Why doesn't everyone have a jetpack? - Richard Browning

290,582 views ใƒป 2022-02-10

TED-Ed


ืื ื ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ืœืžื˜ื” ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ.

ืชืจื’ื•ื: Ido Dekkers ืขืจื™ื›ื”: zeeva livshitz
00:06
On April 12, 1961, Soviet cosmonaut Yuri Gagarin
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ื‘ 12 ื‘ืืคืจื™ืœ, 1961, ื”ืงื•ืกืžื•ื ืื•ื˜ ื”ืกื•ื‘ื™ื™ื˜ื™ ื™ื•ืจื™ ื’ื’ืจื™ืŸ
00:11
piloted a 2,400 kilogram spacecraft in humanityโ€™s first manned space flight.
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ื ื™ื•ื•ื˜ ื—ืœืœื™ืช ื‘ืžืฉืงืœ 2400 ืงื™ืœื• ืœืžืกืข ื”ืื ื•ืฉื™ ื”ืจืืฉื•ืŸ ื‘ื—ืœืœ.
00:19
One week later, Bell Aerosystems debuted another advancement in aviation:
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ืฉื‘ื•ืข ืœืื—ืจ ืžื›ืŸ, ื‘ืœ ืืจื• ืžืขืจื›ื•ืช ื”ืฉื™ืงื• ื”ืชืงื“ืžื•ืช ื ื•ืกืคืช ื‘ืชืขื•ืคื”:
00:24
the gas-powered rocket pack.
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ื—ื‘ื™ืœืช ืกื™ืœื•ืŸ ืจืงื˜ื™ืช ืžื•ื ืขืช ื’ื–.
00:27
Capable of flying 35 meters in just 13 seconds,
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ืฉืžืกื•ื’ืœืช ืœื˜ื•ืก 35 ืžื˜ืจ ืชื•ืš 13 ืฉื ื™ื•ืช,
00:31
the rocket pack thrilled onlookers.
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ื—ื‘ื™ืœืช ื”ืจืงื˜ื” ืจื™ื’ืฉื” ืืช ื”ืฆื•ืคื™ื.
00:33
But the deviceโ€™s engineers were less enthused.
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ืื‘ืœ ื”ืžื”ื ื“ืกื™ื ืฉืœ ื”ืžื›ืฉื™ืจ ื”ื™ื• ื”ืจื‘ื” ืคื—ื•ืช ืžืจื•ื’ืฉื™ื.
00:37
Despite years of cutting-edge work,
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ืœืžืจื•ืช ืฉื ื™ื ืฉืœ ืขื‘ื•ื“ื” ื‘ื˜ื›ื ื•ืœื•ื’ื™ื” ืžืชืงื“ืžืช,
00:39
they knew this short flight was all the rocket pack could muster.
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ื”ื ื™ื“ืขื• ืฉื”ื˜ื™ืกื” ื”ืงืฆืจื” ื”ื–ื• ื”ื™ืชื” ื›ืœ ืžื” ืฉื—ื‘ื™ืœืช ื”ืกื™ืœื•ืŸ ืžืกื•ื’ืœืช ืœืขืฉื•ืช.
00:43
So why was a massive spacecraft easier to send flying than a single pilot?
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ืื– ืœืžื” ื—ืœืœื™ืช ืžืกื™ื‘ื™ืช ื”ื™ืชื” ืงืœื” ื™ื•ืชืจ ืœื˜ื™ืกื” ืžื˜ื™ื™ืก ื‘ื•ื“ื“?
00:49
According to Newton's laws of motion,
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ืœืคื™ ื—ื•ืงื™ ื”ืชื ื•ืขื” ืฉืœ ื ื™ื•ื˜ื•ืŸ,
00:52
the physics behind flight are actually quite simple.
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ื”ืคื™ื–ื™ืงื” ืžืื—ื•ืจื™ ื˜ื™ืกื” ืœืžืขืฉื” ื“ื™ ืคืฉื•ื˜ื”.
00:55
All you need is a powerful enough upward force
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ื›ืœ ืžื” ืฉืืชื ืฆืจื™ื›ื™ื ื–ื” ื›ื•ื— ื—ื–ืง ืžืกืคื™ืง ื›ืœืคื™ ืžืขืœื”
00:58
to counteract the downward force of gravity.
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ื›ื“ื™ ืœื”ืชื ื’ื“ ืœื›ื•ื— ื”ืžืฉื™ื›ื” ื›ืœืคื™ ืžื˜ื”.
01:01
And since objects with more mass experience stronger gravitational forces,
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ื•ืžืื—ืจ ื•ืขืฆืžื™ื ืขื ื™ื•ืชืจ ืžืกื” ื—ื•ื•ื™ื ื›ื•ื—ื•ืช ืžืฉื™ื›ื” ื—ื–ืงื™ื ื™ื•ืชืจ,
01:06
lighter objects should be easier to get off the ground.
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ืขืฆืžื™ื ืงืœื™ื ื™ื•ืชืจ ืฆืจื™ื›ื™ื ืœื”ื™ื•ืช ืงืœื™ื ื™ื•ืชืจ ืœื”ืจืžื” ืžื”ืื“ืžื”.
01:10
However, modern jet engines, our primary tool for flight,
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ืขื ื–ืืช, ืžื ื•ืขื™ ืกื™ืœื•ืŸ ืžื•ื“ืจื ื™ื™ื, ื”ื›ืœื™ ื”ืขื™ืงืจื™ ืฉืœื ื• ืœื˜ื™ืกื”,
01:13
actually get more efficient the larger they are.
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ืœืžืขืฉื” ื ืขืฉื™ื ื™ืขื™ืœื™ื ื™ื•ืชืจ ื›ื›ืœ ืฉื”ื ื’ื“ื•ืœื™ื ื™ื•ืชืจ.
01:17
Jet engines work by sucking in huge volumes of air,
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ืžื ื•ืขื™ ืกื™ืœื•ืŸ ืขื•ื‘ื“ื™ื ืขืœ ื™ื“ื™ ืฉืื™ื‘ืช ื›ืžื•ื™ื•ืช ืขืฆื•ืžื•ืช ืฉืœ ืื•ื™ืจ,
01:20
and then expelling that air as quickly as possible.
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ื•ืื– ืคืœื™ื˜ืช ื”ืื•ื™ืจ ื”ื–ื” ื‘ืžื”ื™ืจื•ืช ื”ื’ื‘ื•ื”ื” ื‘ื™ื•ืชืจ ื”ืืคืฉืจื™ืช.
01:23
While most of this actually bypasses the inner machinery,
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ื‘ื–ืžืŸ ืฉืจื•ื‘ื• ืœืžืขืฉื” ืขื•ืงืฃ ืืช ื”ืžื ื’ื ื•ืŸ ื”ืคื ื™ืžื™,
01:27
it still contributes to a huge portion of the engine's thrust.
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ื”ื•ื ืขื“ื™ื™ืŸ ืชื•ืจื ื—ืœืง ื’ื“ื•ืœ ืœื“ื—ืฃ ืฉืœ ื”ืžื ื•ืข.
01:31
But the air that does enter the engineโ€™s core gets compressed
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ืื‘ืœ ื”ืื•ื•ื™ืจ ืฉื ื›ื ืก ืœืœื™ื‘ืช ื”ืžื ื•ืข ื ื“ื—ืก
01:34
by a series of tightly packed blades.
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ืขืœ ื™ื“ื™ ืกื“ืจื” ืฉืœ ืœื”ื‘ื™ื ื“ื—ื•ืกื™ื.
01:37
That compressed air then enters the combustion chamber,
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ื”ืื•ื•ื™ืจ ื”ื“ื—ื•ืก ื”ื–ื” ื ื›ื ืก ืื– ืœืชื ื”ืฉืจื™ืคื”,
01:40
where it is injected with jet fuel and ignited.
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ืฉื ืžื•ื–ืจืง ืืœื™ื• ื“ืœืง ืกื™ืœื•ื ื™ ื•ื”ื•ื ืžื•ืฆืช.
01:44
The heat causes the compressed air to rapidly expand,
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ื”ื—ื•ื ื’ื•ืจื ืœืื•ื•ื™ืจ ื”ื“ื—ื•ืก ืœื”ืชืจื—ื‘ ื‘ืžื”ื™ืจื•ืช,
01:48
bursting out of the exhaust and propelling the engine forward.
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ื•ืœืคืจื•ืฅ ืžื”ืื’ื–ื•ื– ื•ื›ืš ื”ื•ื ื“ื•ื—ืฃ ืืช ื”ืžื ื•ืข ืงื“ื™ืžื”.
01:52
As air leaves the engine it also turns a turbine embedded in the exhaust nozzle.
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ื›ืฉื”ืื•ื•ื™ืจ ืขื•ื–ื‘ ืืช ื”ืžื ื•ืข ื”ื•ื ื’ื ืžืกื•ื‘ื‘ ื˜ื•ืจื‘ื™ื ื” ืฉืžื•ื˜ืžืขืช ื‘ื ื—ื™ืจ ื”ืคืœื™ื˜ื”.
01:58
This turbine powers the fan and the compressor blades,
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ื”ื˜ื•ืจื‘ื™ื ื” ื”ื–ื• ื ื•ืชื ืช ื›ื•ื— ืœืžืื•ื•ืจืจ ื•ืœืœื”ื‘ื™ ื”ื“ื—ื™ืกื”,
02:01
creating a cycle that maintains thrust for as long as thereโ€™s fuel to burn.
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ื•ื™ื•ืฆืจ ืžื—ื–ื•ืจ ืฉืฉื•ืžืจ ืขืœ ื”ื“ื—ืฃ ื›ืœ ื–ืžืŸ ืฉื™ืฉ ื“ืœืง ืœืฉืจื•ืฃ.
02:07
The more air an engine can take in and expel the more thrust it can produce.
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ื›ื›ืœ ืฉื”ืžื ื•ืข ื™ื›ื•ืœ ืœื”ื›ื ื™ืก ื™ื•ืชืจ ืื•ื•ื™ืจ ืคื ื™ืžื” ื•ืœืคืœื•ื˜ ื”ื•ื ื™ื™ืฆืจ ื™ื•ืชืจ ื“ื—ืฃ.
02:12
On a modern jet, the diameter of a frontal fan is larger than a truck.
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ื‘ืžื˜ื•ืก ืกื™ืœื•ืŸ ืžื•ื“ืจื ื™, ื”ืงื•ื˜ืจ ืฉืœ ื”ืžืื•ื•ืจืจ ื”ืงื“ืžื™ ื’ื“ื•ืœ ืžืžืฉืื™ืช.
02:17
And even spinning at relatively low speeds,
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ื•ืืคื™ืœื• ื›ืฉื”ื•ื ืžืกืชื•ื‘ื‘ ื‘ืžื”ื™ืจื•ื™ื•ืช ื™ื—ืกื™ืช ื ืžื•ื›ื•ืช,
02:19
these engines produce more than enough thrust to maintain the necessary speed
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ื”ืžื ื•ืขื™ื ื”ืืœื” ืžื™ื™ืฆืจื™ื ื™ื•ืชืจ ืžืžืกืคื™ืง ื“ื—ืฃ ื›ื“ื™ ืœืฉืžื•ืจ ืขืœ ืžื”ื™ืจื•ืช ื“ืจื•ืฉื”
02:24
for flying a passenger aircraft.
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ืœื”ื˜ืกืช ืžื˜ื•ืก ื ื•ืกืขื™ื.
02:26
But smaller engines simply canโ€™t take in this much air.
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ืื‘ืœ ืžื ื•ืขื™ื ืงื˜ื ื™ื ื™ื•ืชืจ ืคืฉื•ื˜ ืœื ื™ื›ื•ืœื™ื ืœื”ื›ื ื™ืก ืžืกืคื™ืง ืื•ื™ืจ.
