>>16922893
weather balloons/UFOs

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>>16922895
>he doesn’t know

>>16922893
Off the top of my head (some of these could be wrong) there just isn't a market for them. They're slower than airplanes, require a bigger crew to operate, scale poorly and require more infrastructure.
Though I was delighted to see that some conspiracy theorists already came up with some bullshit about how plane lobbyists set the Hindenburg on fire to end the Airship or some shit like that.

idk I feel like with modern materials you could probably achieve some crazy results with blimps, maybe even some kind of personal vehicle that combines buoyancy with drone tech for improved safety and battery life and less risk of terrorisms

>>16922893
They are kinda just bad. They theoretically have a niche but it's just so limited that there's not a big enough market to justify anyone to build a bunch of balloons. They are mostly useful for the 2 purposes they are currently used which is aerial advertisement and leisure rides around landmarks or vistas.

They should make a blimp filled with vacuum for extra lift.

>>16923167
Actually feasible. Just use some kind of ultra low density foam containing microscopic vacuum bubbles so you don't need tons of steel to stop it from collapsing.

>>16923169
It would be even better if instead of bulky foam you just shot some high energy particles in there and they would bounce off the walls and each other supporting the walls and the vacuum between them that way

>>16923105
>require a bigger crew to operate
I think this is the real killer. it's pretty much 1:1 crew to passengers, whereas with an airliner it's more like 1:50 (at least in the US)

>>16923105
>scale poorly
I think this one is often overlooked. I did some back of the napkin math a while ago and decided that if you put as many passengers on a a380 as the Hindenburg, each one would get more space and pay less per ticket. that's on top of getting to their destination in a quarter the time.

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>take a trip on a vacuum airship
>you know the ship could implode and kill you instantly at any moment
>but at least it's not gas that can burn and smoke and hurt the environment :)

>>16923105
>require a bigger crew to operate
What does all that crew do? Do modern blimps really need that much? Can modern technology replace them?
>scale poorly
They scale fairly well in fact, because volume (and lift) increases faster than linear size or surface area.
>and require more infrastructure.
More than 2+ km long 60m wide landing strip, ideally two, pointing in different directions?

Being slow is really the biggest issue, weather dependence is another one.

>>16923217
Directly comparing economy of the tech 70 years apart has little meaning. You can compare specs though. For example, Hindenburg had an average weight of 215 tons and experienced around 90kN of drag force at 125 km/h cruise, this yields an L/D ratio equivalent of over 23 which blows every modern airliner out of the water with only a few coming close. A modern, properly aerodynamically optimized design with more efficient turboprop engines would have the fuel economy no airplane has any chance to ever reach. So even if it had smaller passenger capacity and longer travel times, it could still be very much competitive.

>>16923272
>For example, Hindenburg had an average weight of 215 tons and experienced around 90kN of drag force at 125 km/h cruise, this yields an L/D ratio equivalent of over 23 which blows every modern airliner out of the water
not when you account for the four-times-longer journey.

>>16923274
>four-times-longer journey
More like 7, but it doesn't matter. Fuel economy is per distance unit travelled.

>>16923278
Fuel-economy per distance unit travelled is irrelevant because no one will pay for a 20h flight that could be 3 hours with a plane, one which is dozens of times more vulnerable to bad weather cancelling the whole thing

>>16923278
yes so you're burning 90kN of engine power for seven hours instead of one hour for the same "distance unit travelled", thus you use seven times as much energy to travel the same distance.

>>16923291
>no one will pay for a 20h flight that could be 3 hours with a plane
People ride trains perfectly fine even when they can take a plane.
>dozens of times more vulnerable to bad weather cancelling the whole thing
That is a valid concern

>>16923299
Work = force * distance
When travelling twice as fast against the same drag force you're doing twice the work and burning twice as much fuel, i.e. the same amount per unit of distance
lrn2physics

>>16923291
>no one will pay for a 20h flight that could be 3 hours with a plane
51% of airliner passengers are traveling for personal leisure. Most of those would likely be fine with a 20 hour trip, maybe even prefer it if conditions were nicer and prices lower than planes.