[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:14.07,0:00:16.37,Default,,0000,0000,0000,,If humans could fly,
Dialogue: 0,0:00:16.39,0:00:17.82,Default,,0000,0000,0000,,without tools and machines,
Dialogue: 0,0:00:17.84,0:00:20.10,Default,,0000,0000,0000,,how fast do you think we would go?
Dialogue: 0,0:00:20.13,0:00:22.51,Default,,0000,0000,0000,,As of 2012, the world record
Dialogue: 0,0:00:22.53,0:00:24.61,Default,,0000,0000,0000,,for fastest short-distance sprint speed
Dialogue: 0,0:00:24.63,0:00:27.34,Default,,0000,0000,0000,,is roughly 27 miles per hour.
Dialogue: 0,0:00:27.36,0:00:29.24,Default,,0000,0000,0000,,Running speed depends on how much force
Dialogue: 0,0:00:29.26,0:00:31.11,Default,,0000,0000,0000,,is exerted by the runner's legs,
Dialogue: 0,0:00:31.14,0:00:34.34,Default,,0000,0000,0000,,and according to Newton's Second\NLaw of Motion,
Dialogue: 0,0:00:34.36,0:00:38.58,Default,,0000,0000,0000,,force is the product of mass\Ntimes acceleration.
Dialogue: 0,0:00:38.60,0:00:40.35,Default,,0000,0000,0000,,And Newton's Third Law states
Dialogue: 0,0:00:40.37,0:00:41.62,Default,,0000,0000,0000,,that for every action,
Dialogue: 0,0:00:41.65,0:00:44.76,Default,,0000,0000,0000,,there is an equal and opposite reaction.
Dialogue: 0,0:00:44.78,0:00:46.74,Default,,0000,0000,0000,,So, that means running requires
Dialogue: 0,0:00:46.77,0:00:48.55,Default,,0000,0000,0000,,having a ground to push off from,
Dialogue: 0,0:00:48.57,0:00:52.68,Default,,0000,0000,0000,,and the ground pushes back\Nagainst the runner's foot.
Dialogue: 0,0:00:52.70,0:00:55.21,Default,,0000,0000,0000,,So, flying would actually be
Dialogue: 0,0:00:55.23,0:00:57.39,Default,,0000,0000,0000,,more similar to swimming.
Dialogue: 0,0:00:57.41,0:01:01.32,Default,,0000,0000,0000,,Michael Phelps is currently\Nthe fastest human in water
Dialogue: 0,0:01:01.34,0:01:04.96,Default,,0000,0000,0000,,and the most decorated\NOlympian of all time.
Dialogue: 0,0:01:04.99,0:01:06.69,Default,,0000,0000,0000,,Guess how fast he swims?
Dialogue: 0,0:01:06.71,0:01:09.36,Default,,0000,0000,0000,,The answer may surprise you.
Dialogue: 0,0:01:09.38,0:01:11.24,Default,,0000,0000,0000,,His fastest recorded speed is
Dialogue: 0,0:01:11.26,0:01:15.09,Default,,0000,0000,0000,,less than 5 miles per hour.
Dialogue: 0,0:01:15.11,0:01:17.37,Default,,0000,0000,0000,,A child on the ground can easily outrun
Dialogue: 0,0:01:17.39,0:01:18.66,Default,,0000,0000,0000,,Michael Phelps in water,
Dialogue: 0,0:01:18.68,0:01:20.54,Default,,0000,0000,0000,,but why is that?
Dialogue: 0,0:01:20.56,0:01:23.22,Default,,0000,0000,0000,,Well, let's go back\Nto Newton's Third Law of Motion.
Dialogue: 0,0:01:23.25,0:01:24.79,Default,,0000,0000,0000,,When we run, we move forward
Dialogue: 0,0:01:24.82,0:01:27.09,Default,,0000,0000,0000,,by pushing against the ground\Nwith our feet
Dialogue: 0,0:01:27.11,0:01:28.40,Default,,0000,0000,0000,,and the ground pushes back,
Dialogue: 0,0:01:28.42,0:01:30.39,Default,,0000,0000,0000,,propelling us forward.
