In East Africa, in the records of the rocks dating back
to about a million years ago, you can find a sequence
of worked tools that our ancestors designed and executed.
Their lives depended on making and using these tools well.
This was, of course, Stone Age technology. Stones were
used for all sorts of activities—chipping, flaking,
cutting, carving. Although there are many ways of making
stone tools, what is remarkable is that in a given site
for enormous periods of time the tools are prepared in
the same way—which means that there must have been
educational institutions hundreds of thousands of years
ago. There must have been professors and students, examinations
and failing grades, laboratory courses, graduating ceremonies
and post-graduate education.
The education that you are receiving is part of a long
and distinguished human tradition. There is a reason for
it. Our ability to learn from experience and to incorporate
what previous generations have uncovered for themselves
is the secret of our success as a species. Unaided, we
are not stronger, or faster, or better camouflaged, or
better swimmers or flyers than other animals. The only
things we are better at are thinking and building. For
that reason we have a long childhood in which many facts
and attitudes are learned, different from generation to
generation. We continue our education into adulthood and,
indeed, for all our lives. That sequence of learning experiences
has produced the most remarkable transformation of ourselves
and our planet. If you drive through Manhattan, there
are vistas in which nothing of the natural landscape is
left, nothing that our ancestors of a hundred thousand
years ago would recognize as familiar—except the
people. We're dressed and coiffed differently, some of
us are clean-shaven, but we ourselves would be entirely
recognizable to our forebears. However, we have changed
the environment profoundly.
Our enormous powers have, as everybody recognizes, not
always been used for human benefit. In the four years
since you have entered Yale College, more than a thousand
strategic nuclear warheads have been deployed in ballistic
missiles by the United States and the Soviet Union. These,
in turn, were responses to other warheads introduced in
previous years. Many of these warheads have yields of
one or two megatons. A megaton is the equivalent of a
million tons of TNT going off all at once. If you add
up the yields of all the bombs dropped by all the combatants
in the Second World War, you find that it comes to two
million tons of TNT, the yield of one modern nuclear weapon.
A thousand World War II's have been stockpiled and targeted
while you have been here at Yale College. That is something
that distinguishes this class from other classes. You
are not responsible for it, but you will have an opportunity
to do something about it.
In the same four years, 20 new worlds have been examined
close-up for the first time by the human species by means
of two remarkable spacecraft called Voyager 1 and Voyager
2. They have flown by the planet Jupiter, discovered its
ring system, and examined its remarkably diverse array
of moons. Then they were accelerated by the gravity of
that massive planet to approach Saturn where they examined
that planet and its elegant system of rings and moons.
Voyager 2 will then continue on and in five years (if
it survives that long) will examine the planet Uranus.
Both spacecraft will eventually find themselves expelled
from the solar system as the human species' third and
fourth interstellar spacecraft.
Until this four-year period, 1977-1981, Jupiter, its rings
and its moons, and Saturn, its rings and its moons, could
be seen indistinctly at best. No surface details on these
moons were detectable at all from the Earth. But now we
have a vast library—approaching 100,000 detailed
photographs of these worlds, and their diversity is astonishing.
There is a world with an underground ocean of liquid sulfur.
There is one that looks like a sphere of cracked crystal.
There is a moon with an atmosphere denser than that of
the Earth, and an unbroken cloud layer made of organic
molecules. There are worlds made of ice. There are ring
systems of billions of individual orbiting snowballs.
There are many worlds we have never seen before. Only
one generation in the history of the human species is
privileged to live during the time those great discoveries
are first made; that generation is ours.
It is remarkable that these two sets of events use very
much the same physics, that of Isaac Newton, which is
equally good at propelling devastating warheads to Moscow
and to Washington, and at sending vehicles engaged in
the peaceful and benign exploration of the solar system
to Jupiter and Saturn.
We have instruments of mythic power at our command. The
question clearly is: Are we wise enough to use them properly?
Science and technology are ancient tools, the distinction
of our species. They are also a kind of seed-corn. They
are the means for our future survival. They provide solutions
to many problems, some of which we are not yet wise enough
even to identify. Eating the seed-corn can get you through
one more winter. But the following winter you are in desperate
trouble.
At the same time that these and hundreds of other remarkable
scientific accomplishments have been happening, there
have been some interesting pushes and pulls: conflicting
trends in opposite directions. One trend is illustrated
by the recent request by the Reagan administration in
the United States to cut essentially to zero all of the
budget of the National Science Foundation devoted to science
education, particularly in keeping science teachers up-to-date.
