I have been toying with an idea now, for several weeks. I have a friend at
the University of Surrey, who recently graduated and wrote his thesis in
plant biology. Together, we have been examining the problems associated
with small-enclosed ecosystems, primarily the build-up of organic toxins
and the instability of the atmosphere. The biosphere-2 experiments found
that the balance of gases within a small ecosystem is unstable. Oxygen
levels can fall to intolerably low levels. In the case of the Russian
BIOS-3 experiment, the plants produced too much oxygen. The atmosphere was
effectively emptied of CO2 and many plants could not photosynthesise. The
atmospheric balance of biosphere's tends to swing between the two extremes.
The human inhabitants of small biosphere's could compensate for
varying atmospheric gas concentrations, if given enough time. If the
atmosphere were found to be depleted in oxygen, more flora could be
grown. If the atmosphere were found to be too rich, a portion of the
flora would be removed.
What is needed most of all, is a mechanism that buffers the effect of
ecosystem changes and allows the crew time, in order to react to the
changing needs of the habitat. A mechanical atmospheric processing plant
is required. If high levels of CO2 are registered within the atmosphere,
the efficiency of photosynthetic organisms that convert it into O2 and
sugar will increase. The huge CO2 swings within a biosphere can easily
swamp this ability. A mechanical atmospheric processing device, equipped
with both a CO2 and O2 gas storage tanks, could be used to buffer the
changes. If too much CO2 is produced, the system will remove it from the
atmosphere and liquefy it. If too much oxygen and not enough CO2 are
present, Oxygen would be removed and stored and CO2 released. In order
to compensate for high levels of either gas, rapidly growing algae could
be farmed within large tanks of water. Algae provide a very effective
mechanism for storing unwanted carbon within a compact space.
ecosystems? What is needed is an airtight environment where various
experiments can be conducted at low cost.
Tony
You might consider looking at a similar problem with PH in fish tanks
and ponds. The answer used there is buffering compounds. I would
favor a large mass chemical solution over a simple mechanical solution
and that over a complex mechanical solution. The lithium perchlorate
"candles" used by the Russians is a simple chemical solution but
it needs more work on safety (fire) issues.
mejames@...
http://www.InnerTransit.net (Email distribution for multilevel organizations)
http://www.InnerTransit.org (Homebase for collaborative engineering)
>I have been toying with an idea now, for several weeks. I have a
friend at
>the University of Surrey, who recently graduated and wrote his thesis
in
>plant biology. Together, we have been examining the problems associated
>with small-enclosed ecosystems, primarily the build-up of organic
toxins
>and the instability of the atmosphere. The biosphere-2 experiments
found
>that the balance of gases within a small ecosystem is unstable. Oxygen
>levels can fall to intolerably low levels. In the case of the Russian
>BIOS-3 experiment, the plants produced too much oxygen. The atmosphere
was
>effectively emptied of CO2 and many plants could not photosynthesise.
The
>atmospheric balance of biosphere's tends to swing between the two
extremes.
> The human inhabitants of small biosphere's could compensate for
> varying atmospheric gas concentrations, if given enough time. If the
> atmosphere were found to be depleted in oxygen, more flora could be
> grown. If the atmosphere were found to be too rich, a portion of the
> flora would be removed.
> What is needed most of all, is a mechanism that buffers the effect
of
> ecosystem changes and allows the crew time, in order to react to the
> changing needs of the habitat. A mechanical atmospheric processing
plant
> is required. If high levels of CO2 are registered within the
atmosphere,
> the efficiency of photosynthetic organisms that convert it into
O2 and
> sugar will increase. The huge CO2 swings within a biosphere can
easily
> swamp this ability. A mechanical atmospheric processing device,
equipped
> with both a CO2 and O2 gas storage tanks, could be used to buffer
the
> changes. If too much CO2 is produced, the system will remove
it from the
> atmosphere and liquefy it. If too much oxygen and not enough CO2 are
> present, Oxygen would be removed and stored and CO2 released.
