Plant Nursery In Space?

From: "victoriatangoman"
To:
Sent: Wednesday, August 28, 2002 6:19 PM
Subject: Re: Fw: [spacesettlers] Plant Nursery In Space?

[snikt]
Ok, so the mechanical system does away with the need for recycling.

My intention is to give away with the need to rely *exclusively* on
recycling. No closed system is 100% efficient, so to expect that everything
will be solved by recycling alone is not a realistic assumption.

By the way, even Earth itself is *not* 100% efficient nor 100% stable. We
usually don't notice that because changes in a system this size occur
through geological timescales.

Now we are continuously introducing new inputs into the system.

Since no recycling is 100% efficient, of course we need to continuously
introduce new inputs into the system. Also, the system has to have outputs.

Don't get me wrong. I'm not opposed to a mechanical system. I just
can't see it being less complex, nor less expensive.

Considering that even an staggering complex system like an oil refinery is
probably much less complex than even a single-celled organism, I think that
the complexity issue should be obvious. ;-) Also, while ecosystems tend to
exhibit a chaotic, non-linear behavior, mechanical systems can be made to
behave as linearly as the engineers want. So predictability is definitely an
additional advantage.

As for cost, a biosphere is probably cheaper, since it is kind of
"self-constructing". But what would you buy to light your house: a bulb that
costs one cent but works unpredictably, like a candle in the wind, or a bulb
that costs ten cents but provides a continuous, unchanging, strong light
100% of the time?

A biosphere equalizes the inputs and outputs needed for life to exist.

As I said before, this is a completely unrealistic assumption. It amazes me
that I see this idea over and over again when closed ecosystems are
discussed.

[snikt]
Lucio Coelho