Nanotechnology and the Next 50
Years
R. E. Smalley Presentation When most people first hear the term 'nanotechnology',
they most readily think of the term 'microtechnology': the technology
of microelectronics that has so transformed society in the past two
decades. And that is really
the appropriate analogy. Microtechnology is the technology that allows
you to fabricate objects on the micron scale. (Fig. 1)
A micron is a millionth of a meter. You know what a
meter is - it's about the distance from the tip of your nose to the
end of your hand when you stretch your arm out. You take a little one
thousandth of that and you can still see it - it's a millimeter. Image
now that you take one side of this little millimeter and touch it to
your nose and stretch out the other side to the end of your arm. Now
take one thousandth of that. So that's a thousandth of a thousandth
(which is a millionth) of a meter, also called a "micron". That is the
length scale that is relevant to building devices such as computers,
memories, and logic devices -- the wonderful electronics that to a
remarkable degree has its true roots here near Dallas, Texas.
Back in 1985 the computer and memory devices that were
sold had sizes for the structures being made that were about one
micron across, as shown in this slide.
Now in 1995, the current state of the art in the most
recent Pentium computer chip, for example, is about a third of that,
350 nanometers, or a third of a micron. It's expected with pretty
solid lines of reasoning that a decade from now the size of these
microelectronic objects is going to shrink to less than one-tenth of
what it was in 1985: a tenth of a micron,
which is 100 nanometers. (Fig. 2)
A nanometer is what you get if you take a micron and
stick one end of it to your nose and stretch the other end to the
length of your arm and take a thousandth of that. That is now a
thousandth of a millionth of a meter (a billionth of a meter). It's
called a "nanometer".
This nanometer is about as far down in size as it is
sensible to go, because from one side of the nanometer to the other
there are only about three to five atoms. Although there are smaller
things in the universe than atoms, these are not the sort of things
you can put in a bottle or play with out in the open. For us, and the
things around us in ordinary life, atoms are the ultimate building
blocks.
Now when we think in terms of atoms and look at the
picture in this slide, we realize that even though this structure is
only a millionth of a meter across, it still very big. It must have
thousands of atoms across the top of it, and millions -- actually
billions -- of atoms on the inside. It is still a piece of the bulk
world. But inside that bulk, that one micron object, there is a
possibility of a thousand-fold higher level of detail.
If you could get down to that nanometer level, and craft the object
with atomic precision, the power of your ability to control the
behavior of this object would become immense.
The greatest example of that power at present is in
every living thing. It requires water to be around - the elixir of
life - and I like to call it the "wet side of nanotechnology". All
life forms are built up of water-filled cells, little bags of life
that are typically several microns across - like the human white blood
cell shown in this next slide.
Every one of these cells (Fig. 3) is chock full of
thousands of little machines that move around in the wet, water world
of the cell doing the business of life -- enzymes, hormones, RNA, and
DNA -- all these things you hear about in news stories covering
medicine, biotechnology and genetic engineering. These little machines
are molecules. They range in size from
about one to several tens of nanometers across - they are
nanomachines! They are built of thousands to hundred of thousands of
atoms. But each and every one of these thousands of atoms is in a
precisely engineered place, arranged "just so" in order to make the
overall molecular nanomachine function perfectly.
To me the most stunning examples are provided by the
enzymes, each of which is a whole chemical factory on a nanometer
scale. These enzymes have been evolved over billions of years to make
their chemical product about as well as could possibly be done. In
most cases the enzymes have reached the limit of perfection. They are
the ultimate catalyst for the specific chemical reaction that is their
little "job in life". Such molecular nanomachines are what enable life
to work, not only in ourselves, but in every plant and bird, in
everything you ever thought about that ever crawled on the surface of
the earth.
This wet nanotechnology is incredibly powerful. In fact,
the more you get to know about it, the more you are drawn in absolute
awe. You think of how beautiful your daughter is, or a flower, or how
incredible a human eye is that it can see, or a brain that can think.
And then you think, this wet side of nanotechnology (what most people
call biotechnology) can do
anything.