In order
> to compensate for high levels of either gas, rapidly growing
algae could
> I have been toying with an idea now, for several weeks. I have a friend at
> the University of Surrey, who recently graduated and wrote his thesis in
> plant biology. Together, we have been examining the problems associated
> with small-enclosed ecosystems, primarily the build-up of organic toxins
> and the instability of the atmosphere. The biosphere-2 experiments found
> that the balance of gases within a small ecosystem is unstable.
messed it up rather (mainly way too much carbon, and not enough light).
In fact closed ecospheres are available over the counter. Fish tanks
are another case in point. There seems to be a Gaia like life stabilisation
principle going on in fish tanks. They're not sealed atmospherically, but
most other chemicals go around and around; except you feed the fish, but
then there are usually too many fish.
You throw everything in, and stir, measure and adjust ratios, repeat, repeat,
and then suddenly after a week or two it 'pops' and everything becomes stable you
don't need to adjust anymore; you can leave it.
> Oxygen
> levels can fall to intolerably low levels. In the case of the Russian
> BIOS-3 experiment, the plants produced too much oxygen. The atmosphere was
> effectively emptied of CO2 and many plants could not photosynthesise. The
> atmospheric balance of biosphere's tends to swing between the two extremes.
Yes, it can happen. Ecospheres can unravel occasionally. Possibly they
all do eventually. Often you can control it enough to stop everything dying
and then something will happen- some organism will sort out a fix for the
problem and everything will be ok. Too much light in the Russian experiment
perhaps?
> Has anyone on this list conducted experiments with closed
> ecosystems? What is needed is an airtight environment where various
> experiments can be conducted at low cost.
All you need is an airtight jar. I used to do this as a child. Not rocket
science. Working out what the heck is happening IS rocket science of
course.
> Tony
>
civilization?"
Interesting recent URL: http://www.spaceref.com/news/viewnews.html?id=355
Ian Woollard
ssi_list@...
05/29/01 09:31
PM
Please respond
to ssi_list
> I have been toying with an idea now, for several weeks. I have a friend
at
> the University of Surrey, who recently graduated and wrote his thesis in
> plant biology. Together, we have been examining the problems associated
> with small-enclosed ecosystems, primarily the build-up of organic toxins
> and the instability of the atmosphere. The biosphere-2 experiments found
> that the balance of gases within a small ecosystem is unstable.
That isn't the case. That particular ecosphere was unstable, but they
messed it up rather (mainly way too much carbon, and not enough light).
In fact closed ecospheres are available over the counter. Fish tanks
are another case in point. There seems to be a Gaia like life stabilisation
principle going on in fish tanks. They're not sealed atmospherically, but
most other chemicals go around and around; except you feed the fish, but
then there are usually too many fish.
You throw everything in, and stir, measure and adjust ratios, repeat,
repeat,
and then suddenly after a week or two it 'pops' and everything becomes
stable you
don't need to adjust anymore; you can leave it.
> Oxygen
> levels can fall to intolerably low levels. In the case of the Russian
> BIOS-3 experiment, the plants produced too much oxygen. The atmosphere
was
> effectively emptied of CO2 and many plants could not photosynthesise. The
> atmospheric balance of biosphere's tends to swing between the two
extremes.
Yes, it can happen. Ecospheres can unravel occasionally. Possibly they
all do eventually. Often you can control it enough to stop everything dying
and then something will happen- some organism will sort out a fix for the
problem and everything will be ok. Too much light in the Russian experiment
perhaps?
> Has anyone on this list conducted experiments with closed
> ecosystems? What is needed is an airtight environment where various
> experiments can be conducted at low cost.
All you need is an airtight jar. I used to do this as a child. Not rocket
science. Working out what the heck is happening IS rocket science of
course.
> Tony
>
civilization?"
I think it's marvelous that the chambers are hypobaric. O'Neill assumes atmospheres with twice the oxygen percentage at half the pressure. Savage and Zubrin recommend atmospheres with even lower pressures. But we have no data on how plants grow at lower pressures, and these kind of experiments are what we need to answer these questions.
