Unplanned and highly contingent

The last time I was out with the camera my subjects were some unusual ice formations and, when I wrote about them, I elected not to offer a mechanism for their development. I will correct that, now. The days which preceded the day on which the photos were taken were quite cold, and the intervening nights were even colder. Average temperatures for the three days before I recorded the images ranged below zero. Winds during the period were calm and precipitation came as 0.05″ of snow. I think it is fair to say that the days preceding the day the images were taken were very cold, still, and dry and I would argue that the co-occurrence of these conditions lead to the fortuitous formation of the intricate ice patterns. Let’s take January 1 as the start date for a thought experiment. I can add an end date as well, since we had very moderate temperatures and 0.5″ of rain on January 10. So, on January 1 the water in our stream was at a particular level. Because it was quite cold, ice crystals began to form at nucleation sites at the interface between air and water. Once crystals began to grow, they continued to do so by accretion. Now, imagine that the water in the run drops just a bit, especially during the day when perhaps some evaporation may occur and when, at the same time, liquid water is drawn deeper into the soil by a range of biological activities. With the water level just a bit lower, ice crystals will continue to accumulate, but lower down. Because the level of water in the stream drops only slowly, the successive icy plateaus can be smoothly connected. Eventually the elaborate pattern emerges. By the tenth of the month everything is erased by rising temperatures and falling rain. As I’ve said, just the right conditions were necessary for these patterns to occur and, as I walked the run yesterday, nothing like the formations I saw two weeks ago, were in evidence. Soon after I posted the ice images, I responded to a comment made by Shoreacres  with the following,  “This is taken from Richard Dawkins (The Blind Watchmaker) … If you walk up and down a pebbly beach, you will notice that the pebbles are not arranged at random. The smaller pebbles typically tend to be found in segregated zones running along the length of the beach, the larger ones in different zones or stripes. The pebbles have been sorted, arranged, selected. A tribe living near the shore might wonder at this evidence of sorting or arrangement in the world, and might develop a myth to account for it, perhaps attributing it to a Great Spirit in the sky with a tidy mind and a sense of order. We might give a superior smile at such a superstitious notion, and explain that the arranging was really done by the blind forces of physics, in this case the action of waves. The waves have no purposes and no intentions, no tidy mind, no mind at all. They just energetically throw the pebbles around, and big pebbles and small pebbles respond differently to this treatment so they end up at different levels of the beach. A small amount of order has come out of disorder, and no mind planned it. I like this description of how order may arise from disorder and play games with our [mostly visual] senses.” To close, let me point out another series of concentric rings, this time as they were observed on a Bracket Fungus, just yesterday. The cause of the repeated sequence you see is no more due to happenstance than is the rising and setting of the sun. These are annual growth rings and, like those that may be observed in a felled tree,  represent alternating periods of rapid (light bands) and of slower growth (darker bands) of the individual. So, what’s the point of all of this? Just that, as organisms, we are programmed to see and to react to patterns in our environment. Some of nature’s patterns occur entirely by happenstance while others occur for reasons which are just the opposite. How’s one to know? By learning to read nature, that’s how.


17 thoughts on “Unplanned and highly contingent

  1. Really an interesting ice pattern. I wonder if the ‘ripples’ in the pattern are related to something that happens periodically with time, like accelerated / decelerated growth during the day and during the night.
    Another factor that might be important is the lower density of ice. If a block of ice would form in the middle of a still pond, 10% of it have to be visible above pond level. So if ice would grow from below, the tip of the existing block would gradually move away from the surface. However, density of water is highest at 4°C, so it is most likely warmer below the ice block and it should grow from the air / at the surface. But no matter how it grows, it needs to move out of the water while growing … unless it is not contrained because it is attached to stones or soil. But then, if ice is forced to stay under water, strain will build up due to buoyancy, and maybe strain is released step by step, and a part of the structure moves a bit, giving rise to visible ripples / steps.

    (Not a ‘theory’ … just stream of consciousness…)

    • I had never thought of that. Yes. Perhaps I’ve got the mechanism entirely reversed. Perhaps this has nothing to do with a drop in the water level, and everything to do with a rise in the developing structure itself! Ha! Love it. It’s always fun to have my eyes opened by an alternate working hypothesis (which never, ever, occurred to me). Ah, the wonderment of collaborative brainstorming. Science at its best. Thanks so much Elke.

  2. How deep was the water where the ice structures in the top picture formed? There were some very similar ones in puddles at Zindel, mostly in wheel ruts in the path.

    • Really? These formed in the little stream that runs into our pond, along its banks where the water below must have been only a few inches deep. I wonder if my hypotheses conform to your recent weather pattern there? Thanks for checking in. D

      • Probably. The water puddles built up during some warm rainy weather and the formations happened after it turned very cold. The water level in the ruts was certainly falling bit by bit, which seems to fit in well with your theory.

  3. Generally there are logical scientific explanations for most of what happens. Tectonics is a good example along with the tidal sorting of pebbles. What can’t yet be explained most likely shall be given scientist’s curiousness. There’s a lot more to the formation of ice than 32°. As water cools it grows more dense and eventually sinks with the less dense warmer water rising to cool allowing the water to stop exchanging and become cold enough to freeze, first thinly on the surface and then, as you describe, further down. The speed at which the water freezes determines whether it captures impurities like bubbles which help to form the pattern you display or freezes clear which allows us to see black water below and the occasional prism.

    • Just saw that you are not teaching, which I expected, at least not right away. Do you have a plan or pretty much retired? Is there enough land to do a small farm or is that totally in the past as well?

      • Funny you should ask. In more than 30 years of teaching, I never took a sabbatical leave. Joanna and I thought that perhaps it was time. So, I am taking this year off, and will then see about finding some gainful means of employment then. Who knows, maybe I’ll open a Dunkin’ Donuts franchise?

  4. I envy you the ice patterns in this post and in your previous one, though I don’t envy you the cold you had to endure to record them. In contrast, the predicted high in Austin today is 83°.

    Do you know if anyone has done false-color ice pattern photographs in the same way that astronomers have done false-color photographs of galaxies and nebulae?

      • I do use Photoshop but I wouldn’t know how to colorize a photograph in a systematic way based on attributes of the original photograph. All I could do—and wouldn’t want to because of the tedium—is manually paint the image one stroke at a time.

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