(Reasonably-long-time-reader, first-time-poster; making my first mark on a point I've been considering for a couple of days already, hence the forthcoming length...)
eviloatmeal wrote:What if we built a big tube - sort of like a hydraulic lift - and then lifted the Jetta up out of the atmosphere by pumping CO2 in underneath it?
That way we kill two birds with one bush: Shoot the cause into space, and flush the symptom out along with it.
This would help flush some
from the overpressure1
, just so long as nobody expects a pipe to space to fully
evacuate itself to vacuum, once its job as a spud-gun/launcher has completed.
Barring a bit of oscilation-induced overspill and after the effects of temperature on localised gas-volume have equalised or matched the atmosphere, you'll probably end up with a tube into space filled with carbon dioxide at roughly atmospheric pressure (perhaps 1.5x?) at ground level and petering out to be exactly-as-thin-as-space-is-at-the-top at the top. Then you've got a pipe full of carbon-dioxide that you don't want to let uncontrollably empty back out, at all. (Although it appears the infamous Lake Nyos episode released several million times more gas than would be potentially contained within this pipe, so it might not be catastrophic on that
You could keep pumping waste gas into the bottom at greater than atmospheric pressure and it would move up and out the open end. But I'm wondering if, as a comparitively 'heavy' gas, it may well just mostly 'pour' back down the outside the pipe if not also given supplemental heat at the top end to give it some form of brownian escape velocity to rival the lighter elements that are
being slowly stripped away by the various methods of atmospheric loss we already have. Certainly you'd be putting a large amount of energy into the 'CO2
waterfall', so I hope you've at least used carbon-neutral methods to power the CO2
extractor/pressuriser, if not in the construction of the space-pipe itself.
(If the pipe was made to reach beyond geostationary, rather than just 'into space', then you'd perhaps have something like the inverse of the siphon idea, from What-If 143. Enough pressure at the bottom2
to make the 'constrained atmosphere' within the tube be thick enough and extensive enough to stretch beyond the limits of any
practical atmosphere, against the centripetal/whatever force. All gas exiting the tube top would spill 'outwards'. But then so would the car. But then that would cause no
further impact on Earth's environment, by re-entering, except perhaps by a fluke of orbital mechanics or some other outside mechanism shoving it back again...)
If I had a spare envelope, I probably should have been making some calculations on the back of it. But it appears I didn't.1
Needed to 'float' the projectile, although it wouldn't be buoyancy, and would depend on whether you're making it an air-tight plug or relying on the gas rushing past at great speed, probably somewhat greater than the terminal velocity of the projectile, however so affixed into the tube.2
And a suitably pressure-resistant pipe. Is graphene laterally impermeably to CO2
? Could a single-layer 'metre-or-so'-diameter graphene tube hold both itself up from the pressure (perhaps graphene-laying nanomachinery adding to its top-edge using, as feedstock, the carbon-rich gas being pumped past or at least into a temporary 'cap'?) and
resist the outwards pressure eventually required? Or would it need to be multi-walled, to be sure...Hmmm....