What's so sexy about math?
-
0:01 - 0:05What is it that French people
do better than all the others? -
0:06 - 0:08If you would take polls,
-
0:08 - 0:10the top three answers might be:
-
0:10 - 0:14love, wine and whining.
-
0:14 - 0:16(Laughter)
-
0:16 - 0:17Maybe.
-
0:18 - 0:20But let me suggest a fourth one:
-
0:20 - 0:21mathematics.
-
0:22 - 0:25Did you know that Paris
has more mathematicians -
0:25 - 0:26than any other city in the world?
-
0:27 - 0:29And more streets
with mathematicians' names, too. -
0:30 - 0:34And if you look at the statistics
of the Fields Medal, -
0:34 - 0:36often called the Nobel Prize
for mathematics, -
0:36 - 0:40and always awarded to mathematicians
below the age of 40, -
0:40 - 0:44you will find that France has more
Fields medalists per inhabitant -
0:44 - 0:45than any other country.
-
0:46 - 0:49What is it that we find so sexy in math?
-
0:50 - 0:53After all, it seems to be
dull and abstract, -
0:53 - 0:57just numbers and computations
and rules to apply. -
0:59 - 1:01Mathematics may be abstract,
-
1:01 - 1:02but it's not dull
-
1:02 - 1:04and it's not about computing.
-
1:04 - 1:06It is about reasoning
-
1:06 - 1:08and proving our core activity.
-
1:09 - 1:10It is about imagination,
-
1:10 - 1:12the talent which we most praise.
-
1:12 - 1:14It is about finding the truth.
-
1:16 - 1:18There's nothing like the feeling
which invades you -
1:18 - 1:21when after months of hard thinking,
-
1:21 - 1:24you finally understand the right
reasoning to solve your problem. -
1:25 - 1:29The great mathematician
André Weil likened this -- -
1:29 - 1:30no kidding --
-
1:30 - 1:31to sexual pleasure.
-
1:32 - 1:38But noted that this feeling
can last for hours, or even days. -
1:39 - 1:41The reward may be big.
-
1:41 - 1:45Hidden mathematical truths
permeate our whole physical world. -
1:46 - 1:48They are inaccessible to our senses
-
1:48 - 1:51but can be seen
through mathematical lenses. -
1:52 - 1:54Close your eyes for moment
-
1:54 - 1:57and think of what is occurring
right now around you. -
1:58 - 2:02Invisible particles from the air
around are bumping on you -
2:02 - 2:05by the billions and billions
at each second, -
2:05 - 2:07all in complete chaos.
-
2:07 - 2:08And still,
-
2:08 - 2:13their statistics can be accurately
predicted by mathematical physics. -
2:14 - 2:17And open your eyes now
-
2:17 - 2:20to the statistics of the velocities
of these particles. -
2:21 - 2:24The famous bell-shaped Gauss Curve,
-
2:24 - 2:26or the Law of Errors --
-
2:26 - 2:29of deviations with respect
to the mean behavior. -
2:30 - 2:34This curve tells about the statistics
of velocities of particles -
2:34 - 2:36in the same way as a demographic curve
-
2:36 - 2:40would tell about the statistics
of ages of individuals. -
2:41 - 2:44It's one of the most
important curves ever. -
2:44 - 2:47It keeps on occurring again and again,
-
2:47 - 2:50from many theories and many experiments,
-
2:50 - 2:53as a great example of the universality
-
2:53 - 2:57which is so dear to us mathematicians.
-
2:58 - 2:59Of this curve,
-
2:59 - 3:02the famous scientist Francis Galton said,
-
3:02 - 3:07"It would have been deified by the Greeks
if they had known it. -
3:07 - 3:10It is the supreme law of unreason."
-
3:12 - 3:18And there's no better way to materialize
that supreme goddess than Galton's Board. -
3:20 - 3:23Inside this board are narrow tunnels
-
3:23 - 3:28through which tiny balls
will fall down randomly, -
3:28 - 3:34going right or left, or left, etc.