Dialogue: 0,0:01:30.41,0:01:32.59,Default,,0000,0000,0000,,The ground is solid.
Dialogue: 0,0:01:32.62,0:01:34.85,Default,,0000,0000,0000,,By definition, it means the particles
Dialogue: 0,0:01:34.87,0:01:37.18,Default,,0000,0000,0000,,are essentially locked into place
Dialogue: 0,0:01:37.20,0:01:40.43,Default,,0000,0000,0000,,and must push back instead\Nof getting out of the way,
Dialogue: 0,0:01:40.46,0:01:43.64,Default,,0000,0000,0000,,but water is liquid and flows easily.
Dialogue: 0,0:01:43.67,0:01:44.73,Default,,0000,0000,0000,,When we move our limbs
Dialogue: 0,0:01:44.75,0:01:46.23,Default,,0000,0000,0000,,to push back against the water,
Dialogue: 0,0:01:46.26,0:01:47.64,Default,,0000,0000,0000,,a part of the water molecules
Dialogue: 0,0:01:47.66,0:01:49.40,Default,,0000,0000,0000,,can just slide past one another
Dialogue: 0,0:01:49.43,0:01:50.89,Default,,0000,0000,0000,,instead of pushing back.
Dialogue: 0,0:01:50.92,0:01:52.53,Default,,0000,0000,0000,,Now, let's think about flying.
Dialogue: 0,0:01:52.55,0:01:54.45,Default,,0000,0000,0000,,Air has a lot more free space
Dialogue: 0,0:01:54.47,0:01:56.86,Default,,0000,0000,0000,,for particles to move past one another,
Dialogue: 0,0:01:56.89,0:01:59.91,Default,,0000,0000,0000,,so even more of our energy\Nwould be wasted.
Dialogue: 0,0:01:59.93,0:02:02.18,Default,,0000,0000,0000,,We would need to push\Na lot of air backwards
Dialogue: 0,0:02:02.20,0:02:03.98,Default,,0000,0000,0000,,in order to move forward.
Dialogue: 0,0:02:04.00,0:02:05.83,Default,,0000,0000,0000,,Astronauts move around in shuttles
Dialogue: 0,0:02:05.86,0:02:07.90,Default,,0000,0000,0000,,in zero gravity when\Nthey're in outer space
Dialogue: 0,0:02:07.93,0:02:10.92,Default,,0000,0000,0000,,by pulling on handles installed\Non the ceiling walls
Dialogue: 0,0:02:10.94,0:02:12.64,Default,,0000,0000,0000,,and floors of the shuttle.
Dialogue: 0,0:02:12.67,0:02:16.47,Default,,0000,0000,0000,,Now, imagine you were\Ngiven the ability to float.
Dialogue: 0,0:02:16.49,0:02:19.26,Default,,0000,0000,0000,,How would you move\Naround in the middle of the street?
Dialogue: 0,0:02:19.29,0:02:20.76,Default,,0000,0000,0000,,Well, you wouldn't get very far
Dialogue: 0,0:02:20.79,0:02:23.04,Default,,0000,0000,0000,,by swimming in air, would you?
Dialogue: 0,0:02:23.06,0:02:24.38,Default,,0000,0000,0000,,Nah, I don't think so!
Dialogue: 0,0:02:24.41,0:02:26.98,Default,,0000,0000,0000,,Now, assuming you were\Ngranted the ability to float
Dialogue: 0,0:02:27.00,0:02:29.73,Default,,0000,0000,0000,,and the speed to move around efficiently,
Dialogue: 0,0:02:29.76,0:02:32.60,Default,,0000,0000,0000,,let's discuss the height of your flight.
Dialogue: 0,0:02:32.62,0:02:34.78,Default,,0000,0000,0000,,According to the Ideal Gas Law,
Dialogue: 0,0:02:34.80,0:02:36.32,Default,,0000,0000,0000,,P-V N-R-T,
Dialogue: 0,0:02:36.35,0:02:38.82,Default,,0000,0000,0000,,pressure and temperature has\Na positive correlation,
Dialogue: 0,0:02:38.85,0:02:42.20,Default,,0000,0000,0000,,meaning they increase\Nand decrease together.
