Behind the cover: September 2022

Each month, Physics Today editors explore the research and design choices that inspired the latest cover of the magazine.

Sightings of rocks perched atop thin ice pedestals on frozen lakes are relatively rare. Phenomena known as Zen stones, named for their resemblance to a stack of rocks sometimes found balancing in a Japanese Zen garden, require specific meteorological conditions. Not only must the temperature remain below freezing, but the ice surface must remain free of snow for several weeks. The climate of Siberia’s Lake Baikal, where the photograph on the cover of the September issue was taken, meets both conditions. In the cold, dry air, sublimation causes surface ice to vaporize at a rate—about 2 mm per day—set by the temperature, humidity, and amount of sunlight it receives.

But only part of the ice sublimates. The rock atop the ice pedestal acts as an umbrella that shades the ice just beneath it from solar irradiance. It remains at constant altitude on an increasingly taller and narrower pillar of ice, before eventually falling off.

In his Quick Study this month , the University of Lyon’s Nicolas Taberlet reports how he and his colleague Nicolas Plihon confirmed that sublimation is responsible for the natural phenomenon. The two scientists reproduced it artificially in the lab. Prior to their work, the formation of the ice pillar had remained unexplained.

Physics Today‘s senior graphic designer, Freddie Pagani, wanted just the right “tall and stretchy” font in the cover line, “Siberia’s Zen stones,” to mimic the shape of that pillar. “When I think of Zen, I think of elevation,” she says of her inspiration for using the classic light and condensed Helvetica LT Std font for “Zen stones.” For the preceding word, she wanted a complementary serif font and thought that Bookman Old Style was a good match.

As for where to place the text, she used the negative space next to the pillar to balance the weight of the stone. (Image credit: iStock.com/MikhailZykov.)