Matters Most Grey A lot of ink has been spilled about Elon Musk's rapidly developing Neuralink program, owing in no small part to the kind of hype the billionaire's able to drum up around his companies. But Neuralink, like its founder, has a little brother: Mark Zuckerberg's Meta, the tortoise to Musk's hare. Since 2016, Meta's brain-interface technology has developed steadily along two paths: one, an module allowing subjects to "hear with their skin," the other, a "silent speech system" meant to help users communicate with just their brains. The latter venture was skuttled a few years ago,