Different type of habitat

Lucio,

>On 9/1/06, Darren > wrote:
>(...)
>> The Time Almanac 2001 gives total area of Earth as 148,429,000Km sq so you
>> have a habitat with about 1.5 times the surface area of the Earth.
>> The same reference gives the total land area of Earth as about 57,308,738Km
>> sq, so your habitat now has about 4 times the land area of the Earth.
>
>I think that there is an error in the Time Almanac, then. The surface
>of an sphere is given by 4*pi*r . r=6,380 Km for Earth. Thus the
>total are of Earth is 512 million square kilometers.
>
>The Wikipedia page on Earth confirms my calculation:
>http://en.wikipedia.org/wiki/Earth . Also, it is interesting to note
>that the land are of Earth is 148 million square kilometers, so
>apparently the Almanac mistakenly considered Earth's land are as the
>total are of the planet.

Mea Culpa, I need to have my glasses checked, all I can plead is old age, 46
is such an advanced age and decrepitude is setting in. , I looked up
the total area of the Earth and the total land area in the same book and
then somehow mixed A with B and didnt check it again. Please excuse me as
Im going to go and pack my bags and get sit down and wait for the move into
the old folks home. Thanks for the correction guys, the power of the list
shows its self again :)

Of course that doesnt change the figures for the population density, pack
the people in like Tokyo and you are looking at populations measured with
trillions but can anybody see people capable of building such a thing
settling for that kind of living condition?

>> With no atmosphere at the axis of rotation you could leave the end-caps at
>> the axis open and ships could fly directly into the habitat (not sure I like
>> that idea).

My problem with having ship fly into the open end-caps is they could do a
9-11 and plough into the ground at high speed. Perhaps the way around it
would to have something like the harbour pilot system, the ship comes up,
slows, a second ship transfers a pilot to the ship and they bring it in to
dock. In fact there is another possibility. Consider this, you have the mega
hab or man made planet (yes, I have to say it is a little odd calling
something this big a habitat, it is as large as a planet, if not as
massive), we have a cylinder that is 5,000 Km wide and 15,000 Km long, the
end-caps are open, say 1,000 Km wide (I do not know if this is enough to
keep the air inside, anybody out there know? I do know that there will be a
very slow leak, we have that here on Earth but that kind of leak aside) and
through this hole is protruding is a thick bar from 500 to 900 Km, like the
axle of a wheel, it goes right through the structure and out the other side,
this would give you a large space between the axle and the rim of the hole,
spokes would hold the rim and the axle in place. Now extend the axle and put
a second wheel on it, rotating in the opposite direction, and then extend
as far as needed or wanted. Each wheel would be like adding an entire new
planet (equal to the Earths surface area ).
Put a few hundred or up to a thousand kilometres between each wheel and you
now have a perfect docking port and manufacturing site. Mag-lev trains would
be perfect for travelling along the axle, in vacuum you could get up to
hypersonic speed (though without air it wouldnt really be hypersonic, would
it?) this type of structure could be built as needed and of course smaller
versions of this cold be done, rather than an Island 3 type habitat a series
of rings/wheels could be a way to build and expand as your population grows,
this has been discussed before.

This hyper-habitat would also make a very good way to populate the stars,
even by the diffusion methods it would soon ( by astronomical standards) put
people in a considerable human empire. Go out to the where the KBOs are
take them apart to build the structures and supply the reserves to maintain
you during a trip between the stars.

>I like it, it makes this artificial planet (lets stop pretending it is
>a "habitat" ;-) very, well, planet-like. Ships could in theory even
>aerobrake in the internal atmosphere! Conversely, there could be a
>nice, uh, "internal space elevator" - basically spikes connecting the
>axis to the ground. Finally, ships could also attach to magrails in
>the outer hull, equalize their speeds to the structure and then enter
>hatches that would give access to the inside - those ships would
>emerge from the "underground", which in fact would be the outside.

Okay, Ill stop calling it a habitat but now we need a new name, it isnt a
planet, so what is it, suggestions anybody? Um, a Hyperhab, a Pellucidar
(check here http://en.wikipedia.org/wiki/Pellucidar and
http://en.wikipedia.org/wiki/Hollow_Earth ) not exactly right but kind of
like it or maybe a Mini-Dyson :-) Well, whatever name we come up with, the
structure would be the answer to many of the objections I hear when you talk
to people about orbital habitats. When I discuss them with people I know,
they come up with a few common objections (other than, But its in
space!):
They would feel closed in because it is inside; theyd get bored with such a
small place & what if I wanted to go on a holiday; the sight of the ground
going up around me would creep me out; and my personal favourite; I wouldnt
be able to do what I like on my time off because on the weekend I like going
caving/rock climbing/water-snow
skiing/bushwalking/car-boat-plane-bike-horse-skidoo racing/marathon running/
cross country rally driving/ any other activity that takes a lot of space,
and I wouldnt have the room to do it on a habitat. Well, plenty of room
here, you could even fly planes, mind you, I think things like passenger
planes would be a non-starter, ultra high speed mag-lev trains would beat
them hands down and you could go up to the centre and from the axle the view
would be just like the view from the shuttle, the whole world under you.

>> With no spin-grav above the atmosphere you would be able to have other
>> habitats, each spinning to give its inhabitants gravity, of course with a
>> few trillion people living on the spinning surface would you need more more
>> habitats inside?
>
>You could have many "floors", concentric rotating cylindrical surfaces.
>

Like the idea of habitats floating in the vacuum near the axis, concentric
floors falls into the WHY category, if you need more space then you just
build a new wheel or two, I can not see free floating habs or multi layer
floors in our mega habitat. Of course that is free floating habitats, the
same is not true of some kind of structure attached to the axle, either a
ring around it that spins or protrudes from it that spins, it could be used
as a kind of high priced housing, imagine a house in orbit that you could
commute to work from, now that would be possible, the ring around the axis
is what I think would be the most likely.

>(...)
>> One other point I would like to mention, when I show people this article,
>> the first thing most say is, building something like that is impossible, the
>> reason why? Its too big, how could people build something that big?
>(...)
>
>I would suppose this would require some sort of geometric
>manufacturing process, like self-replicating robot factories or
>nanotech. I would guess that the comparatively "linear" processes of
>our current industrial economy would take centuries to build something
>that scale - and then we have a financial problem, for no investor
>would put his or her money on something that would give profit only
>centuries in the future.

Maybe, maybe not, I dont know how it could be done but the idea appeals to
me a lot.

Now if I can just find that magic wand, I know I had it here a moment ago
.

Darren