Play! Experiment! Discover!

Biochemist Kary Mullis talks about the basis of modern science: the experiment. Sharing tales from the 17th century and from his own backyard-rocketry days, Mullis celebrates the curiosity, inspiration and rigor of good science in all its forms.

I'll just start talking
about the 17th century.

I hope nobody finds that offensive.

I -- you know, when I --
after I had invented PCR,

I kind of needed a change.

And I moved down to La Jolla
and learned how to surf.

And I started living down there
on the beach for a long time.

And when surfers are out waiting

for waves,

you probably wonder, if you've never
been out there, what are they doing?

You know, sometimes there's a 10-,
15-minute break out there

when you're waiting for a wave to come in.

They usually talk about the 17th century.

You know, they get a real
bad rap in the world.

People think they're sort of lowbrows.

One day, somebody suggested
I read this book.

It was called --

it was called "The Air Pump,"

or something like "The
Leviathan and The Air Pump."

It was a real weird book
about the 17th century.

And I realized, the roots

of the way I sort of thought

was just the only natural
way to think about things.

That -- you know, I was born
thinking about things that way,

and I had always
been like a little scientist guy.

And when I went to find out something,

I used scientific methods.
I wasn't real surprised,

you know, when they first told me how --

how you were supposed to do science,

because I'd already been doing it
for fun and whatever.

But it didn't -- it never occurred to me

that it had to be invented

and that it had been invented

only 350 years ago.

You know, it was --

like it happened in England,
and Germany, and Italy

sort of all at the same time.

And the story of that,

I thought, was really fascinating.

So I'm going to talk
a little bit about that,

and what exactly is it
that scientists are supposed to do.

And it's, it's a kind of --

You know, Charles I got beheaded

somewhere early in the 17th century.

And the English set up Cromwell

and a whole bunch
of Republicans or whatever,

and not the kind of Republicans we had.

They changed the government,
and it didn't work.

And

Charles II, the son,

was finally put back
on the throne of England.

He was really nervous,
because his dad had been,

you know, beheaded for being
the King of England

And he was nervous about the fact

that conversations that got going

in, like, bars and stuff

would turn to --

this is kind of -- it's hard to believe,

but people in the 17th century in England

were starting to talk about, you know,

philosophy and stuff in bars.

They didn't have TV screens,

and they didn't have
any football games to watch.

And they would get really pissy,

and all of a sudden people would spill
out into the street and fight

about issues like whether or not

it was okay if Robert Boyle

made a device called the vacuum pump.

Now, Boyle was a friend of Charles II.

He was a Christian guy
during the weekends,

but during the week he was a scientist.

(Laughter)

Which was -- back then it was

sort of, you know, well, you know --

if you made this thing --
he made this little device,

like kind of like a bicycle pump

in reverse that could suck
all the air out of --

you know what a bell jar is?
One of these things,

you pick it up, put it
down, and it's got a seal,

and you can see inside of it,

so you can see what's going
on inside this thing.

But what he was trying to do
was to pump all the air out of there,

and see what would happen inside there.

I mean, the first -- I think
one of the first experiments he did

was he put a bird in there.

And people in the 17th century,

they didn't really understand
the same way we do

about you know, this stuff is

a bunch of different kinds of molecules,

and we breathe it
in for a purpose and all that.

I mean, fish don't know much about water,

and people didn't know much about air.

But both started exploring it.

One thing, he put a bird in there,
and he pumped all the air out,

and the bird died. So he said, hmm...

He said -- he called
what he'd done as making --

they didn't call it
a vacuum pump at the time.

Now you call it a vacuum
pump; he called it a vacuum.

Right? And immediately,

he got into trouble with the local clergy

who said, you can't make a vacuum.

Ah, uh --

(Laughter)

Aristotle said that nature abhors one.

I think it was a poor
translation, probably,

but people relied
on authorities like that.

And you know, Boyle says, well, shit.

I make them all the time.

I mean, whatever
that is that kills the bird --

and I'm calling it a vacuum.

And the religious people said that

if God wanted you to make --

I mean, God is everywhere,

that was one of their rules,
is God is everywhere.

And a vacuum --
there's nothing in a vacuum,

so you've -- God couldn't be in there.

So therefore the church said that you
can't make a vacuum, you know.

And Boyle said, bullshit.

I mean, you want to call it Godless,

you know, you call it Godless.

But that's not my job. I'm not into that.

