Snowflakes cannot retain their intricate shapes when frozen due to sublimation and thermal motion. When placed in a freezer, the higher humidity and temperature conditions lead to condensation and structural degradation. The discussion confirms that snowflakes are dynamic structures, constantly changing, and will lose their defined shapes over time, particularly when subjected to the conditions found in a typical freezer. The consensus is that while ice can maintain its form under certain conditions, snowflakes are inherently unstable and will not preserve their unique patterns long-term.
PREREQUISITESThis discussion is beneficial for scientists, educators, and anyone interested in the physical properties of ice and snowflakes, particularly those studying meteorology, crystallography, or thermodynamics.
techmologist said:If you were to somehow catch a snowflake and put it in a freezer before it melts, will it keep its shape? My gut says no. Thermal motion will make it slowly jiggle into a blob of ice, or it might fall apart under its own weight. Is my gut right? Unfortunately I don't live in a place where it snows so I have little relevant experience.
sophiecentaur said:An ice crystal would stay the same if it were kept in dry air, I imagine.
Tupperware?
techmologist said:If you sealed off a desk in a very cold room for several eons, would it still look like a desk? My guess is no, but it would still be solid.
This is the correct answer.mrspeedybob said:I'm not so sure. Water will sublime straight from a solid to a vapor and freeze straight from a vapor to a solid. The net effect of these 2 processes will be to shuffle material around so I'm pretty sure the snowflake will loose it's shape.
Drakkith said:Yes, it would.
Here is a link to a fossilized insect dated at 16-20 million years old: http://en.wikipedia.org/wiki/File:Leptofoenus_pittfieldae_(male)_rotated.JPG
A tiny insect formed of fragile materials has been preserved for almost 20 million years. But that's nothing. The oldest fossils in existence are stromalites. Some have been dated to be over 3 BILLION years old and they've still kept their shape.
If your desk was protected from corrosion and decay it would keep its shape effectively forever. Or at least until the Sun enters its red giant phase and engulfs the Earth.
LeonhardEuler said:True, but I think it's important to keep in mind the differences between a desk and a snow flake. For the sake of simplicity, assume the desk is made of iron, but there is no oxygen so it doesn't rust.
Looking around I find the vapor pressure of water to be 600 Pa at 0 Celsius and the vapor pressure of iron to be something like 10^(-59) Pa at the same temperature assuming I didn't mess up the calculation (formula here: http://en.wikipedia.org/wiki/Vapor_pressures_of_the_elements_(data_page ))
So the chances of a water molecule evaporating off a snow flake over a given period of time are much, much higher than an iron atom evaporating off of the desk. The time scale for what mrspeedybob and DH are talking about is far, far faster for ice than most solids. You hear about the humidity levels, but never about the amount of iron vapor in the air, because the evaporation of an iron atom is a rare event.
To answer techmologist's question, the formation of a snow flake is a dynamic process, and how big it grows depends on how long it spends in the air. Under the conditions in the atmosphere where snow flakes grow, equilibrium favors the formation of more solid over vapor, but the particular shape a flake takes depends on its history and is not necessarily the thermodynically most favored for a given set of conditions.
techmologist said:Ah, thanks for that detailed explanation. Does a solid have to sublime in order to rearrange its atoms (while maintaining the same crystal structure, of course)? Can't the atoms just sort of move over each other, like a slow motion version of liquid flow? Or maybe that is an example of sublimation.
techmologist said:I was looking at one of those websites that argues that order or structure or organization doesn't spontaneously arise in nature (it apparently contradicts the spirit of the 2nd Law, if not the letter) without the intervention of an intelligent agent. The only exceptions they allow to this rule are the somewhat humdrum structures resulting from equilibrium, such as the freezing of water into ice. But they lumped snowflakes in with these equilibrium structures. I thought that seemed out of place. Kinda nice of them to provide a beautiful counterexample to the claim they were making.
LeonhardEuler said:The second law of thermodynamics doesn't have a spirit. Either something violates it or it doesn't. Structure and organization do spontaneously arise in nature. The bulk shapes of objects are not really subject to equilibrium because there are a small enough number of degrees of freedom there that unlikely shapes can very well arise simply by chance.
At the microscopic level each atom has three degrees of freedom in position and three more degrees in momentum before you get to an even finer level of description that would consider the degrees of freedom for individual electrons. Since a macroscopic system has at least ~10^20 or so atoms, almost all the degrees of freedom are in the microscopic structure.
When many creationists talk about the 2nd law of thermodynamics they make the mistake of overemphasizing the visible macroscopic structure. Believe it or not, there are many more ways of having a functioning car at 20°C than having a pile of car parts strewn about randomly at 19°C. The cooler car parts have a lower entropy, and the macroscopic order has such a small effect it doesn't even really enter the picture. This is because each atom is farther restricted at a cooler temperature, and the collective effect of this on ~10^25 atoms has a much bigger effect on the number of ways of arranging things than restrictions on how to arrange ~1000 parts.
techmologist said:Very interesting.
I share with creationists their (professed) desire to know how purposeful, organized macroscopic structures got to be the way they are. I think that's a perfectly valid thing to be interested in. But to say that they contradict the second law, and then when pressed say that, okay maybe they don't exactly contradict the second law but it's just so hard to see how they manage to satisfy it without intelligent intervention--that seems like a sneaky tactic. If they had been able to catch you off guard convince you that the second law is actually contradicted, they would just leave it at that and high five each other.
Still, I learn a lot from looking at their stuff once in a while, whether directly or indirectly. They are highly motivated, often clever people. They spend a large part of their lives trying to dig up all sorts of odd facts that might be of use to them (and ignoring ones that aren't). And it is true that scientists sometimes engage in sloppy thinking themselves, or get some facts wrong, or talk confidently about stuff that they aren't well versed in, or say something in an unclear way. I can count on creationists to point these things out, and avoid the same pitfalls myself.
techmologist said:If you were to somehow catch a snowflake and put it in a freezer before it melts, will it keep its shape? My gut says no. Thermal motion will make it slowly jiggle into a blob of ice, or it might fall apart under its own weight. Is my gut right? Unfortunately I don't live in a place where it snows so I have little relevant experience.
SW VandeCarr said:There are ways to do it but ideally all relevant items should be cooled to about -5C for best results: glass slides and slide overs, clear thin superglue, and an artist's paintbrush. This article describes how. Even if the snow crystals eventually melt, you should have a "fossil". It's probably best to catch falling "dry" snow on a chilled piece of cardboard .
http://www.its.caltech.edu/~atomic/snowcrystals/preserve/preserve.htm
LeonhardEuler said:Keep in mind that just because something doesn't violate the laws of thermodynamics doesn't mean it will happen. There are a lot of absurd things that won't happen, but don't violate the laws of thermodynamics, they violate other laws or are extremely improbable.
An example I hear given by creationists is wind blowing through a junk yard and making an airplane. It is nearly impossible, but doesn't violate the laws of thermodynamics, but there are other reasons it is unlikely. They are better off leaving thermodynamics out of it and just arguing that it seems implausible. But we now know a process that can make really complicated things naturally, and that is evolution.
T 01:31 AM