If superpowers were real: Flight - Joy Lin
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0:14 - 0:16If humans could fly,
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0:16 - 0:18without tools and machines,
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0:18 - 0:20how fast do you think we would go?
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0:20 - 0:23As of 2012, the world record
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0:23 - 0:25for fastest short-distance sprint speed
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0:25 - 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, -
0:34 - 0:39force is the product of mass
times acceleration. -
0:39 - 0:40And Newton's Third Law states
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0:40 - 0:42that for every action,
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0:42 - 0:45there is an equal and opposite reaction.
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0:45 - 0:47So, that means running requires
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0:47 - 0:49having a ground to push off from,
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0:49 - 0:53and the ground pushes back
against the runner's foot. -
0:53 - 0:55So, flying 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 -
1:01 - 1:05and the most decorated
Olympian of all time. -
1:05 - 1:07Guess how fast he swims?
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1:07 - 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 - 1:19Michael Phelps in water,
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1:19 - 1:21but why is that?
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1:21 - 1:23Well, let's go back
to Newton's Third Law of Motion. -
1:23 - 1:25When we run, we move forward
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1:25 - 1:27by pushing against the ground
with our feet -
1:27 - 1:28and the ground pushes back,
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1:28 - 1:30propelling us forward.
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1:30 - 1:33The ground is solid.
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1:33 - 1:35By definition, it means the particles
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1:35 - 1:37are essentially locked into place
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1:37 - 1:40and must push back instead
of getting out of the way, -
1:40 - 1:44but water is liquid and flows easily.
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1:44 - 1:45When we move our limbs
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1:45 - 1:46to push back against the water,
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1:46 - 1:48a part of the water molecules
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1:48 - 1:49can just slide past one another
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1:49 - 1:51instead of pushing back.
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1:51 - 1:53Now, let's think about flying.
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1:53 - 1:54Air has a lot more free space
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1:54 - 1:57for particles to move past one another,
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1:57 - 2:00so even more of our energy
would be wasted. -
2:00 - 2:02We would need to push
a lot of air backwards -
2:02 - 2:04in order to move forward.
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2:04 - 2:06Astronauts move around in shuttles
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2:06 - 2:08in zero gravity when
they're in outer space -
2:08 - 2:11by pulling on handles installed
on the ceiling walls -
2:11 - 2:13and floors of the shuttle.
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2:13 - 2:16Now, imagine you were
given the ability to float. -
2:16 - 2:19How would you move
around in the middle of the street? -
2:19 - 2:21Well, you wouldn't get very far
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2:21 - 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 -
2:27 - 2:30and the speed to move around efficiently,
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2:30 - 2:33let's discuss the height of your flight.
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2:33 - 2:35According to the Ideal Gas Law,
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2:35 - 2:36P-V N-R-T,
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2:36 - 2:39pressure and temperature has
a positive correlation, -
2:39 - 2:42meaning they increase
and decrease together. -
2:42 - 2:44This is because the air expands in volume
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2:45 - 2:46with less pressure,
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2:46 - 2:48so the molecules have more
room to wander around -
2:48 - 2:52without colliding into each other
and creating heat. -
2:52 - 2:54Since the atmospheric
pressure is a lot lower -
2:54 - 2:55in high altitudes,
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2:55 - 2:57it would be freezing cold
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2:57 - 2:59if you were flying above the clouds.
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2:59 - 3:00You'd need to wrap yourself up
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3:00 - 3:02to keep your core body temperature
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3:02 - 3:04above 95 degrees Fahrenheit,
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3:04 - 3:06otherwise you'd start shivering violently,
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3:06 - 3:08gradually becoming mentally confused
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3:08 - 3:10and eventually drop out of the sky
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3:10 - 3:11due to loss of muscle control
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3:11 - 3:13from hypothermia!
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3:14 - 3:16Now, the Ideal Gas Law implies
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3:16 - 3:18that as the pressure decreases,
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3:18 - 3:20gas volume increases.
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3:20 - 3:22So, if you were to fly
straight up too quickly, -
3:22 - 3:25the inert gas in your body
would rapidly expand -
3:25 - 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 - 3:33or "divers disease"
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3:33 - 3:36since deep sea scuba
divers experience this -
3:36 - 3:38when they come up too quickly.
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3:38 - 3:39This results in pain,
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3:39 - 3:40paralysis,
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3:40 - 3:42or death,
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3:42 - 3:45depending on how foamy your blood becomes.
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3:45 - 3:46Okay, well, let's say you want to fly
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3:46 - 3:48just a few meters above the ground
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3:48 - 3:50where you can still see the road signs
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3:50 - 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 - 3:56insects,
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3:56 - 3:57street signs,
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3:57 - 3:58electrical wires,
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3:58 - 4:00and other flying humans,
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4:00 - 4:01including flying cops
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4:01 - 4:02ready to hand you a ticket
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4:02 - 4:05if you don't follow
the flying rules, buddy. -
4:05 - 4:07Now remember, if you
have a collision mid-air -
4:07 - 4:09that knocks you unconscious,
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4:09 - 4:11you would experience free fall
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4:11 - 4:13until you hit the ground.
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4:15 - 4:18Without society or the laws of physics,
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4:18 - 4:21flying would be a totally
awesome ability to have. -
4:21 - 4:23But, even if we could
all just float around -
4:23 - 4:24a few feet above the ground
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4:24 - 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, -
4:29 - 4:31wouldn't you?
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4:31 - 4:33Yeah, I thought so.
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4:33 - 4:35Now, which superpower physics lesson
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4:35 - 4:38will you explore next?
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4:38 - 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 - 4:48super strength,
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4:48 - 4:51immortality,
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4:51 - 4:52and
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4:52 - 4:55invisibility.
- 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 |