Just thought I’d mentioned that liquid nitrogen isn’t quite as cost-prohibitive as Cecil thinks. I did a science fair project in middle school involving liquid nitrogen and goldfish. I resisted the urge to tap a frozen goldfish on the table, so I can’t say whether it would shatter.
I got the liquid nitrogen at a welders supply store for $0.05/L and carried it home in a Thermos (being careful not to spill in my lap, as I too had seen what happens to a hot dog). So a cooler full of liquid nitrogen would probably cost less than Cecil’s leg of lamb.
I actually spoke to Cecil about this before the column ran when he was wondering what experiments he could con me into doing…err, convince me to try that is, with liquid nitrogen. While we agreed the cost of the liquid itself was low, I recommended that we would want to get enough of it to do some repeatable tests, and may need to keep it for some time. To facilitate that, I recommended a proper Dewar flask to improve safety, and those are a bit dear. So what he was saying was that if we really wanted to do some serious testing it could run into more money than we probably could spend on it.
I’ve used it a few times and never found it expensive. This link mentions prices ranging from $.06 to $1.50 per liter, depending on quantity and location.
Being cheap, you don’t need to store it in any particularly efficient way (e.g. a fancy Dewar). An ordinary thermos flask, kept in your freezer, does a decent job for amateur use.
My advice would be to try your local university. Mine provides me with Liquid Nitrogen for free, and loans me a dewar to carry it around in. Our physics department makes their own liquid nitrogen, and apparently the cost is just pennies to fill a dewar.
Yes, exactly. Atlhough they warned me at the welding store NOT to close the lid tightly on the Thermos. I’m guessing a Thermos will be strong enough to hold in some pressure, and then make a real mess when it bursts.
I don’t see why Cecil et al can’t just fill a large cooler half-full and place the lid on it gently, and maybe carry it in the back of a pickup truck. Or better yet, perform the experiments in the welding supply store’s parking lot. If you want repeat experiments, get a refill.
In addition to this information; as a world war 2 buff, I have read some books regarding russian sources saying that German soldiers would freeze solid in the horrible winters in Russia, and that the Russians would shoot these “statues”, and that the frozen soldiers would shatter as the bullet impacted the body.
This struck me about the column, too. I haven’t priced LN lately, but when I used it in grad school it was cheaper, liter for liter, than Coke. Expensive it wasn’t, and I can’t imagine how that could have changed.
I figure it was just a snappy way to end the column.
A simple thermos full of liquid nitrogen will not likely be enough to freeze a leg of lamb. Using a proper dewar, I went through liters of the stuff just getting a 100ml flask to freeze. A cooler will hardly hold liquid nitrogen at all. He’d more likely asphyxiate driving home with containment like that.
35 yrs ago the only LN I knew about was what leaked out of the thermoses at the bus terminal, especially when we turned them sideways. It was eventually to be followed by bull cum. The LN turned my boots temporarily white. I didn’t stick around long enough upon spilling a bottle to check the color it would turn my shoes, but a somewhat more permanent shade of white was suggested.
Well, since someone posted about the article I have a quick question. Why was the Mythbusters experiment dismissed so readily? Was it because ballistics gel has a different texture to flesh? It seemed like a pretty decent analogue to me, especially since they included the bone in the psudo-heads before trying to shatter them.
While ballistics gel at room temp is undoubtedly a good analogue for flesh, I’d imagine that it’s characteristics when frozen may be quite a bit different.
Essentially that; while ballistic gel has properties which mimic the response of human tissue to trauma and acceleration forces, as far as we found the support for it being able to mimic a freezing solid with liquid nitrogen condition was pretty weak. Also, we wanted to dig as deep as possible to discover actual human cases of shattering because even if ballistic gel turned out to be an “OK” simulation, we suspected that relying too much on a simulation would not satisfy others, and it wouldn’t answer the question of “has it happened/does it happen in real life.”
I’m sort of surprised the cryogenics folks don’t have any stories to tell about this – they have lots of experience with bodies in liquid nitrogen, no? Including heads. Especially heads.
The problem with cryogenic freezing of a human head is that it has a small surface area in relation to its weight, greatly impeding heat transfer. Even with cryogenic freezing methods, the freezing process will probably not be fast enough to preserve the quality of the head.
Assuming that you’re freezing it because you want to reanimate it some day.
But even cryogenically frozen food products that are not expected to be reanimated would rarely be frozen in pieces as large as a human head because of quality concerns.
Remember, cryogenic freezing methods are the same as any other methods in that the outer part of an object will freeze faster than the inner part. While the surface will freeze immediately, it will take a longer time to transfer the heat out of the core. Slower freezing means lower quality when defrosted.
But if the item in question is not going to be reanimated or eaten, then I suppose quality is less of an issue.
Hmm…I wonder if you could freeze a head in liquid helium. It would definitely be costly, though.
No, I meant we have heard no head-shattering stories from the cryo folks – certainly they have more experience with the situation so you would expect if this was the situation we’d be at least hearing some anecdotes.