But in spite of this awesome power, there are many
things that cannot be done and will never be done on the wet side. One
of the most important is conducting electricity, like a metal wire, or
like the connections in a computer or even the semiconductors when
they are doing their semiconducting. You will never get that (for
reasons I cannot go into tonight) out of this biotechnology. In fact,
most of the industrial revolution that led to our modern society is
not a tribute to biotechnology. It's a tribute to the development of
steam engines, and gasoline-powered motors, and all manner of
electrical devices, including radios, telephones, TV's and
computers -- all of which are technologies from the other side, the
dry side. And increasingly I believe this is going to be an area of
great development.
Imagine what our world would be like if we really could
construct on the dry side, without water and living cells, objects
with the degree of atomic perfection that life achieves routinely on
the wet side. Imagine for a moment the power of what I like to call
the "dry side" of nanotechnology. The list of things you could do with
such a technology reads like much of
the Christmas Wish List of our civilization.
I've listed a few of them here.
The answer to many of our most pressing problems, to the
extent these answers are possible in this universe, will some way or
another be found in the dry world on this nanometer length scale.
(Fig. 4) This is the driving force behind the development of this
area.
In many ways this is the logical extension of chemistry,
because chemistry is about putting atoms in particular places and then
making a molecular object that is stable so that it can go out in the
real world and do good things. Now chemistry has always dealt with
objects on an almost nanometer scale. But the technologies on this
list are in a sense, CHEMISTRY in big,
bold type: an atomically precise technology that lets you build
elaborate structures on a scale of 1 to 100 nanometers. Structures
that can go out do things that are really important - like storing
information, switching electrical signals, converting sunlight to
electricity, transporting electricity in super-strong cables for
thousands of miles without loss, and
converting this electricity into stored chemical energy and back again
in the batteries and fuel cells of the 21st century, and on and on and
on.
I am not going to get into the details of these new
nanotechnologies tonight. Instead, I thought I would talk a bit about
the driving force behind their development: the growing problems that
will inevitably confront human civilization on this planet over the
next 50 years. Problems for which the development of nanotechnology -
particularly on the dry side - seems likely to provide the only
realistic solutions.
To put it simply, I believe it is clear that we have a
little job for nanotechnology. (Fig 5) Except that this job isn't
little. It's so big that it will occupy us for many coming decades. he
job begins to be evident when we look at the following chart - the
world population growth over the past
2000 years. (Fig. 6)
This chart is a plot -- not a artist conception -- but
an actual plot of data to the extent it is known, of human population
on the surface of this planet for the last 2000 years. At the left we
start at year 0 with the birth of Jesus Christ, but of course there
was a time before then. In fact, the plot wouldn't look dramatically
different if we started even five
thousand years before Christ. We are all used to hearing that the
world population is going up dramatically, but one of the most
remarkable facts evident from this plot is that the world population
was stable for so long.
At the time of Christ it is estimated that the
population of the planet was about a third of a billion people, three
hundred million. It had been about that level since well before the
time of Moses. It was that up through the times when Eastern part of
the Roman empire was founded in Constantinople,
and when Mohammed started the Islamic faith, and the population held
about that same level through the time of the battle of Hastings in
1066 -- still about three hundred million people on the planet.
The reason that the world population maintained this
stable level was that we were living with an agrarian economy. We
didn't have high technology. With an agrarian economy based on muscle
power, there is only a certain amount of arable land on the planet,
and just a certain number of people that you could feed, and without
modern medicines there was a certain level of disease and a resulting
rather low average life expectancy. The result was a balance between
births and deaths that leveled out at a population of 300 million - a
balance that was stable for thousands of years.
But, sometime, about four to five hundred years ago,
modern civilization started really taking off with the invention of
the printing press beginning the wide dissemination of knowledge
throughout Europe, as well as the invention of physical science and
the scientific method starting around the time of Galileo. Things
started really taking off, as you know, during the industrial
revolution primarily in England, with James Watt and the perfection of
the steam engine. As a direct result of these new technologies the
population rose rapidly. By the time the of the second world war, we
were at about two and half billion people on the planet.
