Making Venus livable

[m1omg]

http://en.wikipedia.org/wiki/Aerogel

It's insulation capability is incredible, Mars twin rovers have an aerogel shielding that keeps their components at the 25 degress Celsius.

[m1omg]

[m1omg]

Pretty , it isn't ?

[m1omg]

Venus Rover proposal;
http://www.agu.org/meetings/fm05/fm0...fm05_P54A.html

Huh, an engine that convert Venus's heat to electricity and simultanously provide cooling system...how clever

http://www.lanl.gov/thermoacoustics/TASHE.html
About temperature
"All rover systems would be housed in a pressure vessel in vacuum with the internal temperature maintained by the TASHE below 50 °C. No externally deployed or articulated components would be used and penetrations through the pressure vessel are minimized. Science data would be returned direct to Earth using S-Band to minimize atmospheric attenuation."

So good news; it will not heat up rapidly (that mission is designed to last 60 days), and I guess if they will use Aerogel than that temperature will be room temperature and that rover will last year.

Don't be so sceptical and pessimistic .

And about spacesuits, yes, there would be a need for a cryogen but spacewalks usually do not last more than a few hours, so it is not problem imo.

[Van Rijn]

Thanks for your enthusiasm. Speculation on transforming Venus is highly hypothetical. It is better to try to maintain some connections, however tenuous, to known and applied sciences, engineering and technology of today (though at times speculative).

Trying to speculate on Venus transformation goals using today's technology as a basis is actually much more exciting than simply falling back on simple comic book anecdotes (like floating cities) which actually have less engineering basis than the giant sun shields and surface domes.

Floating Venusian cities are no more speculative than the terraforming concepts that we have discussed and are much more modest in physical scale. We're not discussing massive Star Wars style structures held up by anti-gravity machines. Breathable air is a lifting gas in the CO2 atmosphere of Venus. These structures would be somewhat similar to dirigibles, but much larger.

Mind you, I expect we would have many floating cities in Earth's oceans before we would be doing this on Venus, but this is well within the boundaries of physics, and we do have at least as much engineering knowledge related to this concept as we do for planet sized sunshades.

[Van Rijn]

Actually, I'm not in favor of a space station or a cloud city, which also requires breathable air that is not present on Venus or at any altitude and must be self-contained.

If we can terraform a planet, I expect that high closure life support systems would be extremely well developed. There would be a massive space infrastructure. Given that, there easily could be more people living in space structures than on worlds. In the Earth-Moon system alone, there could eventually be habitats with the equivalent of thousands of times the Earth's living area.

One of the reasons why I like Mars as a target is that, with its relatively small gravity well and two orbiting asteroid-like moons, I suspect it would make a great center for economic growth. I could see the Earth-Moon and the Mars systems as two of the solar system's economic hubs in a few centuries. I would think that Venus would be something tackled later, rather than earlier.

[Chip]

If we can terraform a planet, I expect that high closure life support systems would be extremely well developed...I could see the Earth-Moon and the Mars systems as two of the solar system's economic hubs...Venus would be something tackled later, rather than earlier.

Yes, terraforming is quite difficult but Venus is really extra difficult. Occasionally fun to think about though. Mars is equally exciting in its own way. This is a far flung notion but if we were able to make Mars much more like the Earth, that might teach us how to make Venus become more like Mars is now, and then from there, eventually also make Venus more like the Earth.

Floating Venusian cities are no more speculative than the terraforming concepts that we have discussed and are much more modest in physical scale. We're not discussing massive Star Wars style structures held up by anti-gravity machines. Breathable air is a lifting gas in the CO2 atmosphere of Venus. These structures would be somewhat similar to dirigibles, but much larger.

I will reconsider the value of the floating cities scenario as you've explained it as I was under the impression it was more akin to magic beams in Star Trek. I think such structures should be a simultaneous addendum to a long-term Venusian transformation.

I found these writings on the internet about Venusian aerostats.
http://www.lunar-reclamation.org/pap...rehabpaper.htm

[Ara Pacis]

Vacuum flask painted pure white, with an inner dome painted white, covered by the aerogel should cool it, at least it will reduce the need for a cyogen.

I'm not an expert on aerogel, but after reading the wikipedia article I still wonder if they would be able to maintain themselves at the pressures of the venusian surface or if the friable aerogels would shatter. It's an interesting idea worth exploring.

