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#1 Re: Civilization and Culture » Intellectual Bigotry? - The chances of it effecting plans? » 2007-04-13 14:55:06

I think most of the "elitist" tendencies will go pretty quickly.  The "brains" are going to need the "average joe repairmen" to survive.  Either that or they're gonna have to do it all themselves.  Mars is going to be radically different then anything we can possibly expect, and it will probably turn out that the practical doer types are more needed than eggheads.


Eggheads, huh? Nice mouth on you. Let me drop a little reality on you, friend. An education isn't something that just gets poured into somebody's head. It represents long years of hard work, harder than you can probably imagine, and when some of us find that we're being looked down on for having done that work, we resent that pretty damned deeply - and rightly so. I didn't think that this was that kind of forum, but that's useful information and I'm getting it before getting too deeply invested in a place where I would just inevitably get spat upon, so in a weird kind of way, I guess I should thank some of you for being so open about being the hate-filled individuals that you are. Most bigots aren't so forthcoming.

Time to edit my bookmark file. It's been nice knowing you.

#2 Re: Life on Mars » The "White Mars" theory - CO2 not water » 2007-04-13 01:40:18

I have not seen much talk of the "White Mars" theory, which posits that all the so-called water flow sighted on Mars is nothing else than liquid and gaseous CO2 that has suddenly erupted (explosively) when underlying beds of frozen CO2 suddenly reach a critical warm temperature and explode. ...


(Sorry to be the skunk at the dinner party...)


Oh, don't be. Skepticism is a good thing. However ...

Let's take a look at what the triple point of carbon dioxide is. Notice that dry ice (frozen CO2) sublimes even in Earth's atmosphere, which is a lot thicker than Mars' atmosphere:

I was lazy and did a search instead of a trip to the library, but this source will probably be accurate:

http://chemmovies.unl.edu/chemistry/sma … SS071.html

A pressure of five atmospheres is cited, so if the ancient Martian atmosphere had a lower pressure than that, liquid CO2 would not have been stable on the surface, and some of these proposed riverbeds stretch for a good distance, something that one would not expect to see in a channel carved out by a liquid rapidly boiling off.

One might ask what this 5 times denser Martian atmosphere was composed of, because CO2 is known to be a greenhouse gas, and a CO2 atmosphere that thick would have made Mars a lot warmer, certainly more than warm enough to melt any water ice on the surface (if not vaporize it outright), I would guess. (Look at what 90 atmospheres or so worth of the stuff has done to Venus). Mars may be further out in the system than we are, but it's hardly circling Neptune.  smile

I would think that a white Mars scenario would actually be more remarkable than a wet Mars one.

#3 Re: Terraformation » Mars getting pounded » 2007-04-08 05:14:01

I think I can see what nickname is trying to say, and perhaps I can give him (or her) a missing piece of the puzzle.

Let's say that earth was cold and bone dry at the surface, with permafrost near the surface, and frequent powerful meteor impacts, each generating large amounts of heat on impact. The heat would generate steam, which would rise up out of the impact crater, cool and condense back as snow or frost on the surface. Why, then, wouldn't we see similar frost on the surface of a Mars with ice under the surface?

Because Mars, unlike Earth, lacks an ozone layer, and ultraviolet light reaches the Martian surface at almost the full strength one would find it at in space. UV photons are energetic enough to break the bonds in water molecules, so illuminating water ice under martian conditions with the high UV levels found there will result in the liberation of elemental hydrogen, which Mars hasn't a deep enough gravitational well to hold onto, and which won't find much of anything to react with on the way out. A little free oxygen is liberated in the process, which then is removed from the atmosphere through the weathering of rocks on the surface which, on Mars, is not counterbalanced through volcanic outgassing, as it is on Earth. The hydrogen ends up gone and the oxygen ends up bound.

That's where your surface frost went.

#4 Re: Terraformation » Venus vs Mars vs Titan » 2007-04-08 04:58:01

A thread about the issue of the effect of convection in the Venusian atmosphere as it relates to this topic, located ... here

#5 Re: Terraformation » Floating Venusian cities or Venus vs Mars vs Titan revisited » 2007-04-08 04:55:00

Yes, I'm creating a second thread when the first one is still active, kind of. I'm a bad, bad man who must be punished most severely. Be that as it may, brief notes written in reply to lengthy queries have a way of being lost in the shuffle when the threads go off on extended tangents, like the one about planetary migration.

Let's focus this one a little more narrowly. We've presented with the almost poetic image of cities floating in the Venusian atmosphere, I guess slowly drifting downward as centuries or millenia of terraformation convert a Carbon Dioxide atmosphere into a Nitrogen-Oxygen one, the cities coming down to a new earth out of a new heaven (and don't ask me where the Nitrogen is coming from, because I have no idea). A few Christian fundamentalists might be absolutely intrigued by the parallel with the image of the new Jerusalem in Revelations, but as much fun as we could probably all have with the subject of the cultural implications of all of this, one can possibly shoot the idea down in one word.

Convection.

The heat engine on Venus is going to be a lot more powerful than the one on earth, and I have to wonder what is going to happen to one of those floating cities when it floats into a downdraft. Yes, it has bouyancy pushing it back up, but one can say the same of any unfortunate swimmer who gets himself caught in an undertow. He still goes down. Any reputable studies done of how much force our meterological undertow (convection powered downdrafts) would place on those bobbing cities, and how far down one of those cities might drop?

In the Mars vs. Venus vs. Titan competition, this strikes me as being a good reason to favor Mars. Yes, Mars can get very, very cold, BUT one can build underground. In fact, given the reality of radiation levels on the surface pre-terraformation, one would probably have to do so. Rock makes an excellent thermal insulator, so even if the surface is frigid, it doesn't follow that a great amount of energy will be needed to keep a subsurface habitat warm, or that a power failure would rapidly throw everybody into the deep freeze. There would be the difficulty of getting sunlight down to any gardens beneath the surface, but if one is willing to build parasols the size of planets, building a series of reflectors to concentrate and collimate sunlight and then bounce a few ferocious sunbeams underground would seem to be a trivial enterprise by comparison.

One which, by the way, might very well be practical with present-day technology, or something very close to it, unlike that planetary parasol. The beauty of one's Martian burrow is that one doesn't have to worry about where it's going to go. Out of these three choices, my vote would definitely be for Mars.

#6 Re: Terraformation » Why magical nano-tech is a long way off » 2007-04-08 03:46:27

Nanotech again? Here's one for you. One will occasionally hear about a remarkable machine that somebody has in mind, in which a lever (yes, a lever) is made using a single molecular bond as the lever arm, the lever itself consisting of three atims or something like that.

The news that molecular bonds spontaneously break from time to time seems to come as a shock to some of the true believers.

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