Amazingly, the population has now more than doubled just
since the second world war. So, more than half this problem has
happened during the living memories of either ourselves or of people
in our families that are still alive.
You look at this chart and say, "Well, where is the
evidence of the Four Horsemen of the Apocalypse? Wasn't that suppose
to control the population?" In a sense that and the agrarian economy
were what was controlling the population for so many thousands of
years. But you notice that, in spite of the Four Horsemen, this world
population curve basically only goes up. You might even call it
remorseless.
For example, look in this population data for the
effects of the worst epidemic that you can ever remember in history.
How about the Black Death in Europe? As a population control, that was
a good one. It was worth about a third of all Europeans over a fifty
year time period. The actual data during that time was not very well
kept, but you can see from the data
before and afterward, which is pretty firm, that it didn't really
matter. If there was a net dip in the population of the planet, it was
healed almost immediately. The Black Death wasn't enough to affect
this problem long term.
How about war? That's suppose to be pretty good, isn't
it? The second world war was a pretty good one if you care about
limiting population. That was worth about fifty million people. There
isn't a dip there on the population plot either. In fact, if you
really look at the data, there's actually a slight acceleration
afterward: the baby boom. Its being going up, and up, and up
remorselessly.
The biggest driver, actually, has been the development
of modern medicine. Something you would think -- and certainly is -- a
wonderful advance. People were dying of terrible debilitating
diseases, many who never got a chance to live out their first year.
And we fixed a lot of that awful
problem. A lot of this happened because of the armies that the allies
put around the world during the second world war: huge armies in
Africa and Asia. When we pulled those armies out, we left behind the
medical technology of keeping millions of people healthy. And that,
more than anything, had caused this population boom: the medicine of
our current high level of civilization.
Now we are at nearly six billion people on this planet.
I don't know if this is true but I've been told that two billion of
these people don't have access to electricity right now. Somewhere
between three and four billion live so far below anything we in this
audience would consider to be the poverty line, that we would be
appalled. Their chance of living what we
would consider a fulfilling life is extraordinary small.
If all the population in North American, Europe, Eastern
Europe, and Japan somehow disappeared, still we would have a
tremendous population problem on the planet. Something is going to
have to happen to change what has never happened before in the history
of all civilization. This curve, this remorseless rise in population
is going to have to stop.
There are therefore two crucial questions: "How is it
going to stop?", and "How are we going to take care of the people who
are going to be around when it does stop?"
So what's the future going to hold? Amazingly, I find
many people believe the black curve in the next slide, the Armageddon
Scenario, (Fig. 7) is the most likely future for the world.
This Malthusian scenario is a projection that says that
sometime (and, in fact, if you look at the chart, its seems pretty
likely that it will be within the next 50 years) a nuclear weapon
exchange, or a new virus, or something else will cause this population
problem to solve itself. I encourage you to talk with your friends and
find out what they believe. My experience is that over half the people
I talk to actually think this will
happen.
I don't think it will. I think that the scenario I've
marked on this slide in green is more likely. As shown in more detail
on this next slide, this green scenario is the best estimate of the
United Nations of what population trends will be for next couple
hundred years. This is a hopeful scenario, but I believe it is
realistic.
Here we see that in 1995 we are already about at the
inflection point, and we are going to stabilize. This is about as
optimistic as you can get for the next fifty years because we know
what the demographics is of women currently in the population pool.
They are going to have a certain number
of children. We are not going to stop at six billion, virtually
inevitable we will go to at least ten. (Fig. 8)
And the question now is: "Can we sustain this? Can we
have this planet with ten billion plus people on it, and have a stable
world civilization, and give everybody -- every one of these ten
billion people -- a reasonable lifestyle? "
It's not obvious that we can. In fact, it is becoming
fairly clear that we cannot - not with the current technology base.
If you kept with the current technology, you might say:
"Well look, we have a lot of coal, oil, and gas, and we can burn that.
We've got a lot of ground we can irrigate. We can probably handle ten
billion people and things won't change. Is there any evidence that the
planet is being challenged by the population that we have already?"