-
3:34 - 3:37All in complete randomness and chaos.
-
3:38 - 3:44Let's see what happens when we look
at all these random trajectories together. -
3:44 - 3:50(Board shaking)
-
3:50 - 3:52This is a bit of a sport,
-
3:53 - 3:57because we need to resolve
some traffic jams in there. -
4:00 - 4:01Aha.
-
4:01 - 4:05We think that randomness
is going to play me a trick on stage. -
4:08 - 4:09There it is.
-
4:10 - 4:13Our supreme goddess of unreason.
-
4:13 - 4:15the Gauss Curve,
-
4:15 - 4:21trapped here inside this transparent box
as Dream in "The Sandman" comics. -
4:23 - 4:25For you I have shown it,
-
4:25 - 4:31but to my students I explain why
it could not be any other curve. -
4:31 - 4:34And this is touching
the mystery of that goddess, -
4:34 - 4:39replacing a beautiful coincidence
by a beautiful explanation. -
4:39 - 4:41All of science is like this.
-
4:42 - 4:48And beautiful mathematical explanations
are not only for our pleasure. -
4:48 - 4:50They also change our vision of the world.
-
4:51 - 4:52For instance,
-
4:52 - 4:53Einstein,
-
4:53 - 4:55Perrin,
-
4:55 - 4:56Smoluchowski,
-
4:56 - 4:59they used the mathematical analysis
of random trajectories -
4:59 - 5:01and the Gauss Curve
-
5:01 - 5:06to explain and prove that our
world is made of atoms. -
5:08 - 5:09It was not the first time
-
5:09 - 5:13that mathematics was revolutionizing
our view of the world. -
5:14 - 5:16More than 2,000 years ago,
-
5:16 - 5:18at the time of the ancient Greeks,
-
5:20 - 5:21it already occurred.
-
5:22 - 5:23In those days,
-
5:23 - 5:26only a small fraction of the world
had been explored, -
5:26 - 5:29and the Earth might have seemed infinite.
-
5:30 - 5:32But clever Eratosthenes,
-
5:32 - 5:33using mathematics,
-
5:33 - 5:38was able to measure the Earth
with an amazing accuracy of two percent. -
5:40 - 5:41Here's another example.
-
5:42 - 5:46In 1673, Jean Richer noticed
-
5:46 - 5:53that a pendulum swings slightly
slower in Cayenne than in Paris. -
5:54 - 5:59From this observation alone,
and clever mathematics, -
5:59 - 6:01Newton rightly deduced
-
6:01 - 6:07that the Earth is a wee bit
flattened at the poles, -
6:07 - 6:08like 0.3 percent --
-
6:09 - 6:13so tiny that you wouldn't even
notice it on the real view of the Earth. -
6:14 - 6:18These stories show that mathematics
-
6:18 - 6:23is able to make us go out of our intuition
-
6:24 - 6:27measure the Earth which seems infinite,
-
6:27 - 6:29see atoms which are invisible
-
6:29 - 6:33or detect an imperceptible
variation of shape. -
6:33 - 6:37And if there is just one thing that you
should take home from this talk, -
6:37 - 6:38it is this:
-
6:38 - 6:42mathematics allows us
to go beyond the intuition -
6:42 - 6:46and explore territories
which do not fit within our grasp. -
6:48 - 6:51Here's a modern example
you will all relate to: -
6:51 - 6:53searching the Internet.
-
6:54 - 6:55The World Wide Web,
-
6:55 - 6:57more than one billion web pages --
-
6:57 - 6:59do you want to go through them all?
-
7:00 - 7:01Computing power helps,
-
7:01 - 7:05but it would be useless without
the mathematical modeling -
7:05 - 7:07to find the information
hidden in the data. -
7:08 - 7:11Let's work out a baby problem.
-
7:12 - 7:16Imagine that you're a detective
working on a crime case, -
7:16 - 7:19and there are many people
who have their version of the facts. -
7:20 - 7:22Who do you want to interview first?
