ABOUT THE SPEAKER
Paul MacCready - Engineer
Paul MacCready, an aircraft designer and environmentalist, is a pioneer of human-powered flight, alternative energy for transportation, and environmentally responsible design.

Why you should listen

Through his life, Paul MacCready turned his mind, energy and heart toward his two passions: flight and the Earth. His early training as a fighter and glider pilot (glider pilots still use the "MacCready speed ring" he developed after World War II) led him to explore nontraditional flight and nontraditional energy sources.

In the 1970s, he and his company, AeroVironment, designed and built two record-breaking human-powered planes: the Gossamer Condor, the first human-powered aircraft to complete a one-mile course set by the Kremer Prize, and the Gossamer Albatross, the first to cross the English Channel. The planes' avian names reveal the deep insight that MacCready brought to the challenge -- that large birds, in their wing shape and flying style, possess an elegant secret of flight.

He then turned his wide-ranging mind toward environmentally responsible design, informed by his belief that human expansion poses a grave threat to the natural world. His team at AeroVironment prototyped an electric car that became General Motors' pioneering EV-1. They explored alternative energy sources, including building-top wind turbines. And they developed a fleet of fascinating aircraft -- including his Helios solar-powered glider, built to fly in the very top 2 percent of Earth's atmosphere, and the 2005 Global Observer, the first unmanned plane powered by hydrogen cells.

 

More profile about the speaker
Paul MacCready | Speaker | TED.com
TED2003

Paul MacCready: A flight on solar wings

Filmed:
867,651 views

Paul MacCready -- aircraft designer, environmentalist, and lifelong lover of flight -- talks about his long career.
- Engineer
Paul MacCready, an aircraft designer and environmentalist, is a pioneer of human-powered flight, alternative energy for transportation, and environmentally responsible design. Full bio

Double-click the English transcript below to play the video.

