Michio Kaku: The Universe in a Nutshell (Full Presentation)

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
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 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. which could have been calculated by Isaac
Newton himself. So the lesson here is, when scientists unravel
the first force of the universe, gravity, 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. wave, and that wave is called light. And the equations were written down by James
Clerk Maxwell.  Unfortunately, Michael Faraday 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. of light, we physicists today want to have
a one inch equation that summarize all physical reality. Well, Michael Faraday in his own lifetime
was heralded as a great scientist, and how many scientists do you know appear on money?
Well, there he is, on the British 20-pound note.  So it’s very rare that a scientist
appears on a nation’s currency, but so great was a contribution of Michael Faraday that
there he is on the 20-pound note.
The Electromagnetic Revolution and The Nuclear Age The consequences of the electromagnetic revolution
touch all of us.  This is a picture of the 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