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That has to do with the depressurization and the release of gas out of the liquid. I know water has to loose energy at the 32F mark before it will freeze but at -20C I would think that it would freeze if it were as still as being in a bank vault. It also does not look like the water is frozen hard in all the videos because I do not see the bottles expand or break. It looks more like slush what I would expect to see around the 32F degree mark.Quote:
Originally Posted by BeeCurious
Go Science,
Supercooling
Main article: Supercooling
In spite of the second law of thermodynamics, crystallization of pure liquids usually begins at a lower temperature than the melting point, due to high activation energy of homogeneous nucleation. The creation of a nucleus implies the formation of an interface at the boundaries of the new phase. Some energy is expended to form this interface, based on the surface energy of each phase. If a hypothetical nucleus is too small, the energy that would be released by forming its volume is not enough to create its surface, and nucleation does not proceed. Freezing does not start until the temperature is low enough to provide enough energy to form stable nuclei. In presence of irregularities on the surface of the containing vessel, solid or gaseous impurities, pre-formed solid crystals, or other nucleators, heterogeneous nucleation may occur, where some energy is released by the partial destruction of the previous interface, raising the supercooling point to be near or equal to the melting point. The melting point of water at 1 atmosphere of pressure is very close to 0 °C (32 °F, 273.15 K), and in the presence of nucleating substances the freezing point of water is close to the melting point, but in the absence of nucleators water can super cool to −40 °C (−40 °F, 233 K) before freezing.[2][3] Under high pressure (2,000 atmospheres) water will super cool to as low as −70 °C (−94 °F, 203 K) before freezing.[4]
There ya go under ideal conditions, pure water (which is why bottled water works well) can be cooled to -40 before it freezes. You won't see it in nature often because there is usually impurities in the water that allow much easier nucleation. It also would require slow cooling in most cases because in rapid cooling surfaces will get colder faster and allow for nucleation on the surfaces.
Except I think it is staged. Bottled water is not pure. It is filtered and at the very least has a good amount of sodium in it usually from softening it because it comes from a tap. I haven't experimented with this and it is the first that I have seen it demonstrated. I also think they put an inert gas on top of bottled water so there may be some pressurization even if it is not carbonated.
Well I can attest to the effect being real. Like I said it happed to me this week. I left a case of water bottles on the front porch and when I got up to take the dog on a walk it was 12 F out side. I picked up the one of the bottles and opened it the ice crystals formed just like in the movie. It was so cool I did it on 2 other bottles just by tapping the plastic bottle, only a few of the bottles were still liquid and they were the ones on the bottom of the case and were protected from the wind, the rest were frozen solid. It turns into a slush, not a solid block of ice due to the fact that crystization happens so fast that the crystals do not have time to join up into larger crystals (the same effect we try to get when making creamed honey).
I used to do this all the time at work, I would put a bottle of water in the freezer when I got there, several hours later it would still be clear liquid, when I opened it and took a sip I would get one mouthfull of very cold water and then I would watch the ice level starting at the top and go down to the bottom, leaving a botle of firm slush.Quote:
Originally Posted by sqkcrk
The trick is it has to be undisturbed and very pure as it cools. He didn't have to turn it upside down, he could have flicked it on the side, but it is more impressive going top to bottom.
beecurious is right
Quote:
Originally Posted by BeeCurious
oh, ye of little faith. -jsQuote:
Originally Posted by sqkcrk
I think it's so funny that Beesource's resident ace engineer believes that the two videos are staged.
A lot of folks don't trouble themselves to learn about things.
A similar phenomonum can be observed at the other end of the temperature spectrum. A cup of tap water and a cup of distilled water are put in a microwave and heated until the tap water is boiling. Distilled water appears still until something (spoon, sugar cube) is put in it. Stand clear, sometimes it splashes violently.
Saftey tip, heat water in a vessel with a wide open top (such as a bowl) if you heat it in something with a narrow top it acts like a nozzel when the violent splashing begins.Quote:
Originally Posted by cg3
looks like Im buying a bottle of water
got the - 20 outside, just need the water for my experiment
http://www.youtube.com/watch?v=AWbFjfq4X9s
Did you all really think you where watching just water freeze?
First clue it didn't freeze. The bottle didn't split open.
I did find this that could explain how pure water could semi freeze, It does not freeze solid but to a slush. this woudl also explain that the bottle does not burst.
Basically, nucleation
Ice crystals form more easily when they grow on existing ice crystals -- the water molecules like to pack themselves in place on a crystal that's already gotten started. It doesn't take much to start the crystallization process going -- a little piece of dust or other impurity in the water, or even a scratch on the bottle are sometimes all it takes to get ice crystals growing. The process of starting off a crystal is called "nucleation."
In the absence of impurities in the water and imperfections in the bottle, the water can get "stuck" in its liquid state as it cools off, even below its freezing point. We say this supercooled state is "metastable." The water will stay liquid until something comes along to nucleate crystal growth. A speck of dust, or a flake of frost from the screw-cap falling into the bottle are enough to get the freezing going, and the crystals will build on each other and spread through the water in the bottle.
We suspect you have slush in your bottle rather than hard ice when this is done. You can compare with another bottle which froze hard in your freezer overnight how hard it is to squeeze the bottle and how long it takes to melt. The ice will also take up more room than the water it used to be, and some water may spill out the top.
I found the video by searching for Freezing water trick. Which I guarantee you the video presented is. That guy is an illusionist if I have ever see none. his hands give him away.
I found the second by search "instant freezing of water phenomenon" In which I did find what seem to be several genuine reports of this happening with bottled water. The filtering of the water for bottling might explain how it came to not have enough particulates for crystals to form.
Now that's BS.Quote:
Originally Posted by Daniel Y
I don't claim to be an engineer, so excuse me, but, what does this have to do w/ engineering? Brian never claimed to be a scientist.Quote:
Originally Posted by BeeCurious
It's physics...Quote:
Originally Posted by sqkcrk
Which is synonomous w/ engineering? Engineers are physicists? Or are physicists engineers? I'm confused.
"I'm from Missouri. You gotta show me."
One does not need to be a physicist or an engineer, to read (and possibly understand) a few paragraphs... If you like the "LOL" yuk yuk response to to the world around you that's okay. Two key words were offered earlier in this thread: nucleation and supercooling. Hocus Pocus sounds like more fun than nucleation and supercooling...
"Is our beekeepers learning? "
larnin' BC, larnin'
lol
In another life as a pilot, I learned of a thing called a supercooled water droplet. They occur in nature, usually associated with a thunderstorm. In the right conditions these water droplets can ice up your wing in a hurry. Don't understand why, but it has something to do with Daniel Y's explanation about getting the crystalization started. :)
It's not a gimmick. In the video they state that not all the bottles remained liquid when cooled, a lot of them solidified. It doesn't have to be pure water for this to work, just minimal impurities.