Why Waves Don't Freeze: Exploring the Science Behind Freezing Water

[CarbonWater]

Correct me if I'm wrong but my understanding is that waves of water do not freeze in wave form. Doesn't water freeze from the top down? Why don't waves freeze?

 

[Curl]

Wave is just the motion of fluid. If it freezes it means it is not moving.

 

[kowalskil]

Wave is just the motion of fluid. If it freezes it means it is not moving.

1) Yes, a frozen wave-like shape, even if it were formed, would not be a wave.

2) Water particles (in a wave) move mostly up and down. In that way surface temperature, when a wave is present, is slightly higher than it would be in the absence of a wave. Sooner or later water freezes but the surface does not have the shape of a wave.

 

[CarbonWater]

Thanks. I guess my question should have been, "why doesn't water have the shape of a wave when it freezes?"

 

[kowalskil]

Thanks. I guess my question should have been, "why doesn't water have the shape of a wave when it freezes?"

Because freezing is not an instant. Freezing process destroys wave motion gradually.

 

[RedX]

I think in a wave, particle motion ensures mixing of warmth, so that if anyone molecule gets cold, it'll eventually get bumped by a neighbor. Similarly with just flowing water (and not necessarily a wave), turbulence provides mixing: you either freeze all the water, or none of it, because the water won't let anyone of its parts be a weak link (if any individual molecule falls, its comrades will bump it back up at the expense of their own speed). Of course, the downside is that by attacking just one part of the turbulent water with a cold spell, you strike at all the water and the temperature of the entire river goes down, and not just part of a river. So for a total freeze of the entire river I don't think it would matter if the river were moving or not.

Anyways, turbulence is the only answer I can think of that doesn't violate relativity.

 

[klimatos]

Why don't waves freeze?

Part of your confusion stems from a misunderstanding of what freezing actually is. Freezing does not occur instantly over large areas--despite some bad Hollywood movies to the contrary. It occurs on icing nuclei and spreads more or less radially out from there. This process takes time and generally results in the remaining water increasing in temperature (enthalpy of fusion).

There is no single freezing point of atmospheric water. The freezing point of atmospheric water is somewhat dependent upon the ambient pressure, although scholars do not agree exactly how or why. In addition, it is strongly dependent upon the nature and abundance of solutes and the presence and abundance of icing nuclei. In the free atmosphere, liquid water is found at temperatures all the way down to roughly 231 K (-42°C). It is generally stable at these supercooled temperatures, with droplets undergoing collisions, coalescence, fragmentation, strong winds, and vigorous mixing without freezing.

On the other hand, ice has been observed to form on organic proteins inside plant tissues (away from the free atmosphere) with extremely strong icing nuclei propensities at temperatures up to 277 K (4°C). Under pressure (greater than atmospheric pressures), it can form stable clathrates at temperatures up to 291 K (18°C). These clathrates are essentially ice crystal structures (something like "Bucky-balls") surrounding molecules of some substance such as methane, propane, butane, and the like.

Contrary to popular belief, both water and ice are extremely complex substances and are not at all well understood. Check out the superb bibliography prepared by Martin Chaplin of London South Bank University at http://www.lsbu.ac.uk/water/index2.html

 

[olivermsun]

Perhaps you can think of it this way: The motions of waves want to break up ice. Meanwhile, slushy, icing water wants to suppress waves. They don't go together so well.

 

[klimatos]

Meanwhile, slushy, icing water wants to suppress waves

1) How so? Slushy water is lighter than pure liquid water. Theoretically, it should form even larger waves when subject to the same forces. The liquid water between the particles of ice acts as a lubricant, and tends to minimize any tessellation of ice crystals.

2) As one who has sailed the Davis Strait to Thule and back, I can personally testify to having seen very large slushy waves. Any cold-water sailor can probably say the same.

3) Writer's Hint: You will gain more respect from your scientific readers if you avoid anthropomorphic expressions such as "wants to" and substitute more dispassionate terms such as "tends to" in your explanations.

 

[DaveC426913]

1) How so? Slushy water is lighter than pure liquid water. Theoretically, it should form even larger waves when subject to the same forces. The liquid water between the particles of ice acts as a lubricant, and tends to minimize any tessellation of ice crystals.