However, something else comes to mind. Even if you manage to maintain the rigidity of the habitat shell, how do you plan to anchor it? After all, the bouyancy of a 1 atm shell under 90 atm would make it want to pop up like a cork. It'd be like trying to hold a balloon underwater.

[bluelou]

If God had wanted Venus habitable, he would have made it that way.

If God wanted you to post here, he would have created the forum with your posts already in it.

[m1omg]

I'm not an expert on aerogel, but after reading the wikipedia article I still wonder if they would be able to maintain themselves at the pressures of the venusian surface or if the friable aerogels would shatter. It's an interesting idea worth exploring.

However, something else comes to mind. Even if you manage to maintain the rigidity of the habitat shell, how do you plan to anchor it? After all, the bouyancy of a 1 atm shell under 90 atm would make it want to pop up like a cork. It'd be like trying to hold a balloon underwater.

You never heard about deep sea exploration?Pressure on Venuse is like the pressure in the 1 km depth of the sea.It will stay anchored like a deep sea habitat.And batyscape get humans to the depth of 11 km and that wessel survived it without problems.The pressure on the Venus is not as high as you may think, in the laboratory condition there were created much higher pressure, and pressure 11x than on Venus is in the Marianic Abyss - even multicellular life survive there, under 990 bars!

And about the shattering of an aerogel;
http://eetd.lbl.gov/ECS/aerogels/sa-working.html

It will shatter only if there is a RAPID PRESSURE CHANGE, not only high pressure, it can support 1000x it's own weight but can shatter if you punch into it. And why not just place the aerogel under the carbon-metal layer under 1 atm.?The layer of the metal will be a little hotter but if white not too much and that aerogel will completely isolate it from the inside.

[Ara Pacis]

You never heard about deep sea exploration?Pressure on Venuse is like the pressure in the 1 km depth of the sea.It will stay anchored like a deep sea habitat.And batyscape get humans to the depth of 11 km and that wessel survived it without problems.The pressure on the Venus is not as high as you may think, in the laboratory condition there were created much higher pressure, and pressure 11x than on Venus is in the Marianic Abyss - even multicellular life survive there, under 990 bars!

The Trieste, the only manned sub to visit the Challenger deep, had a spherical pressure vessel 6.5 feet in diameter. A vessel designed to handle only 90 atm on Venus might not need to be that over-engineered, but it would require engineering beyond that of most military submarines, which reach maximum depths of around 800 to 1000 ft instead of the equivalent pressure depth of 3300 ft. (BTW, the Trieste did have problems, one of the outer lexan window panes shattered under the pressure. Also, the depth you referr to is the Marianas trench, not an abyss. Abyssal plains are flat and relatively shallow. And though there is life, even vertebrate life, in the ocean depths, those pressures are incompatible with human life.)

A sphere, instead of a dome, would be the optimal pressure vessel geometry. This isn't impossible, and a spherical shell also has the benefit of having the smallest surface area to volume ratio, meaning that insulation is more effective. It would also maximize the strength of the pressure hull, but a dome would be vulnerable on it's flat underside or the seams to it's foundations. Remember, fluid pressure works in all directions, not just downwards.

If you wanted to design a surface colony with a habital volume it would be so large as to make negative or neutral bouyancy incredibly expensive to achieve. Perhaps you could build such a heavy structure on Luna or Venus from your expensive, exotic and fragile materials and anchor ballast and then move it to venus, but it would be incredibly heavy and require massive rockets to lift it even from the lunar surface. Emplacing a ballasted surface colony structure onto the venusian surface would require enormous retro-rockets because aerobraking would risk disintegration from thermal and acceleration forces and either method could result in damge to the internal aerogel insulation from acceleration shock.

A better idea would be to build the shell light and let bouyancy float it in the venusian atmosphere and then add ballast that is gathered from the surface of Venus or sent from another solar system body like Luna or Mercury (which would still be expensive). At this point you've basically designed a floating city that sinks and is more dangerous to live in. The surface colony idea doesn't argue against the idea of floating cities on venus, it argues in favor of it and practically requires it.

Take this idea. Design a surface habitat/factory that looks like the Titan A.E. from the movie of the same name. It's a sphere with multiple hollow legs that could house retro or ascent rockets or ballast or elevators to the surface. Painting the outer hull white probably couldn't hurt, and might help reflect thermal infrared radiation, but convection/advection and conduction would probably result in the outter pressure hull rapidly warming to ambient temperatures anyways. White paint pigments are often titanium or lead. You might just use solid titanium alloys anyways, and the hull might naturally accumulate lead frost if it's on the surface long enough.

