Researchers advance insights into cause of ripples on icicles.

HAVE YOUR SAY.

Join us in The Bullpen, where the members of the Scientific Inquirer community get to shape the site’s editorial decision making. We’ll be discussing people and companies to profile on the site. On Wednesday, December 14 at 5:30pm EST, join us on Discord and let’s build the best Scientific Inquirer possible.


Experimental physicists growing icicles at the University of Toronto are closer to understanding why some form with ripples up and down their outsides, while others form with smooth, slick, even surfaces.

As described in a study published in Physical Review E, by growing icicles from water samples with different contaminants like sodium chloride (salt), dextrose (sugar) and fluorescent dye, the researchers discovered that water impurities become entrapped within icicles as they form and subsequently create chevron patterns that contribute to a ripple effect around their circumferences.

“Previous theories held that the ripples are the result of surface tension effects in the thin film of water that flows over the ice as it forms,” says Stephen Morris, a professor emeritus in the Department of Physics in the Faculty of Arts & Science at the University of Toronto and a co-author of the study describing the phenomenon. “We now see that the ripple formation does not depend on surface tension.  It does not even depend only on features external to the ice, but rather is connected to patterns of impurities inside the ice.”


ON SALE! Charles Darwin Signature T-shirt – “I think.” Two words that changed science and the world, scribbled tantalizingly in Darwin’s Transmutation Notebooks.

“The external shape and internal patterns are different aspects of the same — so far unexplained — problem.”

The findings build on an earlier discovery by Morris and his research team that found the presence of salt in water was responsible for the irregular, rippled shapes of icicles grown in the lab. The new results show that it is not the type of impurity that leads to the ripples, but just the fact that there is something foreign in the water.

“We tested various species of impurities, and the phenomena are unchanged as long as their concentrations are similar,” says John Ladan, a PhD student working with Morris and lead author of the study. “This is consistent with the idea that only physical, as opposed to chemical, processes are involved.”

While their motivation for unlocking the secret behind the ripples is pure curiosity about natural patterns, the study of ice growth has serious applications, including ice accumulation on airplanes, ships and power lines. However, for example, the results show that existing engineering models of ice accretion on power lines do not account for the entire problem. The researchers note that the findings do not resolve the mechanism of the ripples, but rather just add new aspects to the phenomena to be explained.

“We get a more profound appreciation for the complexity of natural ice formations,” says Morris.

IMAGE CREDIT: J. Ladan and S. W. Morris, University of Toronto


Processing…
Success! You're on the list.

SCINQ Basics: Garlic makes the world go ’round.
It is hard to understate the importance of garlic to many of …
DAILY DOSE: Egyptian Mummification for Dummies.
Washington D.C. is trying to reign in scientists who engage in “dangerous” …

Leave a Reply

%d bloggers like this: