The Second Millennium Evening at The White House 
March 6, 1998 

Information and Change - Science in the Next Millennium 
Featuring honored guest Stephen Hawking, the
Lucasian Professor of Mathematics at Cambridge
University, UK. Professor Hawking drew on his deep
understanding of the laws of science and their effect
on human life and led a discussion on how scientific
and technological advancements will shape and be
shaped by human knowledge. 
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             Science in the Next Millennium
               Remarks by Stephen Hawking

 My theme tonight is science in the new millennium. The
 popular picture of science in the future is shown on
 television every night in science fiction series like
 Star Trek. They even persuaded me to take part, not that
 it was difficult.
          	[Clip from Star Trek shown]
 Because of the red alert I never collected my winnings.
 I approached Paramount studios but they didn't know the
 exchange rate.

 The Star Trek appearance was great fun, but I show it to
 make a serious point. Nearly all the visions of the
 future that we have been shown from HG Wells onwards
 have been essentially static. They show a society that
 is in most cases far in advance of ours, in science, in
 technology, and in political organization. (The last
 might not be difficult). There must have been great
 changes with their accompanying tensions and upsets in
 the period between now and then. But by the time we are
 shown the future science, technology, and the
 organization of society, are supposed to have achieved a
 level of near perfection.

 I want to question this picture and ask if we will ever
 reach a final steady state of science and technology. At
 no time in the ten thousand years or so since the last
 Ice Age has the human race been in a state of constant
 knowledge and fixed technology. There have been a few
 set backs like the Dark Ages after the fall of the Roman
 Empire. But the world's population which is a measure of
 our technological ability to preserve life and feed
 ourselves has risen steadily, with a few hiccups like
 the Black Death. In the last two hundred years the
 growth has become exponential, that is, the population
 grows by the same percentage each year. Currently the
 rate is about 1.9% a year. 1.9 % may not sound very much
 but it means that the world population doubles every 40
 years. Other measures of technological development in
 recent times are electricity consumption, or the number
 of scientific articles. They also show exponential
 growth with a doubling time of 40 years or less. Indeed,
 we now have such heightened expectations that some
 people feel cheated by politicians and scientists
 because we have not already achieved the Utopian visions
 of the future. For example, the film Two Thousand and
 One' showed us with a base on the Moon and launching a
 manned, or should I say personned, flight to Jupiter. I
 can't see us managing that in the next three years,
 whoever wins the election.

 There is no sign that scientific and technological
 development will slow down and stop in the near future.
 Certainly not by the time of Star Trek which is only
 about 300 years away. But the present exponential growth
 can not continue for the next millennium. By the year
 2600 the world's population would be standing shoulder
 to shoulder and the electricity consumption would make
 the Earth glow red hot. If you stacked the new books
 being published next to each other you would have to
 move at 90 miles an hour just to keep up with the end of
 the line. Of course by 2600, new artistic and scientific
 work will come in electronic forms rather than as
 physical books and papers. Nevertheless, if the
 exponential growth continued, there would be ten papers
 a second in my kind of theoretical physics, and no time
 to read them.

 Clearly the present exponential growth can not continue
 indefinitely. So what will happen? One possibility is
 that we wipe ourselves out completely by some disaster
 such as a nuclear war. There is a sick joke that the
 reason we have not been contacted by extra-terrestrials
 is that when a civilization reaches our stage of
 development it becomes unstable and destroys itself. Of
 course it is possible that UFO's really do contain
 aliens, as many people believe, and the government is
 hushing it up. I couldn't possibly comment!

 Personally I believe there's a different explanation why
 we have not been contacted, but I won't go into it here.
 However even without that there is a very real danger
 that we will kill everything on this planet now that we
 have the technological power to do so. Even if we don't
 destroy ourselves completely there is the possibility
 that we might descend into a state of brutalism and
 barbarity like the opening scene of Terminator.

 But I'm an optimist. I think we have a good chance of
 avoiding both Armageddon and a new Dark Ages.

 So how will we develop in science and technology over
 the next millennium? This is very difficult to answer.
 But let me stick my neck out and offer my predictions
 for the future. I will have some chance of being right
 about the next hundred years, but the rest of the
 millennium will be wild speculation.

 Our modern understanding of science began about the same
 time as the European settlement of North America. In
 1687 Isaac Newton, the second Lucasian professor at
 Cambridge, published his theory of gravity and in 1864
 Clerk Maxwell, another Cambridge man, discovered the
 equations that govern electricity and magnetism. By the
 end of the 19th century it seemed that we were about to
 achieve a complete understanding of the universe in
 terms of what are now known as classical laws. These
 correspond to what might seem the common sense notion
 that physical quantities such as position, speed, and
 rate of rotation, should be both well defined and
 continuously variable. But common sense is just another
 name for the prejudices that we have been brought up
 with. Common sense might lead us to expect quantities
 like energy to be continuous. But from the beginning of
 the 20th century observations began to show that energy
 came in discrete packets called quanta. It seems that
 Nature is grainy not smooth.

 A new kind of theory called quantum mechanics was
 formulated in the early years of the 20th century.
 Quantum theory is a completely different picture of
 reality so it should concern us all but it is hardly
 known outside physics and chemistry and not even
 properly understood by many in those fields. Yet if, as
 I hope basic science becomes part of general awareness
 what now appear as the paradoxes of quantum theory will
 seem as just common sense to our children's' children.

 In quantum theory things don't have a single unique
 history as our present day common sense would suggest.
 Instead they have every possible history each with its
 own probability. There must have been a history in which
 the Chicago Cubs won the World Series, though maybe the
 probability was low. However for large scale systems
 like base ball games the probability is normally peaked
 around a single history so there is very little
 uncertainty. But when one goes to the small lengths
 scales of individual particles the uncertainty can
 become very large. For example, if one knows that a
 particle is at a point A at a certain time then at a
 later time it can be anywhere because it can have any
 path or history. To calculate the probability that it is
 at a point B one has to add up the probabilities for all
 the paths or histories that take it from A to B. This
 idea of a sum over all possible histories is due to the
 American physicist and one time bongo drum player
 Richard Feynman.

 The possible particle histories have to include paths
 that travel faster than light and even paths that go
 back in time. Before anyone rushes out to patent a time
 machine let me say that in normal circumstances at
 least, one can not use this for time travel. However
 paths that go back in time are not just like angels
 dancing on a pin. They have real observational
 consequences. Even what we think of as empty space is
 full of particles moving in closed loops in space and
 time. That is they move forward in time on one side of
 the loop and backwards in time on the other side. These
 closed loops are said to be virtual particles because
 they can not be measured directly with a particle
 detector. However their effects can be measured
 indirectly. One way is to have a pair of metal plates
 close together. The effect of the plates is to reduce
 slightly the number of closed loops in the region
 between the plates relative to the number outside. There
 are thus more closed loops hitting the outside edges of
 the plates and bouncing off than there are hitting the
 inside edges. One would therefore expect there to be a
 small force pushing the plates together. This force,
 which was first predicted by the Turkish physicist
 Hendrick Casimir, has been observed experimentally. So
 we can be confident that closed particle loops really
 exist.

 The awkward thing is that because there's an infinite
 number of points in space and time there are an infinite
 number of possible closed loops of particles. This
 infinite number of loops didn't matter in the
 calculation of the force between two plates because the
 numbers between the plates and outside them are both
 infinite. There is a well defined way in which one can
 subtract one infinity from the other and get a finite
 answer. It is a bit like the American budget. Both the
 government tax revenue, and its expenditure, are very
 large sums, almost infinite. Yet if one is careful one
 can subtract one from another and get a small surplus,
 at least until the next election.

 Where the infinite number of closed loops caused trouble
 was when people tried to combine quantum theory with
 Einstein's General Theory of Relativity. This is the
 other great scientific revolution of the first half of
 the 20th century. It says that space and time are not
 flat like common sense once told us that the Earth was
 flat. Instead, they are warped and distorted by the
 matter and energy in them. An infinite number of closed
 loops of particles would have an infinite amount of
 energy and would curl space and time up to a single
 point.

