If superpowers were real: Flight - Joy Lin
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0:14 - 0:16If humans could fly,
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0:16 - 0:17without tools and machines,
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0:17 - 0:20how fast do you think we would go?
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0:20 - 0:22As of 2012, the world record
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0:22 - 0:24for fastest short-distance sprint speed
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0:24 - 0:27is roughly 27 miles per hour.
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0:27 - 0:29Running speed depends on how much force
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0:29 - 0:31is exerted by the runner's legs,
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0:31 - 0:34and according to Newton's Second Law of Motion,
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0:34 - 0:38force is the product of mass times acceleration.
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0:38 - 0:40And Newton's Third Law states
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0:40 - 0:41that for every action,
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0:41 - 0:44there is an equal and opposite reaction.
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0:44 - 0:46So, that means running requires
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0:46 - 0:48having a ground to push off from,
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0:48 - 0:52and the ground pushes back against the runner's foot.
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0:52 - 0:55So, flying would actually would actually be
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0:55 - 0:57more similar to swimming.
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0:57 - 1:01Michael Phelps is currently the fastest human in water
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1:01 - 1:04and the most decorated Olympian of all time.
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1:04 - 1:06Guess how fast he swims?
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1:06 - 1:09The answer may surprise you.
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1:09 - 1:11His fastest recorded speed is
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1:11 - 1:15less than 5 miles per hour.
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1:15 - 1:17A child on the ground can easily outrun
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1:17 - 1:18Michael Phelps in water,
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1:18 - 1:20but why is that?
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1:20 - 1:23Well, let's go back to Newton's Third Law of Motion.
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1:23 - 1:24When we run, we move forward
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1:24 - 1:27by pushing against the ground with our feet
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1:27 - 1:28and the ground pushes back,
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1:28 - 1:30propelling us forward.
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1:30 - 1:32The ground is solid.
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1:32 - 1:34By definition, it means the particles
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1:34 - 1:37are essentially locked into place
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1:37 - 1:40and must push back instead of getting out of the way,
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1:40 - 1:43but water is liquid and flows easily.
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1:43 - 1:44When we move our limbs
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1:44 - 1:46to push back against the water,
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1:46 - 1:47a part of the water molecules
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1:47 - 1:49can just slide past one another
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1:49 - 1:50instead of pushing back.
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1:50 - 1:52Now, let's think about flying.
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1:52 - 1:54Air has a lot more free space
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1:54 - 1:56for particles to move past one another,
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1:56 - 1:59so even more of our energy would be wasted.
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1:59 - 2:02We would need to push a lot of air backwards
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2:02 - 2:04in order to move forward.
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2:04 - 2:05Astronauts move around in shuttles
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2:05 - 2:07in zero gravity when they're in outer space
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2:07 - 2:10by pulling on handles installed on the ceiling walls
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2:10 - 2:12and floors of the shuttle.
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2:12 - 2:16Now, imagine you were given the ability to float.
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2:16 - 2:19How would you move around in the middle of the street?
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2:19 - 2:20Well, you wouldn't get very far
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2:20 - 2:23by swimming in air, would you?
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2:23 - 2:24Nah, I don't think so!
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2:24 - 2:27Now, assuming you were granted the ability to float
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2:27 - 2:29and the speed to move around efficiently,
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2:29 - 2:32let's discuss the height of your flight.
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2:32 - 2:34According to the Ideal Gas Law,
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2:34 - 2:36P-V N-R-T,
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2:36 - 2:38pressure and temperature has a positive correlation,
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2:38 - 2:42meaning they increase and decrease together.
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2:42 - 2:44This is because the air expands in volume
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2:44 - 2:45with less pressure,
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2:45 - 2:48so the molecules have more room to wander around
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2:48 - 2:51without colliding into each other and creating heat.
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2:51 - 2:54Since the atmospheric pressure is a lot lower
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2:54 - 2:55in high altitudes,
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2:55 - 2:56it would be freezing cold
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2:56 - 2:58if you were flying above the clouds.
