Anyone feel like riding herd on some comets? Yee, HAW!

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Making the machines fail safe is great as a platitude, but one channel open to chaotic excursions is to cause the "fail safe" to fail. Also, the programming required for the self replicators to replicate, as in the biological world, can be self modifying rendering Pandora's box of little concern by comparison. Human bureaucracies are very self limiting; I can't imagine how ineffective machine bureaucracies would quickly become. Charlie Chaos is about to replace Murphy as the chief mischief maker.

Does anyone know how many tons of protons per day Venus receives from the solar wind?

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

That might even be a good way to remove atmosphere. Imagine having the backspun asteroid skyhooks I mention elsewhere. You gather balloons filled with heated gases. Asteroids yank many millions of square feet away from Venus at the time, slowing the asteroids or large comets contained in the similar balloons. The atmosphere is refined, and stored at Mars. Over centures, Huge amounts of Venus CO2 atmosphere is dropped on Mars at once. Then too since there aren't enough asteroids to blow Venus atmo' off, just using a few with solar flyby and release of the atmosphere from the balloon might work. If the asteroids were slowed enough, you might have some moons.

The big thing is to have a large occulter disk between Sol and Venus. In order to keep it from being a giant solir sail, an asteroid is between the disk and the sun for a gravity gradiant anchor.

You're funny!!!!!

In case you didn't know, Venus is slowly losing its atmosphere to the solar wind because of a weakening of its electromagnetic field--just as Mars did. Be patient and you can start from scratch.

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Venus doesn't have a magnetosphere (it's not weakening), it has far more mass than Mars, and has far more atmosphere. The loss of Venusian atmosphere is insignificant.

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Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

I thought it didn't have a magnetosphere, Van Rijn, but I wasn't sure about that since it's been a long time since I've look into the subject of Venus.

As far as it being insignificant, I didn't mean to suggest that it will lose its atmosphere in our lifetimes or even in the relatively near future. But, over a great period of time, it will lose its atmosphere. The comment was intended as tongue-in-cheek anyway, since I think it's an absurd idea that Venus could ever be terraformed. But, I think the same of Mars, especially since its rotational axis wobbles so wildly over time. Besides, without a magnetosphere how do the terraformers plan on keeping any atmosphere that they may create on Mars from just blowing off into space. I'm not trying to be a smart-***. I'm in earnest about this. We don't even really understand the rhythms of our own planet and we're going to terraform another? Please correct me if I'm wrong.

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“Out yonder there was this huge world, which exists independently of us human beings and which stands before us like a great, eternal riddle, at least partially accessible to our inspection and thinking. The contemplation of this world beckoned like a liberation.” - Albert Einstein

My Astronomy Site
My Geology Site

Its present atmosphere (mostly carbon dioxide, some nitrogen) is very stable. Eventually, as the sun moves off the main sequence and gets much hotter, Venus will lose its atmosphere (and then will be destroyed), but then so will Earth.

Because it isn't that big an issue. Mars would have greater losses (through thermal and non-thermal processes) than Earth or Venus because of its limited mass, but it still could hang onto a thick atmosphere for many millions of years.

Oh, sure, there are a lot of practical problems in terraforming Venus or Mars. It's an interesting idea, though.

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I say there is an invisible elf in my backyard. How do you prove that I am wrong?

Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

Over timescales longer than human civilization, yes. But that might not be a bar against terraforming, any culture high-tech enough to even begin the process would be capable of adapting to climate changes that take that long.

They don't. Just add a small amount of gas every few millenia.

We don't fully understand quantum mechanics, but we use it all the time.

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I disagree. We can start colonization tomorrow. We don't need to wait for a planet to become a shirt-sleeve environment before moving in.

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There seems to be a significant amount of planet chauvinism in this thread. Planets are not very good places to live on and require immense amounts of effort to make them suitable for living on.

Space habitats with artificial gravity however are actually feasible forms of life beyond earth that don't take centuries to make semi-habitable.

Mars is not suitable because it has too little gravity, if Venus could be terraformed it might match a human's physical requirements but why go to all that effort of getting beyond Earth's gravity well just to go throw yourself into another one just as big.

I suspect you haven't done a high level design of "colonizing tomorrow" including plans to stay a while.

As well there should be; gravity is more a blessing than a curse. Could you present an outline of a design for a non-planet based habitat?

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For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

However high or low level any design may be, work on it can always start ASAP, i.e. tomorrow. More to the point, we currently have mobile environments for use in hostile climes. It will be easier to take an RV into the wilderness than reconstruct the wilderness in the garage.

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Here are some non-planet based habitat designs.
The Stanford Torus
The Bernal Sphere
The O'Neill Cylinder
The McKendree Cylinder
The Bishop Ring

All of these could be built using real materials, rather than the imaginary ones used in some science fiction. Admittedly this would take a lot of time, energy, effort and money to acheive, but in each case less time, energy, effort and money than terraforming a planet.

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None of these designs seem to address the major subsystems needed to get them designed in orbit nor the energy required to initiate and maintain the process nor how to protect them from collisions with various forms of debris with which they will collide. My guess is that when more detail is "fleshed out", the level of expense will be astonishing.

__________________
For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

Compared to the cost of terra-forming an entire planet?

We have the technology to construct the most common designs right now, and they can be scaled down to maintaining only a few hundred people if we wish to start small.