 To deal with this infinite energy requires some really
 creative accounting. The key concept was a new kind of
 balance or symmetry in nature called super symmetry,
 which was first proposed by two Russians, Golfand and
 Likhtman, in 1971. The idea was that as well as the
 ordinary dimensions of space and time with which we are
 familiar, there were extra dimensions that were measured
 in what are called Grassmann numbers. Of course, science
 fiction has been telling us for years that there are
 extra dimensions. But even science fiction did not think
 of anything as odd as Grassmann dimensions. Here the
 word "odd" has a technical use as well as the usual
 meaning of peculiar. Ordinary numbers are said to be
 even because it doesn't matter in what order one
 multiplies them. 6 times 4 is the same as 4 times 6. But
 Grassmann numbers are odd in the sense that x times y,
 is minus y times x.

 The existence of these extra odd dimensions implies that
 every species of particle must have a super partner
 species. The super partner species will also have closed
 loops of particles. But the energy of the super partner
 loops will have the opposite sign to those of the
 original species. Thus the infinite energies tend to
 cancel out. But as the President knows, balancing the
 budget is a very delicate business. Even if one removes
 the main deficit smaller deficits have a nasty habit of
 appearing. Much of the work in theoretical physics in
 the last twenty years has been looking for a theory in
 which the infinities cancel completely. Only then will
 we be able to unify Quantum Theory with Einstein's
 General Relativity and achieve a complete theory of the
 basic laws of the universe.

 What are the prospects that we will discover this
 complete theory in the next millennium. I would say they
 were very good but then I'm an optimist. In 1980 I said
 I thought there was a 50-50 chance that we would
 discover a complete unified theory in the next twenty
 years. We have made some remarkable progress in the
 period since then but the final theory seems about the
 same distance away. Will the Holy Grail of physics be
 always just beyond our reach? I think not. At the
 beginning of the 20th century we understood the workings
 of nature on the scales of classical physics which is
 good down to about a hundredth of a millimeter. The work
 on atomic physics in the first thirty years of the
 century took our understanding down to lengths of a
 millionth of a millimeter. Since then, research on
 nuclear and high energy physics has taken us to length
 scales that are smaller by a further factor of a
 billion. It might seem that we could go on forever
 discovering structures on smaller and smaller length
 scales. However there is a limit to this series as there
 is to the series of Russian dolls within Russian dolls.
 Eventually one gets down to a smallest doll, which can't
 be taken apart any more. In physics the smallest doll is
 called the Planck length and is a millimeter divided by
 a hundred thousand billion billion billion. We are not
 about to build particle accelerators that can probe to
 distances that small. They would have to be larger than
 the solar system and they are not likely to be approved
 in the present financial climate. However, there are
 consequences of our theories that can be tested by much
 more modest machines. By far the most important of these
 is super symmetry which is fundamental to most attempts
 to unify Einstein's General Relativity with Quantum
 Theory. This would be confirmed by the discovery of
 super partners to the particles that we already know.
 The Superconducting Super Collider (the SSC) was being
 built in Texas and would have reached the energies at
 which super partners were expected. However, the United
 States went through a fit of feeling poor and canceled
 the project half way. At the risk of causing
 embarrassment, I have to say I think this was a very
 short sighted decision. hope that the US, and other
 governments will do better in the next millennium.

 I expect super symmetry will be confirmed eventually by
 experiments at CERN in Geneva. But it won't be possible
 to probe down to the Planck length in the laboratory. We
 can study the Big Bang to get observational evidence at
 higher energies and shorter length scales than we can
 achieve on Earth. However, to a large extent we shall
 have to rely on mathematical beauty and consistency to
 find the ultimate Theory of Everything. Nevertheless I
 am confident we will discover it by the end of the 21st
 century and probably much sooner. I would take a bet at
 50-50 odds that it will be within twenty years starting
 now.