00:27
I am known best for human-powered flight,
0
2000
5000
00:32
but that was just one thing that got me going
1
7000
5000
00:37
in the sort of things that I'm working in now.
2
12000
4000
00:41
As a youngster, I was very interested in model airplanes,
3
16000
6000
00:47
ornithopters, autogyros, helicopters, gliders, power planes,
4
22000
6000
00:53
indoor models, outdoor models, everything,
5
28000
3000
00:56
which I just thought was a lot of fun,
6
31000
3000
00:59
and wondered why most other people didn't share my same enthusiasm with them.
7
34000
8000
01:07
And then, navy pilot training, and, after college,
8
42000
6000
01:13
I got into sailplane flying, power plane flying,
9
48000
4000
01:17
and considered the sailplanes as a sort of hobby and fun,
10
52000
8000
01:25
but got tangled up with some great professor types,
11
60000
4000
01:29
who convinced me and everybody else in the field
12
64000
5000
01:34
that this was a good way to get into really deep science.
13
69000
5000
01:39
While this was all going on, I was in the field of weather modification,
14
74000
6000
01:45
although getting a Ph.D. in aeronautics.
15
80000
4000
01:49
The weather modification subject was getting started,
16
84000
4000
01:53
and as a graduate student,
17
88000
2000
01:55
I could go around to the various talks that were being given,
18
90000
4000
01:59
on a hitchhiker ride to the East Coast,
19
94000
2000
02:01
and so on. And everybody would talk to me,
20
96000
3000
02:04
but all the professionals in the field hated each other,
21
99000
3000
02:07
and they wouldn't communicate. And as a result,
22
102000
3000
02:10
I got the absolutely unique background in that field,
23
105000
4000
02:15
and started a company, which did more research
24
110000
4000
02:19
in weather modification than anybody,
25
114000
4000
02:23
and there are a lot of things that I just can't go into.
26
118000
6000
02:29
But then, 1971 started AeroVironment, with no employees --
27
124000
6000
02:35
then one or two, three,
28
130000
2000
02:37
and sort of fumbled along on trying to get interesting projects.
29
132000
4000
02:41
We had AirDynamisis,
30
136000
2000
02:43
who, like I, did not want to work for aerospace companies
31
138000
5000
02:48
on some big, many year project,
32
143000
4000
02:52
and so we did our small projects, and the company slowly grew.
33
147000
9000
03:01
The thing that is exciting was, in 1976,
34
156000
5000
03:06
I suddenly got interested in the human-powered airplane
35
161000
5000
03:11
because I'd made a made a loan to a friend of 100,000 dollars,
36
166000
4000
03:15
or I guaranteed the money at the bank.
37
170000
2000
03:17
He needed them -- he needed the money for starting a company.
38
172000
4000
03:21
The company did not succeed, and he couldn't pay the money back,
39
176000
3000
03:24
and I was the guarantor of the note. So, I had a $100,000 debt,
40
179000
5000
03:29
and I noticed that the Kramer prize for human-powered flight,
41
184000
6000
03:35
which had then been around for -- (Laughter) --
42
190000
3000
03:39
17 years at the time, was 50,000 pounds,
43
194000
3000
03:42
which, at the exchange rate, was just about 100,000 dollars.
44
197000
4000
03:46
So suddenly, I was interested in human-powered flight --
45
201000
3000
03:49
(Laughter) --
46
204000
3000
03:52
and did not -- the way I approached it, first,
47
207000
6000
03:58
thinking about ways to make the planes,
48
213000
3000
04:01
was just like they'd been doing in England, and not succeeding,
49
216000
5000
04:06
and I gave it up. I figured, nah, there isn't any simple, easy way.
50
221000
4000
04:10
But then, got off on a vacation trip, and was studying bird flight,
51
225000
6000
04:16
just for the fun of it,
52
231000
2000
04:18
and you can watch a bird soaring around in circles,
53
233000
3000
04:21
and measure the time, and estimate the bank angle,
54
236000
4000
04:25
and immediately, figure out its speed,
55
240000
3000
04:28
and the turning radius, and so on,
56
243000
3000
04:31
which I could do in the car, as we're driving along on a vacation trip --
57
246000
5000
04:36
(Laughter) --
58
251000
2000
04:38
with my three sons, young sons, helping me,
59
253000
4000
04:42
but ridiculing the whole thing very much.
60
257000
4000
04:46
But that began thinking about how birds went around,
61
261000
5000
04:51
and then how airplanes would, how hang gliders would fly,
62
266000
7000
04:58
and then other planes,
63
273000
2000
05:00
and the idea of the Gossamer-Condor-type airplane quickly emerged,
64
275000
6000
05:06
was so logical, one should have thought of it in the first place,
65
281000
3000
05:09
but one didn't. And it was just, keep the weight down --
66
284000
4000
05:13
70 pounds was all it weighed -- but let the size swell up, like a hang glider,
67
288000
7000
05:20
but three times the span, three times the cord.
68
295000
2000
05:22
You're down to a third of the speed, a third of the power,
69
297000
3000
05:25
and a good bicyclist can put out that power, and that worked,
70
300000
7000
05:32
and we won the prize a year later.
71
307000
5000
05:37
We didn't -- a lot of flying, a lot of experiments, a lot of things that didn't work,
72
312000
6000
05:43
and ones that did work, and the plane kept getting a little better, a little better.
73
318000
5000
05:48
Got a good pilot, Brian Allen, to operate it,
74
323000
3000
05:51
and finally, succeeded. But unfortunately,
75
326000
4000
05:55
about 65,000 dollars was spent on the project.
