Things sand dunes are famous for: being very big, and very changeable. Being hard on your knees when you climb them. Being chaotic in wind (same). Things sand dunes are not famous, or even known, for: being talkative, or generally forthcoming about their emotions. Indeed, as large piles of sand, dunes would not appear to have emotions.
Yet new research suggests sand dunes can nonetheless communicate with one another. According to CNN, sand dunes let their neighbors know when they “need space,” unlike some people — for example, your roommate, who has not responded to any of your texts about rent, although you can hear them pinging away on their phone through your shared wall — you may know.
Anyway: Dunes travel and shape-shift, the small ones moving more quickly than the large ones. Regardless of size, they “rarely occur in isolation, but usually form vast dune fields,” per a paper from researchers in the University of Cambridge’s Department of Applied Mathematics and Theoretical Physics. What does any of that say about inter-dune dynamics, though? To find out, Ph.D. candidate Karol Bacik put two identically sized sand piles next to each other in a water-filled rotator machine, thinking they would move at the same speed. Eventually, they did, but at first the front dune moved more quickly, generating a wake that appeared to hold the back dune at bay.
“They would move away from each other, as though they didn’t like each other,” Bacik told CNN. The dunes ultimately wound up on opposite sides of the tank, much like you and your roommate, stewing on opposite ends of your apartment.
Previous theories of dune movement have posited that individual sand piles keep crashing into one another and piling up, or exchanging mass. This new theory suggests that dunes might repel each other, pushing one another away when they require more space. Granted, I am not a sand dune, but I feel there are bigger or clearer signals one could send? Then again, think about the roommates who’ve let you know they don’t want to talk to you right now by locking themselves in your shared bathroom for hours-long night baths, refusing to answer when you knock on the door. Or the ones who leave angry Post-It reminders in shared spaces, punctuated with smiley faces to let you know that they’re definitely not mad but you need to never move their special mug again. Maybe we would all do better to be at least as communicative as sand dunes. Just no pushing, okay?