 The Star Trek vision of the future that we achieve an
 advanced but essentially static level may come true in
 respect of our knowledge of the basic laws that govern
 the universe. But I don't think we will ever reach a
 steady state in the uses we make of these laws. The
 ultimate theory will place no limit on the complexity of
 systems that we can produce and it is in this complexity
 that I think the most important developments of the next
 millennium will be.

 By far the most complex systems that we have are our own
 bodies. Life seems to have originated in the primordial
 oceans that covered the Earth four billion years ago.
 How this happened we don't know. It may be that random
 collisions between atoms built up macro-molecules that
 could reproduce themselves and assemble themselves into
 more complicated structures. What we do know is that by
 three and a half billion years ago the highly
 complicated molecule DNA had emerged. DNA is the basis
 for all life on Earth. It has a double helix structure,
 like a spiral staircase, which was discovered by Francis
 Crick and James Watson in the Cavendish lab at Cambridge
 in 1953. The two strands of the double helix are linked
 by pairs of nucleic acids like the treads in a spiral
 staircase. There are four kinds of nucleic acids. I
 won't try to pronounce their names because my speech
 synthesizer makes a mess of them. Obviously it was not
 designed for molecular biologists. But I can refer to
 them by their initials, C, G, A, and T. The order in
 which the different nucleic acids occur along the spiral
 staircase carries the genetic information that enables
 the DNA molecule to assemble an organism around it and
 reproduce itself. As the DNA made copies of itself there
 would have been occasional errors in the order of the
 nucleic acids along the spiral. In most cases the
 mistakes in copying would have made the DNA unable to
 reproduce itself. Such genetic errors, or mutations as
 they are called, would die out. But in a few cases the
 error or mutation would increase the chances of the DNA
 surviving and reproducing. This natural selection of
 mutations was first proposed by another Cambridge man,
 Charles Darwin, in 1857, though he didn't know the
 mechanism for it. Thus the information content in the
 sequence of nucleic acids would gradually evolve and
 increase in complexity.

 Because biological evolution is basically a random walk
 in the space of all genetic possibilities it has been
 very slow. The complexity, or number of bits of
 information that are coded in DNA is given roughly by
 the number of nucleic acids in the molecule. Each bit of
 information can be thought of as the answer to a yes no
 question. For the first two billion years or so the rate
 of increase in complexity must have been of the order of
 one bit of information every hundred years. The rate of
 increase of DNA complexity gradually rose to about one
 bit a year over the last few million years. But now we
 are at the beginning of a new era in which we will be
 able to increase the complexity of our DNA without
 having to wait for the slow process of biological
 evolution. There has been no significant change in human
 DNA in the last ten thousand years. But it is likely
 that we will be able to completely redesign it in the
 next thousand. Of course many people will say that
 genetic engineering on humans should be banned. But I
 rather doubt if they will be able to prevent it. Genetic
 engineering on plants and animals will be allowed for
 economic reasons and someone is bound to try it on
 humans. Unless we have a totalitarian world order,
 someone will design improved humans somewhere.

 Clearly developing improved humans will create great
 social and political problems with respect to unimproved
 humans. I'm not advocating human genetic engineering as
 a good thing, I'm just saying that it is likely to
 happen in the next millennium, whether we want it or
 not. This is why I don't believe science fiction like
 Star Trek where people are essentially the same four
 hundred years in the future. I think the human race, and
 its DNA, will increase its complexity quite rapidly.

 In a way the human race needs to improve its mental and
 physical qualities if it is to deal with the
 increasingly complex world around it and meet new
 challenges like space travel. And it also needs to
 increase its complexity if biological systems are to
 keep ahead of electronic ones. At the moment computers
 have an advantage of speed, but they show no sign of
 intelligence. This is not surprising because our present
 computers are less complex than the brain of an
 earthworm, a species not noted for their intellectual
 powers. But computers obey Moore's Law put forward by
 Gordon Moore of Intel. This says that their speed and
 complexity double every 18 months. It is one of these
 exponential growths which clearly can not continue
 indefinitely. However it will probably continue until
 computers have a similar complexity to the human brain.
 Some people say that computers can never show true
 intelligence whatever that may be. But it seems to me
 that if very complicated chemical molecules can operate
 in humans to make them intelligent then equally
 complicated electronic circuits can also make computers
 act in an intelligent way. And if they are intelligent
 they can presumably design computers that have even
 greater complexity and intelligence.

