I read a science fiction novel where supercooled distilled water was used as a novel method of assassination. The milieu was a lunar colony. The governor liked to swim laps in a cold pool of distilled water in the morning. The assassin turned the heater off, and overnight the water supercooled (It’s the moon after all). When he dove in in the morning he was instantly encased in ice.
And don’t forget “Ice 9” from Vonnegut’s “Cat’s Cradle”, which was a solid at room temperature and ended up bringing about the end of the world.
Jinx, you might want to take a look at that three-phase diagram you mentioned for an answer…
In 9th grade science class, our teacher showed us a mind-boggling trick. He put a glass bowl of water in a bell jar with a vacuum pump attached. As the pressure dropped inside the jar, the water came to a rolling boil. However, since the boiling came from the pressure drop instead of applied heat, the evaporation quickly chilled the water. Ice formed on the surface. Soon a big flat chunk of ice was floating in the dish of boiling water! It’s pretty gee-whiz stuff, if you have the gear.
AskNott
I live in central Indiana, where winter often contains many freeze-and-thaw cycles. Ice fishermen rarely have to deal with more than four or five inches of ice on ponds and lakes. Part of the accepted wisdom among these guys is that when ice thaws and refreezes, its strength is compromised. That is, three inches of refrozen ice is not as safe as three inches of first-time ice. I don’t pretend to understand the physics behind this.
AskNott
The conditions where a substance can exist in gas, liquid, and solid forms and still be in equilibrium is the triple point, for water that’s .006 ATM of pressure and .01C temperature. As Asknott pointed out, if you apply a vacuum and let the water boil you’ll reach those conditions.
As for the ice on the lake, I think that’s more a matter of the snow that can get incorporated into the re-frozen ice. Obviously, snow has much less strength than ice. The snow also insulates, meaning that the snowy spots are not only weaker, but the ice beneath the snow is thinner. Not a good combination for ice fishing.
>Jinx
>Dry ice (CO2), sure, but H2O ice?
Yep its effected by humidity of course, but I’ve had frost sublime off my ski goggle while I was just sitting on the chairlift.
And speaking of supercooled, on newyears I poured some 100proof schnappes I kept it the freezer and threw an ice cube in it. It was perfectly clear at first, but almost instantanly large ice crystals formed in my glass, and not just around the ice cube.
Kinna weird considering the ice and the booze were the same temp in the freezer, but I guess the alcohol melts the ice a bit, and the sligtly more watery booze doesnt have enough energy to remain liquid.
And speaking of liquid ice, I’ve seen several Discovery channel show (or maybe the same show several times) where the ice at the bottom of a glacier is under soo much presure that it actually flows
AskNott, the reason refrozen ice is not as safe as first-time ice of the same thickness is because the internal structure of the ice itself. Basically, instead of one thick sheet of ice, you have two thinner sheets of ice. Obviously the later is more likely to break under the same pressure. And once one of the two layers break, the next is pretty much waiting for the end too.
I don’t know how snow will affect this, since your ice is on water and you specifically said it was “refrozen” (implying that it melted first, ice or snow). I’m sure compacted snow would be weaker in comparison to ice, but I’m sure that’s not what you’re asking for.
And Straighterdope, the mechanism that triggerse the dramatic freezing does not require the seed to be of a different temperature than the liquid. All the supercooled liquid needs is a little diturbance. Sometimes just shaking the container of your supercooled liquid will be enough to start the process. I have no idea if your booze was supercooled however. If it was, the booze would certainly freeze around that piece of ice. In addition to that, the disturbance of the ice entering the booze itself can also cause the booze to freeze on the container’s surface (when the, shall we say, shock waves hit the surface).
Here’s another strange phenomenon for you-I like my beer well-chilled, and frequently place the cans in the freezer. many times I’ve poured a can of beer out into a glass (it is all liquid-no ice), and the beer will start to spontaneously freeze in the glass!This usually starts from the foam. Why does this happen-does the evolution of the CO2 gas superchill the beer?
I’ve always assumed it’s the pressure - the freezing point is higher under pressure, but as soon as you open the tin the pressure drops, the freezing point drops, and the beer freezes. do I have that right?
and the stars o’erhead were dancing heel to toe
This may be a false memory or an urban legend, but I’m pretty sure I saw it on a nature documentary. Apparently hibernating lemmings (or it may have been some other rodent) let their body temperature go below zero Celcius, but they don’t freeze because ice nucleation is inhibited by something in their blood. But if you pierce their skin with an icicle you get an instant solid lemming! Confirmation or refutation welcome.