Obviously the solution is to colonize Venus instead. I mean, at the rate things are going here on earth, moving to Venus wouldn't be that big of a change.
Well, I mean, technically you're right in that we've got oceans that are deep enough to say that we've got conditions with the same surface pressure here... but water doesn't quite heat up the same way a column of air does when compressed unless you've got like gas giant quantities of it. Honestly there really isn't much that gets on my nerves as badly as the idea that Venus is so hot because CO2 is the devil instead of the fact that there's something like 90 times as much atmosphere sitting on the surface under roughly the same acceleration as ours is with roughly the same area under it as ours has.
Fun thought experiment: suppose you have a tube floating in space with an engine capable of producing and sustaining 1 G of acceleration along the long axis which is currently turned off, let's say it's 10 km long (and made of oh, Xeelee Construction Material so it can withstand said acceleration) with a cap on the end where the engine is, the other end is open, and the diameter of the tube is 50 m. Suspended within it are evenly distributed super bounce balls which are on average 1 m apart from each other and the nearest wall of the tube, and for the fuck of it, let's say that they're not moving at all.
What happens inside the tube when the engine is turned on and it begins accelerating at 1 G?
Did you guess "the super bounce balls remain evenly distributed and nothing else happens?"
Of course not, you probably had a general image of the engine end of the tube colliding with the nearest balls, accelerating them, colliding with more, etc, right?
After it has moved the full 10 km distance so the acceleration would have a chance to affect all the balls, what would it look like?
After enough time for it to approach an equilibrium state what would it look like?
Did you guess there would be a greater density of super bounce balls at the end near the engine?
I'll assume you did, but what about the rest? Would they all end up packed at one end or would the ones bounced off the more densely packed ones end up scattered towards the open end until only the few fastest ones were left there?
Assuming that the balls were durable enough to not end up smushed into a blob of goop at the engine end, those ones would be getting bashed far more often than the ones further away right?
So they'd be bouncing and buzzing around down there rather violently while the ones knocked the other way would share their energy with ones they met going that way and end up slower as the rest came towards them.
So you'd expect it to end up with a sparse collection towards the open end, some moving fairly quickly, some damn near hanging in place relative to the walls, closer to the middle there would be a greater density and a higher average velocity, while the engine end would have the greatest density and highest average velocities.
Now label the open end "up" and the engine end "down" and imagine the tube had been created in the initial motionless state with the closed/down/engine end sitting on the surface of a planet with 1 G surface gravity.
The same thing would happen, gravity is acceleration, after all.
If you make the tube 100 km long with the same 50 m width and 1 m spacing before undergoing 1 G acceleration, would the bottom/engine end have the same average velocity distribution and density as the 10 km tube?
Of course not.
Now, if you waited long enough you'd expect the system to relax until the balls were all packed at one end or the extreme outliers got ejected entirely from the open end, so let's suppose any ball visible when looking down from the open end were to receive a tiny kick towards the engine end, call it 1 cm/s for now.
This little bit of additional energy should be more than enough to keep the system from settling down for a very long time, if ever, yeah?
So now we've got what is essentially a column of atmosphere on a planet receiving energy from above and accelerated by gravity, it is most dense at the surface, and it will be warmest at the surface even if none of the energy from above were to reach that surface directly.
Kinda like Venus, where the initial 2,600 W/m2 is reduced to a couple hundred W/m2 by the time you're down inside the clouds at a habitable altitude, and something like 5~15 W/m2 at the surface which is warm enough to be giving off something like 16,000 W/m2 in black body radiation.
Is it warm down there because of the huge amount of gas being accelerated by gravity, but not allowed to cool due to the cap of clouds and trickle of sunlight preventing it from relaxing?
Or is it warm because the trickle of sunlight that made it down to the surface made it warmer, which made the gas near it warmer, and then that gas began to transfer heat back to it's own heat source apparently?
It is dishonest to imply that there is even a remote similarity between conditions here and those on Venus, and as much as I love Sagan I wish he would have shut the fuck up rather than popularize the idea that Venus being hot means Earth will get hot because they're totally comparable, when they're actually as different as the 100 km tube and the 10 km tube examples above.
You can still get all worked up and whatnot about the climate if you want, but don't spread that particular bit of nonsense by implying Venus is hot due to the atmosphere there being ~95% CO2, please.
I mean, fuck, Mars also has a roughly 95% CO2 atmosphere, but that would be comparing a 1 km tube under 0.4 G acceleration to the other two, and that might be overly charitable really.
Then you've got Jupiter with a thousands of km long tube at several G's of acceleration which ends up climbing over 1000 C before you even reach the goopy liquid hydrogen, and probably peaks out around 18,000 C or so at the core. Jupiter emits more than it receives, but I'm sure if someone tried they could find a way to blame it on a greenhouse effect!
This isn't supposed to be a strange idea: gas under acceleration by gravity ends up with a pressure gradient, the temperature at the bottom of the pressure gradient is highest (barring extremely rarified sections where the temperature may be hundreds of C because each of the molecules whizzing around up there is rarely interrupted by a neighbor to transfer/lose energy), and this takes place regardless of the particular composition of said atmosphere.
Now, engineering sulphuric acid resistant plants which hang themselves in the upper atmosphere with grown oxygen bladders and sail along to keep themselves on the day side longer? That's another story.
Why would we be shaken around violently? What's the windshear across the scope of a venusian blimp at the appropriate altitude? Needs far more study. Being just slightly out of sight, being roughly between the acid clouds and the acid haze layers...
I've had a look for various facts and figures, but I can only find the windspeeds, with which a floating venusian city would be freely travelling, not much about localised turbulence outside of the polar vortices (and, even then, it's mega-scale convection currents, not anything to indicate inexplicable gusts).
Yeah, the winds are FAST, but steady as hell since the atmosphere does the actual "Earth-like day/night" rotation rather than the "I've been having the worst day ever for months now" thing the surface does.
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Topic: SCIENCE, Gravitational waves, and the whole LIGO OST! (Read 516875 times)