(dramatic music)
- And I have a confession to make.
It's true that New York
Magazine voted me as one
of the 100 smartest people in New York.
However, in all fairness, I
have to admit that Madonna
also made that same list.
(laughter)
So, how authoritative could that list be?
Now today I'm gonna take
you on a guided tour
of the future.
And it's always dangerous
to make predictions.
I quote from the physicist Niels Bohr.
Bohr once said quote, "Prediction
is awfully hard to do,
especially if it's about the future."
(laughter)
And we physicists, we invented the laser.
We invented the transistor,
we helped to create the internet,
we wrote the world wide web,
we created television, radio, X-rays.
Almost everything you
see in the 20th century
we helped to create.
But when we physicists and
computer sciences created
the internet one scientist
made a prediction.
And he hoped that the internet
would become a forum of
high culture, high art, and high society.
(laughter)
Well today we know that 5% of the internet
is pornography.
But that's because teenage
boys log on to the internet,
not you guys.
(laughter)
Just wait 'til the grandmas
and grandpas log on
to the internet.
Then 50% of the internet
will be pornography.
(laughter)
Now, you may think that
we physicists know it all.
But let me tell you a little
story about the dangers
of knowing it all.
Over 200 years ago we had
the great French Revolution,
and many people lost their
heads to the guillotine.
Well one day there were
three gentlemen about to lose
their head to the guillotine.
There was a priest, a lawyer,
and a theoretical physicist
just like Paul and me.
So they put the priest's
head on the chopping block
and they asked him do
you have any last words
before we cut your priestly head off?
And the priest said yes,
yes, I have some last words.
And he said maybe God, God from above,
surely he will set me free.
Well all eyes were on the blade.
The blade rose and the blade fell, swish,
and it stopped right before
it hit the neck of the priest.
Well, the crowd had
never seen this before.
Magic they said.
God has spoken the mob said.
Let the priest go.
And now let's see about the lawyer.
Yes, the lawyer.
Now the blood lust was really
starting, yes, the lawyer.
We want his head.
So they asked the lawyer
do you have any last words?
And he said yes, he said maybe justice,
yes the spirit of justice
shall set me free.
Well all eyes were on the blade.
The blade came down, swoosh,
and it stopped right before
it hit the next of the lawyer.
Well the crowd was amazed,
dancing in the streets of Paris.
They said let there be a
holiday, God has spoken.
Justice has spoken.
And now let's see about
that theoretical physicist.
(laughter)
So they put the physicist's
head on the chopping block.
And they asked him do you have
any last words before we cut
your physicist head off?
And he said, yeah, yeah,
I got some last words.
And he said you know, I don't
know too much about God,
and I know even less about the law,
but I do know one thing.
If you look up you'll see that the rope
is stuck on the pulley.
(laughter)
And then he said if you remove
the rope the blade should
come down real good.
(laughter)
Big mistake.
(laughter)
Big mistake.
Well, the rope came
down, the blade came down
and the poor physicist's head came down.
And it just goes to show
that sometimes we physicists
have to know when to keep our mouths shut.
(laughter)
Nonetheless, today I will
talk about the impossible.
Things that are impossible today,
but may be possible in the
coming decades, centuries,
maybe millennia.
And some things which are probably just
downright impossible.
For example, how many people
here have seen the movie "2001"?
Raise your hand.
Now how many people have
understood that movie?
Raise your hand.
(laughter)
About two people.
How many people have seen the
movie "Back to the Future"?
Well, you're probably asking a question,
yourself a question.
What happens if you go back in time
and meet your teenage
mother before you're born
and she falls in love with you?
What happens then?
You're in deep doo doo okay?
I'm gonna be talking about
"Physics of the Impossible."
And the book much to my
surprise hit the New York Times
bestseller list for five weeks running.
When was the last time you saw a book.
(applause)
When was the last time
you saw a book on the
New York Times bestseller list
with the word physics on it.
(laughter)
Let us now talk about the impossible.
First of all the impossible
has always been part
of history.
In the 1800s this is Lord Kelvin,
the most famous physicist of the 1800s.
And he was asked about
airplanes, heavier than aircraft,
heavier than air aircraft.
And Lord Kelvin said bah, humbug.
Airplanes violate the laws of physics.
Also how old is the Earth he was asked.
And he said the Earth
cannot be any more than
a few million years old.
Otherwise it would've cooled down.
Impossible for it to be
billions of years old
as Darwin and other biologists claimed.
And then he said X-rays hah!
X-rays were a hoax.
Radio, no practical application
for radio whatsoever.
So, why did they make so
many mistakes in the 1800s?
And then in the 20th
century, Robert Goddard,
pioneered the work in rocketry,
sending rockets that
eventually took us to the moon.
The New York Times railed
against Robert Goddard.
Called him a fool, said
he was wasting money with
these rockets because
said the New York Times,
rockets cannot move in
outer space because there's
no air in outer space
said the New York Times.
Well we now know that the
only hot air is in the
New York Times editorial room.
(laughter)
So, I like to look at the laws
of impossibility laid down
by Arthur C. Clarke.
He laid down three laws of the impossible.
My favorite one is the third one.
The third law of the
impossible is any sufficiently
advanced technology is
indistinguishable from magic.
So the difference between
magic and physics is not that
one breaks the laws of physics,
and the other one obeys
the laws of physics.
Magic is any sufficiently
advanced technology.
So I divide these into
three types of technologies.
First we have class one, which
are possible in 100 years.
In 100 years invisibility
will become a reality,
certain forms of teleportation
at the atomic level,
starships.
Today I'm even gonna talk about telepathy,
artificial intelligence.
Class one impossibilities.
Class two impossibilities
stretch the boundaries
of the known laws of physics.
Time machines for example.
Stephen Hawking tried very
hard to prove that time travel
was impossible.
And he gave up.
In physics we have the
expression if it's not forbidden
it is mandatory.
(laughter)
And then we have class three
impossibilities which simply
violate everything we
know about the universe.
Like perpetual motion machines.
The New York Times, well Wall
Street Journal often calls
me on the phone saying
that "professor we have yet
another perpetual motion machine
that's making the rounds.
Millions of dollars have been
pledged by wealthy investors.
Do you have something to say
to The Wall Street Journal?"
And I quote from the
immortal words of that great
philosopher of the western
world, P.T. Barnum.
(laughter)
It was P.T. Barnum who once said quote,
"There's a sucker born every minute."
(applause)
