"Faster than a speeding bullet. More powerful than a locomotive. Able to leap tall buildings in a single bound. This amazing stranger from the planet Krypton, the Man of Steel: Superman!"
Whether or not you're a fan of superheroes and comic books, you know who Superman is. It might be from the classic 1940s Fleischer cartoons (where I got that famous quote above), Christopher Reeve's sublime 1976 portrayal, the entertaining Superman animated series in the late '90s or the most recent action-packed movie outing with Henry Cavill, or one of the many other Superman outings.
Either way, you know that Superman can fly (or, in the early years, jump very far), has super strength, super speed, X-ray vision, heat ray vision, is invulnerable to everything but Kryptonite and routinely surprises audiences with other powers. And you know he gets those powers by absorbing light from Earth's yellow sun.
Now scientists are thinking that might not be such a bad idea for the rest of us ordinary humans. Giving our cells an energy boost with solar power could, in theory, help us heal faster and extend life spans by decades.