Well, since you mention lubricant: given a choice between:
- a volume containing solid particles (ice) supended in lubricant (water), and
- a volume containing nothing but lubricant (water),
which do you think will have less friction?

What is the risk of tesselation occurring in a pure liquid? (Hint: none.)

2) As one who has sailed the Davis Strait to Thule and back, I can personally testify to having seen very large slushy waves. Any cold-water sailor can probably say the same.

Which tells us nothing. (Perhaps the waves might have been even larger if it had been all liquid.)

3) Writer's Hint: You will gain more respect from your scientific readers if you avoid anthropomorphic expressions such as "wants to" and substitute more dispassionate terms such as "tends to" in your explanations.

Bah, nonsense. We're all intelligent here, you can judge that by the quality of his answers. We know what he means and that's not an uncommon shorthand.

 

[sophiecentaur]

Bah, nonsense. We're all intelligent here, you can judge that by the quality of his answers. We know what he means and that's not an uncommon shorthand.

Can't agree with you entirely there, Dave.
It may be shorthand to you, 'cos you know about these things, but many people (readers of these erudite ramblings who know no better) take such statements almost as gospel and it can only get them in a muddle. There's always a reasonable way of stating things without anthromorphising. (That is if it's actually possible to state them at all.)

"Nature abhors a vacuum" wouldn't be a good explanation for anything, nowadays, would it?

 

[olivermsun]

Here, fixed it for those who find it confusing!

The motions of waves [STRIKE]want[/STRIKE] tend to break up ice. Meanwhile, slushy, icing water [STRIKE]wants[/STRIKE] tends to suppress waves. They don't go together so well.

 

[klimatos]

What is the risk of tesselation occurring in a pure liquid? (Hint: none.)

I assume you misspoke in haste. Or,are you telling me that a pure liquid cannot form crystals of the solid phase, and that these crystals cannot thenceforth propagate themselves naturally? And no cop-outs by saying that no real-world liquid is pure. Let us confine our discussion to commonly-accepted laboratory standards of purity.

 

[boneh3ad]

I just want to point out that contrary to some of the posts earlier, if water could freeze into the shape of a wave, it would still be a wave. Waves needn't be moving through space. They can be stationary.

 

[RedX]

My initial reaction was that moving water has higher thermal conductivity than non-moving water, so that as long as some parts of the water are warm it's hard to freeze other parts.

Adding things like solutes will cause the freezing point to go down (colligative properties), but non-moving water and moving water should have the same solute concentration, so that shouldn't create a difference.

So the only thing left is to consider nucleation. Does moving water disrupt the nucleation process on some impurity? What impurity are the ice crystals nucleating on? Salt?

In any case it seems to me that if anything, moving water should be easier to freeze, because the impurity will get to collide more with water molecules due to turbulence, and if it can find a particularly slow molecule, it can start nucleating ice.

 

[DaveC426913]

I assume you misspoke in haste. Or,are you telling me that a pure liquid cannot form crystals of the solid phase, and that these crystals cannot thenceforth propagate themselves naturally? And no cop-outs by saying that no real-world liquid is pure. Let us confine our discussion to commonly-accepted laboratory standards of purity.

Let me rephrase:

"What is the risk of tesselation of a pure liquid?" Zero. (There's no tesselation where there are no solid particles.)


You were claiming that a slush should make higher waves than a liquid, yes?

Quote:

The liquid water between the particles of ice acts as a lubricant, and tends to minimize any tessellation of ice crystals.

You're claiming that the friction in the slush would be lowered because the particles would be lubricated by liquid, preventing them from tesselating (i.e. locking together), yes?

Well how would that make it less frictive than if there were no solid particles at all?

It only stands to reason that a liquid is going to have less friction than a slush of solid and liquid. Thus, liquid waves will slosh higher than slush waves.

 

[kowalskil]

I just want to point out that contrary to some of the posts earlier, if water could freeze into the shape of a wave, it would still be a wave. Waves needn't be moving through space. They can be stationary.

A "standing wave" is not the same phenomenon as a "wave." The net energy flow is zero, in both directions.