I do that on the weekend. And like --

what I'm trying to do
is figure out what happens

when you suck everything
out of a compartment.

And he did all these
cute little experiments.

Like he did one with --
he had a little wheel,

like a fan, that was

sort of loosely attached,
so it could spin by itself.

He had another fan opposed to it

that he had like a --

I mean, the way I would have done
this would be, like, a rubber band,

and, you know, around a tinker
toy kind of fan.

I know exactly how he did
it; I've seen the drawings.

It's two fans, one which he could
turn from outside

after he got the vacuum established,

and he discovered that if he pulled
all the air out of it,

the one fan would no longer
turn the other one, right?

Something was missing, you know.
I mean, these are --

it's kind of weird to think that someone
had to do an experiment to show that,

but that was what was going
on at the time.

And like, there was big arguments about it

in the -- you know, the gin houses
and in the coffee shops and stuff.

And Charles

started not liking that.

Charles II was kind of saying, you
know, you should keep that --

let's make a place where
you can do this stuff

where people don't get so -- you know,

we don't want the -- we don't want to get
the people mad at me again. And so --

because when they started
talking about religion

and science and stuff like that,

that's when it had sort of gotten
his father in trouble.

And so,

Charles said, I'm going
to put up the money

give you guys a building,

come here and you can
meet in the building,

but just don't talk
about religion in there.

And that was fine with Boyle.

He said, OK, we're going
to start having these meetings.

And anybody who wants to do science is --

this is about the time that Isaac
Newton was starting to whip out

a lot of really interesting things.

And there was all kind of people
that would come to the Royal Society,

they called it. You had to be
dressed up pretty well.

It wasn't like a TED conference.

That was the only criteria,
was that you be --

you looked like a gentleman,
and they'd let anybody could come.

You didn't have to be a member then.

And so, they would come
in and you would do --

Anybody that was going
to show an experiment,

which was kind of a new word at the time,

demonstrate some principle,

they had to do it on stage,
where everybody could see it.

So they were --

the really important part of this was,

you were not supposed to talk

about final causes, for instance.

And God was out of the picture.

The actual nature of reality
was not at issue.

You're not supposed to talk
about the absolute nature of anything.

You were not supposed
to talk about anything

that you couldn't demonstrate.

So if somebody could see it, you could
say, here's how the machine works,

here's what we do, and then
here's what happens.

And seeing what happens, it was OK

to generalize,

and say, I'm sure that this
will happen anytime

we make one of these things.

And so you can start making up some rules.

You say, anytime you have a vacuum state,

you will discover that one wheel
will not turn another one,

if the only connection between them

is whatever was there before the vacuum.
That kind of thing.

Candles can't burn in a vacuum,

therefore, probably
sparklers wouldn't either.

It's not clear; actually sparklers will,

but they didn't know that.

They didn't have sparklers. But, they --

(Laughter)

-- you can make up rules,
but they have to relate

only to the things
that you've been able to demonstrate.

And most the demonstrations
had to do with visuals.

Like if you do an experiment on stage,

and nobody can see it, they can just hear it,
they would probably think you were freaky.

I mean, reality is what you can see.

That wasn't an explicit
rule in the meeting,

but I'm sure that was part of it,
you know. If people hear voices,

and they can't see and associate
it with somebody,

that person's probably not there.

But the general idea
that you could only --

you could only really talk
about things in that place

that had some kind of experimental basis.

It didn't matter what Thomas Hobbes,

who was a local philosopher,

said about it, you know,

because you weren't going
to be talking final causes.

What's happening here,

in the middle of the 17th century,

was that what became my field --

science, experimental science --

was pulling itself away,

and it was in a physical way, because we're
going to do it in this room over here,

but it was also what -- it
was an amazing thing that happened.

Science had been all interlocked

with theology, and philosophy,

and -- and -- and mathematics,

which is really not science.

But experimental science had
been tied up with all those things.

And the mathematics part

and the experimental science part

was pulling away from philosophy.

And -- things --

we never looked back.

It's been so cool since then.

I mean, it just -- it just -- untangled
a thing that was really impeding

technology from being developed.

And, I mean, everybody in this room --

now, this is 350 short years ago.

Remember, that's a short time.

It was 300,000, probably, years ago

that most of us, the ancestors
of most of us in this room

came up out of Africa
and turned to the left.

You know, the ones that turned
to the right, there are some of those

in the Japanese translation.

