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Comment by VonGuard | Hacker News Reader

This article doesn't seem to take into account that Helium is becoming scarce, and when used in airships, it's eventually just released and lost forever. NYT Article on the shortage: https://www.nytimes.com/2019/05/16/science/helium-shortage-p...

We used to have a strategic Helium reserve in the US for zepplins and so forth, then it was just kept for chemistry and other purposes. I think we started selling it down under GW. Helium seems like it's more valuable as a component in chemistry, super cooling, etc, rather than just using it for lift.

Also, we tend to think of Zepplins as rare things, like singular one-off vessels like the Hindenburg. In actuality, the Germans produced 131 of them! Most were used in World War 1 https://en.wikipedia.org/wiki/List_of_Zeppelins

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Why not use hydrogen, its cheap and zeppelins can be smaller and fly higher.

We will maybe better in avoiding accidents compared to 1937:

- have better materials

- can use it only for cargo with drones - no human should travel with them!

- should/can use routes to avoid cities, and should/could build some separate safe landing space

etc...

finally:

Hydrogen fires are less destructive to immediate surroundings than gasoline explosions because of the buoyancy of H2, which causes heat of combustion to be released upwards more than circumferentially as the leaked mass ascends in the atmosphere; hydrogen fires are more survivable than fires of gasoline or wood.[22] The hydrogen in the Hindenburg burned out within about 90 seconds

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

I would also rather use hydrogen.

The Hindenburg disaster was spectacular, but not especially deadly! 36 fatalities, 62 survivors. Compare to modern passenger airplanes, where EVERYONE tends to die. If modern dislike for zeppelins is mostly due to Hindenburg, it's irrational.

I think there were a series of disasters - of which the Hindenburg was just the last.

All the same, I think with modern materials, Hydrogen would be pretty safe.

Indeed, Iron Maiden wrote a song about the British Airship R101, called "Empire of the clouds"

It’s at least worth considering whether modern zeppelins could be safe. All options need to be on the table for dealing with climate change.

doesn't seem that bad https://en.wikipedia.org/wiki/List_of_airship_accidents

The Hindenburg accident happened while the ship was about to land; people on the ground were already holding the ropes hanging from its nose. Had the explosion happen at a higher altitude nobody wold have survived.

Using hydrogen, especially today, is a disaster waiting to happen, since any idiot with a medium quadcopter drone carrying a small explosive charge could easily outrun and shot down an airship then post the FPV video on social networks.

I think since Hindenburg fabrics has developed tremendously, and collision, perhaps even explosion safe fabrics for zeppelin hulls could be possible.

Hope they still get covered with a thick layer of thermite.

You mean "thermite, the well-known incendiary compound"? https://www.wikiwand.com/en/Thermite

There's a myth that the hindenburg was coated with different layers of metallic paint that triggered a thermite reaction when the hydrogen caught fire.

>>Using hydrogen, especially today, is a disaster waiting to happen, since any idiot with a medium quadcopter drone carrying a small explosive charge could easily outrun and shot down an airship then post the FPV video on social networks.

Literally the exact same thing could happen with a regular plane(just send a drone into a plane as it takes off), and yet somehow it doesn't happen. I guess people aren't psychotic murderers, or at least there isn't enough of them to worry about it.

I think it would be far more difficult to take down a plane than an airship given the enormous difference in velocities. Even at takeoff, a drone-sized IED would probably only be fatal to a small part of the plane's occupants, while it could probably 100% destroy a hydrogen airship in flight.

That said, I don't see any reason we'd need to put humans on these, so that probably lowers the risk massively.

> quadcopter drone ... could easily outrun

Even the old Hindenburg did 135 km/h (85 mph), which is quite a lot faster than most drones.

With predictable trajectories this does not would make a unsolvable obstacle. A drone can shoot a fireweapon so it would need just to place itself within fire range.

Airline crashes have a surprisingly high survivability rate (because the typical crash is not the craft plummeting from 30k feet, but some kind of runway incident).