76
330000
4000
05:59
(Laughter)
77
334000
2000
06:01
And there was only about 30 to help retire the debt.
78
336000
4000
06:05
But fortunately, Henry Kramer, who put up the prize for --
79
340000
4000
06:09
that was a one-mile flight -- put up a new prize
80
344000
2000
06:11
for flying the English Channel, 21 miles.
81
346000
3000
06:14
And he thought it would take another 18 years for somebody to win that.
82
349000
4000
06:18
We realized that if you just cleaned up our Gossamer Condor a little bit,
83
353000
6000
06:24
the power to fly would be decreased a little bit,
84
359000
4000
06:28
and if you decrease the power required a little,
85
363000
3000
06:31
the pilot can fly a much longer period of time.
86
366000
3000
06:34
And Brian Allen was able, in a miraculous flight,
87
369000
4000
06:38
to get the Gossamer Albatross across the English Channel,
88
373000
4000
06:42
and we won the 100,000-pound, 200,000-dollar prize for that.
89
377000
7000
06:49
And when all expenses were paid, the debt was handled, and everything was fine.
90
384000
8000
06:57
It turned out that giving the planes to the museum
91
392000
3000
07:00
was worth much more than the debt,
92
395000
4000
07:04
so for five years, six years, I only had to pay one third income tax.
93
399000
7000
07:11
So, there were good economic reasons for the project, but --
94
406000
5000
07:16
(Laughter) --
95
411000
3000
07:19
that's not, well, the project was done entirely for economic reasons,
96
414000
7000
07:26
and we have not been involved in any human-powered flight since then --
97
421000
4000
07:30
(Laughter) --
98
425000
2000
07:32
because the prizes are all over.
99
427000
3000
07:36
(Laughter)
100
431000
1000
07:37
But that sure started me thinking about various things,
101
432000
4000
07:41
and immediately, we began making a solar-powered plane
102
436000
5000
07:46
because we felt solar power was going to be so important
103
441000
3000
07:49
for the country and the world,
104
444000
2000
07:51
we didn't want the small funding in the government to be decreased,
105
446000
5000
07:56
which is what the government was trying to do with it.
106
451000
2000
07:58
And we thought a solar-powered plane wouldn't really make sense,
107
453000
5000
08:03
but you could do it and it would get a lot of publicity for solar power
108
458000
4000
08:07
and maybe help that field.
109
462000
2000
08:09
And that project continued, did succeed,
110
464000
4000
08:13
and we then got into other projects in aviation
111
468000
6000
08:19
and mechanical things and ground devices.
112
474000
8000
08:27
But while this was going on,
113
482000
3000
08:30
in 1982, I got a prize from the Lindbergh Foundation --
114
485000
5000
08:35
their annual prize --
115
490000
2000
08:37
and I had to prepare a paper on it,
116
492000
4000
08:41
which collected all my varied thoughts
117
496000
3000
08:44
and varied interests over the years.
118
499000
2000
08:46
This was the one chance that I had to focus on what I, really, was after,
119
501000
5000
08:51
and what was important. And to my surprise,
120
506000
4000
08:55
I realized the importance of environmental issues,
121
510000
5000
09:00
which Charles Lindbergh devoted the last third of his life to,
122
515000
5000
09:05
and preparing that paper did me a lot of good.
123
520000
6000
09:11
I thought back about if I was a space traveler,
124
526000
3000
09:14
and came and visited Earth every 5,000 years.
125
529000
3000
09:17
And for a few thousand visits, I would see the same thing every time,
126
532000
7000
09:24
the little differences in the Earth.
127
539000
2000
09:26
But this last time, just coming round, right now,
128
541000
4000
09:30
suddenly, there'd be huge changes in the environment,
129
545000
5000
09:35
in the concentration of people,
130
550000
3000
09:38
and it was just unbelievable, the amount of -- all the change in it.
131
553000
10000
09:50
I wanted to -- well, one of the biggest changes is, 200 years ago,
132
565000
5000
09:55
we began using coal from underground, which has a lot of pollution,
133
570000
6000
10:01
and 100 years ago, began getting gasoline from underground,
134
576000
4000
10:05
with a lot of pollution. And gasoline consumption, or production,
135
580000
6000
10:11
will reach its limit in about ten years, and then go down,
136
586000
5000
10:16
and we wonder what's going to happen with transportation.
137
591000
5000
10:22
I wanted to show the slide --
138
597000
3000
10:25
this slide, I think, is the most important one any of you will see, ever, because --
139
600000
9000
10:34
(Laughter)
140
609000
2000
10:36
(Applause) --
141
611000
3000
10:39
it shows nature versus humans, and goes from 1850 to 2050.
142
614000
7000
10:46
And so, the year 2000, you see there.
143
621000
3000
10:49
And this is the weight of all air and land vertebrates.
144
624000
5000
10:54
Humans and muskrats and giraffes and birds and so on, are --
145
629000
5000
10:59
the red line goes up. That's the humans and livestock and pets portion.
146
634000
7000
11:06
The green line goes down. That's the wild nature portion.
147
641000
3000
11:10
Humans, livestock and pets are, now, 98 percent of the total world's mass
148
645000
6000
11:16
of vertebrates on land and air.
149
651000
3000
11:19
And you don't know what the future will hold,
150
654000
3000
11:22
but it's not going to get a lower percentage.
151
657000
4000
11:26
Ten thousand years ago, the humans and livestock and pets
152
661000
4000
11:30
