--- In spacesettlers@yahoogroups.com, Joe Strout wrote:
> the solar system as a whole can support many orders of magnitude more than just the Earth

Maybe not, given that Earth accounts for almost half the free rocky mass in the solar system:
http://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size

"The relative masses of the solid bodies of the Solar System. Earth at 48% and Venus at 39% dominate."

They won't be building planets, they'll be building space habitats.
Which will use many orders of magnitude less material per person.

A Bernal Sphere I think weighs 4 megatons and houses 140,000 people.
Earth, or 28 tons per person, not the whatever tons per person that
planet Earth currently "houses".

--- In spacesettlers@yahoogroups.com, "hitssquad" wrote:

On 1/25/12 11:54 PM, hitssquad wrote:

>> the solar system as a whole can support many orders of magnitude
>> more than just the Earth
>
> Maybe not, given that Earth accounts for almost half the free rocky
> mass in the solar system:
> http://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size

Hah. Fair enough point, I suppose, though I for one would not support
dismantling the Earth. It's special.

Do what you like to Venus, though!

Best,
- Joe

> They won't be building planets, they'll be building space habitats.
> Which will use many orders of magnitude less material per person.

Here's good article explaining why orbital habitats are so much more efficient than planets:

Why We Must Flee the Planet: The Geometry of Earth is All Wrong
http://www.space.com/2554-flee-planet-geometry-earth-wrong.html

Regards,

Mike Combs

From: spacesettlers@yahoogroups.com [mailto:spacesettlers@yahoogroups.com] On Behalf Of William
Sent: Thursday, January 26, 2012 9:49 AM
To: spacesettlers@yahoogroups.com
Subject: [spacesettlers] Earth: Rock City (was Re: Carrying capacity of the solar system)

They won't be building planets, they'll be building space habitats.
Which will use many orders of magnitude less material per person.

A Bernal Sphere I think weighs 4 megatons and houses 140,000 people.
Earth, or 28 tons per person, not the whatever tons per person that
planet Earth currently "houses".

--- In spacesettlers@yahoogroups.com, "hitssquad" wrote:

On 1/26/12 12:26 PM, Combs, Mike wrote:

> Here's good article explaining why orbital habitats are so much more
> efficient than planets:
>
> Why We Must Flee the Planet: The Geometry of Earth is All Wrong
> http://www.space.com/2554-flee-planet-geometry-earth-wrong.html

Thanks for the reference! That's a good article.

It's still one of those "scholarly essays" I was referring to before,
though. For many people, it might be better to let them try their own
hand at spreading out at the solar system (through simulation). Let
them choose to live on Mars and the Jovian moons if they wish... or let
them build space colonies out of the smaller chunks of stuff lying
around. Keep all the numbers as realistic as possible, and see what
works out best for them.

Hmm. Maybe I should do a Kickstarter...

On Jan 26, 2012, at 7:48 AM, William wrote:

> They won't be building planets, they'll be building space habitats.
> Which will use many orders of magnitude less material per person.
>
> A Bernal Sphere I think weighs 4 megatons and houses 140,000 people.
>
The target population was 20,000-30,000 (http://en.wikipedia.org/wiki/Bernal_sphere
)