02:30
For most of the 20th century, engineers couldnโ€™t produce an engine
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ื‘ืžืฉืš ืจื•ื‘ ื”ืžืื” ื” 20, ืžื”ื ื“ืกื™ื ืœื ื™ื›ืœื• ืœื™ื™ืฆืจ ืžื ื•ืข
02:34
small and light enough for an individual to wear,
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ืงื˜ืŸ ื•ืงืœ ืžืกืคื™ืง ืœืื“ื ื‘ื•ื“ื“ ืœืœื‘ื•ืฉ,
02:37
yet powerful enough to lift itself alongside its pilot and fuel.
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ื•ืขื“ื™ื™ืŸ ื—ื–ืง ืžืกืคื™ืง ื›ื“ื™ ืœื”ืจื™ื ืืช ืขืฆืžื• ื™ื—ื“ ืขื ื”ื˜ื™ื™ืก ื•ื”ื“ืœืง.
02:42
Designs could only carry enough fuel for 30 seconds of flight,
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ืขื™ืฆื•ื‘ื™ื ื™ื›ืœื• ืœืฉืืช ืจืง ืžืกืคื™ืง ื“ืœืง ืœื˜ื™ืกื•ืช ืฉืœ 30 ืฉื ื™ื•ืช,
02:46
and when airborne, the powerful thrust in a single direction
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ื•ื›ืฉื”ื ื”ื™ื• ื‘ืื•ื•ื™ืจ, ื”ื“ื—ืฃ ื”ื—ื–ืง ื‘ื›ื™ื•ื•ืŸ ื‘ื•ื“ื“
02:49
made jetpacks difficult and dangerous to control.
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ื”ืคืš ื—ืœื™ืคื•ืช ืกื™ืœื•ืŸ ืœืงืฉื•ืช ื•ืžืกื•ื›ื ื•ืช ืœืฉืœื™ื˜ื”.
02:53
But the new millennium brought advances in materials, manufacturing,
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ืื‘ืœ ื”ืžื™ืœื ื™ื•ื ื”ื—ื“ืฉ ื”ื‘ื™ื ื”ืชืงื“ืžื•ืช ื‘ื—ืžืจื™ื, ื™ืฆื•ืจ,
02:57
and computing technology,
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ื•ื˜ื›ื ื•ืœื•ื’ื™ื•ืช ืžื—ืฉื•ื‘,
02:59
including systems which could manage fuel injection with incredible precision.
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ื›ื•ืœืœ ืžืขืจื›ื•ืช ืฉื™ื›ื•ืœื•ืช ืœื ื”ืœ ื”ื–ืจืงืช ื“ืœืง ืขื ื“ื™ื•ืง ืžื“ื”ื™ื.
03:04
Together, these dramatically improved the fuel efficiency
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ื™ื—ื“, ืืœื” ืžืฉืคืจื™ื ื“ืจืžื˜ื™ืช ืืช ื”ื™ืขื™ืœื•ืช
03:07
and power-to-weight ratio of jet engines.
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ื•ืืช ื™ื—ืก ื”ื”ืกืคืง ืœืžืฉืงืœ ืฉืœ ืžื ื•ืขื™ ืกื™ืœื•ืŸ.
03:11
By 2016, micro-engines the size of a coffee can
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ืขื“ 2016, ืžื™ืงืจื• ืžื ื•ืขื™ื ื‘ื’ื•ื“ืœ ืฉืœ ืคื—ื™ืช ืงืคื”
03:14
and weighing less than 2kg
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ื•ืฉืฉื•ืงืœื™ื ืคื—ื•ืช ืž 2 ืงื™ืœื•
03:17
could achieve 220 Newtons of force.
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ื™ื›ืœื• ืœื”ืฉื™ื’ 220 ื ื™ื•ื˜ื•ืŸ ืฉืœ ื›ื•ื—.
