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[-] Kolanaki@yiffit.net 10 points 6 months ago

Why not use helium instead of hydrogen, and also maybe don't coat the skin in thermite? 🤷‍♂️

[-] SkaveRat@discuss.tchncs.de 33 points 6 months ago

because helium is f'ing expensive an valuable. Once used, it's basically gone. There's a reason that countries have strategic helium reserves.

Also on the topic, modern day companies that try to resurrect airships exist. Just every single one of them goes bust, as it's just not really a viable solution for modern transport

[-] officermike@lemmy.world 4 points 6 months ago

On the optimistic side, helium is a product of nuclear fusion, so we will eventually be able to produce it.

[-] qjkxbmwvz@startrek.website 12 points 6 months ago

I'm too lazy to work through the numbers but I think helium production would be very small


which is another way of saying fusion (as envisioned for energy use) produces a huge amount of energy.

[-] grue@lemmy.world -4 points 6 months ago

fusion produces a huge amount of energy.

That's the kind of claim that'll age like "640k ought to be enough for anyone."

[-] qjkxbmwvz@startrek.website 1 points 6 months ago* (last edited 6 months ago)

Googling around, you get about 1e11 kJ/gram of He produced (source.

Wikipedia says Hindenburg volume is 200,000 m cubed . Multiply by density of He at stp and you get north of 1e7 grams.

Multiply and you get 1e21 J. Estimate for worldwide energy consumption in 2010, from Wolfram Alpha, is half of that.

So, if all energy were from local fusion, it would take about two years of production to fill a single Hindenburg-sized Zeppelin. That is a huge amount of energy.

I don't think it's equivalent to compare energy with RAM like this. Energy is the realm of thermodynamics; things like boiling water don't care about technology, they just need a certain amount of energy. Unless we're talking about fundamentally new uses of energy, like floating cities or something whacky, I think the amount of energy here is really, really big.

[-] pete_the_cat@lemmy.world 2 points 6 months ago

If it's so "expensive and valuable" then why have we been using it for decades to fill balloons here in the US? It costs like a few bucks to buy a bunch of balloons and get them filled. I just looked it up and Dollar Tree (a dollar store) will fill them for free as long as the balloons are purchased there.

You can buy a 14.9 cubic foot tank from Amazon for $80 (unfilled of course), which is enough to fill 50 balloons.

[-] SkaveRat@discuss.tchncs.de 10 points 6 months ago

If it’s so “expensive and valuable” then why have we been using it for decades to fill balloons here in the US?

good question! lots of people actually lobby to wither ban this (unlikely that it will happen) or at least make it more expensive.

Helium is increadibly important in the medical and science field. Having it "wasted" in party balloons is honestly, well, wasteful (if fun).

Helium is already getting more expensive, and it will only rise in the future

The reason it was so cheap in the last couple decades is, that the US basically sold off most, if not almost all of its stockpile, dumping the price on the market.

And now with very few sources for helium worldwide, the price will go up massively in the next couple years

[-] someacnt_@lemmy.world 1 points 6 months ago

Where do I buy this helium thing

[-] limelight79@lemm.ee 1 points 6 months ago

I thought I read that the helium used in party balloons was a grade that wasn't useful for medical devices. For example, this link. They of course are a company that is selling party balloon helium, so... This link might be more reliable.

[-] GenosseFlosse@lemmy.nz 1 points 6 months ago* (last edited 6 months ago)

You know whats basically free, lighter than helium and not dangerous: Vacuum! /s

Quick, someone give me Elons private number, i know how to revolutionize air travel!!1!

[-] Subverb@lemmy.world 23 points 6 months ago* (last edited 6 months ago)

You may know this, but the Nazis were forced into using hydrogen instead of helium because the only commercial sources at the time were in he USA and we wouldn't sell it to them. But also, since the ship was built for German propaganda they would have wanted it to be a fully German endeavor.

The Hindenburg was painted with silvery powdered aluminium, to better show off the giant Nazi swastikas on the tail section. When it flew over cities, the on-board loudspeakers broadcast Nazi propaganda announcements, and the crew dropped thousands of small Nazi flags for the school children below. This is not surprising, because the Nazi Minister of Propaganda funded the Hindenburg.

At that time, the US government controlled the only significant supplies of helium (a non-flammable lifting gas), and refused to supply it to the Nazi government. So the Hindenburg had to use flammable hydrogen.

As the Hindenburg came in to Lakehurst on May 6, 1937, there was a storm brewing, and so there was much static electricity in the air - which charged up the aircraft. When the crew dropped the mooring ropes down to the ground, the static electricity was earthed, which set off sparks on the Hindenburg.

The Hindenburg was covered with cotton fabric, that had to be waterproof. So it had been swabbed with cellulose acetate (which happened to be very inflammable) that was then covered with aluminium powder (which is used as rocket fuel to propel the Space Shuttle into orbit). Indeed, the aluminium powder was in tiny flakes, which made them very susceptible to sparking. It was inevitable that a charged atmosphere would ignite the flammable skin.

In all of this, the hydrogen was innocent. In the terrible disaster, the Hindenburg burnt with a red flame. But hydrogen burns with an almost invisible bluish flame. In the Hindenburg disaster, as soon as the hydrogen bladders were opened by the flames, the hydrogen inside would have escaped up and away from the burning airship - and it would not have not contributed to the ensuing fire. The hydrogen was totally innocent. In fact, in 1935, a helium-filled airship with an acetate-aluminium skin burned near Point Sur in California with equal ferocity. The Hindenberg disaster was not caused by the hydrogen.

The lesson is obvious - the next time you build an airship, don't paint the inflammable acetate skin with aluminium rocket fuel.

https://www.abc.net.au/science/articles/2004/02/26/1052864.htm

[-] Wirlocke@lemmy.blahaj.zone 13 points 6 months ago

To add on the point of helium being expensive and valuable, it's also extremely important for supercooling MRI's and supercomputers.

I'd rather have more MRI's than zeppelins.

[-] mkwt@lemmy.world 5 points 6 months ago

So MRI helium is scarce because the required purity is very high to get the 4 Kelvin superfluid behavior. Helium for filling balloons (of the party type) is a lot, lot cheaper. I don't know exactly how that translates into airship envelope helium, but you can't take balloon-grade helium and put it in your MRI machine.

[-] Wirlocke@lemmy.blahaj.zone 2 points 6 months ago

Huh, Today I Learn

[-] HaywardT 2 points 6 months ago

Look at the Akron and Macon. Big advanced helium filled. Zeppelins don't handle weather well.

[-] PhlubbaDubba@lemm.ee 1 points 6 months ago

Helium is twice as heavy as Hydrogen, much harder to find on earth (it's literally named Helium because until recently it was believed to only exist on the Sun)

So more expensive and you gotta use a lot more of it for the same lifting power, also Hydrogen can be used for this safely, the Nazis just were cutting corners to not have to give any credit to the Americans who at the time had a monopoly on the resources that would have let them go with helium or that would have let them coat the ship safely.

this post was submitted on 20 May 2024
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