To your overall point though, hydrogen isn't that much worse. In fact, many leading airship disasters involved helium.

USS Shenandoah is typical of the most common enemy of airships--strong winds. The captain warned that the updrafts and storms in the Midwest would destroy the ship but was ordered to fly over several cities anyway, just for a promotional tour.

The deadliest airship disaster in history is not the Hindenburg, but the lesser known USS Akron, a helium ship that was simply destroyed in bad weather.

> airplanes, where EVERYONE tends to die

Overall, about 95% of passengers survive airplane crashes. If you arbitrarily restrict the stats to just the most severe crashes, it's still over 50%.

This is for cargo - hydrogen is fine. They don’t even need a crew on board.

I wouldn't say that helium is becoming scarce in the sense that we can't get any more, though. I may be wrong, but my understanding is that it's just expensive to store, so nobody wants to do it if it's not worth the money. If air ships started to "take off", there would surely be more money in producing helium.

Helium is scarce in much the same way that crude oil is scarce: there are plenty of reserves still in the ground, but we are consuming them orders of magnitude faster than they were produced, and as the reserves dwindle the costs of extraction will rise.

Helium is a chemical element, and aside from nuclear reactions (which are economically infeasible for non-microscopic quantities) we can't produce more of it.

In fact our helium supply is a by-product of the petroleum industry. As we transition to renewable energy our supply of helium will diminish as well.

We can produce more of it by distilling it out of the atmosphere, it is just rather expensive.

This is exclusively how neon is produced (as far as I can find) so it is obviously economically viable at a certain price.

I did a calculation once about nuclear production of helium and found that the heat from the nuclear reactors producing enough helium to match current usage would be on the same order of magnitude as the power received from the sun across the whole planet.

Helium is light enough to escape Earth's atmosphere though. Eventually the atmosphere will run out of it.

It is also constantly being emitted by radioactive elements decaying on Earth, that's how it got in the natural gas deposits in the first place and also the atmosphere. Alpha decay makes helium, or more accurately is helium. An alpha particle is just a helium-4 nucleus.

Over what time period?

Continuous. I compared power (energy/second, watts) not energy.

Take the helium used in a year, calculate the amount of energy produced by nuclear reactions to make that helium. Compare to the solar intensity at earth's orbital distance (W/m^2) multiply by 1 year, multiply by area of circle with earth's diameter.

The result I got was within a factor of 10 between the two.

There is so little helium in the atmosphere that distillation is totally pointless. Almost all the refined helium we get is a byproduct of fossil fuel extraction.

Neon is distilled out of the atmosphere, and it is only about 3x as prevalent.

We do not produce crude oil any more because bacteries are more efficient at digesting dead trees.

So is hydrogen, and we produce that in droves.

Now granted perhaps there is no He + ? compound which we can easily split, but the fact it is an element does not imply we can't make more of it. (Pedantry aside; I of course do not mean "from something that isn't helium")

Sure, we can chemically extract hydrogen from compounds that contain it, but since helium compounds don't exist (for all practical purposes) that's not a relevant point.

Did you mean to imply we are consuming crude oil "orders of magnitude faster than [reserves are] produced"? Because that isn't true - the amount of oil "known reserves" is how much we've bothered to find and figure out to tap thus far, but whenever it seems like we might be running out we just go find and figure out how to produce more such that total known reserves are approximately stable-to-mildly-increasing.

Here's a plot of known oil reserves since 1980: https://www.indexmundi.com/energy/?product=oil&graph=reserve...

Does a similar plot exist for helium? My impression is that helium reserves are low because the world hasn't been trying very hard to increase the amount we capture as a proportion of the amount we could capture.

I consider discovering reserves to be very different from "producing" them.

With a few billions investment and very high operating costs, we may be able to create a few kilograms of helium per year.

According to [1] Helium actually escapes Earth's atmosphere at the rate of 50g/s. And most of the production of Helium is from gas reserves, and not capturing from the atmosphere.

