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Comment by ReptileMan | Hacker News Reader

If we get serious about reducing emissions - airtravel has to go in its current form. So there could be an opening for lighter than air approach.

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Nah. The most likely scenarios are a switch to pure ammonia combustion and/or sourcing "all green" methane to make carbon-neutral or near-zero emissions flight. Unfortunately, ammonia combustion is inefficient and synthetic hydrocarbon fuel is far too expensive atm.

We'll never get away from the brutal physics:

1. Long flights require planes to get lighter (burn fuel) as they go further so battery power doesn't work.

2. Wings are just too damn efficient at producing lift.

3. Putting enough on-board safe-station-keeping power (weight) on an airship makes it a very poor airship.

4. A very good airship is least safe to fly precisely where is has the most potential to cause damage and loss of life.

>1. Long flights require planes to get lighter (burn fuel) as they go further so battery power doesn't work.

Up to a critical density/weight/kwh, afterwards it doesn't matter.

This would be such a big dent in humanity learning that the people on the other side of the world are just that: people.

I sincerely hope we will be able to maintain current air-travel by switching to efuels and similar means.

Humanity having to ditch air-travel at todays levels would be a massive social negative.

We won’t. We still haven’t even started touching geo-engineering at scale yet.

Getting humanity to give up anything without either killing or enslaving a large swath is not happening or realistic. We can’t even get rid of nuclear weapon stockpiling which has a much lower positive vibe from nearly everyone.

I just don't see how it's a better idea than high-speed rail.

Probably cheaper to deploy, but the capacity will always be low and speed slow.

I'm not one for an "either or" generally, but I really have a hard time seeing the benefit of blimps beyond "this is neat and kinda fun".

Intra-continental I don't think anything beats high-speed rail. Inter-continental I don't think high speed rail is viable, unless you have a transatlantic locomotive in your pocket that you aren't telling anyone about.

I don't think this is an issue. It's a 1% problem.

Most of the population of the world lives on 2 contiguous land masses. Flights to bridge the masses is fine but would represent a small fraction of the transport needed.

Rail doesn't have to solve all problems. It's a good solution to most problems.

But back to the blimp proposals, I can't see how a blimp would be a better option vs a boat. (Traditional flight is probably better than either).

https://en.wikipedia.org/wiki/Submerged_floating_tunnel

Imagine a hexagonal grid of these between continents, with aqua-farms, data-centers, resorts, casinos, floating cities/solar/wind sprinkled in between. Err... Aqua-Loop?

Maybe 'grow' them 'in-situ' like corals, funghi, sponges, seaweed, algae, bamboo, whatever, by means of genetic manipulation.

edit: Not to forget, conduits for HVDC, ZBLAN, and all sorts of pipelinable stuff for the global super smart grid.

FUCK YEAH!

edding: Icebergs, yes, yes, Gridguards no less!

"I don't see how it's a better idea than high-speed rail" is pretty much my follow up to almost any proposal for transportation improvements in the states, which critically are never rail, what wild is almost everyone I've ever spoken with agree and yet..crickets

That's because the only way to make rail work in the US is via a federal government implementation.

New rail will be very expensive to install and politicians are afraid of saying "we may need taxes to cover this".

High speed rail is slow. NY to LA, Miami to Seattle will take forever. And a tunnels under the Rockies will be quite the challenge.

> I just don't see how it's a better idea than high-speed rail.

How can you build a railroad across an ocean?

https://en.wikipedia.org/wiki/Submerged_floating_tunnel

That does not appear practical to replace intercontinental flights.

One of the reasons why air travel is practical, and rail isn't, is because you don't need to build any infrastructure between airports. The other reason is because you can adjust flights between airports without needing to adjust infrastructure.

That would depend on several things. For one, how dense that grid would be. For another, what would be built into/next to/adjacent to the nodes/hubs and spokes of that grid, making building such a grid of floating, submerged tunnels worthwile in the first place. Hen<->Egg, bootstrapping, yadda yarr yarr...

edding: Also imagine something like really long freight trains, a mile or so, double stacked, only running at something like 200 mph. And compare the capacity with any freight plane in use, vs. the speed of container ships. Also the possibility for pipelines right next to it. Conduits for energy and data. On and on and on...

edding: In case you havn't noticed, linking myself, elsethreads:

https://news.ycombinator.com/item?id=43131224

https://news.ycombinator.com/item?id=43130680

It's 2-4% at worst. While it might be nice to reduce, it's not pressing.

The transition is well under way for the big 3 carbon emission sources -- electricity generation, ground transportation and heating. After agriculture, air travel is one of the biggest remaining obstacles to net zero.

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