Most often though, if you fill up the bottle with too much nitrogen, it won't explode. It'll just freeze up and slowly disperse through whatever cracks are present. If it didn't explode over night, it probably wouldn't have at all.
I suspect it might have started to fizzle due to air leaving the bag, or due to a small leak, which is pretty harmless. Nitrogen explosions of half-litre bottles are very large, and can shake the ground 20-30m away. I can test it later today if time permits and upload a video, but overall, it would've been much clearer if it went off.
Edit: to people saying the cap is the weak point: 9/10 times it's the bottom that gives in first.
There's the product
Every now and then some friends and I will get some dry ice, a bunch of plastic bottles and other containers with a screw-on lid and have a laugh making small explosions.
Basically you take a bottle, fill it 1/4 with water and 1/2 with dry ice and screw the cap on. You then have around a minute before it explodes.
A 1/2 liter coke bottle will make a nice whooompf and a 20 liter plastic gasoline can (the largest we have tried) will make a bang that can be heard maybe half a mile away. They very rarely sizzle out, and the ones that do probably have a defect, or we didn't get the cap screwed on properly. There's some time pressure, so you don't stand around checking before you throw the container. I would imagine that a metal container will make a pretty big bang (higher pressure before it ruptures) and may throw out some nasty debris.
It's good fun!
That may no longer hold, since 20oz bottles feel flimsier these days and all have low-profile caps. Haven't tried in a while.
Also, PVC pipe burried in ground, drop dry ice bomb in, drop another bottle with some water in it on top = dry ice mortar. Those little plastic bubble things that toys in vending machines come in? A little dry ice, a little water, close it, place lid down. POP, the bubble part flies a meter or so in the air.
I will note for anyone trying this that the parent's ratios are very different from what I used. Crushed dry ice to 1/10-1/8 full, about twice that much water. Unusually warm water (say, from near the surface of a pond or lake in late August) will greatly reduce time-to-boom, so beware. Too little water and it'll freeze before boom, greatly delaying or even preventing it. Very annoying. Attaching to something heavy (but NOT shrapnel-genrating) and sinking in ~5-10 feet of water is fun. Huge bubble, explosion can be felt on land nearby.
It may be the case for a typical water bottle but thermoses have much larger caps. The maximal force that a cap can hold is proportional to its perimeter (~r), the force itself is proportional to the area of the cap (~r^2) and the pressure. So larger caps can blow off by lower pressure. I would bet that for a thermos the weak point is the cap.
+1 - I'm always up for a good explosion video!
That was a pretty cool read.
"I had to keep zig-zagging to avoid pointing the bit which was going to explode at people coming up the street towards me" and "the canal is a crowded place on a Sunday morning"
My god, man :/
Our go-to example in an Economics of Law course was firing a gun while in a crowd. Similarly, attempted murder is a crime even in the case where no harm befalls the victim.
Enforcement should occur up to the point where the marginal cost of extra enforcement is equal to the marginal cost of the activity we are seeking to deter.
I would agree with you that the particular circumstance described in the article does not warrant legal action, but your original post made no allowance for enforcement directed at anything other than purposeful and effective crime.
duty of care?
- Assuming the inside of the thermos is at room temperature (and that there was enough dry ice initially), the pressure should be around 60bar. This is the vapor pressure of carbon dioxide at room temperature .
- At 60 bar and with a volume of, say, 1 liter, the energy available for the explosion is roughly 60bar x 1liter = 6kJ . This is a TNT-equivalent  of about 1.5g, or about 10-100 firecrackers. Enough to cause injuries, but not enough for structural damage to a balcony .
In my personal opinion, the most dangerous thing was handling the thermos. I believe letting the thermos sit on the balcony for a few days and closing doors and curtains (to prevent glas shards flying in) would have been a much safer alternative.
Also, he mentions ~100bar, not ~60 bar.
When I did a first approximation assuming adiabatic expansion, I got ~22KJ.
However, I maintain that the pressure inside the thermos should only be 60atm, since this is the vapor pressure of CO2 at room temperature , where the liquid and the gas phase are in equilibrium. This is like the butane in a lighter: Butane evaporates at room temperature, but there is an equilibrium between liquid phase and gaseous phase when the pressure is higher.
Using 60bar and the adiabatic formula, I get 12.5kJ of energy.
I was just going from the article's figure of 100atm. I probably should have double-checked that figure.
experiment start at 3:00
The initial explosion drops the pressure in the bin below atmospheric pressure. Assuming there's enough kick to separate the bin from the floor, you've got a higher pressure pressing up on the bottom from below than down from inside the container, so the bin accelerates up.
I'm not sure if it'd be a significant effect, however.
Then we had the bright idea of tying a 5lb weight to the water bottle and let it sink. This was a bad idea on our part. When it exploded, it sent a shock wave through the ground. It was pretty intense make us brothers kinda freak out. People rushed from inside the house and asked what explosion was. We were afraid we had cracked the pool, the concussion wave was so strong. Luckily, we hadn't for my brother's sake. It just makes me think twice before containing dry ice.
