There are two ways to look at a terraforming discussion
(1) you believe nanotech is possible.
(2) you don't believe nanotech is possible.
I will leave aside the discussion of "when" you think it is possible, because unless you fall into the category of "it is possible, but only in the far & distant future", the benefits that you individually and we as a society derive from it make it *senseless* to focus your energy, attention and support on *anything* other that getting nanotech here as soon and as safely as possible.
If you believe nanotechnology *is* possible and in the not too distant future (say 20-30 years), then you should frame the terraforming discussion from the perspective of what can I do with a Mars Base and/or terraforming now vs. what can I do with a Mars Base/terraforming after nanotechnology.
I will only deal with the "what can I do with a Mars Base/terraforming" *after* nanotechnology part, because the amount of money that would have to be spent on the development of the rockets, equipment, habitats, etc. (probably > $10s of billions) that even a simple Mars Base would require would be better invested in nanotechnology development (that I personally could derive some benefit from).
In summary, what you can do with nanotechnology is disassemble Mars in ~180 days. Eugene is the only person who has raised any objections to my planetary dismantlement methods, and so far I feel those objections can be dealt with.
In fact if you first disassemble Mercury (~2 weeks) or the asteroids (even faster but requires more nanoseeds) then your disassembly time for Mars drops to 12 hours (because you have the entire solar energy output to use).
The concept of *terraforming* Mars after nanotechnology develops is completely *stupid*. It is an idea locked in a framework of a pre-(nanotech/upload) mindset. If you can dismantle planets but can't upload, then you construct O'Neill-type space colonies that let us all be libertarians & kings or queens of each of the realm we oversee. If you can dismantle planets and can upload then we construct supercomputers in space and evolve into a superintelligence.
Dyson and many others have pointed out the pointlessness and expense of having all of your material stuck at the bottom of gravity wells. Given that we will have the genome next year, if NASA does a single reasonably intelligent thing on the pile of pre-nanotech metal they are assembling, it will be to determine concretely what genes are turned on in cells in response to gravity. It should then develop ways of turning them on permanently.
If you have nanotech (even good biotech), it is likely that when we send humans into space they will be enhanced so space is a less inhospitable environment. I agree however, with a comment Eugene made in another thread that after you have nanotech, retaining human bodies makes questionable sense.
Simple, end of discussion.
For anyone to argue Mars Base (or worse terraforming) over nanotech, implies they *strongly* believe nanotechnology is impossible or would never arrive in the time frame that the development of a Mars Base (or worse plans and methods of terraforming) could be developed. I have to believe that the only reason they say this is because they can do the calculations on how to get to Mars and we have built, in the past, reasonable prototypes of the machines necessary to do it. I would counter that argument with the fact that we have equivalent proof that self-assembling, replicating molecular nanomachines can exist. They are called bacteria. The difference between the two areas is that one area the technology is "mature", being ~70 years old and in the other it is no more than 20. But we are advancing up the biotech/nanotech/computer "automoton" curves much faster because they involve smaller and smaller scales, while rocketry & terraforming involve larger & larger scales. Since moving around atoms requires much less energy than moving around humans, the technology development should be cheaper and faster (given equal levels of support).
Now, addressing some points made by other authors --
> From: Gregory Hather <firstname.lastname@example.org>
> Why mars won't be teraformed for a long time...
> 1. The atmasphere is to thin. If we tried to add more, it would just
> float off because > mars's gravity is too weak.
> (surface gravety = .4*earth surface gravity)
Irrelevant, put the atmosphere in enclosed O'Neill colonies. You don't want the gravity anyway because it is an impediment to travel.
> 2. It would be cheaper to "teraform" the Aulstralian desert or build
> taller buildings.
True, if all we wanted to do was have more space for people.
> 3. Space flight takes too long. Asuming you acellarate at 1 g,
> it would take at least 6 months to reach mars.
Eric documents in his JBIS article (JBIS 45:401-405 (1992)) that using nanotechnology based solar-electric propulsion, 1 AU trips can be accomplished in 17 days. So if you have nanotechnology getting to Mars fast isn't a problem. This method uses 0.8 m/s^2 accelerations which is much lower than the constant 1-g accelerations that provide the ~2 day trip times that others have discussed. Solar-electric (ion) drives (of a primitive design) exist today and are in-use in space.
> 4. There is no infastructure, and no one to live with.
No, but since you can dismantle the planet in ~12 hours you certainly could build it fairly fast. :-)
> 5. Everyone benifits from teraforming, no matter who pays.
Everyone benefits *more* from having all of the sun's power output available to do matter manipulation or for computer power (unless someone manages to get a monopoly on the power collection).
> 6. No one on earth will allow the transfer of oxygen.
