Jane Evans and Joanne Osmond are sisters with a superpower: they only need about four hours of sleep a night! The sisters each carry a rare genetic mutation that experts like Dr. Ying-Hui Fu say makes them “natural short-sleepers” – people who only need a few hours of sleep to live their best lives. They don't need caffeine to get through their day. They don’t experience jetlag. Many short-sleepers have no health issues. Dr Fu believes Jane and Joanne may hold the key for how to live better: through "optimal" sleep. The future of her research might just revolutionize all of our sleeping and waking lives. Learn more and submit your own sleep questions at www.vox.com/areyousleeping And, let us know what you think of the show at www.vox.com/survey Learn more about your ad choices. Visit podcastchoices.com/adchoices