I'm not against the idea of surface structures on Venus. I think it'd be necessary to have small habitats for mining operations and for research. However there is no need to place colonies on the surface when it is safer and cheaper and easier to place them in the clouds.

[Chip]

...I'm not against the idea of surface structures on Venus. I think it'd be necessary to have small habitats for mining operations and for research. However there is no need to place colonies on the surface when it is safer and cheaper and easier to place them in the clouds.

Another idea might be to have kamikaze automated excavating machines that land and, based on earlier detailed surveying research, start digging out underground spaces. Such specialized construction equipment would be tough and last for a certain time after which further machines land, cannibalize them if possible and continue building and finishing underground dwellings. (This of course would be applicable where cooler, underground areas are discovered.) There would still be the problem of access to and escape from the harsh surface to upper atmosphere locations, but such surface access points would present a much lower surface profile than a dome and could be very durable below the intense heat and pressure.

Maintaining breathable atmosphere, water, food, life support, etcetera, would be similar to a surface dwelling. Gravity would feel almost the same as on Earth.

To me, the eventual long term goal in this poll/thread is altering the surface for habitation.

[Noclevername]

Okay, here's the relevant text (and I'm skipping some bits) from New Earths, page 212:

"If we wish to remove 98% of the mass of the Venusian atmosphere in a reasonable time, say, 100 years, we must haul up a mass 10 quintillion tons, or 300,000 tons per second. Compare that to the flow along the Amazon river . . . 10,000 tons per second. The largest machines built which handle flowing water . . . handle 400 tons per second.

Or look at it from an energy requirement: hauling the mass of gas 100 km high, and then accelerating it by 20 km per second requires about 10²⁵ ergs over a 100-year period. That's all the sunlight falling over the same period on an area of 10,000 square km assuming 100% efficiency . . .Throw in a factor of 10 for engineering reality, and the air scoopers must have an area of . . . three times the total area of Venus."

He suggests giant ramscoops connected by elevator/cable to hardware higher up. The ramscoop collects air, compresses or liquifies it, ships it by tanks up the elevator, where it is accelerated away from the planet. There are a number of design issues with these scoopers.

I wonder...

Would it take more or less energy than this to build a sunshade, freeze out the atmosphere, and then transfer it to orbit or beyond? After all, if you are already talking about building a planet-sized solar collector, a simple shade would be easier, and you wouldn't have any friction/wind resistance or weather conditions to worry about, plus the stuff would be easier to move.

The excess gasses could be stored frozen in some convenient orbit behind a permanent sunshield, ready to transfer its contents wherever needed.

[m1omg]

The Trieste, the only manned sub to visit the Challenger deep, had a spherical pressure vessel 6.5 feet in diameter. A vessel designed to handle only 90 atm on Venus might not need to be that over-engineered, but it would require engineering beyond that of most military submarines, which reach maximum depths of around 800 to 1000 ft instead of the equivalent pressure depth of 3300 ft. (BTW, the Trieste did have problems, one of the outer lexan window panes shattered under the pressure. Also, the depth you referr to is the Marianas trench, not an abyss. Abyssal plains are flat and relatively shallow. And though there is life, even vertebrate life, in the ocean depths, those pressures are incompatible with human life.)

A sphere, instead of a dome, would be the optimal pressure vessel geometry. This isn't impossible, and a spherical shell also has the benefit of having the smallest surface area to volume ratio, meaning that insulation is more effective. It would also maximize the strength of the pressure hull, but a dome would be vulnerable on it's flat underside or the seams to it's foundations. Remember, fluid pressure works in all directions, not just downwards.

If you wanted to design a surface colony with a habital volume it would be so large as to make negative or neutral bouyancy incredibly expensive to achieve. Perhaps you could build such a heavy structure on Luna or Venus from your expensive, exotic and fragile materials and anchor ballast and then move it to venus, but it would be incredibly heavy and require massive rockets to lift it even from the lunar surface. Emplacing a ballasted surface colony structure onto the venusian surface would require enormous retro-rockets because aerobraking would risk disintegration from thermal and acceleration forces and either method could result in damge to the internal aerogel insulation from acceleration shock.

