My name is Professor Michio Kaku. I'm a professor of theoretical physics at the City
University of New York and I specialize in something called string theory. I'm a physicist.
Some people ask me the question, "What has
physics done for me lately? I mean, do I get better color television, do I get better
internet reception with physics?" And the answer is yes. You see, physics is at the
very foundation of matter and energy. We physicists invented the laser beam, we invented
the transistor. We helped to create the first computer. We helped to construct the
internet. We wrote the World Wide Web. In addition, we also helped to invent television,
radio, radar, microwaves, not to mention MRI scans, PET scans, x-rays. In other words,
almost everything you see in your living room, almost everything you see in a modern hospital,
at some point or other, can be traced to a physicist.
Now, I got interested in physics when I was a child.
When I was eight, a great scientist had just died. I still
remember my elementary school teacher coming into the room and announcing that the greatest
scientist of our era has just passed away. And that day, every newspaper published
a picture of his desk. The desk of Albert Einstein. And the caption said, I'll never
forget, "The unfinished manuscript of the greatest work of the greatest scientist of
our time." And I said to myself, "Why couldn't he finish it? I mean, what's so hard? It's
a homework problem, right? Why didn't he ask his mother? Why can't he finish this
problem?" So as a child of eight, I decided to find out what was this problem.
Years later, I began to realize that it was the theory of everything, the Unified Field
Theory.
An equation that would summarize all the physical forces in the universe. An
equation like E=mc². That equation is half an inch long and that equation unlocks the
secret of the stars. Why do the stars shine? Why does the galaxy light up? Why do we
have energy on the earth?
But then there was another thing that happened to me when I was around eight years old. I
got hooked on the Saturday morning TV shows. In particular, Flash Gordon. And I was
hooked. I mean, every Saturday morning watching programs about alien from outer space, star
ships, ray guns, invisibility shields, cities in the sky, that was for me. But after a
few years, I began to notice something. First of all, I began to notice that well, I didn't
have blond hair and blue eyes, I didn't have muscles like Flash Gordon, but it was a scientist
who made the series work. In particular, a physicist. He was the one who discovered
the ray gun, the star ships. He
was the one who created the invisibility shield. And then I realized something else. If
you want to understand the future, you have to understand physics. Physics is at the
foundation of all the gadgetry, the wizardry, all the marvels of the technological age,
all of it can be traced to the work of a physicist.
Physics and the Impossible
Most of science fiction is in fact well within the laws of physics, but possible within maybe
100 years. And then we have impossibilities that may take 1,000 years
or more. That includes time travel, warp drive, higher dimensions, portals through
space and time, star gates, worm holes.
You know, if you were to meet your grandparents at the year 1900, they were dirt farmers back
then. They didn't live much beyond the age of 40, on average. Long distance communication
in the year 1900 was yelling at your neighbor. And yet, if they could see you now, with
iPads and iPods and satellites and GPS and laser beams, how would they view you? They
They would view you as a wizard or sorcerer.
However, if we can now meet our grandkids of the year 2100, how would we view them?
We would view them as gods, like in Greek mythology. Zeus could control objects around
him by pure thought. Materialize objects just by thinking. And there're perks to
being a Greek god, Venus had a perfect body, a timeless body. And we are beginning now
to unravel the genetics at the molecular level, of the aging process. And then Apollo, he
had a chariot that he could ride across the heavens. We will finally have that flying
car that we've always wanted to have in our garage.
By the year 2100, we will have the power of the gods.
To paraphrase Arthur C. Clark, "Any sufficiently advanced technology is indistinguishable from
from divinity."
So let's now begin our story.
The History of Physics
The history of physics is the history of modern civilization. Before Isaac Newton, before
Galileo, we were shrouded with the mysteries of superstition. People believed in all
sorts of different kinds of spirits and demons. What made the planets move? Why do things
things interact with other things? It was a mystery.
So, back in the Middle Ages, for example, people read the works of Aristotle. And
Aristotle asked the question, "Why do objects move toward the earth? And that's because,"
he said, "objects yearn, yearn to be united with the earth. And why do objects slow
down when you put them in motion? Objects in motion slow down because they get tired."
