The Mysterious Morphology of Icicles
It takes about six hours for an icicle to form in the laboratory of Professor Stephen Morris and graduate student Antony Szu-Han Chen. The icicle’s nursery is a foam-insulated box, within which the air temperature is kept at a frigid negative eight degrees Celsius. Water comes out of a dripper and there is a mechanism that keeps the budding icicle rotating. A camera that’s inserted into a tunnel attached to the machine captures 16 images per rotation, totalling in 32 measurements being taken every five minutes. But why grow icicles and bother with all these measurements? According to Prof. Morris, there’s a lot about icicles that we don’t know, and studying their formation “can have profound physical implications.”
Prof. Morris is particularly interested in morphogenesis, or the emergence of shape. His lab is currently working on the emergence of ripples in icicles, but they’ve also studied such phenomena as ripples in roads and cracks in mud. This field of study is called pattern formation, which is a branch of classical physics and applied math. As of now, Prof. Morris’s lab is the only one in the world that is seriously examining icicle formation. The icicle project began around seven years ago, and is mainly the work of Szu-Han Chen, who constructed the icicle-growing machine himself. Prof. Morris acknowledges that “some think it’s trivial,” but when it comes down to it, icicle formation is intriguingly mysterious.
For starters, current physics theory can’t explain the ripples that form in icicles. The lab has made some headway in seeking the answers by experimenting with different impurities being added to the water that they use to make their icicles. So far they’ve tried using tap water, distilled water, salt water, and water with polymers added to it. As it turns out, the water that makes an icicle needs to have dissolved salts in it in order for ripples to form; this discovery violated the theory that was used up to that time. Ice formation is sensitive to even the smallest amounts of impurities. Distilled water, which is nearly pure, can form an icicle that doesn’t have ripples.
Perhaps the most mind-boggling aspect of ripple formation is the fact that, no matter how large the icicle, the ripples will consistently be one centimetre in wavelength. The speed at which the ripples form can vary depending on the amount of water and other external conditions, but the size of the ripples stays the same. Always. And we have no idea why.
Another project that has stemmed from this study is the Icicle Atlas, an online open source database. By early 2015, this database will contain all of the experimental data from this study, in accordance with Prof. Morris’s belief that he “shouldn’t have exclusive rights to the data.” When I asked him if the ultimate goal was for others around the world to re-create his experiments, he answered, “I’m hoping that people will do surprising things with it.” There are many pictures of icicles that he’s grown in the lab already available online. He suggested that people could use those images for Christmas cards, or perhaps even print out 3-D plastic renditions of them. He told me about Continuum, a musical ensemble that conceived a project involving original music and media art that draws inspiration from science, including the Icicle Atlas. Prof. Morris calls the Icicle Atlas “a sort of performance art in itself.” And here we were thinking that icicles are boring. ncomments powered by Disqus