New Mars Forums

That is quite a Freudian slip there Tom 

Don't be afraid Tom, I'm sure Hillary will be merciful.  I've heard her aides are putting together a program whereby traitors to their country can get their sentence commuted to a type of community service as long as they agree to castration and a course of reeducation through labor.  Perhaps you'll be able to achieve so prestigious a position as domestic servant to a party member!  You probably shouldn't set your aims so high though.  Society is not unwisely reluctant to trust those who have tried to divide and betray them.  Regardless, seven years in a concrete box in Guantanamo should make your heart fairly bloom with compassion.  They say a liberal is just a conservative who has been arrested 

So you read about the EPR paradox

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

and quantum teleportation and think "okay, I can live with non-local reality" but apparently, that's not good enough ...

Quantum physics gets unreal
http://www.nature.com/nature/journal/v4 … 19-06.html

Luckily, the Patriot Act will make it easy for us to round up people like Tom after the 2008 elections.

Hillary's angels gonna be knockin' on your door Tom.  Where ya gonna run to?

Maybe.  Depends on how high a strong magnetosphere can raise the effective escape velocity.

BTW, check out this shockwave atmospheric retention simulator ...

http://astro.unl.edu/naap/atmosphere/an … ulator.swf

You lose all your hydrogen in nothing flat 

The outer layers of the atmosphere would have to be an ionosphere and then plasmasphere.  Happily this seems to be the natural order of things in the presence of the Sun's ionizing radiation.  Outer solar system atmospheres may need an ionizing radiation boost.

It's like baby pictures of our first L5 colony.  Awww, cute little ISS 

The nice thing about a superconducting structure though, is that rather than just dissipating the terrawatts (i^2*R -> heat, light, etc), it can store them - act like a planetary power reservoir while providing the magnetic field.  I think that's meaningful, even at terraforming scales.

Superconductors aren't that much extra effort outside the cryogenics.  One of the interesting aspects of the orbiting asteroid-electromagnet idea is that you could organize free cryogenics pretty easily, especially since you want to suck up all the sunlight in the locality anyway to power-up the device.  I think you'd want the orbit to be as regular as possible though (geostationary?) to minimize interference with ordinary electronics.

You'd also have to explain away this MARSIS result  ...

Plaut et al: South pole has enough water to cover planet
http://www.newmars.com/forums/viewtopic.php?t=5287

I don't think so.  Methane is really stable.  Best bet is to oxidize it.

Current theory says that Venus is hot inside like Earth.  So the temperature would just get higher as you go deeper.  Water couldn't exist in liquid form to support life as we know it.

However, Venus may currently host microbes in the clouds of the 50km zone we've been discussing ...

http://www.astrobio.net/news/article311.html

The clouds of Venus apparently have a much longer lifespan than those of Earth - months instead of days.  Speaks of a nice stable atmosphere, no?

An excellent thought!  Constrained only by CO2 cracking efficiency.

Reading a bit more, it seems that some atmospheric models do predict violent but "narrow" downdrafts in the upper convection layer (60-45kms).   It may turn out that you can dodge anything dangerous, however, if these platforms are to be manned, you need to work from worst case ... if a meteor punctures the dome and the repair systems malfunction and it takes a week to get a patch in place, are there backup systems that can still provide a survivable environment?

Perhaps tethered networks of floating domes/spheres, each designed to lift, say, 200% of the dome's fully loaded weight.

It’s true that Venus+50km is metal-poor, although I imagine that adequate hydrogen could be procured, at least at first, from the sulfuric acid clouds.  I could conjure scenarios that give advantage to high ambient temperature for ore processing, but there is a larger discussion here about what constitutes economic advantage in this context. 

“Who pays for it and why?” is perhaps the crucial question for all extraterrestrial activity.  My opinion: governments will perhaps sponsor a scientific outpost, but anything more will require profit.  The question then: what can possibly be profitable?  Right now it isn’t looking good for our heroes.  “A Venus/Mars support base may lower the cost of asteroid mining by 20% and thus justify itself at some unspecified time in the future” doesn’t exactly scream goldrush.

