261–270 of 385 posts
I would say no, because if they had stopped reminding us of it every single time, we'd have airships back in the sky by now.
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If I were living on Mars, I would absolutely not be willing to let the rare minerals get sent up into space then down to Earth. Learn to recycle, damn lazy Earthers.
I think you'd appreciate the complex manufactured items and goods requiring plastics that only Earth can export to you. If tons of mined materials or produced goods thereof were the cost, you would be keen to pay it.
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I mean if the alternative transports also don't work in bad weather I'm not sure you can use some failures to disqualify airships. So long as they work "more" days of the year it's a better solution. Weather doesn't really sneak up on us anymore.
Aircraft are substantially more resistant to bad weather: you can fly an airplane into a hurricane. Aircraft are also a lot faster -- it's unlikely that a thunderstorm will catch up with you (max speed of a storm is something like 50-80 mph) and trips are a lot shorter. Airships are much closer to the storm speed and may need to stay aloft for several days. That makes it more likely that they'll hit unexpected weathe…
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I wonder if there is a sweet spot between the two. Have a rigid structure with an internal pressure less than one, but more than zero atmospheres.
There is not. The costs of dealing with pressure differentials are extreme, and there are a lot of small thorny issues. For one, if you have a pressure differential, you need to care very much about even the tiniest leaks. A surprising fact about airships is that they don't actually have to be very gas-tight to work just fine. As people found to their surprise in both world wars, you can shoot an airship full of smal…
wait.. how did the rest survive being on a giant fiery gas balloon hundreds of feet in the air?
Probably a very stupid question, but can someone help me understand the following: once you have airships that have a rigid shell, why isn't using a vacuum better than a lifting gas? Isn't the buoyant force simply the result of displacing some volume of air with something less dense? (i.e. any excess lifting force comes from the fact that the mass of the hydrogen or whatever is less than the mass of the displaced air…
I think the key is in the wikipedia article: You only gain 14% lift with a vacuum vs helium. The tradeoff is either: - Build a pressure vessel to withstand the differential to the atmosphere - Let the helium do the pushing from the inside but make the thing 14% bigger I don't see how the vacuum ever wins.
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I looked into this a while back, and there's simply no feasible way to construct an airship from known materials that could sustain a vacuum of the necessary volume without being crushed by atmospheric pressure. You can keep reinforcing the vacuum chamber, but by the time it's strong enough, it'll be too heavy for the buoyant forces to lift it.
You could make many small vacuums in a honeycomb structure but at that point is just cheaper to use a lifting gas...
> the Hindenburg erupted into flames in front of newsreel cameras, killing 35 of the 97 people on board in the inferno. wait.. how did the rest survive being on a giant fiery gas balloon hundreds of feet in the air?
Is there anything there that would not have been true 50 years ago? What's changed about airships that makes them practical now, when (presumably) they weren't before?
But when you cover a airship with lightweight solar foil and power it electrical, you could get transportation for allmost free (in sunny areas). But even without that, they fly way more economic, since you get the uplift for free. (starting of a plane and reaching height, consumes the most fuel)