Dialogue: 0,0:02:42.23,0:02:44.50,Default,,0000,0000,0000,,This is because the air expands in volume
Dialogue: 0,0:02:44.52,0:02:45.82,Default,,0000,0000,0000,,with less pressure,
Dialogue: 0,0:02:45.84,0:02:48.25,Default,,0000,0000,0000,,so the molecules have more\Nroom to wander around
Dialogue: 0,0:02:48.27,0:02:51.92,Default,,0000,0000,0000,,without colliding into each other\Nand creating heat.
Dialogue: 0,0:02:51.94,0:02:54.09,Default,,0000,0000,0000,,Since the atmospheric\Npressure is a lot lower
Dialogue: 0,0:02:54.11,0:02:55.31,Default,,0000,0000,0000,,in high altitudes,
Dialogue: 0,0:02:55.33,0:02:56.87,Default,,0000,0000,0000,,it would be freezing cold
Dialogue: 0,0:02:56.89,0:02:58.64,Default,,0000,0000,0000,,if you were flying above the clouds.
Dialogue: 0,0:02:58.67,0:03:00.10,Default,,0000,0000,0000,,You'd need to wrap yourself up
Dialogue: 0,0:03:00.12,0:03:01.74,Default,,0000,0000,0000,,to keep your core body temperature
Dialogue: 0,0:03:01.76,0:03:03.57,Default,,0000,0000,0000,,above 95 degrees Fahrenheit,
Dialogue: 0,0:03:03.59,0:03:06.44,Default,,0000,0000,0000,,otherwise you'd start shivering violently,
Dialogue: 0,0:03:06.46,0:03:08.14,Default,,0000,0000,0000,,gradually becoming mentally confused
Dialogue: 0,0:03:08.17,0:03:09.79,Default,,0000,0000,0000,,and eventually drop out of the sky
Dialogue: 0,0:03:09.81,0:03:10.92,Default,,0000,0000,0000,,due to loss of muscle control
Dialogue: 0,0:03:10.95,0:03:13.18,Default,,0000,0000,0000,,from hypothermia!
Dialogue: 0,0:03:14.27,0:03:16.20,Default,,0000,0000,0000,,Now, the Ideal Gas Law implies
Dialogue: 0,0:03:16.22,0:03:17.90,Default,,0000,0000,0000,,that as the pressure decreases,
Dialogue: 0,0:03:17.93,0:03:19.73,Default,,0000,0000,0000,,gas volume increases.
Dialogue: 0,0:03:19.76,0:03:21.100,Default,,0000,0000,0000,,So, if you were to fly\Nstraight up too quickly,
Dialogue: 0,0:03:22.02,0:03:24.60,Default,,0000,0000,0000,,the inert gas in your body\Nwould rapidly expand
Dialogue: 0,0:03:24.62,0:03:27.43,Default,,0000,0000,0000,,the way soda fizzes up when shaken.
Dialogue: 0,0:03:27.46,0:03:30.01,Default,,0000,0000,0000,,The phenomenon is called "the bends,"
Dialogue: 0,0:03:30.03,0:03:31.16,Default,,0000,0000,0000,,decompression sickness,
Dialogue: 0,0:03:31.18,0:03:32.87,Default,,0000,0000,0000,,or "divers disease"
Dialogue: 0,0:03:32.90,0:03:35.58,Default,,0000,0000,0000,,since deep sea scuba\Ndivers experience this
Dialogue: 0,0:03:35.60,0:03:37.52,Default,,0000,0000,0000,,when they come up too quickly.
Dialogue: 0,0:03:37.55,0:03:39.38,Default,,0000,0000,0000,,This results in pain,
Dialogue: 0,0:03:39.40,0:03:40.38,Default,,0000,0000,0000,,paralysis,
Dialogue: 0,0:03:40.40,0:03:41.61,Default,,0000,0000,0000,,or death,
Dialogue: 0,0:03:41.63,0:03:44.64,Default,,0000,0000,0000,,depending on how foamy your blood becomes.