Mike Combs
Interesting recent URL: http://www.spaceref.com/news/viewnews.html?id=355
In a message dated 5/30/01 9:31:05 AM Eastern Daylight Time, mikecombs@...
writes:
atmospheres with twice the oxygen percentage at half the pressure. Savage
and Zubrin recommend atmospheres with even lower pressures. But we have no
data on how plants grow at lower pressures, and these kind of experiments
are what we need to answer these questions.
Regards,
Mike Combs
>>
Why bother with these partial pressure experiments? If we can get the cost of
space transportation down so we can lift half a bar into orbit, why not wait
a little while longer so we can lift the whole bar? Anyway the idea was to
create an Earthlike environment, a half bar environment with twice as much
oxygen is not Earthlike, no place on Earth has conditions like this.
Tom Kalbfus
Why bother with these partial pressure experiments? If we can get the cost of
space transportation down so we can lift half a bar into orbit, why not wait
a little while longer so we can lift the whole bar? Anyway the idea was to
create an Earthlike environment, a half bar environment with twice as much
oxygen is not Earthlike, no place on Earth has conditions like this. The issue is not lift costs, but load stresses. The number one source of load stress in a large habitat is the air pressure (most people expect it to be the centrifugal force, but it's not). The reduced-pressure atmosphere means less stress loading which means relaxed structural requirements. Zubrin and Savage make far less conservative assumptions on this than O'Neill did. Zubrin proposes 1/3 sea level air pressure. Savage advocates a 1/5 pressure atmosphere of nearly pure O2.
Mike Combs
>
> Why bother with these partial pressure experiments? If we can get the cost of
> space transportation down so we can lift half a bar into orbit, why not wait
> a little while longer so we can lift the whole bar?
the pressure chamber enclosure, which is proportional to the pressure,
and
the difficulties with entry and exit for EVA's (space suited
excursions); a space suit works much better (esp. the gloves) with 1/2
or 1/4 atmospheric pressure, than with a full atmosphere. If the wearer
has to change atmospheric pressure all the time there's a lot wasted
time there in adjusting. The Space Shuttle and ISS have to deal with
this a lot now; ISS is at a full atmosphere, but the Space Shuttle is at
lower pressure when doing EVA's.
(I notice Mike Combs has now responded similarly to the above)
The other reason for going this way is so we don't have to bring it all
up from Earth. At least in near Earth space, oxygen is likely to be
plentiful (plenty on the Moon) but nitrogen much rarer; adjusting the
atmospheric balance makes a lot of sense as long as it doesn't harm
living things or overly increase fire hazards.
Arthur (apsmith@...
I simply must respond to "Anyway the idea was to create an Earthlike
environment ..." I could not disagree more. The idea is to make an
environment where we humans can do our best. The Earth's environment is not
as "good" as it can be. To illustrate, for plants, it is awful. They do
much better in a green house, with less oxygen, more carbon dioxide, etc.
We humans would do better with less gravity, fewer molds, fungus, pollen,
etc., not to mention industrial air pollution. We really don't know enough
about how humans would do in the long term with physically modified
environments, but since we are programmed to age and die here after 70 or 80
years, there is the possibility that we could live much longer under some
other conditions, but I repeat this is uncertain. But, consider how long we
live now that we live in houses with air conditioners as compared to the
people who lived in the same areas without them. In Florida that is about
80 years now versus 36 years 500 years ago. Not a bad improvement, surely
not entirely due to air conditioners, but mostly due to "our modern
environment" which includes lots of things which I assume are known to
you-all.
Sincerely,
Jay S. Huebner at jhuebn@...
Hi All
Hawaii in the 70's-80's. He basically went down to the sea with bottles and
scooped up various bits of algae and microbial life. He then closed the
bottles and set them in a reasonably warm and sunny place and let them get
on with it. Small functional ecosystems soon arose out in many bottles.
I'm pretty sure I read somewhere that many of these systems are still closed
and still functional. I gather that its not hard to get a stable closed
ecosystem if you are prepared to take whatever random result survives.