Well, it turns out that the scientific evidence
concluding that the planet is already being challenged is really
getting to be quite solid. I will give you a quick synopsis.
The first lesson to be learned from the scientific
evidence is that life actually has long had control over this planet.
The atmosphere that we have around us was built by life
and is controlled by life. (Fig. 9) When the planet was first born, we
did not have any oxygen in the environment. It was mostly nitrogen and
carbon dioxide. Life, at least elementary life, was formed very
rapidly in the beginning within about a half a billion years of the
formation of the planet. And early on, about one billion years,
photosynthesis was developed and started generating oxygen. It took
about one and half billion years to precipitate out all the iron out
of the ocean until the oxygen the atmosphere started going up. Then it
finally leveled out, not because photosynthesis got tired, but because
animals started to be developed and they breathed oxygen. And for
roughly a billion years the atmosphere has been controlled by life, by
the balance between plants and animals.
It is a striking thing to realize. You wouldn't think
life could be that important. But it has long since controlled the
planet's atmosphere. And it's been doing a fine job of it.
Just recently, though, we have a life form that has
started to tip the balance. You might have already heard reports about
this, but one thing that is very striking is to see what the real
scientific data looks like, and where it comes from. We actually have
a great record of what the atmosphere has been on this planet for the
past 150,000 years. It comes from boring into the ice caps in
Greenland and Antarctica. Because the farther down into the ice caps
one drills, the older the ice is.
It turns out when you go down to get a little ice cube,
from say five hundred feet down in these ancient ice caps, and you
take it out and you put it in a place where you pump the air out and
melt the ice, bubbles come out. This air was trapped between the
snowflakes that fell and was compacted to form the ice thousands of
years ago. (Fig. 10) Very careful analysis has been done to make sure
that this air hasn't changed its
composition in the intervening time, and we are quite sure this is
safe data. So we can look now at what the atmosphere actually was like
on the planet as deep as these ice caps will let us go - a little over
150,000 years (which incidentally is about to the age of the human
genome). So we have knowledge of what the atmosphere has been during
basically the entire human experience of this planet.
Here's all the data. (Fig. 11) And plotted on the top is
carbon dioxide and, lower down the chart in green is methane gas
(natural gas) over these time periods. The concentration of these
gases have gone up and down because we have had two ice ages over this
period. We're just coming out of
the last ice age, about 10,000 years ago. In fact, human civilization
started with the end of this last ice age.
Therefore we know what the carbon dioxide level has been
for this time period. During the hottest period for the previous
interglacial, which is about 110,000 years ago, the peak on the
right-hand side, the highest level that CO2 ever had been during the
last 110,000 years was 300 parts per million, about 0.03%. Well, you
may be able to see it as I have drawn in a
nearly vertical yellow line on the left-hand side, corresponding to
the last 200 years. The current CO2 level concentration is about 370
parts per million, and almost all of that rise has happened since the
industrial revolution.
Methane, which turns out to be an important greenhouse
gas as well, comes primarily from the decay of organic matter under
water. For example, when you make rice in flooded fields, you produce
a tremendous amount of methane from those fields. Making food makes
methane, which gets into the atmosphere and actually warms the planet,
sort of like a blanket around the
earth. The highest methane has ever been in the last 150,000 years was
700 parts per million, but now it is 1,700, almost 2½ times what it
was, and all of that increase is a result of modern civilization.
This rapid change in the composition of the atmosphere
has happened over the last 200 years-it is more rapid a change than at
any time during the last 150,000 years of the planet. Here is the
carbon dioxide data since about 800 up unto the present time. (Fig.
12) Basically, it's a level line and had been level for a thousand
years, and then it starts turning up
about 1800 and then it's been going up ever since. There is no
question why that line is going up. It's because of the technology of
the industrial revolution where we started burning coal and wood in
vast amounts, and people started multiplying and producing more and
more.
This is more of the data showing you that methane
started coming up at the same time. (Fig. 13) There is no question
from where the methane is coming. It's not just human beings, it's
civilization, modern civilization that is causing the change in the
planet.