-
7:23 - 7:25Sensible answer:
-
7:25 - 7:26prime witnesses.
-
7:27 - 7:28You see,
-
7:28 - 7:32suppose that there is person number seven,
-
7:32 - 7:34tells you a story,
-
7:34 - 7:36but when you ask where he got if from,
-
7:36 - 7:39he points to person
number three as a source. -
7:39 - 7:41And maybe person number three, in turn,
-
7:41 - 7:44points at person number one
as the primary source. -
7:44 - 7:46Now number one is a prime witness,
-
7:46 - 7:49so I definitely want
to interview him -- priority. -
7:50 - 7:51And from the graph
-
7:51 - 7:55we also see that person
number four is a prime witness. -
7:55 - 7:57And maybe I even want
to interview him first, -
7:57 - 7:59because there are more
people who refer to him. -
8:00 - 8:03OK, that was easy,
-
8:03 - 8:08but now what about if you have
a big bunch of people who will testify? -
8:09 - 8:10And this graph,
-
8:10 - 8:16I may think of it as all people
who testify in a complicated crime case, -
8:16 - 8:20but it may just as well be web pages
pointing to each other, -
8:20 - 8:22referring to each other for contents.
-
8:23 - 8:25Which ones are the most authoritative?
-
8:26 - 8:27Not so clear.
-
8:28 - 8:30Enter PageRank,
-
8:30 - 8:33one of the early cornerstones of Google.
-
8:33 - 8:38This algorithm uses the laws
of mathematical randomness -
8:38 - 8:41to determine automatically
the most relevant web pages, -
8:41 - 8:47in the same way as we used randomness
in the Galton Board experiment. -
8:47 - 8:50So let's send into this graph
-
8:50 - 8:53a bunch of tiny, digital marbles
-
8:53 - 8:56and let them go randomly
through the graph. -
8:56 - 8:58Each time they arrive at some site,
-
8:58 - 9:02they will go out through some link
chosen at random to the next one. -
9:02 - 9:04And again, and again, and again.
-
9:04 - 9:06And with small, growing piles,
-
9:06 - 9:10we'll keep the record of how many
times each site has been visited -
9:10 - 9:12by these digital marbles.
-
9:12 - 9:13Here we go.
-
9:13 - 9:15Randomness, randomness.
-
9:16 - 9:17And from time to time,
-
9:17 - 9:21also let's make jumps completely
randomly to increase the fun. -
9:22 - 9:24And look at this:
-
9:24 - 9:27from the chaos will emerge the solution.
-
9:27 - 9:30The highest piles
correspond to those sites -
9:30 - 9:34which somehow are better
connected than the others, -
9:34 - 9:36more pointed at than the others.
-
9:36 - 9:38And here we see clearly
-
9:38 - 9:41which are the web pages
we want to first try. -
9:42 - 9:43Once again,
-
9:43 - 9:45the solution emerges from the randomness.
-
9:46 - 9:48Of course, since that time,
-
9:48 - 9:52Google has come up with much more
sophisticated algorithms, -
9:52 - 9:54but already this was beautiful.
-
9:55 - 9:56And still,
-
9:56 - 9:58just one problem in a million.
-
9:59 - 10:01With the advent of digital area,
-
10:01 - 10:06more and more problems lend
themselves to mathematical analysis, -
10:06 - 10:10making the job of mathematician
a more and more useful one, -
10:11 - 10:14to the extent that a few years ago,
-
10:14 - 10:18it was ranked number one
among hundreds of jobs -
10:18 - 10:22in a study about the best and worst jobs
-
10:22 - 10:25published by the Wall Street
Journal in 2009. -
10:25 - 10:27Mathematician --
-
10:27 - 10:29best job in the world.
-
10:30 - 10:33That's because of the applications:
-
10:33 - 10:35communication theory,
-
10:35 - 10:37information theory,
-
10:37 - 10:38game theory,
-
10:38 - 10:39compressed sensing,
-
10:39 - 10:41machine learning,
-
10:41 - 10:43graph analysis,
-
10:43 - 10:44harmonic analysis.
