About this Program  |  HyperForum  |  Transcript  |  Watch the Show  | Show Feedback

SHOW 213 TRANSCRIPT
Will This Universe Ever End?

WILL this universe ever end? If so, how? There are two basic theories, neither pleasant. One is that the Big Crunch is coming: at some point, the universe, which had been expanding, will begin contracting, rushing inward, so that all matter and energy will eventually squash together into a singularity, where mass has no volume and space and time stop. The other is known as the Heat Death (i.e., heat dies): the universe, with its continued expansion, flies more and more apart, so that all matter and energy will dissipate and all will become the ultimate cold void. But startling new challenges throw it all up for grabs. A key question is the amount of matter in the universe. Are there enough stars, planets, gas, dark matter, and exotic particles of one sort or another for gravity to reverse the current expansion and in the end implode the universe in the Big Crunch? Another key question is whether or not the expansion is accelerating--and if so, how much and why? And if this universe does end, might another take its place? Are other universes already in existence, perhaps an infinite number of them, furiously expanding? There's a lot loaded into our titular question--from the geometry of the universe to the existence of multiple universes. There aren't many people who get paid to ponder the end of all things. Fortunately, we have gathered some of the best.

************************************

PARTICIPANTS

Dr. Wendy Freedman, an astronomer at the Carnegie Observatories, provides key data to determine the age of the universe. Wendy explains why the amount of matter in the universe is important in determining its ultimate fate.

Dr. Leon Lederman, author of The God Particle, was awarded the Nobel Prize in physics in 1988 for his work on the Standard Model of particle physics. Leon's insight and humor illuminate and leaven these ultimate questions.

Dr. Andrei Linde, a professor of physics at Stanford, invented the concept of chaotic inflation, which has redefined the beginning of the universe. Andrei believes that there may well be myriad universes, each giving birth to new universes, and that this birthing process will go on forever.

Dr. Nancey Murphy is a professor at Fuller Theological Seminary; her book Theology in the Age of Scientific Reasoning won several awards. Nancey wonders that if this universe ends--by freezing or frying--what is God going to do for the rest of eternity? 

Dr. Frank Tipler, a physicist and mathematician at Tulane, is the author of The Physics of Immortality, in which he speculates that the dead will be resurrected and live eternally (time being a subjective concept) just before the Big Crunch.

*******************

ROBERT: Leon, what are the kinds of questions about the end of the universe that you want high school students to think about?

LEON: I'm a not a cosmologist. I'm the token noncosmologist.

ROBERT: We need diversity.

LEON: High school students are obsessed with the present and not so concerned about the future. But these ultimate questions are fascinating and could awaken their interest. The universe began with a Big Bang; will it end with a whimper? And if so, when? A guy once asked a cosmologist, "How many years?" And the cosmologist said, "Fifty billion." "Oh, thank God!" the guy said. "I thought you said fifty million." I'd sort of like to be around and see what happens. 

ROBERT: Frank, you claim that at the penultimate moment before the Big Crunch--which you have called the Omega Point--everyone who ever lived will be resurrected, and that the Omega Point is God. Why should we believe it? 

FRANK: Because it's the only alternative allowed by the firmly tested laws of physics. 
ROBERT: Why would we like it?

FRANK: Because you'll be brought back into existence near the end of time, and you will exist forever, right before the Big Crunch occurs at the very end of time--this is the Omega Point.

ROBERT: That "forever" is really only a very small fraction of a second, but it's supposed to feel like forever?

FRANK: We'll have new life forever, on a more reasonable timescale. 

ROBERT: Sometimes this show feels like forever.

FRANK: Let's remember that it's a big mistake to try to apply human concepts to the universe as a whole. Our concept of time arose in our present environment, on Earth. A far more reasonable timescale is experienced time. There will be an infinite amount of experienced time between however close you are to the end of time and the actual end of time.

ROBERT: Nancey, you're a Christian theologian who is not threatened by all these cosmologists. Are discussions of the end of the universe based on physics and cosmology important for people who believe in the Judeo-Christian Bible?

NANCEY: I think they're important, but more for negative than positive reasons. When Christians talk about the end of the world, or about last things, what they mean is what happens after the phase of history that this universe belongs to is over--after the end of physics. So anything that physicists could predict about how this universe is going to close down is, in a sense, irrelevant to what Christians are talking about in terms of last things. 

ROBERT: The New Heaven and the New Earth, from the Book of Revelation.

NANCEY: That's right. 

ROBERT: That would take place after the end of this physical universe.

NANCEY: That's right. There's supposed to be personal continuity: I am still "I" in some sense when I'm resurrected afterward. But the afterward occurs following whatever our cosmologist friends can talk about. If the prospects for the physical universe are, in colorful terms, to freeze or to fry [Heat Death or Big Crunch], then that's good motivation for asking whether there is some sort of hope for human life beyond either of these scenarios.

ROBERT: Now, if I wake up in some resurrection, am I going to know whether I'm in Frank's Omega Point or your New Heaven?

NANCEY: I think so. But we'll probably have to talk about that later.
ROBERT: Frank, am I going to know the difference?

FRANK: Well, from the traditional Christian and Jewish descriptions, no.

WENDY: Eating and drinking and all of that good stuff?

FRANK: Certainly.

ROBERT: Wendy, I need to get back to some hard data here--my head's spinning from the Omega Point and the New Heaven. What kinds of observations could help us understand what will happen at the end? 

WENDY: There are two primary things we need to understand to address this question of the ultimate fate of the universe--how fast the universe is expanding and how much matter there is in the universe. These are two very active areas of investigation. We need to know how much matter there is, because if there's enough, the expansion could be slowed down by gravity and possibly reversed. 

