Several years ago I hiked up the Kelso Dunes in the Mohave Desert in California, then sat and slid down them to the bottom. If you’ve ever tried this, or heard a similar avalanche of sand, you know that the sand emits a distinctive and mysterious low whining sound, which some people call “singing” and some call “booming.” According to physicist Bruno Andreotti, who’s been studying the phenomenon, the noise can be as 105 decibels and, being low-frequency, can be heard up to 10 kilometers away.
Studying actual dunes, Andreotti found that vibrations in the sand act like slow-moving elastic sound waves that run across the surface of the dunes. The vibration of the sand bed tends to synchronize the collisions, and the surface of the sand bed acts like the membrane in a loudspeaker, accounting for the sound.
Try it next time you’re out in the desert.
DeepMind’s cofounder: Generative AI is just a phase. What’s next is interactive AI.
“This is a profound moment in the history of technology,” says Mustafa Suleyman.
What to know about this autumn’s covid vaccines
New variants will pose a challenge, but early signs suggest the shots will still boost antibody responses.
Human-plus-AI solutions mitigate security threats
With the right human oversight, emerging technologies like artificial intelligence can help keep business and customer data secure
Next slide, please: A brief history of the corporate presentation
From million-dollar slide shows to Steve Jobs’s introduction of the iPhone, a bit of show business never hurt plain old business.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.