But that happened very -- a long time ago

compared to

350 short years ago.

But in that 350 years,

the place has just undergone
a lot of changes.

In fact, everybody in this room probably,

especially if you picked up your bag --

some of you, I know, didn't
pick up your bags --

but if you picked up your bag,
everybody in this room

has got in their pocket,
or back in their room,

something

that 350 years ago,

kings would have gone to war to have.

I mean, if you can think how important --

If you have a GPS system
and there are no satellites,

it's not going to be much use.
But, like --

but, you know, if somebody
had a GPS system

in the 17th century

some king would have
gotten together an army

and gone to get it, you know.
If that person --

Audience: For the teddy bear?
The teddy bear?

Kary Mullis: They might have done
it for the teddy bear, yeah.

But -- all of us own stuff.

I mean, individuals own things

that kings would have
definitely gone to war to get.

And this is just 350 years.

Not a whole lot of people
doing this stuff.

You know, the important people --

you can almost read about their lives,

about all the really important
people that made advances, you know.

And, I mean --

this kind of stuff, you
know, all this stuff

came from that separation

of this little sort of thing that we do --

now I, when I was a boy

was born sort of with this idea

that if you want to know something --

you know, maybe it's because my old
man was gone a lot,

and my mother didn't
really know much science,

but I thought if you want
to know something about stuff,

you do it -- you make
an experiment, you know.

You get -- you get, like --

I just had a natural feeling for science

and setting up experiments. I thought
that was the way everybody had always thought.

I thought that anybody
with any brains will do it that way.

It isn't true. I mean,
there's a lot of people --

You know, I was one of those
scientists that was --

got into trouble the other night at dinner

because of the post-modernism thing.

And I didn't mean, you know
-- where is that lady?

Audience: Here.

(Laughter)

KM: I mean, I didn't really
think of that as an argument

so much as just a lively discussion.

I didn't take it personally, but --

I just -- I had -- I naively had thought,

until this surfing experience
started me into the 17th century,

I'd thought that's just
the way people thought,

and everybody did,
and they recognized reality

by what they could see
or touch or feel or hear.

At any rate, when I was a boy,

I, like, for instance, I had this --

I got this little book
from Fort Sill, Oklahoma --

This is about the time
that George Dyson's dad

was starting to blow nuclear --

thinking about blowing
up nuclear rockets and stuff.

I was thinking about making
my own little rockets.

And I knew that frogs -- little frogs --

had aspirations of space travel,

just like people. And I --

(Laughter)

I was looking for a --

a propulsion system

that would like, make a rocket, like,

maybe about four feet high
go up a couple of miles.

And, I mean, that was my sort of goal.

I wanted it to go out of sight and then
I wanted this little parachute

to come back with the frog in it.

And -- I -- I --

I got this book from Fort Sill, Oklahoma,

where there's a missile base.

They send it out for amateur rocketeers,

and

it said in there

do not ever heat a mixture
of potassium perchlorate and sugar.

(Laughter)

You know,

that's what you call a lead.

(Laughter)

You sort of -- now you say,
well, let's see if I can

get hold of some potassium chlorate
and sugar, perchlorate and sugar,

and heat it; it would be interesting to see
what it is they don't want me to do,

and what it is going to --
and how is it going to work.

And we didn't have --

like, my mother

presided over the back yard

from an upstairs window,

where she would be ironing
or something like that.

And she was usually just
sort of keeping an eye on,

and if there was any puffs
of smoke out there,

she'd lean out and admonish us all

not to blow our eyes out. That was her --

You know, that was kind of the worst
thing that could happen to us.

That's why I thought, as long
as I don't blow my eyes out...

I may not care about the fact

that it's prohibited
from heating this solution.

I'm going to do it
carefully, but I'll do it.

It's like anything else that's prohibited:

you do it behind the garage.

(Laughter)

So, I went to the drug store

and I tried to buy
some potassium perchlorate

and it wasn't unreasonable then for a kid

to walk into a drug store
and buy chemicals.

Nowadays, it's no ma'am,

check your shoes. And like --

(Laughter)

But then it wasn't -- they didn't
have any, but the guy had --

I said, what kind of salts
of potassium do you have? You know.

And he had potassium nitrate.

And I said, that might do
the same thing, whatever it is.

I'm sure it's got to do with rockets
or it wouldn't be in that manual.

And so I -- I did some experiments.