People might possibly be persuaded by lifeboat arguments (“Earth has a significant probability of rendering itself uninhabitable, we need a backup”), but I think you’ve got to look for megatrends to hook your hopes to.  In the end you’ve got to be exporting energy or complexity.  There is really very little else that you can justify shipping from the bottom of a gravity well.

So, who can concentrate tritium or antimatter more cheaply: Venus or Mars?  Lots of maybes.  Whatever water is on Mars has been bombarded by high energy radiation for an aeon, so maybe it has good tritium concentrations.  Venus has less hydrogen but maybe that’s because all the lightweight hydrogen has escaped leaving higher concentrations of the good stuff.  Maybe Venus’ hydrogen is more efficient to process.  And check out the local energy sources available: high intensity solar, easy geothermal (aerothermal? – send water down a tube in the atmosphere a couple of kilometers and it will come back boiling), and, if I tether to the surface, I can get jet stream wind generation.  Maybe I just exploit all these local energy sources to create antimatter + containment and ship it back. 

Why would you import complexity (very highly processed goods) to Earth?  Maybe there are high-payoff technologies that are too dangerous to R&D in the primary biosphere.  Maybe Drexlerian nanotech can be made to work but it is most productive in high pressure and temperature environments (although maybe it needs near vacuum and Mars wins here).  Maybe the precious temperature and pressure environment of Venus+50kms enables vast biotech-enabled aerofarms that become the true “nanotech assemblers” of the next 1000 years.

In a thousand years.  We could green the deserts, but we don’t.  If, as we hurtle towards the tech singularity, Venus has an economic edge at the right time and for a reasonable duration, then it will get colonized first.  (Personally, I wonder if NEA-fed orbitals at L5 aren’t the way to go, but I admit that we have a ways to go before we can give them the “biosphere stability rating: 1000 years” stamp).

Actually, it turns out not.  There is a set of NEAs which have a lower delta-v to/from Venus.

Yes but no one is going to care about anything but the NEAs for 1000 years.

You definitely require stabilization systems, the question is whether they are a show stopper compared to the benefits.  The Venetian atmosphere may be such that long-term (say 1000 year) stability is not possible at any reasonable price.  On the other hand, it may be that there are calm areas where stabilization is trivial. 

The momentum of massive structures is both a blessing and a curse – like creating artificial islands in the Earth’s oceans, smaller structures need evacuation plans for 100 year waves, larger structures with reefs can ignore them (but maybe not tsunamis).

I believe so.  I seem to remember two main convection zones - one from the ground upto 45km, a second from 45-60km - something like that - unfortunately, you want to live in that second zone.  Also, there is this mystery of atmospheric superrotation right in the area you want to live.  No current Venusian GCM can account for it.  You probably want to understand it pretty well before building cloud cities.

A counterargument is that the Earth's ocean has convection zones as well, but you don't hear about submarines being sucked to the ocean floor by them.  Presumably it comes down to whether it is a economically solvable engineering problem.

My understanding is that they are domes filled with breathable air which just happens to be a lifting gas in the Venusian atmosphere.  If you didn't want them to float you would have to anchor them firmly to the surface.

Lowest bidder.  Surface, NEAs, atmospheric mining, etc.

Same answers as for Mars?  Presumably Venus is preferred if it confers some economic advantage.  Perhaps the abundant solar energy?

Your domes will leak on Mars as well.  Maintaining a breathable atmosphere is a cost of doing business.  Being mobile to boot is not necessarily a disadvantage.

A presumed advantage.  Venus+50kms has shirt-sleeve pressure, temperature, radiation shielding, .9g gravity, abundant solar energy and a smaller delta-v to most NEAs.  Variable lat/long/altitude may be a small price to pay.  (Might just be castles in the air though