0:00:14.351,0:00:16.539 Have you ever been floating in a swimming pool, 0:00:16.539,0:00:18.089 all comfy and warm, thinking, 0:00:18.089,0:00:20.247 "Man, it'd be cool to be an astronaut! 0:00:20.247,0:00:21.706 You could float out in outer space, 0:00:21.706,0:00:23.366 look down at the Earth and everything. 0:00:23.366,0:00:24.699 It'd be so neat!" 0:00:24.699,0:00:26.355 Only that's not how it is at all. 0:00:26.355,0:00:27.674 If you are in outer space, 0:00:27.674,0:00:28.934 you are orbiting the Earth, 0:00:28.934,0:00:31.170 it's called free fall. 0:00:31.170,0:00:32.468 You're actually falling towards the Earth. 0:00:32.468,0:00:33.890 Alright, think about this for a moment. 0:00:33.890,0:00:35.488 That's the feeling you get 0:00:35.488,0:00:37.450 if you're going over the top of a roller coaster, 0:00:37.450,0:00:40.286 going, like, "Whoooooaaaahhhh!" 0:00:40.286,0:00:41.602 Only you're doing this the whole time 0:00:41.602,0:00:42.871 you're orbiting the Earth 0:00:42.871,0:00:43.490 for two, 0:00:43.490,0:00:44.021 three, 0:00:44.021,0:00:44.619 four 0:00:44.619,0:00:45.147 hours, 0:00:45.147,0:00:45.610 days, 0:00:45.610,0:00:46.658 whatever it takes, right? 0:00:46.658,0:00:48.371 So, how does orbiting work? 0:00:48.371,0:00:50.320 Let's take a page from Isaac Newton. 0:00:50.320,0:00:51.369 He had this idea, 0:00:51.369,0:00:52.441 a little mental experiment. 0:00:52.441,0:00:53.905 You take a cannon, 0:00:53.905,0:00:54.994 you put it on top of a hill. 0:00:54.994,0:00:56.283 If you shoot the cannon ball, 0:00:56.283,0:00:57.980 it goes a little bit away. 0:00:57.980,0:00:58.774 But if you shoot it harder, 0:00:58.774,0:01:01.620 it goes far enough so that it lands 0:01:01.620,0:01:03.837 a little bit past the curvature of Earth. 0:01:03.837,0:01:04.620 Well, you can imagine 0:01:04.620,0:01:06.596 if you shot it really, really, really hard, 0:01:06.596,0:01:08.916 it would go all the way around the Earth 0:01:08.916,0:01:10.047 and come back, boom! 0:01:10.047,0:01:11.886 and, like, hit you in the backside or something. 0:01:11.886,0:01:13.109 Let's zoom way back 0:01:13.109,0:01:14.632 and put you in a little satellite 0:01:14.632,0:01:16.215 over the North Pole of the Earth 0:01:16.215,0:01:17.591 and consider north to be up. 0:01:17.591,0:01:19.465 You're going to fall down and hit the Earth. 0:01:19.465,0:01:23.795 But you are actually moving sideways really fast. 0:01:23.795,0:01:24.962 So, when you fall down, 0:01:24.962,0:01:26.339 you're going to miss. 0:01:26.339,0:01:28.207 You're going to end up on the side of the Earth, 0:01:28.207,0:01:29.560 falling down, 0:01:29.560,0:01:32.558 and now the Earth is pulling you back in sideways. 0:01:32.558,0:01:33.819 Alright, and so it's pulling you back in 0:01:33.819,0:01:34.714 and you fall down, 0:01:34.714,0:01:36.625 and so you miss the Earth again, 0:01:36.625,0:01:38.153 and now you're under the Earth. 0:01:38.153,0:01:39.375 And the Earth is going to pull you up, 0:01:39.375,0:01:40.907 but you're moving sideways still. 0:01:40.907,0:01:42.463 So, you're going to miss the Earth again. 0:01:42.463,0:01:43.961 Now, you're on the other side of the Earth, 0:01:43.961,0:01:46.686 moving upward and the Earth's pulling you sideways. 0:01:46.686,0:01:48.765 Alright, so you're going to fall sideways, 0:01:48.765,0:01:51.210 but you're going to be moving up and so you'll miss. 0:01:51.210,0:01:53.024 And now you're back on top of the Earth again, 0:01:53.024,0:01:54.333 over the North Pole, 0:01:54.333,0:01:56.582 going sideways and falling down, 0:01:56.582,0:01:57.728 and yep, you guessed it. 0:01:57.728,0:02:01.059 You'll keep missing because you're moving so fast. 0:02:01.059,0:02:03.483 In this way, astronauts orbit the Earth. 0:02:03.483,0:02:05.642 They're always falling towards the Earth, 0:02:05.642,0:02:07.312 but they're always missing, 0:02:07.312,0:02:09.574 and therefore, they're falling all the time. 0:02:09.574,0:02:10.486 They feel like they're falling, 0:02:10.486,0:02:12.261 so you just have to kind of get over it. 0:02:12.261,0:02:16.395 So, technically, if you ran fast enough and tripped, 0:02:16.395,0:02:18.907 you could miss the Earth. 0:02:18.907,0:02:20.169 But there's a big problem. 0:02:20.169,0:02:24.006 First, you have to be going 8 kilometers a second. 0:02:24.006,0:02:26.262 That's 18,000 miles an hour, 0:02:26.262,0:02:28.881 just over Mach 23! 0:02:28.881,0:02:29.836 The second problem: 0:02:29.836,0:02:31.263 If you're going that fast, 0:02:31.263,0:02:32.931 yes, you would orbit the Earth 0:02:32.931,0:02:34.426 and come back where you came from, 0:02:34.426,0:02:36.560 but there's a lot of air in the way, 0:02:36.560,0:02:37.978 alright, much less people and things. 0:02:37.978,0:02:40.099 So, you would burn up due to atmospheric friction. 0:02:40.099,0:02:43.704 So, I do not recommend this.