# The Mysterious Mathematical Principle That Links Bus Systems and Chicken Eyes

iStock

Math is everywhere—if you know where to look. Elegant equations can be observed in everything from flower petals to swirling galaxies. Universality, a phenomenon that strikes a balance between order and randomness, is one of these ubiquitous mathematical patterns that repeats itself again and again in the natural world. As Quanta Magazine lays out in the new episode of its In Theory video series, examples of universality can be seen in biology, quantum physics, and even public transportation.

In math, universality is what determines the spacing between solutions in a large matrix of random numbers. The numbers that go into the matrices may themselves be random, but when they interact, they produce a predictable outcome.

You can see the same principle at work in the world around us. Take bus routes, for instance. In 1999, a Czech physicist named Petr Šeba found the pattern in Cuernavaca, Mexico after observing how the city's bus system operated. Paid "spies" were positioned along the bus routes, and whenever a bus came, they'd let the driver know how long it had been since the last one passed through. Based on this intel, the bus driver would either slow down or speed up to maximize his passengers at the next stop. On paper, this method creates a barcode pattern of lines that appear to be placed at random but actually follow a set pattern.

That same random-looking pattern appears elsewhere, too, like in chicken eyes. While the color-sensitive cone cells in the eyes of some animals, like fish, are laid out uniformly across the retina, the cells in chickens' eyes look different. The cone cells are different sizes and look like they're scattered at random. But these cells are actually distributed according to the universality pattern—the first-ever instance of the pattern recorded in biology.

You can also see universality when you map out the energy spectrum of the uranium nucleus, the spectral measurements of sea ice, and elsewhere. To learn more about the math behind universality and how to spot it in the real world, check out the video below.

[h/t Quanta Magazine]

# Watch Kit Harington Gag After Having to Kiss Emilia Clarke on Game of Thrones

HBO

The romance between Jon Snow and Daenerys Targaryen might be heating up on Game of Thrones (though that could change once Jon shares the truth about his parentage), but offscreen, Kit Harington and Emilia Clarke's relationship is decidedly platonic. The two actors have gotten to be close friends over the past near-10 years of working together, which makes their love scenes rather awkward, according to Harington.

A new video from HBO offers a behind-the-scene peek at "Winterfell," the first episode of Game of Thrones's final season. Starting at about the 12:20 mark, there's a segment on Jon and Dany's date with the dragons and what it took to create that scene. Included within that is footage of the two actors kissing against a green screen background (about 13:50), which would later be turned into a stunning waterfall. But when the scene cuts, Harington can be seen faking a gag at having to kiss the Mother of Dragons.

“Emilia and I had been best friends over a seven-year period and by the time we had to kiss it seemed really odd,” Harington told The Mirror, then went on to explain that Clarke's close relationship with Harington's wife, Rose Leslie, makes the intimate scenes even more bizarre. "Emilia, Rose, and I are good friends, so even though you’re actors and it’s your job, there’s an element of weirdness when the three of us are having dinner and we had a kissing scene that day."

As strange as it may be, Harington finally came around and admitted that, "I love Emilia and I’ve loved working with her. And it’s not hard to kiss her, is it?"

[h/t Wiki of Thrones]