Dialogue: 0,0:03:44.66,0:03:46.34,Default,,0000,0000,0000,,Okay, well, let's say you want to fly
Dialogue: 0,0:03:46.37,0:03:47.99,Default,,0000,0000,0000,,just a few meters above the ground
Dialogue: 0,0:03:48.01,0:03:49.82,Default,,0000,0000,0000,,where you can still see the road signs
Dialogue: 0,0:03:49.84,0:03:51.31,Default,,0000,0000,0000,,and breath oxygen with ease.
Dialogue: 0,0:03:51.33,0:03:53.35,Default,,0000,0000,0000,,You'll still need goggles and a helmet
Dialogue: 0,0:03:53.37,0:03:54.98,Default,,0000,0000,0000,,to protect you from birds,
Dialogue: 0,0:03:55.00,0:03:55.95,Default,,0000,0000,0000,,insects,
Dialogue: 0,0:03:55.98,0:03:56.76,Default,,0000,0000,0000,,street signs,
Dialogue: 0,0:03:56.78,0:03:57.69,Default,,0000,0000,0000,,electrical wires,
Dialogue: 0,0:03:57.72,0:03:59.55,Default,,0000,0000,0000,,and other flying humans,
Dialogue: 0,0:03:59.57,0:04:01.15,Default,,0000,0000,0000,,including flying cops
Dialogue: 0,0:04:01.17,0:04:02.32,Default,,0000,0000,0000,,ready to hand you a ticket
Dialogue: 0,0:04:02.34,0:04:04.53,Default,,0000,0000,0000,,if you don't follow\Nthe flying rules, buddy.
Dialogue: 0,0:04:04.55,0:04:07.02,Default,,0000,0000,0000,,Now remember, if you\Nhave a collision mid-air
Dialogue: 0,0:04:07.05,0:04:08.94,Default,,0000,0000,0000,,that knocks you unconscious,
Dialogue: 0,0:04:08.96,0:04:11.05,Default,,0000,0000,0000,,you would experience free fall
Dialogue: 0,0:04:11.07,0:04:12.93,Default,,0000,0000,0000,,until you hit the ground.
Dialogue: 0,0:04:14.67,0:04:17.55,Default,,0000,0000,0000,,Without society or the laws of physics,
Dialogue: 0,0:04:17.58,0:04:20.96,Default,,0000,0000,0000,,flying would be a totally\Nawesome ability to have.
Dialogue: 0,0:04:20.98,0:04:22.78,Default,,0000,0000,0000,,But, even if we could\Nall just float around
Dialogue: 0,0:04:22.80,0:04:23.76,Default,,0000,0000,0000,,a few feet above the ground
Dialogue: 0,0:04:23.78,0:04:25.46,Default,,0000,0000,0000,,and only moving at a snail's pace,
Dialogue: 0,0:04:25.49,0:04:28.99,Default,,0000,0000,0000,,I'm telling you, it's still\Na cool ability that I'd want,
Dialogue: 0,0:04:29.02,0:04:30.74,Default,,0000,0000,0000,,wouldn't you?
Dialogue: 0,0:04:30.76,0:04:32.89,Default,,0000,0000,0000,,Yeah, I thought so.
Dialogue: 0,0:04:32.92,0:04:35.39,Default,,0000,0000,0000,,Now, which superpower physics lesson
Dialogue: 0,0:04:35.42,0:04:37.78,Default,,0000,0000,0000,,will you explore next?
Dialogue: 0,0:04:37.80,0:04:42.04,Default,,0000,0000,0000,,Shifting body size and content,
Dialogue: 0,0:04:42.07,0:04:43.40,Default,,0000,0000,0000,,super speed,
Dialogue: 0,0:04:43.42,0:04:45.02,Default,,0000,0000,0000,,flight,
Dialogue: 0,0:04:45.05,0:04:47.97,Default,,0000,0000,0000,,super strength,
Dialogue: 0,0:04:47.100,0:04:50.66,Default,,0000,0000,0000,,immortality,
Dialogue: 0,0:04:50.68,0:04:52.22,Default,,0000,0000,0000,,and
Dialogue: 0,0:04:52.24,0:04:54.91,Default,,0000,0000,0000,,invisibility.