[1] https://en.wikipedia.org/wiki/Atmospheric_escape#Earth

Should just use hydrogen. We learned how to safely fly airliners full of jet fuel, we can solve the safety problem with a bag full of H.

Is it feasible to design the aircraft so in the case of an accident it can release the hydrogen and safely glide to ground level?

Jet fuel can be contained easily. Hydrogen diffuses even through welded containers. It can also weaken them structurally: https://en.m.wikipedia.org/wiki/Hydrogen_embrittlement

Easy to store in form of water as long as we could create it when needed, but water is heavy as fuel so it cancels the floating effect.

An airbag for airplanes that would create a floating bag of hydrogen in seconds helping to do a safe landing would be awesome on the other hand. We could use the extra oxygen for masks also.

Sorry but these “ideas” are reddit tier naive... I recommend you researching the topic of water splitting.

I'm only rambling. Sometimes is useful for finding new ways to crash things.

Okay... lets see. Water splitting recipe: 1) Put water in a recipient with a pinch of salt, 2) add electricity, 3) hydrogen will float upwards and must be recovered in a different recipient or if mixed again with the oxygen could explode. Anything else that we would need to take in mind?

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

> 2) add electricity,

This is the part you are underestimating. You need a lot of energy to produce the lot of electricity that is necessary to split the water into Hydrogen and Oxygen. You will need very big batteries, or some other source of energy like a big solar power plant.

Zeppelins aren't welded metal containers.

You can throw a lighted match into a can of jet fuel and it will go out - try this with hydrogen.

Despite that, jet fuel burns quite fiercely. The fires that brought down the WTC were started by jet fuel being sprayed through the buildings.

It's the second most abundant element in the universe. Maybe we'll put in a tad more effort to explore it if Helium runs out.

That doesn't really help if it isn't abundant where it's needed. There's no primordial helium on Earth, all of it is created by alpha decay of radioactive elements. As to the rest of the solar system, all that abundant helium is locked in the bottom of particularly deep gravity wells.

There's a huge amount on our only moon.

A few parts per billion, about one gram of helium-3 per 150 tons of regolith. For comparison, economical gold mining on Earth typically requires a deposit of at least 500 ppb or so. And there are no 3He "deposits" on the moon; it's all fairly uniformly distributed across the 38 million square kilometers of lunar surface!

Helium can escape Earth's atmosphere though.

Yeah, we could extract some Helium from the sun. The heat wouldn't be an issue, we'd go at night.

Helium has way more important uses in cryogenic systems, neutron detectors, etc. It's non renewable, and alot of physicists are already concerned about increasing costs. This is especially true for helium 3, the cost of which continues to skyrocket (~$2k/atmosphere*liter) . Creating massive and unnecessary demand for helium when there are renewable alternatives available is a bad idea.

It was mentioned in the article. The claim is that it is a general misunderstanding that we are 'running out'. Watching the embedded video apparently they have tanks where they compress the helium, removing it from the balloon, and saving it for reuse.

I think lower-purity Helium is not as scarce, and that's what you would use for party balloons, etc. No reason why it couldn't be used for Zeppelins too.

Purifying helium is relatively trivial. All helium comes from the same oil/gas wells, and is not renewable. Many sites that could capture helium choose not to because it wouldnt make them enough money, so it floats out of the atmosphere and is lost forever. It's used for party balloons because the market is too short sighted to price it at its true value because of what naively appears to be a surplus. In 100 years people will be WTFing at our senseless waste.

Isn't 131 of something rare relative to the number of cargo airplanes, trains, ships, and trucks produced?

It seems pretty clear that those numbers side by side tell the tale.

According to Sam Burton of The Federal Helium Program [1], we have at-least 100 years worth of Helium in Wyoming with the current supply and demand. This is before taking into account new sources.

https://www.youtube.com/watch?v=mOy8Xjaa_o8 [1]

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