Say that to da Vinci. His flying machines were inspired by birds. He studied Nature and tried to build machines based on the same principles as those that allow

Say that to da Vinci. His flying machines were inspired by birds. He studied Nature and tried to build machines based on the same principles as those that allowed birds to fly. Of course, that led his astray, because it's hard to design machines that fly by flapping their wings. However, the structural part remains. Take a look at how airplanes are designed these days, and you will see that their structure somewhat resembles the bone structure of actual birds. Last but not least: never say never, and never predict more than 10 years into the future. In 20 years your predictions might be ridiculed.