A better idea would be to build the shell light and let bouyancy float it in the venusian atmosphere and then add ballast that is gathered from the surface of Venus or sent from another solar system body like Luna or Mercury (which would still be expensive). At this point you've basically designed a floating city that sinks and is more dangerous to live in. The surface colony idea doesn't argue against the idea of floating cities on venus, it argues in favor of it and practically requires it.

Take this idea. Design a surface habitat/factory that looks like the Titan A.E. from the movie of the same name. It's a sphere with multiple hollow legs that could house retro or ascent rockets or ballast or elevators to the surface. Painting the outer hull white probably couldn't hurt, and might help reflect thermal infrared radiation, but convection/advection and conduction would probably result in the outter pressure hull rapidly warming to ambient temperatures anyways. White paint pigments are often titanium or lead. You might just use solid titanium alloys anyways, and the hull might naturally accumulate lead frost if it's on the surface long enough.

I'm not against the idea of surface structures on Venus. I think it'd be necessary to have small habitats for mining operations and for research. However there is no need to place colonies on the surface when it is safer and cheaper and easier to place them in the clouds.

Sorry, I badly translated it to abyss.
Good ideas!

[m1omg]

But aerogel would be even better to use than just white paint

[Ara Pacis]

Another idea might be to have kamikaze automated excavating machines that land and, based on earlier detailed surveying research, start digging out underground spaces. Such specialized construction equipment would be tough and last for a certain time after which further machines land, cannibalize them if possible and continue building and finishing underground dwellings. (This of course would be applicable where cooler, underground areas are discovered.) There would still be the problem of access to and escape from the harsh surface to upper atmosphere locations, but such surface access points would present a much lower surface profile than a dome and could be very durable below the intense heat and pressure.

Maintaining breathable atmosphere, water, food, life support, etcetera, would be similar to a surface dwelling. Gravity would feel almost the same as on Earth.

To me, the eventual long term goal in this poll/thread is altering the surface for habitation.

Well, if the long term goal in this thread is altering the surface, then it is best to do it from structures locating in the clouds which will survive long enough to accomplish some of those goals. I'm all for terraforming Venus so that we can eventually live on the surface, but floating cities will be crucial to that project, not a diversion from it.

BTW, what makes you think that Venus is cooler underground? Part of the reason that Venus is so hot is because of it's geothermal/volcanic activity. You'll have to determine the heat flow of the crust before digging in it. Also, the immediate surface can't cool much because of the greenhouse effect so it is likely as hot as the lower atmosphere. The earth's crust is only cool for the top few hundred feet, and then it starts getting hot again as you go deeper, and the earth's top crust is only cool because of longwave radiative cooling, atmospheric advection and hydrology, all of which Venus can't do.

[Chip]

Well, if the long term goal in this thread is altering the surface, then it is best to do it from structures locating in the clouds which will survive long enough to accomplish some of those goals.

Fine. We should acknowledge that there is nothing to indicate such structures would last more that 10 to 20 years given past experience with large scale Earthly engineered projects. This includes all necessary refurbishments. Floating cities are great but like all ships, the ISS, dirigibles, harbors, eventually get creaky. I would precede them with test aerostats that measure the turbulence and stability of long term existence.

I'm all for terraforming Venus so that we can eventually live on the surface, but floating cities will be crucial to that project, not a diversion from it.

I like floating cities too. I think the giant sun shield construction will be the biggest initial project and bio-engineered-nanites to aid in initial atmosphere modification soon after that. To me floating cities are like saying, if we have a construction project in a remote area, we need housing for the workers.

BTW, what makes you think that Venus is cooler underground? Part of the reason that Venus is so hot is because of it's geothermal/volcanic activity.

Volcanic activity does not dominate every square mile of Venus. We have theories as to its evolving topography but we don't know what its like under the surface. That's why I wrote "based on earlier detailed surveying research" before we build underground, and: "this of course would be applicable where cooler, underground areas are discovered".

You'll have to determine the heat flow of the crust before digging in it.

Yes we will.

Also, the immediate surface can't cool much because of the greenhouse effect so it is likely as hot as the lower atmosphere.

The "immediate surface" is where pressure domes and surface structures are proposed. I suggested* underground as it offers protection from storms and heat. It probably has as many construction problems in its own way as a floating city.

The earth's crust is only cool for the top few hundred feet, and then it starts getting hot again as you go deeper, and the earth's top crust is only cool because of longwave radiative cooling, atmospheric advection and hydrology, all of which Venus can't do.

