American Scientist

The last time American Scientist featured on its cover a ball from the Beautiful Game (of football, fútbol, calcio, or soccer, depending on your geographic location), was in 2006. That cover focused on the classic-style black-and-white ball, made of 12 pentagons and 20 hexagons, introduced to the World Cup competition in 1970. Although that article was concerned with shape, it focused on the mathematics of all the different ways to put together spheres made of polygons, and it veered off into other topological shapes that could arise from surface mapping (none of which would make a professional footballer happy during a game).

We decided that it was about time for another look at the game. For the past few decades, balls created for the World Cup haven’t looked like the classic version; instead, their panels have involved different curved shapes that are often brightly colored. And as John Eric Goff details in “Balls in the Air,” how these shapes affect airflow matters. Goff and his colleagues study World Cup balls in wind tunnels, detailing their drag coefficients and the wakes that they create behind them at different speeds. The number, placement, length, depth, and width of seams, along with surface texturing, Goff notes, can create significant differences in the behavior of the resulting ball.

Shape is a common theme in the feature articles of this issue. Analyzing shapes is a key way that our brains try to understand what we see—and tricking the brain with unexpected shapes was a main tactic of the surrealist artist René Magritte. In “The Mind and the Mirror,” Russell D. Hamer explains how Magritte’s art achieved its effects by breaking key neurological rules of perception. Magritte often played with transparency and opacity, creating scenes that at first seem to show one illusion until suddenly snapping to another. Hamer describes how the brain separates the shape of a visual subject from its background, and how certain brain areas fill in missing information to create a picture; he explains how Magritte’s surrealistic worlds take advantage of these processes to create unexpected scenes.

The shape of the land over geological timescales, and what that means for Earth’s environment, is a main point of “The Ancient Mississippi River’s Return.” It’s been 19,000 years since the last ice age that partly covered North America, but the land is still rebounding from the removal of that immense weight of ice, and it will continue to do so for another 9,000 to 13,000 years, explain Roy Van Arsdale and his colleagues. One of the consequences of that rebound may be a shift in the Mississippi River back to its ancient watershed, which could exacerbate flooding across the continent.

A wide range of sizes are covered in the article “Diversity from Isolation.” Daniel T. Ksepka focuses here on the diversity of sizes and shapes in early penguins, whose fossils are predominantly found in New Zealand. Ksepka notes that the islands’ isolation may have allowed some of these ancient penguins to grow to nearly human size, which in turn permitted them to develop greater cold tolerance and enabled their move to frigid environments farther south. But New Zealand is also home to some of the tiniest penguins, whose burrowing nests may have protected them from large predators, thereby allowing penguins to survive in New Zealand today.

What shape does your research take? We are still accepting letters about why your research is important. Send your submissions to editors@amscionline.org with the subject line “Science Is Important.” See the call for letters on our website for additional details and formatting information.