Although Kanye West is still hyping his soon-to-be-released line of Adidas Yeezy basketball shoes on the feet of NBA players, concerns about the sneakers raised by industry insiders might kill his vibe. The Yeezys have a prominently shiny feature on the heels, which could lead the NBA to ban the sneakers from the court before the opening games of the 2018-2019 season. If it happens, Western Kentucky University physicist Scott Bonham, Ph.D., wouldn’t be too surprised.
Kanye’s Instagram reveals that the basketball Yeezys sport a glimmering heel-panel that basically lights up like a crossing guard’s reflective vest. After ‘Ye leaked the photos of the shoes, industry sources told ESPN that this “3M reflective panel” could be so distracting to players on the court and viewers at home that it could elicit a league-wide ban.
The panels on the shoes are called “retroreflectives” and can indeed be quite bright, explains Bonham to Inverse. Retroreflective materials, he says, are designed help channel light from many different angles into one common direction, which would be pretty distracting, mid jump-shot.
“The issue with the basketball sneaker is that in some courts you might have certain bright lights overhead,” Bonham, who teaches intro physics, tells Inverse. “If someone’s head has those bright lights behind it and those lights hit the retroreflective, then it could come straight back and temporarily blind them.”
The shoes’ potential for distraction has everything to do with how they reflect light. Usually, when a beam of light hits a flat, shiny surface like a mirror, it bounces off in one single direction, a process called specular reflection. But materials like the Yeezys 3M panel put many different reflective surfaces together to bounce light off of one another and then spit that light back out in the direction it came from, a process called retroreflection:
“In specular reflection a light hits it and scatters in some other direction,” Bonham explains. “In a retroreflection, the light hits it and scatters it all pretty much in the same direction that it came in.”
To imagine how this happens, Bonham says to envision three different mirrors all stacked together, like the interior corner of a cube. When light enters that cube, it will bounce from mirror to mirror. “If you shine a light in, it will bounce from one mirror to the other one and then come back in the direction that light was shined,” Bonham explains. “No matter what direction it started at, it will come straight back.”
This is actually the process behind most reflective bicycle tail lights. If you look very closely at them, you’ll see that each reflective panel is made up of many tiny cubes that are each engineered to spit light back out in the direction it came; in the case of bikers, the light is reflected back to the driver whose headlights illuminate the road ahead. This is also the reflective process that 3M, the company rumored to be behind the Yeezy’s shiny heels, describes on its website.
The NBA has yet to officially review Kanye’s new line of sneakers, so it’s possible that a slight manufacturing change might make them a bit less luminescent under stadium lights. But given the league’s history of banning shiny sneakers — like Carmelo Anthony’s Jordan Melo M10s with a chrome heel — it’s not likely we’ll be blinded by them courtside anytime soon.