 This is why I don't believe the science fiction picture
 of an advanced but constant future. Instead, I expect
 complexity to increase at a rapid rate, both in the
 biological and electronic spheres. Not much of this will
 happen in the next hundred years, which is all we can
 reliably predict. But by the end of the next millennium,
 if we get there, the change will be fundamental.

 Lincoln Steffens once said, "I have seen the future and
 it works." He was actually talking about the Soviet
 Union, which we now know didn't work very well.
 Nevertheless, I think the present world order has a
 future, but it will be very different.

 Mr President, First Lady, This is my view of science in
 the next millennium.
 ---------------------------------------------------------

                     THE WHITE HOUSE
              Office of the Press Secretary
 -------------------------------------------------------------------
    For Immediate Release                           March 6, 1998
                 REMARKS BY THE PRESIDENT
               AT MILLENNIUM LECTURE SERIES
                      The East Room
     8:17 P.M. EST

     THE PRESIDENT: Thank you very much. And Dr. Hawking, you'll have
     to forgive me, I'm a little hoarse. I hope for some genetic
     improvement sometime in the next year or so. (Laughter.)

     Ladies and gentlemen, this was a stunning event for me and I hope
     for all of you. Yesterday, Stephen and Elaine came by the White
     House to see Hillary and me and, as you can imagine, like Hillary,
     I had reread A Brief History of Time and I was utterly terrified
     -- (laughter) -- that he would say something like, you know, I
     went to University College Oxford, too, and then he would ask me
     some incredible comparative academic question about our
     experiences there. Instead, he said, was the food just as bad when
     you were there -- (laughter) -- which was a wonderful relief.
     (Laughter.)

     Albert Einstein once said, because politics is for the present,
     but an equation is something for eternity, equations were more
     important than politics. I don't know about the politics part, but
     Professor Hawking's insights into equations have altered our
     notions of time and the very nature of eternity itself. Tonight
     he's given us a lot to think about, even the ability to imagine a
     future in which we as humans will have finally captured the Holy
     Grail of Physics, reconciling the infinitesimal with the infinite;
     presenting the world with the Ultimate Theory of Everything. Now,
     when a physicist does that, he can totally ignore politics and buy
     a newspaper. (Laughter.)

     The one thing I liked most about thinking about the future in
     Professor Hawking's term is that even when we reach the era of
     Star Trek, which will make a lot of our children very happy, it
     won't be so static. It will still be human and dynamic. And
     according to the visuals accompanying the lecture, it will still
     matter whether you can bluff at poker, which is encouraging.
     (Laughter.)

     I want to get on with the questions now. And again, I want to
     thank Professor Hawking for the extraordinary clarity and vigor of
     his presentation and for sharing his time with us tonight, and for
     placing this particular moment in the larger spectrum of time --
     which I think if we all could do more and more clearly every day,
     we would live happier, more productive lives. Thank you,
     Professor.

     Ellen, would you like to take over and bring in the questions?
     (Applause.)

     MS. LOVELL: Thank you, Mr. President. I would like to begin our
     question and comments session. Because of the way Professor
     Hawking communicates and the time it takes him to select words
     from his screen to assemble his responses, we did give him a few
     questions in advance. I just learned that we're getting two
     e-mails a minute from all over the world and have over 300. The
     students who are here tonight and in the Indian Treaty Room were
     chosen on the basis of the questions they wrote to Professor
     Hawking.
     But for the first live question, I turn to Dr. Vera Rubin,
     astrophysicist, in the Department of Terrestrial Magnetism at
     Carnegie Institute.

     DR. RUBIN: Thank you, Professor Hawking, for this most stimulating
     and entertaining talk. Our knowledge of the universe comes both
     from observations and from theoretical studies. I wonder if you
     would be willing to stick your neck out once again and tell us
     what you think will be the most exciting discovery in connection
     with cosmology in the next 100 years.

