heat that atmosphere to a liveable
temperature?'
|
Fusion power should be readily available in the post nanotech era.
There's always the possibility of zero point energy.
Saturn itself might be a good source of power.
http://www.space.com/scienceastronomy/060214_saturn_lightning.html
[I would be fascinated to see a back of the envelope calculation on the volume
of space required to construct a ZPE power facility capable of heating that
volume of oxygen, even under fairly optimistic assumptions about ZPE.
Likewise, while Saturn is itself a source of power, some basic mathematics and
physics might determine whether this is a feasible notion or not. The starting
point would be to determine just how much heat that volume of oxygen in that
shape would radiate into space, and therefore need replacement, every second.
I expect this amount of energy to be vast.
[Nanotechnology is not magic-- Moderator JSN]
| Quote: |
and 'How might we stabilize two rotating spheres of diamond which
might weigh on the order of a million metric gigatons so they do not crash
into
each other?'
|
Why do we need two shells? Isn't Saturn's gravity enough to hold a
sufficient atmosphere?
[You would have to tell me, based on the altitude and whether you want to
provide protection for the vast amount of crud floating in Saturn-space
[There are easier ways-- Moderator JSN] |
|
| Back to top |
|
|
| |
Ads |
Advertising
Sponsor
|
|
Progress City
Guest
|
| Posted: Sat Jan 05, 2008 10:39 am Post subject: Re: Terraforming Saturn? |
|
|
Why couldn't the shell be supported by Saturn's hydrogen atmosphere?
http://en.wikipedia.org/wiki/Cloud_nine_(Tensegrity_sphere)
Build a web of these things that cover the planet. It could be
hundreds of layers deep. Build your shell on top of this.
On Jan 3, 9:27 am, "Perry E. Metzger" <pe...@piermont.com> wrote:
| Quote: |
Progress City <progressc...@gmail.com> writes:
Would it be possible to build a nanotube shell around Saturn and
terraform it?
Saturn has approximately 95 times the surface area of Earth,
According to Wikipedia, its mass is 95 times that of earth. Its
surface area is smaller, about 83 times.
but only 91% of its gravity.
"91% of its gravity" is a very bad way of putting it. What you
probably should say instead is that the acceleration due to gravity
(or perhaps more colloquially but not as accurately, the force due to
gravity) at the top of the atmosphere is .91 of g on earth.
Would a shell several feet thick be strong enough to support an Earth-
like environment and a large population?
Why don't you calculate it?
To start with, figure out roughly what the tangental compressive
forces will be on your shell. You can do a quick calculation by
pretending you have hoop 60,000km in radius being pulled in at all
points by a uniform force. Pick a figure for the radius and density of
the hoop -- try something like 1m and the density of water for
simplicity -- and then figure out the force of compression along the
tangent at on any point.
This is a fairly simple problem -- the only tricky part is that you're
going to have to do one very simple integral over a quarter of the
circle to get the component of the force at each point along one
direction. I won't spoil your fun by setting up the problem for you --
I'm sure you'll enjoy doing it on your own.
From there, a slightly better calculation over a sphere should be
obvious, but I think you'll quickly decide that you don't need to
bother with that calculation.
[In short, there would seem to be better ways to live in space. --
Moderator JSN]
Without question.
Perry |
|
|
| Back to top |
|
|
| |
Ads |
Advertising
Sponsor
|
|
Perry E. Metzger
Guest
|
| Posted: Mon Jan 07, 2008 2:05 am Post subject: Re: [Sci.nanotech] Re: Terraforming Saturn? |
|
|
Progress City <progresscity@gmail.com> writes:
| Quote: |
Why couldn't the shell be supported by Saturn's hydrogen atmosphere?
|
Try the calculation. You need to remember that PV = nRT, and you need
to estimate the mass of your shell.
| Quote: |
http://en.wikipedia.org/wiki/Cloud_nine_(Tensegrity_sphere)
Build a web of these things that cover the planet. It could be
hundreds of layers deep.
|
It doesn't matter if it is one or eighty layers deep, actually. You
can figure out what is supportable per unit area with PV=nRT.
(Technically, that equation only works when you're in the low pressure
domain, but for our purposes we're in the low pressure domain.)
Perry |
|
| Back to top |
|
|
| |
Ads |
Advertising
Sponsor
|
|
Gordon Copestake
Guest
|
| Posted: Fri Jan 25, 2008 11:51 pm Post subject: Re: Terraforming Saturn? |
|
|
On 6 Jan, 20:05, "Perry E. Metzger" <pe...@piermont.com> wrote:
| Quote: |
Progress City <progressc...@gmail.com> writes:
Why couldn't the shell be supported by Saturn's hydrogen atmosphere?
Try the calculation. You need to remember that PV = nRT, and you need
to estimate the mass of your shell.
http://en.wikipedia.org/wiki/Cloud_nine_(Tensegrity_sphere)
Build a web of these things that cover the planet. It could be
hundreds of layers deep.
It doesn't matter if it is one or eighty layers deep, actually. You
can figure out what is supportable per unit area with PV=nRT.
(Technically, that equation only works when you're in the low pressure
domain, but for our purposes we're in the low pressure domain.)
Perry
|
I think once we have the technology to build a strong enough material
to cover the planet we would likely miss out the middle man and jump
to the full dyson sphere. Teraforming saturn seems like a backwards
step as the amount of technology needed by it's very presence negates
the need to teraform saturn. Perhaps someone would do it as a work of
art or "because it was there". |
|
| Back to top |
|
|
| |
Ads |
Advertising
Sponsor
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