I imagine this isn't some pipe-bomb - the energy density simply isn't there - but you want to ensure that the thermos lid doesn't happen to injure some passer-by.
Quick approximation, assuming adiabatic expansion:
Gamma for CO2 is ~1.29.
Pf*Vf^y = Pi*Vi^y
Vf = (Pi / Pf) ^ (1/y) * Vi
Vf = (100atm / 1atm) ^ (1/1.29) * 1L
Vf = 35.51L
W = (PfVf - PiVi) / (y - 1)
W = (1atm*35.51L - 100atm*1L ) / (1.29 - 1)
W = 22.31 KJ
For example, is it clear that the pressure of 100 atm would actually be attained by a simple thermos and dry ice? What lead you to use that number?
Furthermore, the .50cal round is focused on a small area, the impulse and destructive force are multiplied by the shape of the bullet. Just like how shape-charges magnify the explosive force of munitions to bust armor.
As for the 15JK number, I cannot see any estimates in this thread saying 15JK. Could you link the comment?
The 100atm figure is assuming that the linked article's calculation of final pressure is correct, assuming the thermos doesn't burst beforehand. Although I fully agree that a standard thermos is unlikely to achieve that number.
And as I said a lot of the energy won't be focused. This is just a first approximation, to indicate that yes, potentially the energy is there.
Apparently the vapor pressure of CO2 is ~60atm, which bumps the number down to ~12.5KJ. Though I haven't checked that number yet.
(Especially the section "Derivation of discrete formula" in the latter)
It's only a first approximation, but meh.
Hypothesis: since the valve is only going to be propelled by the expanding gases for a relatively short time before it has cleared the flask opening, I don't even think it accelerates to that great a speed.
Clarification: a thermos is more or less a best-case scenario, since the valve at the top is going to be much weaker than the flask itself. A plastic bottle is worst-case, because it is going to shatter and eject plastic splinters.
I was cringing reading this article. I would never ever have handled one of these things, based on my experience. I think I would've put it in the fridge, left the house for at least a day, and bought a new fridge based on the damage.
This guy died and damaged cars 100ft away from the center:
Now, the article says 100psi not 3k, but you'd still probably rather not be near it.
I inflate bike tyres to 110 and its nothing tbh, 1500psi is a different kettle of fish.
My own personal story:
some friends and I filled a 5 gallon bottle with a bit of isopropyl alcohol, shook it up, and lit the opening to make a "rocket flame". We had seen this done in class, and it went fine. BUT...we wanted to do it again. we had no more alcohol, so we used Acetone instead, but it wouldn't light. There wasn't enough air in the bottle, since we had just burned out the oxygen. Because we were 16, and lacking much foresight, we decided "why just put air in the bottle, when we could use pure oxygen from a welding tank?". We did that. The ensuing incandescent explosion lit up briefly like a lightbulb and then ruptured the bottle into about 100 pieces. the major one landed 2-3 seconds later, about 200 feet away.
Even though that was moronic, I pride myself for having worn welding gloves, a face shield, ear plugs, and used a 12 foot handle with a match on the end. The detonation left me feeling shaky and jittery for about 6 hours.
My point is, speed of failure is important.
What's the weak point of a thermos? It's definitely the cap. I think leaving it alone would have just sent the cap flying, it could have been safely done in a park.
One of the top 5 points, no tightly closing containers. Styrofoam cooler is ok and dry ice will last 2-3 days like that.
Safe way to solve the situation with a metal thermos with a plastic cap: clamp thermos to workbench, pre-drill hole in large sheet of plywood, drill through pre-drilled hole into thermos. Depending on how complete the sublimation is, there may be a boom and you, the plywood, and your drill may potentially get kicked back a meter or two in the worst case, but your plywood shield would likely spare you from any high-velocity plastic fragments that would cause you injury. If you're lucky the pressure is still low enough that it just blows plastic out of the spiral of the drill bit and there is little other than the plastic shavings to work around.
You would definitely want to be wearing earmuffs though.
Aparrently, shooting is the preferred way to disarm potential explosives in such scenarios.
Although in this case, depending on how long the thermos had been shut, I'm not sure whether attempting to relieve the pressure would have been the smartest move.
Now I'm genuinely wondering what I would have done...
Seems very irresponsible to me.
The two aren't mutually exclusive.
edit why is it so hard to say that there is a novel to read and not some specific information? It's okay to be a novel, but some people don't want to read novels.
"Otherwise please use the original title, unless it is misleading or linkbait."
It's not misleading, I think, just uninformative.
The idea, as far as I see it, is that you don't use title changes to increase the attention, e.g., avoiding to use upper case. But you should certainly use the title to increase the information density, e.g. 'translate "10 Ways To Do X" to "How To Do X,"'.
But I see your point.
Look. No matter how wrong or stupid I act, If 10k people watch your link and everyone spends a second considering if they should click it or not, then that's a lot more time compared to choosing a title that says more about what to expect after the click, right? So even if I'm the biggest douche on the planet, we might still agree that it's worth for a link poster to spend some time about its title instead of just copy&pasting the article title.