Stasis/hibernation in humans, for spaceflight, preservation, etc
Can humans hibernate? There would be many good uses for such technology, including long endurance spaceflights to Mars and beyond, stabilization after injury, or waiting until a therapy or other life-saving solution becomes available. I like it best for spaceflight though, just the way science fiction intended.
Source: Space Torpor
Is hibernation just extended sleep or is it something different? Sleep is clearly conserved in humans and animals, which is quite remarkable given the opportunity and safety cost of it. Most sleep researchers agree that it's been evolutionarily conserved for a reason, we’re just not quite sure what it is. It is also very clear that being unconscious, through anesthesia or other means, is not the same as sleep. In fact, it’s a misconception that animals that are hibernating are sleeping. Hibernation is an extended form of torpor, where metabolism is depressed to less than five percent of normal and most physiological functions are extremely slowed or halted. Mammalian species that hibernate regularly include chipmunks, squirrels, bats, and bears, but not humans. We’ll need to hack more than sleep to become a space-hibernating species. We’ll also need to hack our metabolism, preserve our muscle function, and maybe even simulate (or stimulate) sleep in our brains to keep us functional for the long ride. That might take a while - check back in a decade or two!