There is more than enough oxygen in the outer planets in the form of CO2. If you have all of the solar output available you can get all of the material in Uranus out of its gravity well in 3.3 years. Giving it a delta-V to get it to Mars would take a bit longer, but there again you don't need all of the oxygen.
> 7. A teraformed planet may require matenance.
Thats why you build the intelligence into the machines. Last time I checked a majority of the life on the planet didn't need a lot of maintenance (most of it is bacteria). Molecular nanomachines do just fine if you stay out of their way.
> 8. It is too big of a project for any corporation or nation to pay for it.
If the growth of nanotechnology-based "wealth" (capital) parallels the mass-doubling time for nanoassemblers (~1 hour doubling time), then I personally have the equivalent of the World's GDP at my disposal after 9 days. I'll be happy to pay to dismantle Mars but I'll be damned if I'm going to pay to terraform it! [:-;]
Now, onto some of the other comments...
> Michael Wiik <email@example.com> wrote:
> I had an idea years ago on how we could save money by terraforming two
> planets at once. Venus has too much atmosphere, Mars too little, can we
> transfer some?
> ... discussion of moving stuff via solar sails ...
> Would this work?
With nanotech, you dismantle the planets entirely, turn them into self-propelled autonomous solar-sails and let them sail to whereever you want them. You have to partition your power between planetary disassembly and mass relocation but it is probably quite fast (months to years).
Of course after you spent the energy getting the mass out of a gravity well, it seems really silly to put it back into one!
> Tracy Newby <firstname.lastname@example.org> wrote:
> In a magazine article (the title escapes my memory at the moment)
> terraforming Mars is discussed in some technical detail and part of the
> scenario was using comets to increase the water mass. Then factories which
> produce large ammounts of CO2 as a by product woudl be set up with the
> workers (humans) living in bio-domes or underground. Large solar mirrors in
> orbit and on the ground would help raise the temperature.
The Comet/water transport idea was from Freeman Dyson's book Disturbing the Universe, in Chapter 18: Thought Experiments. It has been adapted by many people. Dyson attributes it to some Asimov stories from 1955. Dyson suggested using Saturn's moon Enceladus as the ice source.
> My timeline may be a bit off from the article (I'm going from memory here)
> but as we approach the "singularity" we coudl develop new technologies that
> could concievably speed up this process to take a total of a few decades.
Decades my son!?! Its more like months.
Say we build the first SI shell M-brain layer in the asteroid belt, because for some stupid reason you want to keep Mars & Venus for messy, wet, primitive "humans", then you simply leave holes in the shell where interplanetary materals from Uranus/Neptune are being driven through. It gives you lots of Carbon and O2 to play with in a very short period.
> The initial timeline is assuming we use the technology we have available
> today. The main innovations that are needed to get the ball rolling are
> transport infrastructure (getting there and back efficiently), habitation
> (where the people live while this is going on) and life-support (efficient
> methotds for generating food, water, air and electricty). Economy is
> something I'll leave up to... economists.
Yep and all of those cost much less if you have self-replicating machines and moderately intelligent software (about dog level I'd guess) -- here boy, see the comet, go fetch the comet, thats a good doggie... [Note that I didn't say that you required *nanotechnology* here. To get the costs down you simply have to get rid of the humans from everything execpt the design stage and the construction of the initial set of self-replicators.
It is worth noting that *no* business will ever fund the development of self-replicating factories (unless they have the patents on them and are guaranteed royalties from the production). This needs to be mostly done by governments. Why? Simple -- no business will ever build something that destroys the market for the thing they are building. No business will make a toaster factory factory because once you sell the first one, the market for toasters rapidly gets saturated and you no longer need toasters or their factories. Simple economics.
> The other concerns raised are worthy of consideration but pointless if the
> task is too daunting or restricted by paranoid governments affraid of
> humanity getting out from under their thumbs.
This is worthy of consideration. I think the question comes down to whether the government can make prisoners of you? If I've got 10 kg of nanobots building personal ground-to-space transport seems straight forward. You can bet I'm going where there ain't no taxes... The only way the government can stop this is to shoot me down on takeoff, so if we all do it together they can't get us all... [Actually, if they've got nanotech too they might be able to do it, but I can't believe a free society would stand for this.]
> Even if private industry wants to and can afford to do it, current
> governmental controls (especially those imposed by the US) must be
> lifted or nothing will be allowed to happen.
I don't believe the government is controlling our "access to space". Bill Gates and a number of other individuals could afford to buy rockets to take them there. Anyone with the bucks can get the Russians to ferry them up to space.
I suspect you are referring to using old-style rockets to develop Mars. If there is a market for it, business can do it. However Iridium is a great example of people convincing themselves there was a space application, installing the required infrastructure only to discover their market size estimates and pricing strategies were completely bogus.