These are the works of Aristotle, which held sway for almost 2,000 years until the
beginning of modern physics with Galileo and Isaac Newton.
When the ancients looked at the sky, the sky was full of mystery and wonder, and in
the year 1066, the most important date on the British calendar, there was a comet, a
comet which sailed over the battlefield of Hastings. It frightened the troops of King
Harold, and a young man from Normandy, swept into England and defeated King Harold at the
Battle of Hastings, creating the modern British monarchy.
But the question is, where did the comet come from? What was this comet that mysteriously
paved the way for the coming of the British monarchy?
Well, believe it or not, that same comet, the very same comet that initiated the British
monarchy, sailed over London once again in 1682. This time, everyone was asking the
question, "Where do comets come from? Do they signal the death of the king? Why do
we have messengers from heavens in the sky?" Well, one man dared to penetrate the secrets
of comets, and that was Isaac Newton. In fact, when Isaac Newton was only 23 years
old, he stumbled upon the universal force of gravitation.
According to one story, he was walking on his estate in Woolsthorpe, and he saw an apple
fall. And then Isaac Newton saw the moon, and then he asked the key question which helped
to unlock the heavens. If apples falls, does the moon also fall? And the answer
was, "Yes." And answer overturned thousands of years of mystery and speculation about
the motions of the heavens. The moon is in freefall, just like an apple. The moon
is constantly falling toward the earth. It doesn't hit the earth, because it spins around
the earth, and the earth is round, but it's acting under a force, a force of gravity.
So Newton immediately tried to work out the mathematics and he realized that the mathematics
of the 1600's was not sufficient to work out the motion of a falling moon. So what did
Isaac Newton do? When he was 23 years old, not only did he stumble upon the force of
gravity, but he also created calculus. In fact, he created calculus at the rate at which you
learn it, when you are a freshman in college. And why did he create calculus? To calculate
the motion of a falling moon. The mathematics of his age was incapable of calculating the
trajectories of objects moving under an inverse square force field, and that's what Isaac
Newton did. He worked out the motion of the moon. And then he realized that if he
understands the moon, he also understands the motion of the planets in the solar system.
And Isaac Newton invented a new telescope. It was the reflecting telescope and he was
tracking the motion of this comet.
Well, it turns out that everyone was talking about the comet, including a rather wealthy
Englishman by the name of Edmund Haley. So Edmund Haley,
being a wealthy merchant, decided to make a trip to Cambridge to talk to England's illustrious
scientist, Sir Isaac Newton. Well, Edmund Haley asked Newton, "What do you make of this
comet? No one understands comets, they're a mystery. They've been fascinating people
for centuries, for millennia, what are your thoughts?" And then, I paraphrase, but Isaac
Newton said something like this, he said, "Oh, that's easy. That comet is moving at
a perfect ellipse. It's moving in an inverse square force field. I've been tracking it
every day with my reflecting telescope and the path of that comet conforms to my mathematics
exactly." And of course, we don't know what Edmund Haley's reaction was, but I paraphrase,
he must have said something like this, he said, "For God's sake, man, why don't you
publish the greatest work in all of scientific history? If correct, you have decoded the
secret of the stars, the secret of the heavens. Nobody understands where comets come from."
And then Newton responded and said, "Oh, well, it costs too much. I mean, I'm not
a wealthy man, it would cost too much to summarize this calculus that I've invented and to work
out all the motion of the stars." And then Haley must have said this, he must have said,
"Mr. Newton, I am a wealthy man. I have made my fortune in commerce. I will pay
for the publication of the greatest scientific work in any language." And it was Principia.
The principals, the mathematical principals that guide the heavens.
Believe it or not, this is perhaps one of the most important works ever written by a
human being in the 100,000 years since we evolved from Africa. Realize that this book
sets into motion a physics of the universe. Forces that control the motion of the planets,
forces which can be calculated, forces which govern the motion of cannonballs, rockets,
pebbles, everything that moves, moves according to the laws of motion and the calculus of
Sir Isaac Newton.
In fact, even today, when we launch our space probes, we don't use Einstein's equations,
they only apply when you get near the speed of light or near a black hole. We use Newton's
laws of gravity. They are so precise that when we shoot a space probe right past the
rings of Saturn, we use exactly the same equations that Isaac Newton unraveled in the 1600's.
That's why we have glorious photographs of the rings of Saturn. That's why we have
fly-by's right past Neptune. That's why we've been able to unravel the secrets of
the solar system, compliments of the laws of motion of Isaac Newton.
So what Newton did was not only did he set into motion the ability to calculate planets,
he also set into motion a mechanics. Machines now operated upon well-defined laws:
Newton's three laws of motion. The first law of motion says that objects in motion stay in motion
forever, unless acted on by an outside force. You see that in an ice skating rink. You
should a puck and it goes all the way down forever, unless acted upon by an outside force.
That's different from Aristotle's law of motion. Aristotle said, "Objects in motion
eventually stop, because they get tired."
The second law of motion says, force is mass times acceleration. And that equation made
possible the Industrial Revolution. Steam engines, locomotives, factories, machines,
all of it due to the mechanics set into motion by Isaac Newton's second law of motion, force
is equal to mass times acceleration.
And then Newton had a third law of motion. For every action, there's an equal and opposite
reaction, that's the law of rockets. That's why we have rockets that can sail into outer
space.
that number, 25,000 miles per hour, that's the escape velocity of the earth, a number
So the lesson here is, when scientists unravel the first force of the universe, gravity,
that set into motion the Industrial Revolution. A revolution which toppled the kings and
queens of Europe, which displaced feudalism, ushering in the modern age. All because
a 23-year-old gentleman looked up and asked the question, "Does the moon also fall?"
You know, when I was a kid growing up in California, I would see pictures of the Empire State Building.
And I said to myself, "How could that possibly build such a big building and not know that
it's going to fall? I mean, why doesn't it fall? They didn't build scale models
of the thing, you couldn't have an Empire State Building that big to test whether it's
going to fall or not. How did they know ahead of time that that building wouldn't
fall? And the answer is: Newton's laws of motion.
In fact, today, I teach Newton's laws of motion, and you can actually calculate the forces
on every single brick of the empire state building, using
Newton's second law of motion, force is mass times acceleration.
When Newton unraveled the force of gravity, that was the first force.
Now, let's take a look at the second force, an even greater force which
has touched all of our lives, and that is the electromagnetic force.
Ever since humans saw lightning bolts light up the sky, ever since they were terrified
by the sound of thunder, they've been asking, "Do the gods propel lightening bolts and create
thunder? Are they angry at us?"
Scientists began to realize that the lightning bolts and the
thunder can be duplicated on the earth. That we can actually create mini lightning bolts
using electricity.
But it wasn't until the 1800's that finally we begin to unlock the second great force
which rules the universe, the electromagnetic force.
Michael Faraday would give Christmas
lectures in London, fascinating everyone from adults to children. And he would demonstrate
the incredible properties of electricity.
Some people, for example, ask a simple question. If you're in a car or an airplane, you get
hit by a lightening bolt, why don't you all get electrocuted? Why don't you all die?
Well, Faraday answered the question. He would create a cage. He would
walk into this steel cage, electrify it, and he wouldn't get electrocuted at all. That's
called a Faraday cage and every time you walk into metal structure, you get shielded by
this metal object. Well, what Michael Faraday did was,
he helped to unleash the second great revolution with something calls Faraday's Law.
A moving wire in a magnetic field, has this electrons pushed, creating
an electrical current.
That simple idea unleashed the electric revolution.
And that's why we have hydroelectric generators,
dams that produce enormous amounts of power,
That's why people build nuclear power plants. That's why we have electricity
in this room right now!
On a very small scale, you use that in your bicycle. When you put a bicycle lamp on
your bicycle, the turning of the wheel spins a magnet. The magnet then pushes electrons
in a wire and that's why electricity lights up in your bicycle lamp.
