For the many wondrous things humans can do, we can't fly on our own. But if we could, how big would our wings be?Of course, the answer depends on the person's size. But someone who's about 155 pounds ...

The smallest is the two-inch-long bee hummingbird. Everything about the anatomy of a bird reflects its ability to fly. The wings, for example, are shaped to create lift. The leading edge is ...