Mastodawn

Ray McCarthy 4d ago

@AkaSci
The "toy" balloons filled with helium are a waste.

@raymaccarthy @AkaSci Hopefully the situation will make all of them disappear quickly as the price of helium go high ?

@Sobex @raymaccarthy @AkaSci They've been a waste for a very long time, ever since Congress voted to get rid of our helium reserves in the '70s or something 1996, apparently (wow, do I feel like an idiot XD).

Hydrogen floats just fine and is easily produced with hydrolysis. Just keep it away from the birthday candles unless you want the balloon to get your wish. XD

National Helium Reserve - Wikipedia

Dr. Sobek

@bluestarultor @raymaccarthy @AkaSci Hmm, I wonder from a safety point of view how dangerous would be a flying balloon filled with H2. (From a kaboom & fire hazard perspective)

(In practice we have 1 bar of pressure, in a volume of 4 L, at 20°C, so P = 10^5, V = 4 * 10-3

T = ~300 K
R = 8.314

n = 400/(300*8.314) = 0.16 mol of H2.

@Sobex @raymaccarthy @AkaSci If you mean a dirigible, the Hindenburg technically killed more people by crushing them than by burning and it didn't outright explode. But I have to wonder if really any such craft are in common use regardless. Doing a bit of digging on Wikipedia, Goodyear only has 4 Goodyear Blimps, none for public enjoyment. It seems like it's been a decade since they were in use for any sort of passenger transport. Mostly they seem to be used for military recon and signage.

@bluestarultor @raymaccarthy @AkaSci Nah, I'm talking about a kids birthday party / disneyland floating thingy.

(The Hindenburg definitely contained more than 4L of H2)

Ray McCarthy 4d ago

@Sobex @[email protected] @AkaSci
The USA Airships used Helium. They had large reserves as a byproduct. They would not sell it to others.

The USA airships destroyed by bad weather. Actually advised not to go out!
They had two airship based aircraft carriers. The biplanes matched speed to hook on to a trapeze and hung underneath. Launching was simple!

Ray McCarthy 4d ago

@Sobex @[email protected] @AkaSci
Nevil Shute may have worked on and travelled on the R100. R101 used hydrogen as the USA would not sell helium.
The idea was airships to link the British Empire, but 1918 was the peak and it was gone in 1948.

@Sobex @raymaccarthy @AkaSci Ah, by "flying balloon" I thought you meant "one you fly with."

The answer is that I actually had a very large (beach ball sized) hydrogen balloon popped in an auditorium and while I was told to cover my ears, and it pressed my shirt into my chest, it did not set the school on fire.

A party venue will have an 8-10 foot ceiling and a table will be about 3 feet off the ground. If you bring the balloon to the cake, it will not reach the ceiling. This vid can serve as a model of what a single balloon vs. a cluster would do. Neither would reach an 8 foot ceiling. It may be bad for whoever is that close to it that a birthday candle would be the flame, but the venue would be fine, assuming the idiot didn't start running around on fire.

What Happens When You Light A Hydrogen Balloon on Fire?

YouTube

@bluestarultor @raymaccarthy @AkaSci So, not too horrible, but perhaps not okay for kids.

@Sobex @raymaccarthy @AkaSci Pretty much. XD