So in other words,
electricity and magnetism were unified into a single force. We once thought that electricity
and magnetism were separate. Now we know they are in fact the same force.
So if a moving magnet can create an electric field, this means that a moving electric field
can create a magnetic field. But if they can create each other, why can't they oscillate
and create a wave? So that moving electric fields create magnetic fields, create electric
fields, create magnetic fields, infinitum to create a wave?
Well, around the time of the American Civil War, a mathematical physicist, James Clerk
Maxwell, calculated, using the work of Faraday, the velocity of this wave.
And in one of the greatest breakthroughs of all time, James Clerk Maxwell calculated
the velocity of this wave and found out it was the velocity of light. And then he made
this incredible discovery: this is light. That's what light is. It doesn't by accident
travel at the speed of electricity, it is light itself.
And the equations were written down by James Clerk Maxwell. Unfortunately, Michael Faraday
himself did not have a formal education. He could not put into mathematical form his own
work. James Clerk Maxwell was a theoretical physicist, just like myself. He wrote down
the mathematical physics of oscillating electric fields and magnetic fields and they are called
Maxwell's equations. These equations have to be memorized by every physicist in grad
school. You cannot get your PhD without memorizing these equations. Every engineer
deals with radar and radio has to memorize
these equations. And so, if you go to Berkley, where I got my PhD, you can buy a t-shirt
which says, "In the beginning God said, the four-dimensional divergence of an antisymmetric,
second rank tensor equals zero, and there was light.
Ladies and gentlemen, this is the equation for light.
The consequences of the electromagnetic revolution touch all of us. This is a picture of the
earth from outer space. Look at this picture. Europe electrified, you can actually see
the fruits of all of our efforts to create electricity, to energize our lives, in one
picture, seeing the earth from outer space. So let's now talk about how Faraday and
Maxwell's work touches your life as well.
This is the internet. The internet is a simple byproduct of the electromagnetic force.
And you can see that where there is the internet,
there is prosperity. There is science, there's entertainment, there's economic activity.
Where there's no internet, there's poverty. And in the future, the internet will be
miniaturized and it will be placed in your glasses. Your glasses will recognize people's
faces and display their biography next to the image as you talk to them, and then when
they speak Chinese to you, your glasses will translate Chinese into English and print out
subtitles right beneath their image. So in the future, you will know exactly who you
are talking to without even talking to them, and this means that at a cocktail party, if
you're looking for a job, but you don't know who the heavy hitters are, in the future you
will know exactly who to suck up to.
In the future, chips will only cost a penny, because we can manufacture tinier and tinier transistors
You will have Faraday's electromagnetic force inside your body
This is a pill. It has a chip in it. The chip is smaller than an aspirin pill,
It also has a TV camera and a magnet.
When you swallow it, the magnet guides the camera, taking pictures of your stomach,
your intestines, because we all know what middle-aged men fear the most:
colonoscopies. And, this gives new meaning for the expression "intel inside."
Now, let's talk about the next great forces which rule the universe. We talked about
gravity, which allows us to calculate the motion of the planets. The mechanics created
by Newton helped to unleash the Industrial Revolution. Michael Faraday worked out the
electromagnetic force, which gave us the wonders of the electric age. And now, let's talk
about the nuclear age, the stars and the sun. People have been fascinated by the sun,
Apollo was the god that strode across the heavens in his fiery chariot. But hey, when
you calculate how long coal or oil will burn like the sun, you realize that in just a few
hundred years, the sun would burn to a crisp. So what could possibly last for billions
of years? There must be a new force, a nuclear force.
Einstein and others helped to unravel the secret of the stars. The nuclear force comes
in two types, weak and strong. The weak nuclear force governs radioactive decay.
The strong nuclear force is one of the strongest forces in the entire universe.
It's so strong it holds our protons together, ever since Genesis, the beginning of time.
The equation which allows for the liberation of energy is Einstein's famous equation E=mc².
What Einstein showed was that the faster you move, the heavier you get.
