So Goodyear has kind of proven they are viable. The problem is that helium scarcity is an issue: https://physicstoday.scitation.org/do/10.1063/PT.6.2.20200605a

So Goodyear has kind of proven they are viable. The problem is that helium scarcity is an issue: https://physicstoday.scitation.org/do/10.1063/PT.6.2.20200605a/full/ https://physicstoday.scitation.org/do/10.1063/PT.6.2.2020060... If we suddenly built thousands of new helium blimps. We will be back to having lots of trouble. It's not really practical to goto scale. Hydrogen blimps? Well that ended with the hindenburg. https://en.wikipedia.org/wiki/LZ_129_Hindenburg#/media/File:Hindenburg_burning.jpg https://en.wikipedia.org/wiki/LZ_129_Hindenburg#/media/File:... The interesting thing. While hydrogen is dumb for cars. It is technically super brilliant for blimps. Not only is it for your lift, it's your fuel. Blimps are slow, instead of a few hour flight from nyc to la. it's like 2 days. The thing is, we are going to see this resurgence. Materials science has greatly improved since 100 years ago. Hydrogen will almost certainly be safe to do. It'll be a huge cost though. I wonder if this would be possible: https://en.wikipedia.org/wiki/Vacuum_airship https://en.wikipedia.org/wiki/Vacuum_airship Maybe with modern tech we could make it happen. No risk suddenly of big fireballs. Could be a big deal and better yet maybe even solar panels all over the top of the blimp.