This state of affairs, of course, does not bode well for human habitable
closed systems and I think this is Tonys point. An orbital ecosystem that
continuously spiraled itself down into grass, rabbits and people would not
be attractive. I expect that getting a stable ecosystem in orbit would be
fairly easy - getting one you want will likely be very hard.
Some interesting links are below
Summary of papers:
http://www.biospherics.org/cfolsome.html
Kevin Kellys Book (Out of Control) Chapters
http://www.well.com/user/kk/OutOfControl/ch6-e.html
http://www.well.com/user/kk/OutOfControl/ch8-d.html
Your own mini closed ecosystem
http://www.eco-sphere.com/care_manual.html
In particular the Kevin Kelly book is well worth a read - the entire text is
online.
Regards
D Evans
>
> I have been toying with an idea now, for several weeks. I have a friend at
> the University of Surrey, who recently graduated and wrote his thesis in
> plant biology. Together, we have been examining the problems associated
> with small-enclosed ecosystems, primarily the build-up of organic toxins
> and the instability of the atmosphere. The biosphere-2 experiments found
> that the balance of gases within a small ecosystem is unstable. Oxygen
> levels can fall to intolerably low levels. In the case of the Russian
> BIOS-3 experiment, the plants produced too much oxygen. The atmosphere was
> effectively emptied of CO2 and many plants could not photosynthesise. The
> atmospheric balance of biosphere's tends to swing between the two
extremes.
> The human inhabitants of small biosphere's could compensate for
> varying atmospheric gas concentrations, if given enough time. If the
> atmosphere were found to be depleted in oxygen, more flora could be
> grown. If the atmosphere were found to be too rich, a portion of the
> flora would be removed.
> What is needed most of all, is a mechanism that buffers the effect of
> ecosystem changes and allows the crew time, in order to react to the
> changing needs of the habitat. A mechanical atmospheric processing
plant
> is required. If high levels of CO2 are registered within the
atmosphere,
> the efficiency of photosynthetic organisms that convert it into O2 and
> sugar will increase. The huge CO2 swings within a biosphere can easily
> swamp this ability. A mechanical atmospheric processing device,
equipped
> with both a CO2 and O2 gas storage tanks, could be used to buffer the
> changes. If too much CO2 is produced, the system will remove it from
the
> atmosphere and liquefy it. If too much oxygen and not enough CO2 are
> present, Oxygen would be removed and stored and CO2 released. In order
> to compensate for high levels of either gas, rapidly growing algae
could
You wrote,
"Why bother with these partial pressure experiments? "
scarce on the Moon. This group often discusses use of Lunar resources.
There is a feeling that cost will be minimized by minimizing the amount of
material shipped up from Earth and maximizing the amount of Lunar material
used. Hence, folk are interested in scenarios that don't require a lot of
nitrogen, because that might involve shipping nitrogen up from Earth.
Ron Menich
ThomasKalbfus
02:27 PM
Please
respond to
ssi_list
In a message dated 5/30/01 9:31:05 AM Eastern Daylight Time,
mikecombs@...
writes:
<< I think it's marvelous that the chambers are hypobaric. O'Neill assumes
atmospheres with twice the oxygen percentage at half the pressure. Savage
and Zubrin recommend atmospheres with even lower pressures. But we have
no
data on how plants grow at lower pressures, and these kind of experiments
are what we need to answer these questions.
Regards,
Mike Combs
>>
Why bother with these partial pressure experiments? If we can get the cost
of
space transportation down so we can lift half a bar into orbit, why not
wait
a little while longer so we can lift the whole bar? Anyway the idea was to
create an Earthlike environment, a half bar environment with twice as much
oxygen is not Earthlike, no place on Earth has conditions like this.
Tom Kalbfus
In a message dated 5/30/01 2:47:50 PM Eastern Daylight Time, apsmith@...
writes:
up from Earth. At least in near Earth space, oxygen is likely to be
plentiful (plenty on the Moon) but nitrogen much rarer; adjusting the
atmospheric balance makes a lot of sense as long as it doesn't harm
living things or overly increase fire hazards.
