WEBVTT 00:00:00.000 --> 00:00:08.133 "The moment you doubt whether you can fly, you cease forever to be able to do it" - J.M Barrie 00:00:09.133 --> 00:00:14.766 Let's make a person glide. 00:00:15.800 --> 00:00:22.300 We have a man wearing a wingsuit on a platform. 00:00:23.833 --> 00:00:32.533 Let's increase the area of the wingsuit to be proportionate to a flying membrane of a flying squirrel. 00:00:34.466 --> 00:00:40.733 Then, make the man run as fast as he can to the end of the platform, and jump off. 00:00:44.100 --> 00:00:50.333 At this point, the airflow speeds up on top of the suit as the result of the suit catching air from below. 00:00:51.400 --> 00:00:56.966 It creates lift. 00:00:57.900 --> 00:01:06.000 If you run as fast as Usain Bolt with this suit, it will support 2.8kg. 00:01:06.766 --> 00:01:11.200 So, naturally this happens. 00:01:21.366 --> 00:01:28.866 For a normal person to glide in a wingsuit like this, the gravity will have to be small and the atmosphere dense. 00:01:30.600 --> 00:01:39.533 Titan, a satellite of Saturn, is one such example that is suitable for gliding with our wingsuit. 00:01:42.233 --> 00:01:50.633 Titan is a harsh environment with a temperature of -179°C and methane rain. 00:01:51.300 --> 00:02:01.000 But its gravity is 1/7th that of Earth, and its atmosphere is four times as dense as our atmosphere. 00:02:01.667 --> 00:02:11.233 We can manage to glide horizontally. 00:02:23.366 --> 00:02:29.600 If you do it on Earth, you'd have be running at 200 km/h in order to glide. 00:02:33.166 --> 00:02:38.666 This person can also enjoy horizontal gliding. 00:02:48.900 --> 00:02:59.200 If you can't run at 200 km/h, you'll need this much suit area. 00:03:15.233 --> 00:03:22.566 Now, let's think about making humans fly by flapping wings. 00:03:24.000 --> 00:03:32.466 A small hummingbird hovers by moving its wings in a "figure 8" motion 80 times per second. 00:03:33.766 --> 00:03:44.100 Let's put some light wings on a 60kg person and make him do the same motion. 00:03:44.866 --> 00:03:53.233 And increase the rate of flapping. 00:03:53.233 --> 00:04:02.566 Try flying at 80 times per second, the same rate as a hummingbird. 00:04:04.800 --> 00:04:13.366 When you are as large as a human, such flapping will only support 3.1kg. 00:04:13.366 --> 00:04:20.200 Ten times that of a hummingbird, 800 times per second, still looks like this. 00:04:28.833 --> 00:04:36.233 At 1540 times per second... 00:04:38.933 --> 00:04:46.166 Our human can now hover. 00:05:02.933 --> 00:05:11.733 Estimates from the data of other birds, a man-sized wing should be 7 meters long. 00:05:14.933 --> 00:05:21.533 You could glide with this wing. 00:05:23.400 --> 00:05:31.233 It can hover at 70 times per second, which is less than that of a hummingbird. 00:05:37.633 --> 00:05:45.666 So, as long as you don't doubt our ability to fly, we can fly.