Many people argue that maybe the planet can adjust and
absorb this. Well, evidently it can't keep the CO2 level where it was,
because we're actually pouring even more into the environment than we
were back in the early 1800's and it was already starting up then. The
planet is unable to control at the levels of the pollutants that we
are putting into the atmosphere
right now. Of course, ultimately if you give it enough time, it will
adjust to a new steady state, but for carbon dioxide in particular,
it's expected it would take over 200 years for the planet to finally
reach some equilibrium.
In this next slide (Fig. 14) you can see in the data
collected more recently from the top of Mauna Loa in Hawaii, looking
at carbon dioxide in the atmosphere, and also from Barrow in Alaska,
Samoa, and the South Pole, and now you see yearly oscillations of
carbon dioxide going up and down because of the growth and die-back of
vegetation in the Northern Hemisphere, where most of the land mass is
on this planet. The magnitude of
oscillation obviously depends on where you are on the planet, but
there's no question that the overall level of CO2 is going up.
Now up to a few years ago some scientists were peering
at the last part of the curve, where it looks that maybe it started to
level off and slow down. But just recently there had been a very
careful measurement and analysis in an article in Nature magazine,
(Fig. 15) the bottom line of which is no, the dip was just a little
fluctuation and now the slope is back up. Nothing is stopping this.
It's going up and up and we have hardly begun to burn the carbon that
we are going to burn, as China, for example, continues to develop.
So there's no mystery, no argument that carbon dioxide
and methane are going up. There's no argument that it's coming from
civilization. We don't know how to stop it. The question is "is it
starting to do anything yet to the climate?"
There is also an important molecule called N20, nitrous
oxide, which actually is a colorless molecule, it's very innocuous,
except it's a greenhouse gas that floats up into the stratosphere,
breaks apart and starts destroying the ozone. This is the N20
production over the past 100 years or so. (Fig. 16) There's no
question where that is coming from. It mimics the production of
fertilizer in the world.
Fertilizer, you ask, "What could be bad about
fertilizer?" Well, nothing is particularly bad about it except that it
helps to grow plants that when they decay anaerobically put more of
this gas into the atmosphere that the planet is not readily able to
control. (Fig. 17) Ultimately, of course, there will be some new
leveling off. One wonders what the planet will be like then.
Are these new gases warming the planet now? Well, there
is also no question amongst anyone who looks at this that there has
been a warming of the planet in the past 100 years or so since data
has been collected-both in the Northern and Southern hemisphere the
average surface temperature of the planet has gone up about 0.6 of a
degree centigrade over this time period. (Fig. 18)
Recently, it has been getting warmer faster and the
issue is why.
This is the temperature deviation from an baseline
around the 1950's of the yearly average surface temperature of the
earth. This is now very carefully collected data from all over the
planet. And you can see that the last decade has been abnormally warm.
(Fig. 19) Those of you that are close enough to see it, will notice
that back in 1990 we had at that time what
was an unprecedentedly warm year. That was about the time that global
warming became an issue in the worldwide press. It was quite heavily
hyped: there were pictures of New York City being halfway under water.
Then there was enough discussion going on with sensible people that
showed that, well, this extra greenhouse gas warming isn't really so
clear, these hot years
may be just a fluctuation. And just about that time, Mount Pinatubo
went off in the Philippines and threw a lot of dust up in the
stratosphere, changed the average albedo of the earth and we actually
started cooling down a little bit. And those two reasons are why we
haven't heard very much about this in the press since then.
But by the beginning of 1994, last year, the dust from
Mount Pinatubo had settled out of the atmosphere and the warming
resumed. And 1994 was the third hottest year in history. We're
currently almost done with 1995. If we took the numbers we have at
this moment, 1995 would be the hottest year in history. So whether
this is a fluctuation, or this is the beginning of the
signature of global warming caused by civilization's increase in CO2
and other green house gases in the atmosphere, that's the issue.