Arthur (apsmith@...
>>
It might make it more difficult for birds and insects to fly. Also if you
hard boil an egg at 1/2 pressure you might get salmanella. A person might
suffer greater injury from falling since the terminal velocity is higher and
things falling from great heights will cause more damage to the things they
fall on top of.
Tom Kalbfus
In a message dated 5/30/01 2:48:24 PM Eastern Daylight Time, mikecombs@...
writes:
load stress in a large habitat is the air pressure (most people expect it to
be the centrifugal force, but it's not). The reduced-pressure atmosphere
means less stress loading which means relaxed structural requirements.
Zubrin and Savage make far less conservative assumptions on this than
O'Neill did. Zubrin proposes 1/3 sea level air pressure. Savage advocates
a 1/5 pressure atmosphere of nearly pure O2.
Regards,
Mike Combs >>
So you make the walls of the habitat thicker or use stronger material, you
have a whole asteroid to work with, no need to be miserly with materials.
Tom Kalbfus
In a message dated 5/30/01 2:55:51 PM Eastern Daylight Time, jhuebn@...
writes:
environment ..." I could not disagree more. The idea is to make an
environment where we humans can do our best. The Earth's environment is not
as "good" as it can be. To illustrate, for plants, it is awful. They do
much better in a green house, with less oxygen, more carbon dioxide, etc.
We humans would do better with less gravity, fewer molds, fungus, pollen,
etc., not to mention industrial air pollution. We really don't know enough
about how humans would do in the long term with physically modified
environments, but since we are programmed to age and die here after 70 or 80
years, there is the possibility that we could live much longer under some
other conditions, but I repeat this is uncertain. But, consider how long we
live now that we live in houses with air conditioners as compared to the
people who lived in the same areas without them. >>
We evolved to live in Earthlike conditions so naturally our bodies are
optimized for an Earthlike environment. Marshall Savage for instance would
have had humans living in zero-gee conditions at 1/3 bar using electrical
stimulation to keep our muscles in tone. Such conditions make dining and
going to the bathroom an abnormal experience. Its hard to sit down at a table
and have a family meal when all the silverware, plates tableclothes, napkins,
food, soups and drinks go floating off. Sure it might be fun to chase after
the food once and a while, but who wants to do this everytime one sits down
to eat? Also cleaning up after meals is a major hassle. How do you wash and
stack the dishes, the silverware woun't stay in the drawers, and who wants to
eat out of squeeze tubes all the time, it is hard to have good table manners
in an environment such as this.
Tom Kalbfus
In a message dated 5/30/01 6:51:01 PM Eastern Daylight Time, rmenich@...
writes:
"Why bother with these partial pressure experiments? "
Nitrogen is the biggest component of the Earth's atmosphere. Nitrogen is
scarce on the Moon. This group often discusses use of Lunar resources.
There is a feeling that cost will be minimized by minimizing the amount of
material shipped up from Earth and maximizing the amount of Lunar material
used. Hence, folk are interested in scenarios that don't require a lot of
nitrogen, because that might involve shipping nitrogen up from Earth.
Ron Menich
>>
If you can get half a bar from extraterrestrial sources, you can get the full
bar, the cost of sending the necessary mining and processing equipment is the
same, you just have to run it twice as long, the biggest expense is getting
enough of the necessary equipment to build the space colony out of local
material, whether its 1/2 a bar or one full bar of nitrogen, thats still alot
of nitrogen, and the difference between those two amounts is not even an
order of magnitude. I don't think the amount of nitrogen will be the biggest
expense in contructing the colony, it won't be the limiting factor in how
many people will go into space.
Tom Kalbfus
> It might make it more difficult for birds and insects to fly.
> [...] A person might
> suffer greater injury from falling since the terminal velocity is higher and
> things falling from great heights will cause more damage to the things they
> fall on top of.
care of all of these issues for 1/2 atmosphere... I agree though that
boiling is not a very effective method of cooking at low pressure.
Arthur (apsmith@...