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2:58 - 3:00You'd need to wrap yourself up
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3:00 - 3:01to keep your core body temperature
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3:01 - 3:03above 95 degrees Fahrenheit,
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3:03 - 3:06otherwise you'd start shivering violently,
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3:06 - 3:08gradually becoming mentally confused
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3:08 - 3:09and eventually drop out of the sky
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3:09 - 3:10due to loss of muscle control
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3:10 - 3:13from hypothermia!
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3:14 - 3:16Now, the Ideal Gas Law implies
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3:16 - 3:17that as the pressure decreases,
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3:17 - 3:19gas volume increases.
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3:19 - 3:21So, if you were to fly straight up too quickly,
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3:21 - 3:24the inert gas in your body would rapidly expand
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3:24 - 3:27the way soda fizzes up when shaken.
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3:27 - 3:30The phenomenon is called "the bends,"
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3:30 - 3:31decompression sickness,
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3:31 - 3:32or "divers disease"
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3:32 - 3:35since deep sea scuba divers experience this
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3:35 - 3:37when they come up too quickly.
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3:37 - 3:39This results in pain,
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3:39 - 3:40paralysis,
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3:40 - 3:41or death,
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3:41 - 3:44depending on how foamy your blood becomes.
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3:44 - 3:46Okay, well, let's say you want to fly
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3:46 - 3:47just a few meters above the ground
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3:47 - 3:49where you can still see the road signs
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3:49 - 3:51and breath oxygen with ease.
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3:51 - 3:53You'll still need goggles and a helmet
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3:53 - 3:55to protect you from birds,
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3:55 - 3:55insects,
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3:55 - 3:56street signs,
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3:56 - 3:57electrical wires,
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3:57 - 3:59and other flying humans,
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3:59 - 4:01including flying cops
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4:01 - 4:02ready to hand you a ticket
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4:02 - 4:04if you don't follow the flying rules, buddy.
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4:04 - 4:07Now remember, if you have a collision mid-air
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4:07 - 4:08that knocks you unconscious,
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4:08 - 4:11you would experience free fall
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4:11 - 4:12until you hit the ground.
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4:14 - 4:17Without society or the laws of physics,
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4:17 - 4:20flying would be a totally awesome ability to have.
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4:20 - 4:22But, even if we could all just float around
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4:22 - 4:23a few feet above the ground
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4:23 - 4:25and only moving at a snail's pace,
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4:25 - 4:29I'm telling you, it's still a cool ability that I'd want,
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4:29 - 4:30wouldn't you?
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4:30 - 4:32Yeah, I thought so.
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4:32 - 4:35Now, which superpower physics lesson
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4:35 - 4:37will you explore next?
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4:37 - 4:42Shifting body size and content,
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4:42 - 4:43super speed,
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4:43 - 4:45flight,
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4:45 - 4:47super strength,
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4:47 - 4:50immortality,
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4:50 - 4:52and
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4:52 - 4:54invisibility.
- Title:
- If superpowers were real: Flight - Joy Lin
- Speaker:
- Joy Lin
- Description:
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View full lesson: http://ed.ted.com/lessons/if-superpowers-were-real-flight-joy-lin
What if human flight wasn't just the stuff of epic comic book stories? Is it scientifically possible to fly? In this series, Joy Lin tackles six superpowers and reveals just how scientifically realistic they can be to us mere mortals.
Lesson by Joy Lin, animation by Cognitive Media.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:12
Krystian Aparta edited English subtitles for If superpowers were real: Flight | ||
Bedirhan Cinar edited English subtitles for If superpowers were real: Flight | ||
Jessica Ruby approved English subtitles for If superpowers were real: Flight | ||
Jessica Ruby accepted English subtitles for If superpowers were real: Flight | ||
Jessica Ruby edited English subtitles for If superpowers were real: Flight | ||
Jessica Ruby edited English subtitles for If superpowers were real: Flight | ||
Andrea McDonough edited English subtitles for If superpowers were real: Flight |