Hydrogen is not picky about fuel air mixture; it will explode at any concentration between 4% and 74% (in air). I rewatched the footage and it sure looks like an explosion to me.

https://www.youtube.com/watch?v=OetzoO3Csj4

The thermite paint hypothesis is interesting but a bunch of hydrogen airships exploded. The Hindenburg was partly made from metal recovered from the R101. The R101 exploded on her maiden voyage.

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LargoLasskhyfv 5 days ago | parent [-]

At 24 seconds in, that looks indeed fast. But still not what one would expect of "Knallgas" going boom.

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maxbond 5 days ago | parent [-]

We might expect it to look differently, but it would appear that that's exactly what a hydrogen explosion looks like. By what means do you believe the camera, at least a hundred meters away, shakes?

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LargoLasskhyfv 5 days ago | parent [-]

Did it shake by a blast? Or was it just hastily turned around, to catch the flames?

I've watched many videos about that in the past, even ones where there were overlays with 3d-point-clouds.

Not in the mood to analyze this one further. Have doubts about it being really 'real time', conversion errors, whatver.

Maybe our understanding of 'explosion' is different. By explosion I mean something coming apart fast in an instant, with a bang, things flying away, shockwave.

That wasn't that, more like a https://en.wikipedia.org/wiki/Deflagration

Caused by whatever. Very likely propagated by the flammable paint on the hull. Like a flash fire.

Which was my initial point.

	▲	maxbond 5 days ago \| parent [-]
		For sure, in my mind a deflagration is a type of explosion, but I certainly don't mean to quibble about terms or to litigate this video more than is interesting to you. I guess for me, I don't know whether it was hydrogen leaking around the rear or thermite in the paint which caused the ignition, and I don't know whether a helium airship would've also caught fire and how disastrous such a fire would've been. But I do know that what happened next was that the hydrogen ignited and the ship blew up. That being said I think airships are a criminally under explored mode of transit, and that the Hindenburg shouldn't be a reason to abandon it altogether. At a minimum we're much more experienced in handling hydrogen now, and modern hydrogen blimps don't seem to blow up all that often.