 Hi, my name is Jade. And I'm Lauren. We're PCVS students, and we're studying genetics in our class. And we want to ask you a question. Is it genetically possible to grow wings under back and be able to fly? Hi, I'm Dr. Sarah Thornton, and I'm a biologist here at MIT. If you haven't already seen the videos about how we would build a human with wings, I really recommend that you watch this video. But even if you can make a human with wings, would that human be able to fly? Professor Perieri is going to answer the other half of your question. My name is Jaime Pereire. I am a faculty member here in the Department of Aeronautics and Astronautics at MIT. Humans obviously cannot fly. And the reason is because they've been able to successfully develop and reproduce and thrive without having to fly, unlike birds that require flying in order to be able to survive and develop. From an engineering perspective, on the other hand, we can look at what are the shortcomings of the human body in order to be able to fly. And the first one that comes to mind is essentially the shape. It has very heavy relative to the surface that we have. And this surface is very important because in order to fly, you need to be able to generate aerodynamic forces. And that can only be done if you have sufficient surface. You look at birds. The ratio of wing surface to the weight is much larger than the surface of our bodies relative to our weight. If you look at a large bird, like an albatross, it would have a wing span of about two meters and weigh approximately 20 kilograms. Two meters is about the wing span we might have with our open arms if we were to think of our arms as wings. But obviously, we are a lot heavier than 20 kilograms. The Daedalus aircraft, which is a human-powered aircraft, was built here a few decades ago. At that time, it held a world record for human power flight. It flew for about 100 kilometers, or perhaps even more. And essentially, what you have here is a human pedaling. But what is around the human is an aircraft, which is about 30, 40 kilograms. And the wings span is probably of the order of 15 meters, maybe. And that's the type of surfaces that it would take to lift the human. If we really were not to go to wings of this size and we were to stay with the smaller wings, that would be possible if we were able to fly faster. But in order to fly faster, then the energy consumption would be quite significant. The faster you fly, the more energy you need, and the less wings you need. But to fly, say, in a bird-like class, you would need a significant amount of energy. And our bodies are just not created to deliver this amount of energy. A bat would eat about each weight, perhaps once or twice a day, in order to be able to fly. So that's the amount of food intake that a bat would take. On the other hand, humans do not usually eat their way in food every day. In fact, they eat a lot less. So here you can see that the amount of energy that a bat produces is much higher relative to their weight. And that's something that would have to be addressed to make a body like that of a human to be able to fly.