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Why is Venus hell and Earth an Eden?

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Re: Why is Venus hell and Earth an Eden?

#271

Post by glenstein »

Symmetry wrote: post #243
rkagerer wrote: post #124

Venus is arguably the worst place in the solar system From another perspective, its atmosphere is "one of the most Earth-like in the solar system", and scientists long ago postulated the idea of establishing floating cloud cities. Big balloons filled with nitrogen and oxygen would naturally settle at the right altitude, 30 miles above the surface, where gravity, ambient pressure, and radiation aren't far off that of…

The Venusian atmosphere at that altitude is super dry, only a few score ppm of water making it much drier as Earth's Atacama desert. So while that water vapor is extremely acidic in terms of raw ppm its not too far outside the limit of what OSHA allows and is probably fine since you aren't breathing it.

If I understand correctly there's still a little bit of residual hydrogen bound up in the sulfuric acid molecules. And if you added it all up close to the amount of water you'd get from one of our Great lakes in North America. (At least if you combined it with oxygen, of which there's plenty on Venus).

The article mentioned something about heavy water which I don't understand very much. But it's a problem.

The tragedy of both Mars and Venus is that billions of years ago? It seems like they both might have had abundant liquid oceans of water. Which doesn't mean they would have supported life, but they would have been so much closer to habitable and a much better starting point. Instead, it's like if you're deadbeat brother house-sat them for a weekend and threw a bender and trashed the houses, that's what we're left with now.

Re: Why is Venus hell and Earth an Eden?

#272

Post by woopsn »

b112 wrote: post #126
woopsn wrote: post #97

Earlier quoted context omitted.

My impression was that pulverized rock/iron is not actually "soil", so after forming the atmosphere you need lengthy biochemical processes playing out on the surface. I admit though, I don't know too much about this.

I think that we should consider "the future". Yes, it's intangible but consider this; go back 2 centuries and ask someone if they could setup a business concern which produced millions of widgets a year. They'd think you daffy. Now beyond that, ask them to produce any manner of modern device with the precision and high consistency we have. Again, they'd think you mad, and think that such was impossible. Yet here we a…

You make a lot of good points. Including that the technology to do all that incredibly dangerous to develop - I still can't see a path to terraforming where in the end it's human people left to take pleasure in Mars.

I had thought due to the eons we'd simply have evolved, but even on shorter time frames there is the transhumanist possibility. When we can engineer rabbit that eats chlorine moss, I don't know what we're aiming for at all. "People" by then could have robust gut culture that just digests the regolith.

There's a difference between considering all this vs thinking it's realistic. It's speculation, as any forecast into the centuries ahead must be.

Re: Why is Venus hell and Earth an Eden?

#273

Post by glenstein »

bryanrasmussen wrote: post #186
JumpCrisscross wrote: post #147

Earlier quoted context omitted.

> such a way that your inflatable balloon city comes to a gentle stop, 30 miles up, and just floats there? Literally how floating works. > Worse still, when people need to leave and return to Earth, how do you launch a rocket from the balloon city and return to orbit? By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.) > Where are materials manufactured for…

>By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.) I believe they are having trouble envisioning how you would launch rockets from a balloon city without disturbing the equilibrium of the balloon city because it is assumed that rockets thrusting down with great force would damage the balloon city in a way it would not easily recuperate from. I also find t…

>I also find the idea difficult to understand, but assume that is because it is in an area I know nothing about and the problems that I think sound bad are actually totally solvable engineering problems otherwise it would not be have been suggested as a solution by engineers expert in that area.

A refreshingly sober approach that I think is a lot more healthy than hip firing incredulous questions.

I agree though, I don't intuitively understand how it would work. I would think you would do horizontal takeoffs. Also Seveneves by Neil Stevenson gives some interesting examples of ways to escape gravity wells without rockets, but I won't spoil anything there.

Re: Why is Venus hell and Earth an Eden?

#274

Post by [deleted] »

robotomir wrote: post #242
HPsquared wrote: post #201

Earlier quoted context omitted.

Living on a ship at sea, or underground / underwater, should give enough protection against whatever post-apocalyptic situation exists on Earth, it's pretty much always going to be more survivable than Mars or outer space. You might need a protective suit, air filters etc. Still 100x easier than having no atmosphere at all.

What if the threat is not environmental collapse but hostile government?

[deleted]

Re: Why is Venus hell and Earth an Eden?

#275

Post by glenstein »

JumpCrisscross wrote: post #195
bryanrasmussen wrote: post #186

Earlier quoted context omitted.

>By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.) I believe they are having trouble envisioning how you would launch rockets from a balloon city without disturbing the equilibrium of the balloon city because it is assumed that rockets thrusting down with great force would damage the balloon city in a way it would not easily recuperate from. I also find t…

> how you would launch rockets from a balloon city without disturbing the equilibrium of the balloon city because it is assumed that rocks thrusting down with great force would damage the balloon city in a way it would not easily recuperate from It's a floating platform. Same as the ones SpaceX lands its rockets on. Same as a gunboat firing projectiles. Will a launching rocket impart force to the platform? Yes. But u…

>It's a floating platform. Same as the ones SpaceX lands its rockets on. Same as a gunboat firing projectiles.

It's a great comparison that helps me understand it a bit. In many respects, Venus's atmosphere is as heavy as an ocean. That said, I can still see how if you're talking about the upper atmosphere with pressure similar to what you would have on Earth, the force necessary to do a straight vertical takeoff imparted against a platform seems like it could cause problems.

