Billy Brown writes:
> The U.S. Navy routinely operates nuclear submarines (with a crew
> of several hundred men) submerged for several months, and it has
> conducted a number of endurance trials in which submarines stayed
> down for much longer periods. During such a deployment the air
> supply is completely cut off from the outside world and recycled
> by mechanical systems. I think this provide adequate proof that
> atmospheric regulation can be handled by non-biological systems.
A few months is not a very long time. Perhaps you would feel just fine committing yourself to being a member of the first group that gets to test such systems in their twelfth month, eighteenth month, etc.
> So, where exactly is the fatal problem supposed to be?
If we knew in advance where all the fatal problems are, technology would not need to be tested. Our difference is that you are impressed with the amount of testing that has been done so far, and I am not. We know how to keep people alive in space for a few months at a time. We know nothing about how to do it longer than that. We know nothing about conventional human reproduction in space. Zip. Nada. Now conventional human reproduction may become obsolete in fifty years, or it may not. I don't think it's a good idea to pin the future of our civilization on the belief that conventional human reproduction will be completely replaced by different processes sooner than we will require access to offplanet material resources.
> I don't follow 'closure' experiments for the very good reason that
> they have absolutely nothing to do with practical life support
Absolutely nothing, eh? Strong words. Using prejudices of this kind to justify a failure to investigate alternative approaches leads to tunnel-vision research, which is generally the least productive approach to unsolved problems. Another unproductive approach to unsolved problems is pretending that they are already solved.
As for "closure experiments" being about Gaia worship, I'm not talking specifically about rich-ecosystem closure experiments, but *any* and *all* closure experiments, including Mir and your submarines. You think technology can be designed and deployed successfully without being tested. I don't. If we are serious about taking advantage of offplanet resources, and we are not in a state of Blind Faith that uploading and other technologies will relieve us of having to study what are the *current* obvious obstacles to this, then we need to study more long-term closures. I don't care if they are full of wombats and woad-painted Wiccans or do all their material transformations in a laboratory full of glassware and filters, they need to be closed, and they need to be closed for years, and we need to study the ways they change over time, including changes beyond the twenty-four month timescale which have *never* been studied for any closed systems other than the planet as a whole and small terraria incapable of supporting a human being.