So your weight is not a constant. When you move very rapidly you get heavier,
something which we measure every day in the laboratory.
Now, this means that the energy of motion transformed into
mass, because you get heavier. Now, listen carefully. The faster you move, the heavier
you get. Which means that the energy of motion, "E" turns into "m", your mass. And
the relationship between E and m is very simple, it takes one second to write it down on a
sheet of paper, it is exactly E=mc².
So the nuclear force helped to explain the secret of the sun. But it also created a
Pandora's box, because inside the nucleus of the atom, are particles. And when you
smash these particles, what do you get? More particles. And when you smash them, what
More particles. In fact, we are drowning in subatomic particles. Hundreds,
thousands of subatomic particles every time we smash atoms.
Now, we smash atoms using something called atom smashers, or particle accelerators. I
built my own particle accelerator when I was in high school. When I was in high school,
I went to my mom one day and I said, "Can I have permission to build a 2.3 million electron
volt betatron particle accelerator in the garage?" And my mom said, "Sure, why not?
And don't forget to take out the garbage!"
And as a high school kid I asked for 400 pounds of transformer steel.
I asked for 22 miles of cooper wire.
Because I wanted to create a six kilowatter, 10,000 gauss magnetic field,
to energize my atom smasher.
With 22 miles of copper wire, how could you wind it?
We did it on the high school football field. With 22 miles
of copper wire on the goalpost, gave it to my mother,
she ran to the 50 yard line unraveling the spool of wire, she gave it to my father
who then ran to the goalpost and we wound 22 miles of copper wire on the high school football field.
Well, finally my atom smasher was ready.
It consumed six kilowatts of power, that's every single ounce of power my house could deliver.
I plugged my ears, I closed my eyes, I turned on the power, and I heard this huge crackling sound
as six kilowatts of power surged through my capacitor bank and then
I heard a "pop pop pop" sound as I blew out every single circuit breaker in the house.
The whole house was plunged in darkness.
My poor mom, every time she'd come home she'd see the lights flicker and die.
And she must've wondered "why couldn't I have a son who plays baseball?"
Why can't he learn basket ball? And for god's sake why can't he find a nice Japanese girl?"
I mean, why does he have to build these machines in the garage?
Well, these machines that I built in my garage earned the attention of a physicist
Edward Teller, father of the hydrogen bomb.
And he arranged for me to get a scholarship to Harvard.
And my career got a head start! He knew exactly what I was doing.
I didn't have to explain to him that I was experimenting with antimatter.
I was creating anti-electrons in my mom's garage, and using atom smashers to eventually create
beams of antimatter.
Antimatter is the opposite of matter. It has an opposite charge.
So an electron has negative charge. The positron, or anti-electron, has positive charge.
This means that you can now create anti-molecules and anti-atoms.
Anti-hydrogen was made at CERN, outside Geneva, Switzerland
And also at Fermilab outside Chicago
Where you have anti-electrons circulating around anti-protons.
And in Brookhaven National Laboratory on Long Island just recently
they detected anti-helium!
We have two anti-protons with two anti-neutrons to create anti-helium.
For every piece of matter there is a counterpart made out of anti-matter.
And when the two collide, by the way, it releases the greatest energy source in the universe.
It is 100 percent conversion of matter to energy by Einstein's equations E=mc squared.
Inside the nucleus of the atom we have particles upon particles when you smash them apart.
In the 1950's we were drowning in subatomic particles.
In fact, J. Robert Oppenheimer, the father of the atomic bomb, once made a statement.
He declared that "the Nobel Prize in physics should go to the physicist who does not discover
a new particle this year."
That how many particles were being discovered.
So, let's talk about the Particle Zoo.
Right now, we physicists have unlocked hundreds, thousands of subatomic particles.
And we've been able to piece them together into a jigsaw puzzle.
It's called the "standard model." It has 36 quarks, 19 free parameters, 3 generations of quarks
no rhyme, no reason, but this is the most fundamental basis of reality that we physicists
have been able to construct.
Billions of dollars. 20 Nobel prizes.
have gone into the creation of the standard model.
and it is the ugliest theory known to science, but it works.