Now there is an international organization that looks at
this, the Intergovernmental Panel on Climate Change, a very
substantial organization of thousands of scientists around the world,
involving the science and technology agencies of essentially every
government in the United Nations. Their report is coming out now in
about two weeks. It will say for the first time that the signature of
global warming is now evident in the
record and we are beginning to see the effects. The effects are still
small, but they are there.
The next question is what happens in the future-what can
we predict. The trouble is we probably cannot predict very well in
advance because the earth is, as we say in technical circles, not a
linear system. It's not just that our average temperature is going to
go up by a degree or so (centigrade) every two decades. It's a
nonlinear, complex system. I don't want take the time to tell you what
these mathematical terms mean, except to say that the earth's climate
a sort of system that if you perturb it past a certain point, it will
say "Okay, now I'm going to do something completely different."
Remember the "butterfly effect" so memorably discussed
in the movie Jurasic Park? Instead of a butterfly in China changing
the weather in Texas, we're concerned here about passing a threshold
in the amount of greenhouse gases in the atmosphere changing the
climate of the world.
If you want to talk to me later, I can tell you about a
few of the things that we're specially worried about that can change
the climates of particular regions of the planet because, for example,
ocean currents suddenly stop going where they used to go. We're also
worried about changes that happen so rapidly that local ecologies
cannot adapt to it. Forests, for example, will gradually move forward
to accommodate to climate change, but what happens if the temperature
changes so quickly that the forests don't have 1,000 years they need
to start marching off in the right direction?
So the indication is that human-induced climate change
has already begun. This conclusion still may be wrong. The effects are
small. Maybe it hasn't begun yet. But the "street talk" is that
probably it has already.
Well, what are we going to do about it? We have 6
billion people on this planet. Over two-thirds of these, roughly 4
billion people, live in undeveloped countries. And they are not going
to go away unless there is some completely unprecedented holocaust,
and we certainly don't want that. As the information age spreads
within this undeveloped world, perceptions of vast imbalances in
well-being will become vastly destabilizing.
These billions of people are all going to have to be
brought up to a reasonable lifestyle in fact they're going to insist
on it. We in the highly developed part of the world can talk to each
other about riding our bicycles to work and using solar power. But
you're not going to tell the billions of people living in undeveloped
countries to keep riding bicycles, avoid the cheap, dirty power of our
current oil and coal technology and
still live in misery. They're going to burn all the oil and coal they
can. It's predicted within the next 10 years that the CO2 production
in China alone will become larger than all we're currently putting out
over the planet right now.
We're going to have to have at least the increase in the
energy production depicted in this slide (Fig. 20) by going from the
little black dot on the left to the big black dot on the right for the
estimated energy usage by the middle of the next century. And actually
that's very pessimistic. That still assumes that a huge imbalance
persists between the developed and
underdeveloped world. It really ought to be about 5 to 10 times that
amount to bring what will become about 10 billion people up to a
reasonable lifestyle.
Currently 95% of all energy produced in the world is
made one way or another by burning carbon, carbon dioxide in the
atmosphere. If it is true that we're starting to see this signature of
climate change already, we've got to stop this. We cannot go to the
big black dot with carbon burning. If it's not true, we'll be very
lucky. If you wonder or hope that it's not
true, just remember we're playing a giant experiment with this planet
and its a very complex, nonlinear system for which we cannot predict
it's outcome. Once it becomes clear that it's starting to have an
effect, we aren't going to be able to suddenly fix it, because the
length of time it takes for carbon dioxide to equilibrate with the
oceans is estimated to be
100-200 years.
It is as though you're asleep and it's very hot in your
dream, you're sweating. It's just insufferable. But then you wake up,
and it is insufferable, and you are sweating, you're not in a dream,
it really is hot. So you take your arm and try to throw the blanket
off. Except there isn't a blanket, or in a sense there is-the
atmosphere of the planet is the blanket- and it will take about 100
years to change that blanket. So there
is a reason to worry about this now, even before the warming becomes
insufferable.
And the question is, "What do we do about it?"