Venus is not the Earth. The Earth also does not become hot a few hundred feet bellow the surface over every square mile. Venus also doesn't have vast oceans and there is reason to surmise that Venus actually regurgitates vast areas of its hot surface periodically. But on the human time scale it MIGHT be possible to have underground structures on Venus as well as floating structures.
*All of these things are hypothetical suggestions worth mentioning.

[Ara Pacis]

Fine. We should acknowledge that there is nothing to indicate such structures would last more that 10 to 20 years given past experience with large scale Earthly engineered projects. This includes all necessary refurbishments. Floating cities are great but like all ships, the ISS, dirigibles, harbors, eventually get creaky. I would precede them with test aerostats that measure the turbulence and stability of long term existence.
I like floating cities too. I think the giant sun shield construction will be the biggest initial project and bio-engineered-nanites to aid in initial atmosphere modification soon after that. To me floating cities are like saying, if we have a construction project in a remote area, we need housing for the workers.

Volcanic activity does not dominate every square mile of Venus. We have theories as to its evolving topography but we don't know what its like under the surface. That's why I wrote "based on earlier detailed surveying research" before we build underground, and: "this of course would be applicable where cooler, underground areas are discovered".

Yes we will.

The "immediate surface" is where pressure domes and surface structures are proposed. I suggested* underground as it offers protection from storms and heat. It probably has as many construction problems in its own way as a floating city.

Venus is not the Earth. The Earth also does not become hot a few hundred feet bellow the surface over every square mile. Venus also doesn't have vast oceans and there is reason to surmise that Venus actually regurgitates vast areas of its hot surface periodically. But on the human time scale it MIGHT be possible to have underground structures on Venus as well as floating structures.
*All of these things are hypothetical suggestions worth mentioning.

Yes, there are caveats in any plan, and much to be learned. However, humanity already has much experience designing and building floating habitats. We could do it on Venus now, with current tech, if we desired and have a place to live as soon as we got there. Surface and subsurface habitats would require leaps in engineering and much longer pre-inhabitation construction times. I think that could be done in short order, but such habitats would be more expensive and do less.

I think you underestimate the liftspan of human constructions. All structures require maintenance, but a 10-20 year service life is a lowball estimate. The Iowa class battleships are still serviceable after 60 years, even if they are decommissioned and other ships have been in service even longer and the USS Constitution is still in service after 200 years. Still, even 10 years would probably be several orders of magnitude longer than the lifespan of a permanent surface structure on Venus.

[Noclevername]

Assuming that other problems can be overcome and the atmospheric pressure could be reduced to a livable level, how much nitrogen, hydrogen etc. would need to be imported to make it a happy home?

[Chip]

Unless anyone is willing to move beyond floating cities, I'm pretty much done here. Several folks checked "Wouldn't Venus need a moon as well as a new atmosphere?" This was a whim on my part based on an idea someone (don't recall who) put forth years ago that Earth's climate would become radically unstable without the gravitational influence of our moon. I have not found further evidence of that. If it were true, then maybe Venus would need a moon for similar reasons. (I don't know.)

Personally, I like the idea of stages wherein we don't try to get Venus to become another Earth at first, but strive to reform its environment into something less hostile if still deadly, and from there, with a different set of circumstances, move to reform it again into a more Mars-like and finally Earth-like world. This offers advantages over trying to solve all problems with an initial magic formula that has to bend and break with contradictory and conflicting conditions.

An interesting hypothetical question would also be: If we magically could replace Venus with the Earth /Moon system as it is right now, would Earth simply become a little warmer, a lot warmer or fall into becoming a runaway oven world like Venus is now?

[Noclevername]

Personally, I like the idea of stages wherein we don't try to get Venus to become another Earth at first, but strive to reform its environment into something less hostile if still deadly, and from there, with a different set of circumstances, move to reform it again into a more Mars-like and finally Earth-like world. This offers advantages over trying to solve all problems with an initial magic formula that has to bend and break with contradictory and conflicting conditions.

I've never heard of a terraforming proposal that didn't happen in stages. There is no magic formula (well, okay, some of the nanotech-replicator ideas are pretty magic-sounding, and pretty speculative too.) I don't think there's any way that Venus could ever be made Mars-like.

[Ara Pacis]

The use of a moon has been speculated for several reasons I can think of. A planet's rotation is more easily maintained with a moon acting as a flywheel so that the planet does not become tidally locked with the sun. A moon causes tides that induce weathering, depending on the fluids. A moon tends to stabilize the rotational axis over the long term so that seasons are maintained and precession is minimal, which can help maintain cold polar regions. A moon might help maintain the internal dynamo of a planet so as to increase it's magnetic field. I'm not sure how important some of these are, but it's what I seem to remember hearing.