That is clearly eating the seed-corn. The budgetary savings
are trivial, the potential damage enormous.
In many areas of science the great accomplishments are
made by young people, people in their twenties and early
thirties. I think it likely that a number of science graduates
in this class will make such significant contributions.
But because this tends to happen at early ages the generation
time for scientific progress is short. Abandoning scientific
education for a decade turns out to be something not easily
repaired. It can produce an enormous gap in our scientific
expertise, one extremely difficult to remedy later on,
when we come to our senses.
Any attempt to back away from understanding the world,
any attempt to obscure what science is about is dangerous.
One of the reasons that there is unease about science
in certain quarters is because it challenges the prevailing
wisdom. It sometimes is counterintuitive. It requires
a certain intellectual effort. It occasionally leads us
along a road that jars our predispositions.
We can understand the world because there has been a match
made by natural selection between how our brains work
and how the world works. For example, how is it that the
laws of falling bodies are so simple? Why is the distance
that an object falls proportional to the square of the
time? Why is the velocity linearly proportional to the
time? Why such a simple relationship? Why not the Chebyshev
polynomial of the time? Why not a full spherical harmonic
expansion of the time? Why just proportional to the time?
Let us imagine some of our ancestors of five or ten million
years ago brachiating from branch to branch. Those who
had to compute the Chebyshev polynomials of the trajectory
never made it to the next branch; they left few descendants.
The guys who could figure it out left descendants. We
come from them. We spring from the creatures who could
figure it out. And that figuring out is what we must continue
to do.
In Newtonian physics, in relativity, in quantum mechanics,
there are many results which seem counterintuitive, which
we are not prepared for. Even the idea that an object
in motion tends to stay in motion does not conform in
a ready way to everyday experience because there is so
much friction and atmospheric resistance down here on
Earth. The prediction of special relativity that time
slows down as you go close to the speed of light does
not correspond to everyday experience. That's because
we are not in the habit of traveling close to the speed
of light. The prediction from quantum mechanics that a
particle can ooze through a barrier and find itself on
the other side of a wall without having made a hole, sounds
absurd. But, in fact, natural radioactivity depends exactly
on that process. The idea in evolutionary biology that
creatures change slowly from one species to another is
not in perfect conformity with everyday experience because
it is rare that we find a creature that has transmogrified
before our eyes into another species: we have not stuck
around long enough.
In many such areas, but especially in the last, you can
find today a kind of resurgent know-nothingism, a reactionary
response to the findings of human beings objectively addressing
the world around them. There is something called "scientific
creationism" which claims that the school system
should teach the supposed evidence in favor of the cosmology
in the first chapter of Genesis on an equal level with
the evolutionary findings that Charles Darwin initiated.
I believe that this is exceptionally dangerous.
Let me give just one example of how the argument goes.
By adding up all the begets in the Book of Genesis you
can get the age of the Earth. It turns out to be about
six thousand years old—A begat B, B begat C, C begat
D. A's lifetime is stated, B's, C's and so on. Then you
get up to historical times. Add it all up: 4004 B.C. according
to Archbishop Usher. Now, if that is the case, then an
interesting question arises. How is it that there are
astronomical objects more than 6000 light-years away?
It takes light a year to travel a light-year, so if we
see an object that is a million light-years away or two
million light-years away, we are seeing it as it was one
or two million years ago in the past. If the entire universe
is only 6,000 years old, what must we deduce from this?
I think the only possible conclusion is that 6,000 years
ago God made all the photons of light coming to the Earth
in a coherent format so as to deceive astronomers into
thinking there are such things as galaxies, that the universe
is vast and old.
Since most of the matter and energy in the universe is
in external galaxies farther away than a million light-years,
God must have created most of the matter and energy in
the universe to deceive human beings. That is such a malevolent
theology as well as such an arrogant pretension that I
cannot believe anyone, no matter how devoted to the literal
interpretation of this or that religious book, could seriously
consider it.
Nevertheless, this sort of doctrine is being urged upon
us. Already there are trends essentially to prevent the
teaching of Darwinian evolution in schools. Since evolution
is one of the major insights in the biological sciences,
this restriction can only be understood as a serious and
major attack on the teaching of science itself.
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