From handwarmers to snowflakes and what they have in common

This weekend the winter really arrived. It is freezing cold out here and I finally get my hopes up for some snow to arrive (pleaaase!). Ever since I was a small child, snow raised fascination inside myself as it probably did for most children. And also now, every year I hope for a white Christmas. And since this didn’t happen this year (as so many other years before), I still remain looking forward to some snow. To the excitement when you wake up and everything is white, to snowball fights, building snowmen and to the peaceful silence caused by the snow muffling all kinds of sounds.

But let’s go back a day…

Yesterday we tried out two of these funny handwarmers. You know these tiny pillows filled with a liquid and a small metal plate inside. When you bent the metal, the liquid becomes solid, spreading from the disc onwards, and the pillow turns cosily warm for some 20 minutes or so. Simple enough, afterwards you can boil the handwarmers in hot water for a few minutes to turn them back to the liquid state. Magic? Actually not! After having asked myself many times before how this magic works, this time I decided to ask google instead for the hope of a more satisfying answer. And tadaaa indeed I got an explanation. I don’t wanna elaborate extensively here about that (you all know how to google) but essentially it works like this: Inside you have a supersaturated salt solution, which means you have actually more salt dissolved than the solution is supposed to hold at room temperature. All you need is a “seed”, where the salt crystals can build on, in order to disturb this fragile state. Once the “seed” is present the salt crystals precipitate onto that substrate within seconds. The stored energy is thereby released in an exothermic reaction making the handwarmer fulfill their purpose of warming our hands. Okay so far so good, just where does the seed “suddenly” comes from and why the metal plate? As you can imagine, both is connected. When you force the salt into solution by boiling the pillow, some of the salt crystals get trapped in small cavities in the metal disc instead of going into the solution. When the metal disc is bent, these crystals are released and form a seed for the following crystal growth. Magic executed!


Now, while I was reading about this there was a striking comparison I was not aware of. The “seed” concept” can also be found in the formation of snowflakes. Call me ignorant, but despite my fascination by snow ever since I was little, I never knew that snowflakes – as well – need a seed before they can be formed. Most of you probably know that each snowflake is unique and that they are formed by freezing water when humid air becomes too cold. But the precipitation of water needs a substrate to crystallize on, such as fine dust or pollen. So in the heart of each of these pure, clean, wonderful snowflakes there is a particle.

The seed concept of freezing water becomes very nicely visible in these freezing soap bubbles (<– you have to click there!). It is wonderful, how the ice crystals grow in a geometric and still playful way. But what it needs is a base to grow on. What if needing a seed for growth does not only apply to crystals but also to people and their personal lifes? You can grow in any direction that you can imagine, but what you need is a seed, an anchor or starting point – then you can go anywhere from there… Now it’s your turn! What is your seed, where do you start growing? Go find it, because once you started you won’t be stoppable.

PS: Never eat yellow snow!!!


2 thoughts on “From handwarmers to snowflakes and what they have in common

  1. zoraaurora says:

    @openbrainsurgeon actually snowflakes are not truly symmetrical. I just recently read a book about the study of snowflakes and the first two questions in this book were: why are they all so different and how is the growth of the arms coordinated?
    The shape is determined by the history of its growth it says. They travel through varying environmental conditions during formation. Depending on temperature and humidity the crystals build up differently. Thats why they all look different. But the arms of each individual flake experience the same conditions and crystal growth follows the same strict dynamics, so they all form in the same way…making it look very symmetrical. But when you look closely, you see that they all have their flaws 🙂
    This thing with the seed you find in many interesting microhabitats…look at manganese nodules. Or cryoconite holes to keep it icy.

    Liked by 2 people

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