     MS. LOVELL: And while Professor Hawking is responding, I want to
     turn to Dr. Silvester Gates, past president of the American
     Association of Black Physicists, to expand on a point Professor
     Hawking made.
     Dr. Gates, for the average listener, like me, how do "super
     partner species" and "closed loops" of particles cancel each other
     out? Advanced physics in two minutes. (Laughter.)

     DR. GATES: Well, first of all, as we all know, we can't walk
     through walls. It's a very obvious property. You don't have to
     teach any student a physics course to know that. In the idea of
     super symmetry, where we think that there's another part to the
     universe that we haven't seen, there may be objects for which this
     isn't true. There may be things, the super partners -- and we
     don't know how much they are, how many there are, or how they
     behave -- but if they are there, they will lead to new forms of
     energy and matter and the possibilities are beyond our imagination
     at this point. Thank you.

     MS. LOVELL: I think I got it. (Laughter.) We got an intriguing
     question from a University of Maryland student, Daniel Manilow
     (phonetic), which I would like to direct to Dr. William Phillips,
     1997 Nobel Laureate in Physics.
     Dr. Phillips, why does the universe obey any laws at all?
     (Laughter.)

     DR. PHILLIPS: Well, that's a really good question, and I really
     wish I had a really good answer for it. (Laughter.) It's the kind
     of question that has intrigued and vexed scientists and, I
     suppose, philosophers and theologians for a long time. It's really
     quite remarkable.

     All of the wonderful things Professor Hawking talked about can
     actually be described in a very small number of relatively simple
     equations and then a lot of complicated mathematics. Why is it
     that the universe is so simple? Why is it that it follows
     mathematical laws? Well, people have speculated about this, and
     one possible answer is that if the universe had been any different
     from what it is, we wouldn't be here. That is, if the laws of the
     universe hadn't been what they are or if there were no laws at
     all, it would have been impossible for life to have evolved. It
     would have been impossible for us to have evolved to the point
     that we could ask that question. So that's sometimes called the
     "enthropic principle." Not perhaps to put too much emphasis on
     people, but it probably applies to amoebas as well, that they
     wouldn't have been able to evolve either.

     On the other hand, there is another answer, which isn't actually
     that far from that answer, and if you're a person with religious
     faith, as I am, you could answer that the reason we have a
     universe that follows laws is because God decided to make the
     universe in that way because God wanted us to develop the way we
     have and to evolve in the way that we have; and that this is, of
     course, a philosophical and theological answer and it has more to
     do with one's faith than one's scientific conclusions, but it's an
     answer that I like very much and that I don't find very different
     from the first one.

     MS. LOVELL: Thank you. Professor Hawking raised the question of
     redesigning our DNA. Dr. Francis Collins, head of the Human Genome
     Project at the National Institutes of Health, is here.
     Dr. Collins, what would be the implications of genetic engineering
     of the human race?

     DR. COLLINS: Well, I appreciate the question and certainly
     Professor Hawking's presentation was very thought-provoking in
     this regard -- having physicists speculate about biology is
     welcome, indeed. (Laughter.) No, I mean that. I mean that.

     Certainly, the proposal about the widespread application of
     genetic engineering to human beings raises a couple of points.
     This kind of knowledge is, in itself, neither good, nor evil --
     it's knowledge. It's the use to which we put it that determines
     sort of the moral character of it. To what extent are these
     improvements in human beings moral or immoral is a question that
     we, as society, will have to wrestle with. If, in fact, the goal
     is to wipe out a dread disease, then I think that's entirely
     consistent with our moral obligations as human beings to try to
     alleviate suffering. And if that could be done without inducing
     other harms, then I suspect many of us would celebrate it.

     If, on the other hand, it is to achieve improvements, you quickly
     begin to wonder who defines what an improvement is, and does that,
     in fact, allow one group of people to decide that their
     characteristics are more improved than others and, therefore, more
     in need of being transferred to various recipients. And that puts
     one into a bit of an ethical dilemma.