>>>Why bother with these partial pressure experiments? If we can get the
cost of
space transportation down so we can lift half a bar into orbit, why not
wait
a little while longer so we can lift the whole bar? Anyway the idea was to
create an Earthlike environment, a half bar environment with twice as much
oxygen is not Earthlike, no place on Earth has conditions like this.
The issue is not lift costs, but load stresses. The number one source of
load stress in a large habitat is the air pressure (most people expect it
to be the centrifugal force, but it's not). The reduced-pressure
atmosphere means less stress loading which means relaxed structural
requirements.
O'Neill did. Zubrin proposes 1/3 sea level air pressure. Savage
advocates a 1/5 pressure atmosphere of nearly pure O2.>>>
High oxygen atmospheres result in increased arterial pressure, which
leads to headaches, nausea and increased probability of stroke. However, is
it not the oxygen partial pressure which is operative in these two cases? A
1 bar atmosphere of pure O2, would be extremely unhealthy. But, 1/5th bar
of O2 gives an oxygen partial pressure identical to that of Earth.
Tony
>>>Also if you hard boil an egg at 1/2 pressure you might get
salmanella.>>>
Tony
For Christmas, I purchased an "Ecosphere" (c.f.,
http://www.eco-sphere.com/) for my wife's stepmother. They can be found
at Nature Company or Discovery Channel stores in shopping malls.
"D Evans"
ssi_list@...
05/30/01 03:23
PM
Please respond
to ssi_list
Hi All
Clair Folsome did some pioneering work on small closed ecosystems out in
Hawaii in the 70's-80's. He basically went down to the sea with bottles and
scooped up various bits of algae and microbial life. He then closed the
bottles and set them in a reasonably warm and sunny place and let them get
on with it. Small functional ecosystems soon arose out in many bottles.
I'm pretty sure I read somewhere that many of these systems are still
closed
and still functional. I gather that its not hard to get a stable closed
ecosystem if you are prepared to take whatever random result survives.
This state of affairs, of course, does not bode well for human habitable
closed systems and I think this is Tonys point. An orbital ecosystem that
continuously spiraled itself down into grass, rabbits and people would not
be attractive. I expect that getting a stable ecosystem in orbit would be
fairly easy - getting one you want will likely be very hard.
Some interesting links are below
Summary of papers:
http://www.biospherics.org/cfolsome.html
Kevin Kellys Book (Out of Control) Chapters
http://www.well.com/user/kk/OutOfControl/ch6-e.html
http://www.well.com/user/kk/OutOfControl/ch8-d.html
Your own mini closed ecosystem
http://www.eco-sphere.com/care_manual.html
In particular the Kevin Kelly book is well worth a read - the entire text
is
online.
Regards
D Evans
>
> I have been toying with an idea now, for several weeks. I have a friend
at
> the University of Surrey, who recently graduated and wrote his thesis in
> plant biology. Together, we have been examining the problems associated
> with small-enclosed ecosystems, primarily the build-up of organic toxins
> and the instability of the atmosphere. The biosphere-2 experiments found
> that the balance of gases within a small ecosystem is unstable. Oxygen
> levels can fall to intolerably low levels. In the case of the Russian
> BIOS-3 experiment, the plants produced too much oxygen. The atmosphere
was
> effectively emptied of CO2 and many plants could not photosynthesise. The
> atmospheric balance of biosphere's tends to swing between the two
extremes.
> The human inhabitants of small biosphere's could compensate for
> varying atmospheric gas concentrations, if given enough time. If the
> atmosphere were found to be depleted in oxygen, more flora could be
> grown. If the atmosphere were found to be too rich, a portion of the
> flora would be removed.