There's one piece missing, and that one piece missing is called the Higgs-Boson.
We expect to find it. We want to create a higher version of this theory
and that theory, we think, is string theory.
String theory is based on the simple idea that all the four forces of the universe
Gravity, electromagnetic force, and the two nuclear forces, can be viewed as
music.
Music of tiny little rubber bands.
So if I had a super microscope, and I could look right into the heart of an electron
What would I see?
I would see a vibrating rubber band.
And if I "twang" it, it turns into a neutrino.
I "twang" it again and it turns into a quark.
I "twang" it again and it turns into a Yang-Mills particle
In fact, if I "twang" it enough times, I get thousands of subatomic particles that have been cataloged
patiently by physicists.
String theory, we think, is a theory of everything.
Now, string theory, in turn, can be summarized in an equation about an inch long
That's my equation!
This is called string field theory. And how will we test it?
We are building a machine. The biggest machine of science ever built
in the history of the human race.
Outside Geneva, Switzerland.
It is the Large Hadron Collider.
So the Higgs-Boson, we think, will be created by the Large Hadron Collider.
A tube 17 miles in circumference with two beams of protons circulating in opposite directions
Then slamming together creating a shower of particles, and among these particles
we hope to find the Higgs-Boson, but not only that.
We hope to find particles even beyond the Higgs-Boson.
The next set of particles beyond the Higgs-Boson are "sparticles"
The next layer of the jigsaw puzzle are called sparticles—super particles
Nothing but higher vibrations, higher musical notes of a vibrating string.
And what else can we do? We can also unlock secrets of the big bang.
You see, Einstein's equations break down and the instant of the big band and the center of a black hole.
The two most interesting places in the universe
are beyond our reach using Einstein's equations.
We need a higher theory, and that's where string theory comes in.
String theory takes you before the Big Bang, before Genesis itself.
And what does string theory say? It says that there is a multiverse of universes.
Where did the Big Bang come from?
Well, Einstein's equations give us this compelling picture that we are like insects on a soap bubble.
A gigantic soap bubble which is expanding.
and we are trapped like flies on fly paper, we can't escape the soap bubble
and that's called the Big Bang Theory.
String theory says there should be other bubbles out there
in a multiverse of bubbles.
When two universes collide it can form another universe.
When a universe splits in half it can create two universes, and that, we think, is the Big Bang.
The Big Bang is caused by either the collision of universes or by the fissioning of universes.
If there are other dimensions, if there are other universes, can we go between universes?
Well that, of course, is very hard, but Alice in Wonderland gives us a possibility
that maybe one day we might create a wormhole between universes.
This is a wormhole.
Think of taking a sheet of paper and putting two dots on it.
The shortest distance between two points is a straight line.
But if I can fold, if I can fold that sheet of paper
Then perhaps I can create a shortcut.
A shortcut through space and time, called a wormhole.
This is a genuine solution of Einstein's equations.
We can actually see this in string theory.
The question is: how practical is it to go through one of these things?
We don't know. In fact there's a debate among physicists today, Stephen Hawking, many physicists
are jumping into the game of trying to figure out whether it's physically possible
to go all the way through a wormhole.
Because if you could, then you might be able to use this as a time machine.
Since string theory is a theory of everything, it's also a theory of time.
And time machines are allowed in Einstein's equations, but to build one
is extremely difficult.
Far more energy is required than a simple Delorean with plutonium.
You know, trillions of years from now the universe is going to get awfully cold.
We think the universe is headed for a big freeze.
Stars will blink out, stars will cease to twinkle, and the universe will be so big
it'll be very cold.
At that point all intelligent life in the universe must die.
The laws of physics are a death warrant for all intelligent life.
There is only one way to escape the death of the universe, and that is
leave the universe.
We are now entering the realm of science fiction, but at least now we have equations
equations of string theory which will now allow us to calculate if
it is possible to go through a wormhole,
to go to another universe where it's warmer, and perhaps we can start all over again.