One answer is okay we'll all tax ourselves every time we
burn a pound of carbon we'll pay some number of dollars into a giant
fund and then start trying to help this problem go away in the third
world. It's never going to work, the amount of money involved is too
great, and the incentives are too diffuse. In fact I think there is
only one answer. We have to find a way of making that big black dot on
the right hand side of this picture out of clean energy that is so
cheap that there is no longer any incentive to burn coal, gas, or oil.
There's really only two ways to do that right now. One
is nuclear fission. We can hope for nuclear fusion, but this data
actually comes off the WWW from Princeton Plasma Physics Laboratory,
which is dedicated to doing energy production by nuclear fusion, and
their most optimistic scenario does not have them taking a very big
hunk of that big dot with nuclear fusion by 50 years from now. It may
be that in a 100 years they can do it, but not 50.
No, if the answer over these next 20-50 years is
nuclear, it highly unlikely to be fusion. It will have to be fission.
Now maybe in the U.S., Europe and Japan, we can assure ourselves that
we can produce most of our power by nuclear fission safely, with no
Chernobyl's, no Three Mile Islands. I think that's quite possible. And
maybe we can find ways of
sequestering the waste which will be radioactive for ten's of
thousand's of years, and we'll promise you -- even though our
civilization is only 200 years old -- we promise you: "okay trust us -
we're going to take care of it for 20,000 years". But, that will take
care of no more than about a quarter of the big black dot. The other
three quarters of the world is going to have stop producing carbon
dioxide as well. How about all of the 185 countries in the United
Nations being nuclear?
In fact there is a question as to whether you could do
it: do the whole black dot with nuclear fission of uranium. Is there
enough uranium 235 to do it? Probably not. Most likely the big black
dot would have to come from breeder reactors. Imagine the world in
2050, with a 100 nations running breeder reactors. It doesn't sound
like a very stable world.
What is the alternative? Wind power? There isn't enough
wind on the earth to take care of very much of that big black dot.
There's really only one other alternative: solar. But
right now the fraction in the world for energy production that is
solar is laughably small-less than 1%. And although we have solar
technologies we could roll out right now that could take maybe 10% of
the black dot, we haven't got a clue how to do the whole black dot.
That's got to come from somewhere new -
a brand new technology.
Could it happen? Could we provide for all the world's
energy needs with solar power? The answer is clearly, Yes! It turns
out on a square of West Texas, 100 miles on a side, there is enough
light coming down that if you can collect that and turn it into
transportable energy at 10% efficiency, you could take care of our
current little black dot, just 100 x 100 =
10,000 square miles of Texas ( or maybe only 90,000 square miles of
Arizona). So there's plenty of light coming down. Striking the earth
every year there is over 10,000 times more solar energy than required
to provide for the worlds expected energy needs in 2050, the big black
dot.
So, in principal, you could do it with solar energy, but
we don't know how to do it yet. We don't have any technology now that
if we just apply it within a ten year time horizon it can begin to be
affect the problems we have been talking about. But on the other hand,
we can really imagine that
there could be technologies that would do it. And when you think about
what those would be, it turns out you could take nearly each and every
photon, every little corpuscle of light that hits the earth even on a
cloudy day wherever you put these solar collectors, and change it
efficiently into some form of stored energy.
In this super-efficient, low light level, solar energy
converter of the future, down 'where the rubber meets the road', where
that photon turns into stored energy, that's going to occur on a
length scale less than the wavelength of the sunlight (about 400 to
1000 nanometers), and it's going to have to store the energy somehow:
chemically, or as an electron going up into some sort of capacitor, or
something like that. All this,
intrinsically, is going to have to occur on the nanometer scale. It
will be a nanotechnology. And we need it desperately.
So it turns out that with such a solar nanotechnology
you could create a solar power industry which could actually start
solving some of these global environmental problems-it does have the
muscles to address this energy issue worldwide.
I use to think that we have 100's of years to solve this
problem. But for the reasons I've discussed - this explosive growth in
the world population, and the vast poverty of billions of people --I'm
not so sure we have 100's of years. Maybe this problem becomes
critical within only a couple of decades. World energy production is
such a huge enterprise: tens to hundreds of trillions of dollars of
installed plants around the world. You
aren't going to change that just by saying I've got some great new
technology, shut your plants down, we'll just build this wonderful new
nanotech solar industry to replace them. It's going to take at least
20 years to roll that out and we don't have the technology to do it
yet. So I think we've got to get busy.