> What is needed most of all, is a mechanism that buffers the effect of
> ecosystem changes and allows the crew time, in order to react to the
> changing needs of the habitat. A mechanical atmospheric processing
plant
> is required. If high levels of CO2 are registered within the
atmosphere,
> the efficiency of photosynthetic organisms that convert it into O2 and
> sugar will increase. The huge CO2 swings within a biosphere can easily
> swamp this ability. A mechanical atmospheric processing device,
equipped
> with both a CO2 and O2 gas storage tanks, could be used to buffer the
> changes. If too much CO2 is produced, the system will remove it from
the
> atmosphere and liquefy it. If too much oxygen and not enough CO2 are
> present, Oxygen would be removed and stored and CO2 released. In order
> to compensate for high levels of either gas, rapidly growing algae
could
If the biosphere-2 team are correct, and it really does require a whole 3
acres to support 8 healthy human beings (1500m2 each), then a colony the
size of island-1 would support only 800-900 people.
Tony
It might make it more difficult for birds and insects to fly. Also if you
hard boil an egg at 1/2 pressure you might get salmanella. A person might
suffer greater injury from falling since the terminal velocity is higher and
things falling from great heights will cause more damage to the things they
fall on top of.
Some additional ones are: lowered conduction of heat away from fires, lowered conduction of heat away from electrical equipment, lowered conduction of sound, and plant transpiration.
But my attitude is that O'Neill's more-conservative assumptions are less likely to get us in trouble than those of Zubrin or Savage.
Regards,
Mike Combs
So you make the walls of the habitat thicker or use stronger material, you
have a whole asteroid to work with, no need to be miserly with materials. O'Neill's original Physics Today article did work out the engineering requirements assuming a full sea-level air pressure, although that was an assumption that O'Neill later called "naive". I don't think it's so much the quantity of building materials involved as it is the engineering requirements (and hence cost).
Mike Combs
In response to, "We evolved to live in Earthlike conditions so naturally
our bodies are optimized for an Earthlike environment." I don't think most
biologists would agree that we are optimized for some particular conditions
on Earth, say Europe of a few thousand years ago, but even if we were, many
of us don't live there any more. We keep moving and out technologies evolve
much faster than we can. And even if we are optimized for earth-normal
conditions in some particular place and life-style, it would be for living
in small groups of hunter-gathers, having children as young as possible and
dying young, not living long industrial lives, going to school, mostly
working with our brains, using computers, etc. as we do now. My point again
is that we did not evolve with flush toilets, soap, air conditioners, glass
windows, etc. We did, however, evolved with the plague, polio, small pox,
the flu, and so on, not to mention mosquitoes, roaches and rodents. I hope
we do not take them all along so it will seem like our natural Earth home.
I think we want a place different from Earth which we hope will be better.
Not that we will get it right before we go and live there, but we should try
to think through as many of the issues as we can, as we are doing now.
And about nitrogen for the space habitat; carbonaceous asteroids contain
lots of nitrogen as do comets. The solar wind should have deposited some
nitrogen in the top of the lunar regolith (I am not sure how much), and the
"water" at the lunar poles is likely a mixture of the ices found in comets,
which are the ices of water, ammonia, and methane, all of which contain
hydrogen, which was what was really detected, and carbon dioxide, which does
not contain hydrogen. Ammonia (NH3) contains about 14/17ths nitrogen by
weight.
Jay S. Huebner at jhuebn@...
If the biosphere-2 team are correct, and it really does require a whole 3
acres to support 8 healthy human beings (1500m2 each), then a colony the
size of island-1 would support only 800-900 people.
In "The High Frontier", O'Neill said that his original estimates regarding productivity/acre had been looked at by experts in the field and they felt we could probably do even better.
Regards,
Mike Combs
>
> If the biosphere-2 team are correct, and it really does require a whole 3
> acres to support 8 healthy human beings (1500m2 each), then a colony the
> size of island-1 would support only 800-900 people.
>
> The biosphere-2 people were trying to re-create a wide variety of diverse
> biomes as seen on Earth. In the agricultural areas of Island One, the only
> concern would be providing good conditions for growing crops, with
> conditions probably being a good deal more monotonous. So we might expect
> greater productivity.
>
on by the maximum number of people the Biosphere could comfortably
support, but as an ideal team size for a group of people entering
"extreme" conditions. While it's true that the team lost a lot of weight
due to not enough food, it seems likely that the biosphere could undergo
considerable tweaking to support more people if required or desired.
--Justin