But it might just be the Archimedes thing of "give me a prop large enough and deliver long enough and I can move the world" applied to atmospheric dynamics, e.g. enough buoyancy and you're good to go. I just don't know how much is "enough" when you're talking about Venus and if that runs into prohibitive engineering complexity that makes it different from our familiar Earth examples.

Not saying it can't be done but I think that one question at least, was reasonable.

Re: Why is Venus hell and Earth an Eden?

#276

Post by Symmetry »

glenstein wrote: post #271
Symmetry wrote: post #243

Earlier quoted context omitted.

The Venusian atmosphere at that altitude is super dry, only a few score ppm of water making it much drier as Earth's Atacama desert. So while that water vapor is extremely acidic in terms of raw ppm its not too far outside the limit of what OSHA allows and is probably fine since you aren't breathing it.

If I understand correctly there's still a little bit of residual hydrogen bound up in the sulfuric acid molecules. And if you added it all up close to the amount of water you'd get from one of our Great lakes in North America. (At least if you combined it with oxygen, of which there's plenty on Venus). The article mentioned something about heavy water which I don't understand very much. But it's a problem. The traged…

A big issue is that neither seem to have developed photosynthetic life[1] and without a lot of oxygen in the atmosphere they don't have an ozone layer. That means that UV light penetrates further and breaks up water into its constituent parts allowing the light hydrogen to be blown away by the solar wind over geological time scales.

[1] It's looking increasingly plausible that Mars developed primitive life, but I'd bet heavily against photosynthesis. That took way longer than chemosynthetic life on Earth.

Re: Why is Venus hell and Earth an Eden?

#277

Post by ben7799 »

a3w wrote: post #229
rkagerer wrote: post #124

Venus is arguably the worst place in the solar system From another perspective, its atmosphere is "one of the most Earth-like in the solar system", and scientists long ago postulated the idea of establishing floating cloud cities. Big balloons filled with nitrogen and oxygen would naturally settle at the right altitude, 30 miles above the surface, where gravity, ambient pressure, and radiation aren't far off that of…

Venus is room temperature with low radiation, if you dig in. Living on Venus was floating around as an easier alternative to living on the Mars surface. Room temperature is 21°C, I have no idea how many freedom fries units that is.

The Fahrenheit scale is European, not American. It was created in Poland well before the United States broke off from Great Britain. We're just slow to change.

Re: Why is Venus hell and Earth an Eden?

#278

Post by glenstein »

eloisant wrote: post #181
JumpCrisscross wrote: post #147

Earlier quoted context omitted.

> such a way that your inflatable balloon city comes to a gentle stop, 30 miles up, and just floats there? Literally how floating works. > Worse still, when people need to leave and return to Earth, how do you launch a rocket from the balloon city and return to orbit? By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.) > Where are materials manufactured for…

I'm sure we can figure out stuff, but I guess my point is, why would we do that at all? How fucked up Earth needs to be than living on a floating oil platform above Venus is better? The point is already hard to make for the Moon or Mars.

I understand this became a hot take in recent years, because you can always just "Colonize Earth". I do think there is an independent strategic value in terms of existential threats. It shouldn't be a rationale for abandoning environmental preservation and conservation on Earth.

One thing I see, all too often in Internet comment sections is things that could be complimentary are turned against each other and juxtaposed as if one interferes with the other. I don't know if there's a name for that but it happens often enough that it should have a name.

Re: Why is Venus hell and Earth an Eden?

#279

Post by potato3732842 »

dredmorbius wrote: post #261
potato3732842 wrote: post #249

Earlier quoted context omitted.

>The dock/barge case is addressed here: https://news.ycombinator.com/item?id=45330638 > Addressed naively and wrongly hence the ongoing discussion >An aerostat doesn't float on a liquid at stable equilibrium through draft displacement, it is suspended in a fluid, with the problems noted previously. If you let a baloon go will it reach space? No, because the atmosphere is not constant density. Balloon type objects hav…

The analogy isn't letting go of a balloon, it's of dumping a large mass of payload (rocket + fuel) from an aerostat quickly. The aerostat will rise. It will float higher in the atmosphere, with decreased pressure around it. It will expand. It will then rise still further. And there's no ready supply of solid or liquid ballast (as would be available on a near-ground cargo drop) to compensate for the lost mass. This is…

>The aerostat will rise. It will float higher in the atmosphere, with decreased pressure around it. It will expand. It will then rise still further.

Now explain weather balloons. Why don't they rise to infinite altitude?

Like I said, the numbers are all wonky, but the principals are the same.

If there is too little mass for the amount of bouncy just compress your gas and hold some reserve buoyancy/balloons to inflate if you expect to be able to deal with rapidly increasing mass.

Re: Why is Venus hell and Earth an Eden?

#280

Post by euroderf »

bryant wrote: post #254
ubermonkey wrote: post #250

Earlier quoted context omitted.

A shockingly useful "quick and dirty" estimate for C to F for temps humans are likely to encounter is 2x + 30. It's not precise at all, but for purposes of "what does that feel like outside" or "should I bring a sweater" it works pretty well. 21C would, by this estimate, be 72F. The true conversion is just shy of 70F, so, again, it's not correct but it's close enough for this kind of conversation.

for what it's worth: add 9 degrees F (or 18 if it's easier to remember) for every 5 degrees C (10 C, easier), and peg 32F to 0C. You get: -40F=-40C -22F=-30C -4F =-20C 14F =-10C 32F = 0C 50F = 10C 68F = 20C 86F = 30C 104F= 40C and then approximate in between from there. It's quick enough for me now that I skip the 2x+30.

10c is 50f (easy to remember) 27c is 81f (it's all threes!)
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