-
10:44 - 10:47And why not stochastic processes,
-
10:47 - 10:49linear programming,
-
10:49 - 10:51or fluid simulation?
-
10:51 - 10:55Each of these fields have
monster industrial applications. -
10:55 - 10:56And through them,
-
10:56 - 10:58there is big money in mathematics.
-
10:59 - 11:01And let me concede
-
11:01 - 11:04that when it comes to making
money from the math, -
11:04 - 11:08the Americans are by a long shot
the world champions, -
11:08 - 11:12with clever, emblematic billionaires
and amazing, giant companies, -
11:12 - 11:16all resting, ultimately,
on good algorithm. -
11:17 - 11:21Now with all this beauty,
usefulness and wealth, -
11:21 - 11:23mathematics does look more sexy.
-
11:24 - 11:26But don't you think
-
11:26 - 11:30that the life a mathematical
researcher is an easy one. -
11:31 - 11:34It is filled with perplexity,
-
11:34 - 11:35frustration,
-
11:36 - 11:39a desperate fight for understanding.
-
11:40 - 11:42Let me evoke for you
-
11:42 - 11:46one of the most striking days
in my mathematician's life. -
11:47 - 11:48Or should I say,
-
11:48 - 11:49one of the most striking nights.
-
11:51 - 11:52At that time,
-
11:52 - 11:55I was staying at the Institute
for Advanced Studies in Princeton -- -
11:55 - 11:57for many years, the home
of Albert Einstein -
11:57 - 12:02and arguably the most holy place
for mathematical research in the world. -
12:03 - 12:07And that night I was working
and working on an elusive proof, -
12:07 - 12:08which was incomplete.
-
12:09 - 12:12It was all about understanding
-
12:12 - 12:15the paradoxical stability
property of plasmas, -
12:15 - 12:17which are a crowd of electrons.
-
12:18 - 12:21In the perfect world of plasma,
-
12:21 - 12:23there are no collisions
-
12:23 - 12:27and no friction to provide
the stability like we are used to. -
12:27 - 12:29But still,
-
12:29 - 12:32if you slightly perturb
a plasma equilibrium, -
12:32 - 12:34you will find that the
resulting electric field -
12:34 - 12:37spontaneously vanishes,
-
12:37 - 12:39or damps out,
-
12:39 - 12:42as if by some mysterious friction force.
-
12:43 - 12:45This paradoxical effect,
-
12:45 - 12:46called the Landau damping,
-
12:46 - 12:49is one of the most important
in plasma physics, -
12:49 - 12:52and it was discovered
through mathematical ideas. -
12:53 - 12:54But still,
-
12:54 - 12:58a full mathematical understanding
of this phenomenon was missing. -
12:58 - 13:03And together with my former student
and main collaborator Clément Mouhot, -
13:03 - 13:05in Paris at the time,
-
13:05 - 13:09we had been working for months
and months on such a proof. -
13:10 - 13:11Actually,
-
13:11 - 13:16I had already announced by mistake
that we could solve it. -
13:16 - 13:18But the truth is,
-
13:18 - 13:20the proof was just not working.
-
13:20 - 13:25In spite of more than 100 pages
of complicated, mathematical arguments, -
13:25 - 13:26and a bunch discoveries,
-
13:26 - 13:28and huge calculation,
-
13:28 - 13:29it was not working.
-
13:29 - 13:31And that night in Princeton,
-
13:31 - 13:35a certain gap in the chain of arguments
was driving me crazy. -
13:36 - 13:40I was putting in there all my energy
and experience and tricks, -
13:40 - 13:42and still nothing was working.
-
13:43 - 13:461 a.m., 2 a.m., 3 a.m.,
-
13:46 - 13:48not working.
-
13:49 - 13:53Around 4 a.m., I go to bed in low spirits.
