Michio Kaku: The Universe in a Nutshell

The Universe in a Nutshell: The Physics of Everything
Michio Kaku, Henry Semat Professor of Theoretical Physics at CUNY

What if we could find one single equation that explains every force in the universe? Dr. Michio Kaku explores how physicists may shrink the science of the Big Bang into an equation as small as Einstein's "e=mc^2." Thanks to advances in string theory, physics may allow us to escape the heat death of the universe, explore the multiverse, and unlock the secrets of existence. While firing up our imaginations about the future, Kaku also presents a succinct history of physics and makes a compelling case for why physics is the key to pretty much everything.

The Floating University
Originally released September, 2011.

[Music]

[The Floating University]

[Michio Kaku] My name is Professor Michio Kaku.

I'm a professor of theoretical physics at the City University of New York,

[Dr. Michio Kaku - Professor of theoretical Phyics, The City University of New York - Specialist in String Theory
The Universe in a Nutshell - The Physics of Everything]

and I specialize in something called String Theory.

I'm a physicist, and 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.

(Michio Kaku - Age 8)
When I was 8, 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 = mc^2. That equation is half an inch long,

and that equation unlocks a 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 aliens from outer space:

Starships, 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 blonde hair and blue eyes,

I didn't have muscles like Flash Gordon, but there was a scientist who made the series work.

In particular, a physicist.

He was the one who discovered the ray gun, the starships.

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 a hundred years.

Then we have impossibilities that may take a thousand years or more.

That includes time travel, warp drive, higher dimensions,

portals through space and time, stargates, worm holes.

You know--if you were to meet your great grandparents of 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 may view you as a wizard or sorcerer.

However, if we can now meet our grand kids 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 pure thinking,

and there are 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 have always wanted to have in our garage by the year 2100.

We will have the power of the gods.

To paraphrase Arthur C. Clarke, [Arthur C. Clarke (1917-2008)]

"Any sufficiently advanced technology is indistinguishable from divinity."

[HISTORY OF PHYSICS]

So, let's now begin our story.

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 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 a 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 words of Aristotle, which held sway for almost 2,000 years until the beginning of modern physics

[HISTORY OF PHYSICS]

[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 would sail 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, [inaudible], 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 kings?

Why do we have messengers from the heavens in the sky?

Well, one man dared to penetrate the secrets of comets,

and that was Isaac Newton.

[Isaac Newton] [1643-1727]

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 Wilsthorpe 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 fall, does the moon also fall?"

And the answer was: Yes.

And that answer overturned thousands of years of mystery and speculation about the motions of the heavens.

The moon is in free fall 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--the force of gravity.

[Gravity: FOUR FORCES OF THE UNIVERSE]

So, Newton immediately tried to work out the mathematics.

And he realized that the mathematics of this 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 this 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 Halley. [Edmund Halley: 1656-1742]

So, Edmund Halley, being a wealthy merchant, decided to make a trip to Cambridge

to talk to England's illustrious scientist, Sir Isaac Newton.

Well, Edmund Halley asked Newton, "What do you make of this comet?"

"No one understands comets, they're a mystery."

"They've been fascinating people for centuries, 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 Halley's reaction was, but I paraphrase.

He must have said something like this, "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 Halley must have said this, "Mister Newton, I am a wealthy man."

"I have made my fortune in congress. I will pay for the publication of the greatest scientific work in any language."

And it was "Principia" the principles--the mathematical principles that guide the heavens.

[PRINCIPIA: Mathematical Principles of Natural Philosphy]

Believe it or not, this is perhaps one of the most important works

ever written by a human being in the hundred thousand 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've been able to unravel the secrets of the solar system--

complements 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 operate upon well-defined laws.

[HISTORY OF PHYSICS]

[NEWTON'S THREE LAWS OF MOTION]

Newton's three laws of motion: the first law of motion says that objects in motion stay in motion forever

unless acted upon by an outside force.

You see that in an ice skating rink.

You shoot a puck and it goes all the way down forever, unless acted on 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 is an equal and opposite reaction."

That's the law of rockets.

That's why we have rockets that can sail into outer space.

So, the lesson here is when scientists unraveled 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 they possibly build such a big building and not know that it's going to fall?"

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.

[Gravity: FOUR FORCES OF THE UNIVERSE]

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.

[FOUR FORCES OF THE UNIVERSE] [GRAVITY] [Electromagnetism]

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 lightning 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 began to unlock the second great force that 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 and you get hit by a lightning 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 a 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 called Faraday's Law.

A moving wire in a magnetic field has its electrons pushed, creating an electrical current.

That simple idea, unleashed the electric revolution, and that's why we have hydro-electric generators,

dams that can 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 amp 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.

[ELECTROMAGNETISM]

We once thought that electricity and magnetism were separate.

Now we know that they are, in fact, the same force.

[FOUR FORCES OF THE UNIVERSE] [Gravity][Electromagnetism]

So, if a moving magnet can create an electric field,

this means that the 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,

[JAMES CLERK MAXWELL: 1831-1879]

calculated using the work of Faraday the velocity of this wave.

In one of the greatest breakthroughs of all time, James Clerk Maxwell calculated the velocity of this wave

and found that 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 can not get your PhD without memorizing these equations.

Every engineer who deals with radar and radio has to memorize these equations.

And so, if you go to Berkeley, where I got my PhD, you can buy a t-shirt which says,

"In the beginning God said the four dimensional divergence of an anti-symmetric, second rank tensor = 0, and there was light."

Ladies and gentleman, this is the equation for light.

The consequences of the electromagnetic revolution touched 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's 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 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,