Incidentally, I'm going to put this in since this is a
Texas audience. A special thing has happened in Texas just recently.
This is a plot from the strategic plan for energy for the state of
Texas. (Fig. 21) There are a number of curves. One is this red line,
the consumption of energy in the state of Texas has been going up
linearly for some time. Actually Texas is the biggest consumer of
energy in the country-40% more energy consumed in Texas than in the
state of California for example And the green line is the production
of energy in the state of Texas. And just recently the green line went
under the red line, so Texas is now a net energy importing state. Very
few people in the state of Texas believe the green line is going to
start heading back up. And almost no one in the state of Texas wants
the red line to come around and head down.
The projection is that by the year 2005, ten years from
now, every year $10 billion will leave the state of Texas and will go
somewhere else to buy energy to cover the state. This strategic plan
is rather interesting because it shows that, if you believe what's in
it -- and I'm not sure that I do, that Texas turns out to be very rich
in renewable resources, solar
and wind, and we could actually pretty well track this dotted green
line with renewable resources. Of course that would make a tremendous
impact on the finances in the state of Texas.
To me the issue is not so much that we need to find a
way to make Texas rich, and economically powerful while beggaring our
neighbors, or to make the USA economically better off than the rest of
the world. It seems to me, the real issue is the rest of the world,
the four billion people who live in the undeveloped nations. We can't
afford to beggar them because in the end it will be a tremendously
unstable planet both politically and environmentally. We're going to
have to solve the problem with high technology. I think we can.
If you get into discussions like this with people,
depending upon their political persuasion, they'll say "You darn
technologists! You got us into this problem. Why don't you just stop,
and leave us alone?" In fact back in the 60's it was popular among
some in my age group to think the answer was for everyone to go back
to the farm, live a nice simple life and everything would be okay
again. But remember that curve, the population of the planet prior to
the industrial revolution. Somewhere between 0.3 and 1 billion is the
number you can support on this planet with an agrarian economy. Now
for those people, maybe it was a good life, though I'm not at all
convinced it
was all that good. But to sustain this level with a low-tech, agrarian
way of life, you will have to go to the other 5+ billion people on the
planet and say something like: "Excuse me, I hate to tell you this,
but you're just awfully inconvenient; wouldn't you please go away? The
rest of us want to live happily on the farm, and there just isn't room
for you." (Fig. 22)
On the other hand, I agree with many who point out that
the full answer cannot be just technology. In the long run, the world
population problem can only be solved by a change in world culture,
and probably the most important single factor will be the improved
status and self-image of women. Not so much in this case in the
developed countries where the fertility rates are generally already
acceptable, but in the third world where the majority of the
population growth has occurred since the second world war. I
understand that there are still areas in rural China, for example,
where women don't even have given names. A woman is only known by her
husband's name. It is still true for most of the 3 billion women on
this planet that they live in a culture where their lives have worth
only through their ability to raise children. So the women's
liberation movement
in general, and in the third world in particular, will be of vital
importance in solving the population problem.
Even given that, even if we stop population growth
somewhere between 6 and 10 billion people, we can't sustain even the
current population with the current technology. So for the 50 years,
there's really only one good alternative: we need more technology, not
less. It has to be green, it has to be clean, and it has to be closed
loop. And I am confident that in almost every area the keys to these
technologies are going to come when we
start learning how to put things together one atom at a time on the
nanometer scale.
We've got to learn how to build machines, materials, and
devices with the ultimate finesse that life has always used: atom by
atom, on the same nanometer scale as the machinery in living cells.
But now we've got to learn how to extend this now to the dry world. We
need to develop nanotechnology both on the wet and dry sides. We need
it urgently to get through these next 50 years. It will be a
challenge. But, I am confident we will succeed.
University of Dallas - Board of Councilors
December 7, 1995