-
13:54 - 13:56Then a few hours later,
-
13:56 - 13:58waking up and go,
-
13:58 - 14:01"Ah, it's time to get
the kids to school --" -
14:01 - 14:02What is this?
-
14:02 - 14:04There was this voice in my head, I swear.
-
14:05 - 14:07"Take the second term to the other side,
-
14:07 - 14:09Fourier transform and invert in L2."
-
14:09 - 14:10(Laughter)
-
14:10 - 14:12Damn it,
-
14:12 - 14:14that was the start of the solution!
-
14:16 - 14:17You see,
-
14:17 - 14:19I thought I had taken some rest,
-
14:19 - 14:22but really my brain had
continued to work on it. -
14:23 - 14:25In those moments,
-
14:25 - 14:27you don't think of your career
or your colleagues, -
14:27 - 14:31it's just a complete battle
between the problem and you. -
14:32 - 14:33That being said,
-
14:33 - 14:37it does not harm when you do get
a promotion in reward for your hard work. -
14:38 - 14:43And after we completed our huge
analysis of the Landau damping, -
14:43 - 14:45I was lucky enough
-
14:45 - 14:48to get the most coveted Fields Medal
-
14:48 - 14:51from the hands of the President of India,
-
14:51 - 14:54in Hyderabad on 19 August, 2010 --
-
14:55 - 14:59an honor that mathematicians
never dare to dream, -
14:59 - 15:01a day that I will remember until I live.
-
15:02 - 15:04What do you think,
-
15:04 - 15:06on such an occasion?
-
15:06 - 15:07Pride, yes?
-
15:08 - 15:11And gratitude to the many collaborators
who made this possible. -
15:12 - 15:15And because it was a collective adventure,
-
15:15 - 15:19you need to share it,
not just with your collaborators. -
15:20 - 15:25I believe that everybody can appreciate
the thrill of mathematical research, -
15:25 - 15:30and share the passionate stories
of humans and ideas behind it. -
15:30 - 15:35And I've been working with my staff
at Institut Henri Poincaré, -
15:35 - 15:40together with partners and artists
of mathematical communication worldwide, -
15:40 - 15:45so that we can found our own,
very special museum of mathematics there. -
15:47 - 15:48So in a few years,
-
15:49 - 15:50when you come to Paris,
-
15:50 - 15:56after tasting the great, crispy
baguette and macaroon, -
15:56 - 16:00please come and visit us
at Institut Henri Poincaré, -
16:00 - 16:02and share the mathematical dream with us.
-
16:02 - 16:04Thank you.
-
16:04 - 16:11(Applause)
- Title:
- What's so sexy about math?
- Speaker:
- Cédric Villani
- Description:
-
Hidden truths permeate our world; they're inaccessible to our senses, but math allows us to go beyond our intuition to uncover their mysteries. In this survey of mathematical breakthroughs, Fields Medal winner Cédric Villani speaks to the thrill of discovery and details the sometimes perplexing life of a mathematician. "Beautiful mathematical explanations are not only for our pleasure," he says. "They change our vision of the world."
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 16:23
Brian Greene edited English subtitles for What's so sexy about math? | ||
Brian Greene edited English subtitles for What's so sexy about math? | ||
Brian Greene commented on English subtitles for What's so sexy about math? | ||
Brian Greene edited English subtitles for What's so sexy about math? | ||
Retired user commented on English subtitles for What's so sexy about math? | ||
Natasha Murashkina commented on English subtitles for What's so sexy about math? | ||
Brian Greene edited English subtitles for What's so sexy about math? | ||
Brian Greene edited English subtitles for What's so sexy about math? |
Natasha Murashkina
The following subtitle has a typo. It should be “many” instead of “man.”
15:08 - 15:11
And gratitude to the man collaborators
who made this possible.
Retired user
7:46 should be: so I definitely want to interview him IN priority. (dot is also missing)
Brian Greene
This transcript was updated on 8/17/16.
At 15:08, the phrase "man collaborators" was changed to "many collaborators."