     Furthermore, I think, as the President has recently said, science
     should not be a line that allows us further to discriminate
     between the haves and the have-nots. And one would worry very much
     about a technology which allowed this kind of improvement only to
     be available to certain people.

     Finally -- and I echo what the preceding speaker said -- this does
     get us into an area where you begin to wonder about our view of
     ourselves, especially our view of ourselves as it relates to God.
     If we are to transform our species in this wholesale way, what do
     we end up with?

     So there's plenty of things to think about there. I actually,
     along with Winston Churchill, have a great deal of confidence in
     our ability as a species to make sure that our technologies are
     our servants and not our masters. But it will take a great deal of
     public involvement to make sure that that is the outcome.

     MS. LOVELL: Thank you very much. We're ready for Dr. Hawking's
     reply to Dr. Rubin.

     PROFESSOR HAWKING: The most exciting discovery will probably be
     something we don't expect -- that is, such surprising discoveries
     that have led to the great revolutions in the past.

     MS. LOVELL: Mrs. Clinton, we have a question from the Internet.

     MRS. CLINTON: This is a question from Candra, in Washington: Do
     you ever lose your place while solving mathematical equations in
     your head? And, if so, how do you handle that? (Laughter.)

     DR. HAWKING: It is difficult to handle complicated equations in my
     head. I, therefore, avoid problems with a lot of equations or
     translate them into problems in geometry. I can then picture them
     in my mind.

     MRS. CLINTON: This question is from Larry in Denver: How does it
     feel to be compared to Einstein and Newton? (Laughter.)

     DR. HAWKING: I think to compare me to Newton and Einstein is media
     hype. (Laughter.)

     MRS. CLINTON: I must say, you did look good at the card table.

     DR. HAWKING: I fit the popular stereotype of a mad scientist or a
     disabled genius or, should I say, a physically challenged genius,
     to be politically correct. (Laughter.) I am clearly physically
     challenged, but I don't feel I am a genius like Newton and
     Einstein.

     MS. LOVELL: Mrs. Clinton, there is a special message for you, the
     President, and Professor Hawking.

     MRS. CLINTON: And is that message on the Internet?

     MS. LOVELL: You're going to see it on the screen behind you. It
     comes from very far away.

     MRS. CLINTON: Oh, this is a special message, Professor Hawking,
     from your friends in outer space.

     ASTRONAUT THOMAS: Good evening, Mr. President, Mrs. President and
     Professor Hawking. I'm the NASA astronaut presently orbiting the
     Earth on the space station Mir. I want to thank you for the
     opportunity to join you briefly tonight as I explore the universe
     up here on the space station -- the universe that Professor
     Hawking has so clearly elucidated to us in his writings. I'm
     delighted that students are able to participate in this event. It
     gives us a way of honoring the past and imagining the future, and
     encouraging students to believe in -- I think is the future for us.

     Thank you all for your participation and good evening. (Applause.)

     MS. LOVELL: Well, I have to bring us back to Earth. (Laughter.)
     Sakhile Moyo, from the University of the District of Columbia, I
     know you have a question.

     MS. MOYO: Hi. My question to Professor Hawking is: If you believe
     that the galaxies around the universe will collapse once again, do
     you predict this as being another Big Bang?

     PROFESSOR HAWKING: We don't yet know how much matter there is in
     the universe. The observations at present suggest that there isn't
     enough matter to stop the expansion of the universe, and so it
     will continue to expand forever. But if there is extra dark matter
     that we haven't detected, the universe could collapse again to a
     Big Crunch. However, the Big Crunch would be the end of the
     universe and of time itself. There doesn't seem to be any way one
     can continue through the Big Crunch to a new Big Bang. But don't
     worry, the Big Crunch won't come for at least 20 billion years.
     That will last my time and even that of the President, who is a
     bit younger than me. (Laughter.)

     MS. LOVELL: Dr. Andrea Dupree, I'm going to put you on the spot
     for a short comment on the lecture.