If you were to summarize the march of physics through the last 10,000 years
it would be the distillation of the laws of nature into four fundamental forces.
Gravity, electricity and magnetism, and the two nuclear forces.
But then the question is "is there a fifth force?"
A force beyond the forces we can measure in the laboratory.
And believe it or not there are physicists who have looked very carefully for a fifth force.
Some people think maybe it's psychic phenomena. Maybe it's telepathy.
Maybe it's something called psi power. Maybe it's the power of the mind. Maybe consciousness!
Well, I'm a physicist.
We believe in testing theories to make sure they are falsifiable and reproducible.
We want to make sure that on demand your theory works every single time without exception.
And if your theory fails one time,
It's wrong.
In other words, Einstein's theory has to work every single time without exception.
One time Einstein's theory is proven to be wrong, the whole theory is wrong.
Well, so far we can reproduce these four physical theories, but a fifth theory cannot be reproduced.
We've looked for it. Some people think that maybe a fifth force may be short range.
Like, not over the nucleus of an atom, but ranging over several feet.
And we can't find any.
We physicists in the last ten years have discovered a new energy source larger than the galaxy itself.
Dark energy.
Realized in our universe today
73 percent of our universe, matter and energy, 73 percent is in the form of dark energy.
The energy of nothing!
That's what's blowing the galaxies farther and farther apart. That's the energy of the Big Bang itself.
Kids ask the question, "If the universe banged, what made it bang?"
And the answer is dark energy. 73 percent of the universe's energy is dark energy.
23 percent is dark matter.
Dark matter is invisible matter. If I held it in my hand it would go right through my hand.
It holds the galaxy together. 23 percent of the universe is dark matter.
Stars made out of hydrogen and helium make up four percent of the universe.
And then what about us? We, the higher elements.
We made out of oxygen, carben, nitrogen, tungsten, iron
We make up .03 percent of the universe.
In other words, we are the exception. The universe is mainly made out of dark energy.
The universe is mainly made out of dark matter.
Overwhelming the stars, overwhelming the galaxies in fact.
Now what is dark matter, which makes up 23 percent of the universe?
No one knows.
String theory gives us a clue, but there's no definitive answer.
So in other words, for you young aspiring physicists out there in the audience,
You may be saying to yourself right now,
"Why should I go into physics? Because you guys already have a candidate
for the unified field theory, right?
Just realize that every single physics textbook
is WRONG.
Every single physics textbook on the Earth says that the universe is mainly made out of atoms
Right? There it is!
The universe is mainly made out of atoms. Wrong!
In the past ten years we have come to the realization that most of the universe is dark.
And there's a whole shelf full of Nobel Prizes for the young people
who can figure out the secret of dark matter
and dark energy.
Let me give some advice to you if you are a young physicist, perhaps just getting out of high school
You have dreams of being Einstein, you
have dreams of working on string theory and things like that
and then you hit freshman physics.
Let me be blunt:
We physicists flunk most student taking elementary physics.
And we're more or less encouraged to do so by the engineering department.
We don't want to train engineers who make bridges that fall down.
We don't want to create engineers that create skyscrapers that fall over.
There's a bottom line: you have to know the laws of mechanics.
So before you can work with the laws of Einstein,
you have to work with the laws of friction, levers, pulleys and gears.
As a consequence we have a very high flunk-out rate in elementary physics.
So if you're a young physicist graduating from high school with stars in your eyes,
and you encounter freshman physics for the first time, watch out!
If you have a rough time, that's the way it is.
I started out my life as an experimental physicist. Then I went to Harvard
and then I talked to my adviser, one of the world's greatest experiment physicists, Professor Pound
And he told me maybe it's time to give it a rest. He said to me,
"Your skills are much better suited to what you love the most, which is theory."
"Mathematics. The world of higher dimensions."
And I realized that he was probably right.
The thing about physics, or science that really intrigues me the most
is to find the most fundamental basis for everything
Rather than trying to massage a theory, or make a theory prettier,
Why not find out why it works? What makes it tick?
And that's what I do for a living. I'm a theoretical physicist.
Thank you very much!