03:21
This was when an English engineer named Richard Browning
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ื•ืื– ืžื”ื ื“ืก ืื ื’ืœื™ ื‘ืฉื ืจื™ืฆโ€™ืืจื“ ื‘ืจืื•ื ื™ื ื’
03:25
saw the opportunity to create a new kind of lightweight jetpack.
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ืจืื” ื”ื–ื“ืžื ื•ืช ืœื™ืฆื•ืจ ืกื•ื’ ื—ื“ืฉ ืฉืœ ื—ืœื™ืคืช ืกื™ืœื•ืŸ ืงืœื”.
03:30
In addition to a single engine strapped to the back,
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ื‘ื ื•ืกืฃ ืœืžื ื•ืข ื‘ื•ื“ื“ ืฉืงืฉื•ืจ ืœื’ื‘,
03:33
this so-called Jet Suit involved a pair of micro-engines on each arm
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ื—ืœื™ืคืช ื”ืกื™ืœื•ืŸ ื”ื–ื• ื›ื‘ื™ื›ื•ืœ ื›ื•ืœืœืช ืฉื ื™ ืžื™ืงืจื• ืžื ื•ืขื™ ืกื™ืœื•ืŸ ืขืœ ื›ืœ ื–ืจื•ืข
03:38
to split and balance the thrust.
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ื›ื“ื™ ืœื—ืœืง ื•ืœืื–ืŸ ืืช ื”ื“ื—ืฃ.
03:42
Working with the back engine, these provided three-points of stability,
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ื‘ืขื‘ื•ื“ื” ืขื ื”ืžื ื•ืข ืขืœ ื”ื’ื‘, ื”ื ืžืกืคืงื™ื ืฉืœื•ืฉ ื ืงื•ื“ื•ืช ืฉืœ ื™ืฆื™ื‘ื•ืช,
03:46
which some pilots describe as being akin to comfortably leaning on crutches
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ืฉื›ืžื” ื˜ื™ื™ืกื™ื ืชื™ืืจื• ื›ื“ื•ืžื” ืœื”ื™ืฉืขื ื•ืช ื‘ื ื•ื—ื™ื•ืช ืขืœ ืงื‘ื™ื™ื
03:51
while a friend supports your back.
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ื‘ื–ืžืŸ ืฉื—ื‘ืจื™ื ืชื•ืžื›ื™ื ืœื”ื ื‘ื’ื‘.
03:53
It may seem complicated to manage all these engines at once,
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ื–ื” ืื•ืœื™ ื ืจืื” ืžืกื•ื‘ืš ืœื ื”ืœ ืืช ื›ืœ ื”ืžื ื•ืขื™ื ื”ืืœื” ื™ื—ื“,
03:57
but many pilots master it in less than a day
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ืื‘ืœ ื”ืจื‘ื” ื˜ื™ื™ืกื™ื ืžืฉืชืœื˜ื™ื ืขืœ ื–ื” ืชื•ืš ืคื—ื•ืช ืžื™ื•ื
04:00
with the help of another advanced computer systemโ€” their brain.
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ืขื ืขื–ืจื” ืฉืœ ืžืขืจื›ืช ืžื™ื—ืฉื•ื‘ ืžืชืงื“ืžืช ื ื•ืกืคืช -- ื”ืžื•ื— ืฉืœื”ื.
04:05
Various brain regions and multiple sensory systems
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ืื–ื•ืจื™ื ืฉื•ื ื™ื ื‘ืžื•ื— ื•ืžืขืจื›ื•ืช ื—ื™ืฉื” ืžืจื•ื‘ื•ืช
04:08
perfectly calibrate our sense of balance and spatial orientation,
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ืžื›ื™ื™ืœื•ืช ื‘ืื•ืคืŸ ืžื•ืฉืœื ืืช ื—ื•ืฉ ืฉื™ื•ื•ื™ ื”ืžืฉืงืœ ืฉืœื ื• ื•ื”ื›ื•ื•ื ื•ืŸ ื”ืžืจื—ื‘ื™,
04:12
helping pilots smoothly direct their flights.