[Noclevername]

The use of a moon has been speculated for several reasons I can think of. A planet's rotation is more easily maintained with a moon acting as a flywheel so that the planet does not become tidally locked with the sun. A moon causes tides that induce weathering, depending on the fluids. A moon tends to stabilize the rotational axis over the long term so that seasons are maintained and precession is minimal, which can help maintain cold polar regions. A moon might help maintain the internal dynamo of a planet so as to increase it's magnetic field. I'm not sure how important some of these are, but it's what I seem to remember hearing.

By the time some aspects of Venus terraforming become possible, like spinning up the planet to give it a decent day-night cycle, most of those things will be able to be done artificially, as part of the regular maintainance of the planet's environment. If we can spin it, we can correct its spin. And weathering/erosion can be stimulated if need be. If a civilization has enough energy and resources to tackle such a massive terraforming job, it'll be able to spare a bit more to keep it going.

[agingjb]

If we had the technology to transfer angular momentum on the scale needed to spin up Venus (and give it a substantial moon) - a technology based on new physics to say the very least, then the chemistry and temperature of the atmosphere ought to be relatively easy.

[Van Rijn]

A few points:

The idea of impactors to spin up Venus and remove atmosphere has been looked at. At the time the two terraforming books were written, very few Kuiper belt objects were known, so this resource didn't come into discussion. Anyway, it's possible to remove atmosphere, but efficiency drops as the pressure goes down. It would take a lot of impacts to get down to a reasonable pressure.

Also, Venus has a lot of mass, so it isn't easy to spin it up. It would be one thing to spin it up a bit, and another to get anywhere near a 24 hour rotation. Unfortunately, numerous extreme impacts would tend to get Venus rather warm (lots of added energy). Then, the Venusian interior probably isn't solid, and the surface looks fairly young. It is entirely possible that a spin up attempt could make it even harder to live on Venus. We wouldn't want to initiate a resurfacing event.

There have been other more controlled methods proposed for spinning up Venus within the bounds of known physics, but would require enormous structures be built and require a lot of energy if done in reasonable periods (a good fraction of the total solar output) and great mass transfers. Given self replicating machines this isn't completely ridiculous, but the technological requirements are daunting.

[Noclevername]

There have been other more controlled methods proposed for spinning up Venus within the bounds of known physics, but would require enormous structures be built and require a lot of energy if done in reasonable periods (a good fraction of the total solar output) and great mass transfers. Given self replicating machines this isn't completely ridiculous, but the technological requirements are daunting.

(bold mine)

Again, it goes back to what is defined as "reasonable time". Anyone taking time to tackle this project (centuries at minimum) is clearly either not interested in immediate benefits, or has found a cure for aging, in which case they can afford to wait a few thou'.

[Ara Pacis]

I wonder how much momentum might be gained from condensing the atmosphere. I haven't heard any figures on this, but it'd be like a spinning skater pulling her arms in and speeding up. It might not be a lot, maybe only a few minutes of rotation. But if it worked, Perhaps pulsing the atmosphere on certain areas of the planet could use solar tidal effects to increase the spin. After all, it's thought that the solar tidal forces acting upon the thick atmosphere are what slowed it down in the first place. Or maybe a partial solar shade could cause differential insolation that could use the yarkovsky effect to pulse the atmosphere in a direction that would increase rotation. EDIT, I'm not sure if it's the Yarkovsky effect or something else just weather that would do it.

[Van Rijn]

(bold mine)

Again, it goes back to what is defined as "reasonable time". Anyone taking time to tackle this project (centuries at minimum) is clearly either not interested in immediate benefits, or has found a cure for aging, in which case they can afford to wait a few thou'.

Well, for these purposes, I make a distinction between a few hundred to thousand years versus hundreds of thousands or millions of years. Terraforming in decades seems nearly impossible without invoking new physics.

[Noclevername]

Terraforming in decades seems nearly impossible without invoking new physics.

Okay, then, let's just invoke new physics! I call dibs on magic!

[Occam's Shaving Cream]

We don't need magic, we need components for the new Venus Fly Tra... Flying Habitat. Just disassemble the ISS and the Mir and make a nice multi-cultural flying Venus Colony.

That might* work.





*might not