were not even one tenth of one percent
153
665000
2000
11:32
and wouldn't even have been visible on such a curve.
154
667000
4000
11:36
Now they are 98 percent, and it, I think, shows human domination of the Earth.
155
671000
11000
11:47
I give a talk to some remarkable high school students each summer,
156
682000
7000
11:54
and ask them, after they've asked me questions,
157
689000
3000
11:57
and I give them a talk and so on. Then I ask them questions.
158
692000
4000
12:01
What's the population of the Earth?
159
696000
2000
12:03
What's the population of the Earth going to be
160
698000
2000
12:05
when you're the age of your parents?
161
700000
2000
12:07
Which I'd never, really -- they had never, really, thought about
162
702000
2000
12:09
but, now, they think about it.
163
704000
2000
12:11
And then, what population of the Earth would be an equilibrium
164
706000
7000
12:18
that could continue on, and be for 2050, 2100, 2150?
165
713000
6000
12:24
And they form little groups, all fighting with each other,
166
719000
3000
12:27
and when I leave, two hours later,
167
722000
2000
12:29
most of them are saying about 2 billion people,
168
724000
4000
12:33
and they don't have any clue about how to get down to 2 billion,
169
728000
5000
12:38
nor do I, but I think they're right and this is a serious problem.
170
733000
8000
12:46
Rachel Carson was thinking of these, and came out with "Silent Spring," way back.
171
741000
7000
12:53
"Solar Manifesto" by Hermann Scheer, in Germany,
172
748000
4000
12:57
claims all energy on Earth can be derived, for every country,
173
752000
5000
13:02
from solar energy and water, and so on.
174
757000
8000
13:10
You don't need to dig down for these chemicals,
175
765000
3000
13:13
and we can do things much more efficiently.
176
768000
4000
13:17
Let's have the next slide.
177
772000
2000
13:19
So this just summarizes it. "Over billions of years,
178
774000
3000
13:22
on a unique sphere, chance has painted a thin covering of life --
179
777000
3000
13:25
complex and probable, wonderful and fragile.
180
780000
3000
13:28
Suddenly, we humans, a recently arrived species,
181
783000
3000
13:31
no longer subject to the checks and balances inherent in nature,
182
786000
4000
13:35
have grown in population, technology and intelligence
183
790000
3000
13:38
to a position of terrible power. We, now, wield the paintbrush."
184
793000
4000
13:42
We're in charge. It's frightening.
185
797000
4000
13:46
And I do a painting every 20 or 25 years. This is the last one.
186
801000
5000
13:51
(Laughter)
187
806000
2000
13:53
And [it] shows the Earth in a time flag: on the right,
188
808000
4000
13:57
in trilobites and dinosaurs and so on;
189
812000
3000
14:00
and over the triangle, we now get to civilization and TV
190
815000
5000
14:05
and traffic jams and so on.
191
820000
2000
14:07
I have no idea of what comes next,
192
822000
3000
14:10
so I just used robotic and natural cockroaches as the future,
193
825000
5000
14:15
as a little warning.
194
830000
2000
14:17
And two weeks after this drawing was done,
195
832000
3000
14:20
we actually had our first project contract, at AeroVironment,
196
835000
4000
14:24
on robotic cockroaches, which was very frightening to me.
197
839000
5000
14:29
(Laughter)
198
844000
2000
14:31
(Paper rustling)
199
846000
3000
14:34
Well, that'll be all the slides.
200
849000
3000
14:41
As time went on, we stopped our environmental programs.
201
856000
3000
14:44
We focused more on the really serious energy problems
202
859000
5000
14:49
of the future, and we produced products for the company.
203
864000
7000
14:56
And we developed the impact car that General Motors made,
204
871000
5000
15:01
the EV1, out of --
205
876000
3000
15:04
and got the Air Resources Board to have the regulations
206
879000
7000
15:11
that stimulated the electric cars, but they've since come apart.
207
886000
4000
15:15
And we've done a lot of things, small drone airplanes and so on.
208
890000
7000
15:22
I have a Helios. We have the first video.
209
897000
5000
15:29
(Video) Narrator: With a wingspan of 247 feet, this makes her larger than a Boeing 747.
210
904000
5000
15:34
(Music)
211
909000
9000
15:43
Her designers' attention to detail and her construction
212
918000
3000
15:46
gives Helios' structure the flexibility and strength
213
921000
3000
15:49
to deal with the turbulence encountered in the atmosphere.
214
924000
3000
15:52
This enables her to easily ride through the air currents
215
927000
3000
15:55
as if she's sliding along on the ocean waves.
216
930000
3000
15:58
Paul MacCready: The wings could touch together on top and not break. We think.
217
933000
5000
16:03
(Laughter)
218
938000
3000
16:06
Narrator: And Helios now begins the process of turning her back to the sun,
219
941000
3000
16:09
to maximize the power from her solar array.
220
944000
3000
16:12
(Music)
221
947000
8000
16:20
As the sky gets darker, and the outside air temperatures drop
222
955000
4000
16:24
below minus 100 degrees Fahrenheit,
223
959000
2000
16:27
the most environmentally hostile segment of Helios's journey
224
962000
3000
16:30
has gone by without notice,
225
965000
2000
16:32
except for being recorded by specially designed data acquisition systems
226
967000
4000
16:36
and their associated sensors.
227
971000
2000
16:39
Approaching a peak radar altitude of 96,863 feet,
228
974000
5000
16:44
at 4:12 p.m., Helios is standing on top of 98 percent of the Earth's atmosphere.
229
979000
5000
16:49