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ืฉืขื•ื–ืจื™ื ืœื˜ื™ื™ืกื™ื ืœื›ื•ื•ืŸ ืืช ื”ื˜ื™ืกื” ืฉืœื”ื ื‘ืื•ืคืŸ ื—ืœืง.
04:15
Slight movements of the arms allow operators to increase and decrease lift,
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ืชื ื•ืขื•ืช ืขื“ื™ื ื•ืช ืฉืœ ื”ื–ืจื•ืขื•ืช ืžืืคืฉืจื•ืช ืœืžืคืขื™ืœื™ื ืœื”ื’ื‘ื™ืจ ื•ืœื”ืคื—ื™ืช ืืช ื”ืขื™ืœื•ื™,
04:20
quickly turn in mid-air, or glide forward for up to 5 minutes.
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ืœืคื ื•ืช ื‘ืžื”ื™ืจื•ืช ื‘ื–ืžืŸ ื˜ื™ืกื”, ืื• ืœื’ืœื•ืฉ ืงื“ื™ืžื” ืขื“ 5 ื“ืงื•ืช.
04:24
This technology is still fairly new,
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ื”ื˜ื›ื ื•ืœื•ื’ื™ื” ืขื“ื™ื™ืŸ ื“ื™ ื—ื“ืฉื”,
04:27
and without major advances in fuel efficiency and engine technology,
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ื•ื‘ืœื™ ื”ืชืงื“ืžื•ื™ื•ืช ืžืฉืžืขื•ืชื™ื•ืช ื‘ื™ืขื™ืœื•ืช ื”ื“ืœืง ื•ื‘ื˜ื›ื ื•ืœื•ื’ื™ื™ืช ืžื ื•ืขื™ื,
04:31
donโ€™t expect to have a jetpack of your own any time soon.
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ืืœ ืชืฆืคื• ืฉืชื”ื™ื” ืœื›ื ื—ืœื™ืคืช ืกื™ืœื•ืŸ ืžืฉืœื›ื ื‘ื–ืžืŸ ื”ืงืจื•ื‘.
04:35
But if reaching for the sky already got us this far,
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ืื‘ืœ ืื ืœื”ื’ื™ืข ืœืฉืžื™ื ื›ื‘ืจ ื”ื‘ื™ืื” ืื•ืชื ื• ืขื“ ืœืคื”,
04:38
who knows where we'll fly next?
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ืžื™ ื™ื•ื“ืข ืœืืŸ ื ื˜ื•ืก ื”ืœืื”?
ืขืœ ืืชืจ ื–ื”

ืืชืจ ื–ื” ื™ืฆื™ื’ ื‘ืคื ื™ื›ื ืกืจื˜ื•ื ื™ YouTube ื”ืžื•ืขื™ืœื™ื ืœืœื™ืžื•ื“ ืื ื’ืœื™ืช. ืชื•ื›ืœื• ืœืจืื•ืช ืฉื™ืขื•ืจื™ ืื ื’ืœื™ืช ื”ืžื•ืขื‘ืจื™ื ืขืœ ื™ื“ื™ ืžื•ืจื™ื ืžื”ืฉื•ืจื” ื”ืจืืฉื•ื ื” ืžืจื—ื‘ื™ ื”ืขื•ืœื. ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ื”ืžื•ืฆื’ื•ืช ื‘ื›ืœ ื“ืฃ ื•ื™ื“ืื• ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ ืžืฉื. ื”ื›ืชื•ื‘ื™ื•ืช ื’ื•ืœืœื•ืช ื‘ืกื ื›ืจื•ืŸ ืขื ื”ืคืขืœืช ื”ื•ื•ื™ื“ืื•. ืื ื™ืฉ ืœืš ื”ืขืจื•ืช ืื• ื‘ืงืฉื•ืช, ืื ื ืฆื•ืจ ืื™ืชื ื• ืงืฉืจ ื‘ืืžืฆืขื•ืช ื˜ื•ืคืก ื™ืฆื™ืจืช ืงืฉืจ ื–ื”.

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