You know, I started
off with little tiny amounts

of potassium nitrate and sugar,

which was readily available,

and I mixed it in different proportions,

and I tried to light it on fire.

Just to see what would happen,
if you mixed it together.

And it -- they burned.

It burned kind of slow,
but it made a nice smell,

compared to other rocket
fuels I had tried,

that all had sulfur in them.

And, it smelt like burnt candy.

And then I tried the melting
business, and I melted it.

And then it melted into a little sort
of syrupy liquid, brown.

And then it cooled
down to a brick-hard substance,

that when you lit that,

it went off like a bat.

I mean, the little bowl of that stuff
that had cooled down --

you'd light it, and it would just
start dancing around the yard.

And I said, there

is a way to get a frog
up to where he wants to go.

(Laughter)

So I started developing --

you know, George's dad had a lot of help.
I just had my brother.

But I -- it took me
about -- it took me about,

I'd say, six months

to finally figure
out all the little things.

There's a lot of little things involved

in making a rocket that it
will actually work,

even after you have the fuel.

But you do it, by -- what I just--

you know, you do experiments,

and you write down things sometimes,

you make observations, you know.

And then you slowly build up a theory

of how this stuff works.

And it was --
I was following all the rules.

I didn't know what the rules were,

I'm a natural born scientist, I guess,

or some kind of a throwback
to the 17th century, whatever.

But at any rate, we finally did

have a device that would reproduceably

put a frog out of sight

and get him back alive.

And we had not --

I mean, we weren't frightened by it.

We should have been,
because it made a lot of smoke

and it made a lot of noise,

and it was powerful, you know.

And once in a while, they would blow up.

But I wasn't worried, by the way,

about, you know,

the explosion causing
the destruction of the planet.

I hadn't heard about the 10 ways

that we should be afraid of the --

By the way,

I could have thought,

I'd better not do this because

they say not to, you know.

And I'd better get permission
from the government.

If I'd have waited around for that,

I would have never -- the frog
would have died, you know.

At any rate, I bring it
up because it's a good story,

and he said, tell personal things,
you know, and that's a personal --

I was going to tell you about the first
night that I met my wife,

but that would be too
personal, wouldn't it.

So, so I've got something
else that's not personal.

But that... process
is what I think of as science,

see, where you start with some idea,

and then instead of, like, looking up,

every authority that you've ever heard of

I -- sometimes you do that,

if you're going to write a paper later,

you want to figure
out who else has worked on it.

But in the actual process,
you get an idea --

like, when I got the idea one night

that I could amplify DNA
with two oligonucleotides,

and I could make lots of copies
of some little piece of DNA,

you know, the thinking for that

was about 20 minutes
while I was driving my car,

and then instead of going -- I went
back and I did talk to people about it,

but if I'd listened to what I heard
from all my friends who were molecular biologists --

I would have abandoned it.

You know, if I had gone back
looking for an authority figure

who could tell me if it would work or not,

he would have said, no, it probably won't.

Because the results of it
were so spectacular

that if it worked it was going to change
everybody's goddamn way of doing molecular biology.

Nobody wants a chemist to come in

and poke around in their stuff
like that and change things.

But if you go to authority,
and you always don't --

you don't always get
the right answer, see.

But I knew, you'd go into the lab

and you'd try to make it work yourself.
And then you're the authority,

and you can say, I know it works,

because right there in that tube

is where it happened,

and here, on this gel,
there's a little band there

that I know that's DNA,
and that's the DNA I wanted to amplify,

so there! So it does work.

You know, that's how you do science.

And then you say, well,
what can make it work better?

And then you figure out better
and better ways to do it.

But you always work from, from like, facts

that you have made available to you

by doing experiments: things
that you could do on a stage.

And no tricky shit behind the thing.
I mean, it's all --

you've got to be very honest

with what you're doing if it
really is going to work.

I mean, you can't make up results,

and then do another experiment
based on that one.

So you have to be honest.

And I'm basically honest.

I have a fairly bad memory, and dishonesty
would always get me in trouble,

if I, like -- so I've just
sort of been naturally honest

and naturally inquisitive,

and that sort of leads
to that kind of science.

Now, let's see...

I've got another five minutes, right?

OK. All scientists aren't like that.

You know -- and there is a lot --

(Laughter)

There is a lot -- a lot
has been going on since

Isaac Newton and all that stuff happened.

