In 1932, an inventor patented a phonograph that could play time-affirming messages while listeners slept. Now, scientists are once again taking up the possibility of learning while asleep. https://www.newyorker.com/culture/annals-of-inquiry/its-possible-to-learn-in-our-sleep-should-we?utm_source=voante&utm_medium=social&utm_campaign=dhvoante&utm_content=null