This is more than 10,000 feet higher
230
984000
3000
16:52
than the previous world's altitude record held by the SR-71 Blackbird.
231
987000
5000
16:57
(Applause)
232
992000
8000
17:06
PM: That plane has many purposes, but it's aimed for communications,
233
1001000
5000
17:11
and it can fly so slowly that it'll just stay up at 65,000 feet.
234
1006000
6000
17:18
Eventually, it will be able to have to stay up day, night, day, night,
235
1013000
3000
17:21
for six months at a time, acting like the synchronous satellite,
236
1016000
4000
17:25
but only ten miles above the Earth.
237
1020000
2000
17:27
Let's have the next video. This shows the other end of the spectrum.
238
1022000
3000
17:30
(Video) Narrator: A tiny airplane, the AV Pointer serves for surveillance.
239
1025000
3000
17:33
In effect a pair of roving eyeglasses,
240
1028000
2000
17:35
a cutting-edge example of where miniaturization can lead
241
1030000
3000
17:38
if the operator is remote from the vehicle.
242
1033000
2000
17:41
It is convenient to carry, assemble, and launch by hand.
243
1036000
3000
17:44
Battery-powered, it is silent and rarely noticed.
244
1039000
3000
17:48
It sends high-resolution video pictures back to the operator.
245
1043000
3000
17:51
With on-board GPS, it can navigate autonomously,
246
1046000
4000
17:55
and it is rugged enough to self-land without damage.
247
1050000
3000
17:59
PM: Okay, and let's have the next.
248
1054000
2000
18:01
(Applause)
249
1056000
4000
18:05
That plane is widely used by the military, now, in all their operations.
250
1060000
5000
18:10
Let's have the next video.
251
1065000
2000
18:14
(Video) (Music)
252
1069000
14000
18:28
Alan Alda: He's got it, he's got it, he's got it on his head.
253
1083000
2000
18:30
(Music)
254
1085000
2000
18:32
We're going to end our visit with Paul MacCready's flying circus
255
1087000
3000
18:35
by meeting his son, Tyler, who, with his two brothers,
256
1090000
3000
18:38
helped build the Gossamer Condor, 25 years ago.
257
1093000
3000
18:42
Tyler MacCready: You can chase it, like this, for hours.
258
1097000
2000
18:44
AA: When they got bored with their father's project,
259
1099000
3000
18:47
they invented an extraordinary little plane of their own.
260
1102000
2000
18:49
TM: And I can control it by putting the lift on one side of the wing, or on the other.
261
1104000
5000
18:54
AA: They called it their Walkalong Glider.
262
1109000
2000
18:56
(Music)
263
1111000
1000
18:58
I've never seen anything like that.
264
1113000
1000
18:59
How old were you when you invented that?
265
1114000
2000
19:01
TM: Oh, 10, 11. (AA: Oh my God.)
266
1116000
3000
19:04
TM: 12, something like that. (AA: That's amazing.)
267
1119000
2000
19:06
PM: And Tyler's here to show you the Walkalong.
268
1121000
3000
19:09
(Applause)
269
1124000
5000
19:14
TM: All right. You all got a couple of these in your gift bags,
270
1129000
4000
19:18
and one of the first things,
271
1133000
2000
19:21
the production version seemed to dive a little bit,
272
1136000
2000
19:23
and so I would just suggest you bend the wing tips up a little bit
273
1138000
3000
19:26
before you try flying it.
274
1141000
2000
19:28
I'll give you a demonstration of how it works.
275
1143000
2000
19:30
The idea is that it soars on the lift over your body, like a seagull soaring on a cliff.
276
1145000
6000
19:36
As the wind comes up, it has to go over the cliff, so
277
1151000
3000
19:39
as you walk through the air, it goes around your body, some has to go over you.
278
1154000
5000
19:44
And so you just keep the glider positioned in that up current.
279
1159000
3000
19:47
The launch is the difficult part: you've got to hold it high up, over your head,
280
1162000
3000
19:50
and you start walking forward, and just let go of it, and you can control it like that.
281
1165000
6000
19:56
(Laughter)
282
1171000
2000
19:58
And then also, like it said in the video,
283
1173000
3000
20:01
you can turn it left or right
284
1176000
2000
20:03
just by putting the lift under one wing or another.
285
1178000
2000
20:05
So I can do it -- oops, that was going to be a right turn.
286
1180000
5000
20:10
(Laughter)
287
1185000
1000
20:11
Okay, this one will be a left turn.
288
1186000
2000
20:15
Here, but --
289
1190000
2000
20:17
(Applause) --
290
1192000
1000
20:18
anyway.
291
1193000
2000
20:20
(Applause)
292
1195000
3000
20:23
And that's it, so you can just control it, wherever you want,
293
1198000
3000
20:26
and it's just hours of fun. And these are no longer in production,
294
1201000
4000
20:30
so you have real collector's items.
295
1205000
2000
20:32
(Laughter)
296
1207000
2000
20:34
And this, we just wanted to show you --
297
1209000
4000
20:39
if we can get the video running on this, yeah --
298
1214000
2000
20:41
just an example of a little video surveillance.
299
1216000
6000
20:47
(Laughter)
300
1222000
2000
20:49
This was flying around in the party last night, and --
301
1224000
4000
20:53
(Laughter) --
302
1228000
2000
20:55
you can see how it just can fly around,
303
1230000
3000
20:58
and you can spy on anybody you want.
304
1233000
2000
21:00
(Laughter)
305
1235000
6000
21:06
And that's it. I was going to bring an airplane,
306
1241000
2000
21:08
but I was worried about hitting people in here,
307
1243000
2000
21:10
so I thought this would be a little bit more gentle.
308
1245000
3000
21:14
And that's it, yeah, just a few inventions.
309
1249000
3000
21:17
(Applause)
310
1252000
8000
21:25
All right.
311
1260000
2000