One of the things that happened
right around World War II

in that same time period before,

and as sure as hell afterwards,

government got -- realized
that scientists aren't strange dudes

that, you know, hide in ivory towers

and do ridiculous things with test tube.

Scientists, you know, made World War II

as we know it quite possible.

They made faster things.

They made bigger guns
to shoot them down with.

You know, they made drugs
to give the pilots

if they were broken up in the process.

They made all kinds of --
and then finally one giant bomb

to end the whole thing, right?

And everybody stepped back
a little and said, you know,

we ought to invest in this shit,

because whoever has got
the most of these people

working in the places is going
to have a dominant position,

at least in the military, and probably
in all kind of economic ways.

And they got involved
in it, and the scientific

and industrial establishment was born,

and out of that came a lot of scientists

who were in there for the money, you know,

because it was suddenly available.

And they weren't the curious little boys

that liked to put frogs up in the air.

They were the same people that later
went in to medical school, you know,

because there was money in it, you know. I mean,
later, then they all got into business --

I mean, there are waves of --
going into your high school,

person saying, you want to be rich, you know,
be a scientist. You know, not anymore.

You want to be rich, you be a businessman.

But a lot of people got in it for the money
and the power and the travel.

That's back when travel was easy.

And those people don't think --

they don't --

they don't always tell
you the truth, you know.

There is nothing
in their contract, in fact,

that makes it to their advantage always,

to tell you the truth.

And the people I'm talking
about are people that like --

they say that they're
a member of the committee

called, say, the Inter-Governmental
Panel on Climate Change.

And they -- and they have these big
meetings where they try to figure out

how we're going to -- how we're
going to continually prove

that the planet is getting warmer,

when that's actually contrary
to most people's sensations.

I mean, if you actually measure

the temperature over a period --

I mean, the temperature
has been measured now

pretty carefully for about 50, 60 years --

longer than that it's been measured,

but in really nice, precise ways,

and records have been kept
for 50 or 60 years,

and in fact, the temperature
hadn't really gone up.

It's like, the average temperature

has gone up a tiny little bit,

because the nighttime temperatures

at the weather stations have
come up just a little bit.

But there's a good explanation for that.

And it's that the weather stations
are all built outside of town,

where the airport was, and now

the town's moved out there,
there's concrete all around

and they call it the skyline effect.

And most responsible people

that measure temperatures realize

you have to shield
your measuring device from that.

And even then, you know,

because the buildings get
warm in the daytime,

and they keep it a little warmer at night.

So the temperature has
been, sort of, inching up.

It should have been. But not a lot.
Not like, you know --

the first guy -- the first
guy that got the idea

that we're going to fry ourselves here,

actually, he didn't think of it that way.

His name was Sven Arrhenius.
He was Swedish, and he said,

if you double the CO2
level in the atmosphere,

which he thought might
-- this is in 1900 --

the temperature ought to go
up about 5.5 degrees, he calculated.

He was thinking of the earth
as, kind of like,

you know, like a completely
insulated thing

with no stuff in it, really,

just energy coming down, energy leaving.

And so he came up with this theory,

and he said, this will be cool,

because it'll be a longer
growing season in Sweden,

you know, and the surfers liked it,

the surfers thought, that's a cool idea,

because it's pretty cold
in the ocean sometimes, and --

but a lot of other people later on

started thinking it
would be bad, you know.

But nobody actually
demonstrated it, right?

I mean, the temperature as measured --

and you can find this
on our wonderful Internet,

you just go and look
for all NASAs records,

and all the Weather Bureau's records,

and you'll look at it yourself,
and you'll see, the temperature has just --

the nighttime temperature measured
on the surface of the planet

has gone up a tiny little bit.

So if you just average that and the daytime
temperature, it looks like it went up

about .7 degrees in this century.

But in fact, it was just coming up --

it was the nighttime; the daytime
temperatures didn't go up.

So -- and Arrhenius' theory --

and all the global warmers think --

they would say, yeah, it should
go up in the daytime, too,

if it's the greenhouse effect.

Now, people like things
that have, like, names like that,

that they can envision it, right?
I mean --

but people don't like things
like this, so -- most -- I mean,

you don't get all excited about things

like the actual evidence, you know,

which would be evidence for strengthening

of the tropical circulation in the 1990s.

It's a paper that came out in February,

and most of you probably
hadn't heard about it.

"Evidence for Large Decadal Variability

in the Tropical Mean
Radiative Energy Budget."