I'm all in favor of future cool spacecraft and large-scale "space habitats with artificial gravity" but actually, the incredible harshness of Venus aside for a moment, Earth, (and Earthlike planets) have a much better self-renewing natural environment as a basis to build from whereas man-made technology has a very much shorter lifespan in the harshness of space. Space is very corrosive on technology much as the sea on earth is corrosive to ships. The average ship lasts maybe 30 - 40 years and if carefully mothballed, longer. Large spacecraft will wear out too, so you'll have to have a continuous repair and refitting operation on board and there's no "dry dock" to go too.

Earth (and a second Earth) would have many things that would aid human survival without continuous upkeep, such as an atmosphere to block radiation and incoming pebbles and rocks. A spacecraft might have an electromagnetic screen plus shielding to block radiation but it would not be the natural result of the ship itself. It would have to be artificially maintained all the time. I'm not against it, especially if its lifespan includes the length of its mission somewhere, but a planet with a somewhat friendly environment is better for long term human life.

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But there's only one Earth. And terra-forming a planet would likely also require continual upkeep to keep habitable.

It was said of the dyson sphere

any civilization capable of building one wouldn't need to do it

this is true i think of transforming venus

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ok heres how i would do it

1 go grab a 100 very large asteroids and stick them in venus orbit
2 smash them to smithereens shrouding the planet in a vast high orbit dust cloud for 100 years or more
3 by this time venus has cooled considerable enough to condense a lot of that atmosphere
4 now seed the atmosphere with modifed microbes and the land with modified trees
5 may need to top up that dust cloud over the next 1000 years until u can lock up all that atmosphere into the surface

the pressure on venus isn't really harmful to modified life but the high temperature is too chaotic and disruptive to carbon based life (which is what you are terraforming for isn't it ? )

if u want normal humans to be able to walk about & not just a heavily modifed human and ecosystem you realy have your work cut out..for this u will have to may have to gather a 100 very large comets into the surface to help alter the chemistry

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it could be done with heavily modified microbes but i figure 10,000 years at least with ongoing tweaking

tough very tough indeed

perhaps the cheapest way would be to genetically modify human to live in zero g or low gravity enviroments

that way any where with water and sunshine (eg comet, icy moon) could be our home

Yeah, but what's the point, living on an icy asteroid wouldn't be very pleasant, not to mention that such hypothetical modifications would likely make returning to earth impossible or very difficult.

Actually, many points on the "wish list of useful genetic adaptations for easier space travel" would be quite handy to have back on Earth, too.

How about higher resistance to changes in temperature or pressure?
Or higher tolerance of radiation, toxins or temporary lack of food/water/oxygen?
Or much faster healing capacity?

Yes, but would that be an enjoyable existence?

The parameters of what we consider enjoyable conditions are probably also somewhat genetically determined, and the rest from the enviroment we are brought up in. So an offshoot of human that sucks down methane while walking across the frozen landscapes of an ice moon could in theory be just as happy as you or me.

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And would you ever be willing to be modified to suck down methane? Genetic modification doesn't spontaneously happen, people need to want it to happen.

Would primeval fish have been willing to leave their comfortable ocean behind for good
just in order to try and live on an extremely hostile, lifeless, toxic primordial land environment?

Of course not, and you are absolutely right: these kinds of adaptations don't happen from one day to the next.
The likelier scenario is a very slow and gradual evolution, with lots of intermediate steps, each of which would have to be useful in itself.

Talking about Titan: I don't think switching to methane-breathing - even if feasible - would be necessary or even practical
(you would still die of asphyxiation in most places).

However, higher tolerance of very low temperatures and temporary lack of oxygen (for example),
would be very useful both on Titan and in most other places (including Earth).
So they might be desirable regardless of our plans for space exploration.

If you could cool the atmo to liquid, that might make it easier to dispose of, in a non-gas form.

Bacteria are able to live in extreme environments (Heat, acid, pressure...) all we need to do is combine these characteristics. We can build an organism that would float in the atmosphere and excrete plastics that would fall to the surface. The plastic contains the sulfur, carbon and extra oxygen in the atmosphere and would even make a good start to organic dirt on the surface.

The only logistic problem is phosphorous as the amount of available phosphorous would limit the amount of possible life. Evolution could also create a problem as the plastic creation would be a net loss for the organism so if one mutated to lose that ability the organism would likely thrive. Coupling the plastic creation to a necessary metabolic pathway would be vital and much more difficult than any other task in the bioengineering. Though if the phosphorous problem can be solved this would be cheap and fast.

Also Venus could be used in the intermediate time using floating type habitats that use something like oxygen as the buoyant gas as you only need to be lighter than the surrounding gas CO2 etc...

We would just need to build using carbon based structures as opposed to metals such as plastics and things like carbon nanotubes and carbon fibre. Which would all be available in the atmosphere. We don't need the surface to live just energy, gravity and the base elements.

So let's say, in a hypothetical scenario, you could revamp the atmosphere to match Earths.

What do you do about the rotation period? A full Venusian day is around 5600 hours long. Three solid months of sunshine in an atmosphere attenutated down to Earthlike levels nearly 30 million miles closer to the Sun is going to keep the surface nice and crispy even without the psuedo-Jovian pressures. Even if the atmosphere retains is super-rotation of 4 days, that's still a LOT of built up energy to dissipate. Going from a decent analogue for Hell to a decent analogue of Death Valley is hardly an improvement.

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