▲Back to top

ABOUT THE SPEAKER
Paul MacCready - Engineer
Paul MacCready, an aircraft designer and environmentalist, is a pioneer of human-powered flight, alternative energy for transportation, and environmentally responsible design.

Why you should listen

Through his life, Paul MacCready turned his mind, energy and heart toward his two passions: flight and the Earth. His early training as a fighter and glider pilot (glider pilots still use the "MacCready speed ring" he developed after World War II) led him to explore nontraditional flight and nontraditional energy sources.

In the 1970s, he and his company, AeroVironment, designed and built two record-breaking human-powered planes: the Gossamer Condor, the first human-powered aircraft to complete a one-mile course set by the Kremer Prize, and the Gossamer Albatross, the first to cross the English Channel. The planes' avian names reveal the deep insight that MacCready brought to the challenge -- that large birds, in their wing shape and flying style, possess an elegant secret of flight.

He then turned his wide-ranging mind toward environmentally responsible design, informed by his belief that human expansion poses a grave threat to the natural world. His team at AeroVironment prototyped an electric car that became General Motors' pioneering EV-1. They explored alternative energy sources, including building-top wind turbines. And they developed a fleet of fascinating aircraft -- including his Helios solar-powered glider, built to fly in the very top 2 percent of Earth's atmosphere, and the 2005 Global Observer, the first unmanned plane powered by hydrogen cells.

 

More profile about the speaker
Paul MacCready | Speaker | TED.com

Data provided by TED.

This site was created in May 2015 and the last update was on January 12, 2020. It will no longer be updated.

We are currently creating a new site called "eng.lish.video" and would be grateful if you could access it.

If you have any questions or suggestions, please feel free to write comments in your language on the contact form.

Privacy Policy

Developer's Blog

Buy Me A Coffee