Excuse me. Those papers
were published by NASA,

and some scientists
at Columbia, and Viliki

and a whole bunch of people, Princeton.

And those two papers came
out in Science Magazine,

February the first,

and these -- the conclusion
in both of these papers,

and in also the Science editor's, like,

descriptions of these
papers, for, you know,

for the quickie,

is that our theories about global warming

are completely wrong. I mean,

what these guys were doing,

and this is what -- the NASA people
have been saying this for a long time.

They say, if you measure the temperature
of the atmosphere, it isn't going up --

it's not going up at all. We've doing
it very carefully now for 20 years,

from satellites, and it isn't going up.

And in this paper, they show
something much more striking,

and that was that they did
what they call a radiation --

and I'm not going to go into the details
of it, actually it's quite complicated,

but it isn't as complicated
as they might make you think it is

by the words they use in those papers.
If you really get down to it, they say,

the sun puts out a certain
amount of energy --

we know how much that is --

it falls on the earth, the earth
gives back a certain amount.

When it gets warm it generates --

it makes redder energy --
I mean, like infra-red,

like something that's warm
gives off infra-red.

The whole business
of the global warming --

trash, really,

is that -- if the -- if there's too
much CO2 in the atmosphere,

the heat that's trying to escape

won't be able to get out. But
the heat coming from the sun,

which is mostly down in the --
it's like 350 nanometers,

which is where it's centered --
that goes right through CO2.

So you still get heated,
but you don't dissipate any.

Well, these guys measured
all of those things.

I mean, you can talk about that stuff,

and you can write these large reports,
and you can get government money to do it,

but these -- they actually measured it,

and it turns
out that in the last 10 years --

that's why they say "decadal" there --

that the energy -- that the level

of what they call "imbalance"

has been way the hell
over what was expected.

Like, the amount of imbalance --

meaning, heat's coming
in and it's not going out

that you would get
from having double the CO2,

which we're not anywhere
near that, by the way.

But if we did, in 2025 or something,

have double the CO2 as we had in 1900,

they say it would be
increase the energy budget

by about -- in other words,

one watt per square centimeter more

would be coming in than going out.

So the planet should get warmer.

Well, they found out in this
study -- these two studies

by two different teams --

that five and a half watts

per square meter

had been coming in from 1998, 1999,

and the place didn't get warmer.

So the theory's kaput -- it's nothing.

These papers should have been called,

"The End to the Global
Warming Fiasco," you know.

They're concerned,

and you can tell they have very
guarded conclusions in these papers,

because they're talking
about big laboratories

that are funded by lots of money

and by scared people.

You know, if they said, you know what?

There isn't a problem
with global warming any longer,

so we can -- you know, they're funding.

And if you start a grant request
with something like that,

and say, global warming
obviously hadn't happened...

if they -- if they -- if they actually
-- if they actually said that,

I'm getting out.

(Laughter)

I'll stand up too, and --

(Laughter)

(Applause)

They have to say that.

They had to be very cautious.

But what I'm saying is,
you can be delighted,

because the editor
of Science, who is no dummy,

and both of these fairly professional --

really professional teams, have
really come to the same conclusion

and in the bottom lines in their papers

they have to say, what this means
is, that what we've been thinking,

was the global circulation
model that we predict

that the earth is going to get overheated

that it's all wrong.
It's wrong by a large factor.

It's not by a small one. They just --

they just misinterpreted
the fact that the earth --

there's obviously some mechanisms going on

that nobody knew about,

because the heat's coming
in and it isn't getting warmer.

So the planet is a pretty
amazing thing, you know,

it's big and horrible --
and big and wonderful,

and it does all kinds of things
we don't know anything about.

So I mean, the reason I put
those things all together,

OK, here's the way you're
supposed to do science --

some science is done for other
reasons, and just curiosity.

And there's a lot of things
like global warming,

and ozone hole and you know,

a whole bunch of scientific public issues,

that if you're interested in them,

then you have to get down the details,
and read the papers called,

"Large Decadal Variability in the..."

You have to figure
out what all those words mean.

And if you just listen to the guys

who are hyping those issues,
and making a lot of money out of it,

you'll be misinformed, and you'll be
worrying about the wrong things.

Remember the 10 things that are going
to get you. The -- one of them --

(Laughter)

And the asteroids is the one I really
agree with there.

I mean, you've got to watch out for asteroids.
OK, thank you for having me here.

(Applause)