     DR. DUPREE: Thank you. Well, during this marvelously eclectic and
     imaginative lecture, I couldn't help but think about the
     enormously rapid pace of our understanding and our development in
     things that we couldn't even anticipate. I know when I started out
     in training as an astrophysicist, I never thought that I would be
     able to use the Hubbell space telescope to actually look at the
     surface of a star, a star where the light is coming to us when
     Christopher Columbus arrived in our country. These are just
     wonderful things that we've been able to do.
     And I really draw from much of this that we really have to prepare
     for the unexpected. And that's what basic research is all about;
     that we are looking for things and we're not always sure what
     we're going to find other than a magnificent, better understanding
     of where we are and who we are and where we are going. And I'm
     sure if we keep up the momentum that we've heard about tonight
     that the next millennium will be magnificent and will have
     wonderful scientific rewards.

     MS. LOVELL: Another optimist. (Laughter.) Thank you.

     Mrs. Clinton, the last question comes from the Internet.

     MRS. CLINTON: Oh, this question is from Al in New Hampshire.
     (Laughter and applause.) That is, for our British guests, Al Gore,
     who is never without his computer and, therefore, can log on
     anywhere, and was very sorry that previous obligations kept him
     from being here. So here is the Vice President's question:
     Within the past month, we have seen evidence suggesting a strong,
     repulsive force in the universe -- an anti-gravitational force
     causing the universe to expand, surprisingly, at an accelerating
     rate. How surprised were you by this finding? What are it's most
     important implications? And how could your national cosmology
     supercomputer help to prove or disprove these implications?

     DR. HAWKING: What the Vice President is referring to is some
     observational evidence that suggests that there may be an
     anti-gravitational force that would cause the universe to expand
     at an increasing rate. The existence of such an anti-gravitational
     force is very controversial. Einstein first suggested it might
     exist, but later regretted it and said it was his greatest
     mistake. If it is there at all, it must be very small. It is
     difficult to understand why it should be so small, unless it were
     exactly zero.

     We probably won't know if there's a small anti-gravitational force
     until observations come in from new satellites that the U.S. and
     Europe will put up in the first years of the millennium. But the
     data analysis of this satellite observations will require a
     supercomputer like the national cosmology computer we have in
     Cambridge. If it turns out that there really is an
     anti-gravitational force, it will mean that inflation is a law of
     nature. (Laughter and applause.)

     THE PRESIDENT: Dr. Hawking, my position is we have repealed that
     law. (Laughter.)

     Let me say, first of all, in defense of my Vice President, you
     will all understand that he would love to be here, but there is a
     peculiar gravitational force in New Hampshire that manifests
     itself with a remarkable regularity. (Laughter.) Let me also say
     that in the visual presentation accompanying Dr. Hawking's
     lecture, there was that remarkable project stamped "canceled" on
     it. This administration opposed the cancelation of it, I'm proud
     to say. (Laughter.) But we hope that the Swiss project will take
     up the slack.
     There's so many questions I know you would all like to ask. We
     have hundreds of questions coming in, and one of the questions I
     wish there were time to explore is, if we do, in fact, acquire a
     general understanding that time and space are more
     multidimensional than we have imagined, and computers become ever
     more sophisticated, even if people will never be able to travel at
     the speed of light, will we be able to communicate some day in
     some ways that destroy our common notions of time?

     I've thought about it a lot and I'm not smart enough to know what
     the answer is, but I'd love to -- that's one of the reasons I
     enjoyed re-reading the book.
     Let me also say one other thing to close -- since our Nobel
     Laureate talked about his faith about how the world began -- the
     First Lady started tonight by talking about the marvels of
     technology which enable this astonishing man to communicate with
     us. And it is true that he is here and we did this because of the
     marvels of technology. It is also true, in my mind, that he is a
     genuine living miracle because of the power of the heart and the
     spirit. And we can only hope that all the advances that he has
     foreseen for us tonight in human knowledge will serve to amplify
     the heart and the spirit that we have humbly witnessed this
     evening.
     Thank you and God bless you all. (Applause.)
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