ROBERT: The more matter, the more gravity; and the more gravity, the more the expansion is slowed.

WENDY: That's right. We also need to know whether the universal expansion is in fact accelerating. And we need to know accurately the values for these parameters.

ROBERT: This data recasts all the old questions.

WENDY: And they can now be answered empirically.

ROBERT: They are no longer theoretical questions, whether for cosmologists or theologians.

WENDY: That's right. You need both theory and experiment.

ROBERT: Andrei, what are the implications of inflationary theory for the end of the universe?

ANDREI: The answer to this question may not be quite what you expect, because people in general think that the universe everywhere is the same as it appears in our vicinity--and therefore that the question about its future can be answered once and forever by looking at our part. But inflationary theory says that most probably the universe consists of many different parts, some of them still in the process of being created. And new life may appear in different parts of the universe, all over again. So our part of the universe may collapse, or may become cold and unsuitable for life, but simultaneously other parts of the universe will appear which will be able to support new life.

ROBERT: So whereas our sector of the universe may be subject to either the Big Crunch or the Heat Death, there's far more to the totality of reality, in which vast new things may happen.
ANDREI: Yes. This is analogous to the fact that while individual humans are mortal, the human species is immortal. Though each of us will die, our children will give rise to their children, and humanity as a whole may exist forever. So it seems with the universe.

LEON: Is that encouraging?

ANDREI: It depends on your personal perspective. If you want a personal immortality, I'm afraid that so far science doesn't allow us this.

FRANK: In your theory, our particular civilization and our particular lines of descent will become extinct.

ANDREI: Yes, that's probably so. 

LEON: There's a metaphor I like for whether or not the universe, in the simplest case of the Big Bang theory, will expand forever. The metaphor is the launching of a rocket, and in fact the mathematics of it are similar to the mathematics describing the future of the universe. If you launch a rocket on an austere budget, reflecting NASA's impecunious state, it might go up for a while, but then it will fall back. That's like the Big Crunch. 

ROBERT: Sometimes that happens with a big budget, too. 

LEON: True. But if you have a well-funded rocket, and you put a lot of fuel in it, then it will escape from the earth. It might go into a permanent orbit around the earth--or, with huge thrust, it will escape completely from the solar system and go on outward forever. So the three things that can happen after the launch of a rocket--falling back to earth, orbiting the earth or the sun, and escaping from the solar system--are analogous to the three possibilities for the future of the universe--closed, flat, and open--unless we've left out something that we don't know about, something that happens after the launch.1 

{FOOTNOTE}1 A closed universe is finite, and will one day stop expanding and begin collapsing to an ultimate crunch. An open universe will expand forever; the energy of the expansion is always greater than the gravitational energy. A flat universe is the exact boundary between the two. In a flat universe, the average mass density is exactly enough to keep the gravitational energy equal to the kinetic energy of the expansion; such a universe will also expand forever, but at an ever slower rate. Note that the Steady State theory [chapter 26] is not the flat universe option of the Big Bang theory. {/FOOTNOTE}

ROBERT: To summarize: Originally cosmologists had two competing theories, each of which claimed to explain the origin of the universe: a Steady State theory, which requires the continuous creation of matter, and a Big Bang theory, in which matter was only created at a momentous initial event. Experimental data has consistently supported the Big Bang. So assuming the Big Bang started it all, what's the end of it all? Will the universe ultimately crunch together? Or will it continue flying apart? Are there multiple universes? And in any case, is there any deeper meaning or theological implications? Certainly, there's wishful thinking. Now let's get to some hard data, particularly the total density of matter in the universe.

WENDY: Well, the question comes down to--as Leon [Lederman] was just figuratively explaining--the mass density of the universe. If we live in a low-density universe, then the universe will continue to expand forever. If it's a high-density universe, then in theory the expansion would slow, halt, and reverse, and everything would come back to the Big Crunch. So astronomers have been looking very hard, for decades now, to see how much matter there is in the universe. And early in the 1970s, when people were trying to pin this number down--determine the average density of matter in the universe--it seemed that there was not enough matter to halt the expansion. 

ROBERT: How do you determine the average density of matter in the universe--density being the amount of matter in a specific volume? Where do you look? 

WENDY: You can look on very different scales, so let me give you an example. In our own galaxy, say, you can look at the outermost stars and determine how fast they're moving around the galactic center. You'd predict that they would be moving more slowly than inner stars; if there's not much mass out there, then the velocity is going to fall off even further. [The velocity of stellar movement is a good test for the amount of matter, since velocity is energized by gravitation, which is directly related to the amount of matter]. This is true of our own solar system; you see it in planetary motions. But when people were able to make these sensitive measurements, they found that the stars on the outskirts of galaxies were actually moving quite rapidly.

ROBERT: So you concluded that there had to be more matter in our galaxy than met the eye. Astronomers had to postulate new stuff?

WENDY: People began to postulate the existence of matter that we can't see. Dark matter--matter that doesn't emit light. But we can infer its presence because of its gravitational effect, which is increasing the velocity of stars--and these are motions that we can see. 

ROBERT: But even with all the dark matter in the universe, there's still insufficient mass to achieve the so-called critical density (or closure density), which is a term astronomers use to define the total amount of matter needed to balance the force of the expansion. Anything above that value will eventually cause the universe to stop expanding.

WENDY: That's right. When we add up all the mass we can see, we can only get to about one percent of the critical density. Then we estimate how much dark matter there may be in the universe. As we go to larger scales--more and more galaxies, then clusters of galaxies--the more evidence you find of dark matter. There was a hope, especially in the 1980s, that when we got out to the largest scales, we'd find sufficient dark matter to achieve the critical density--since the universe seems to behave as though it's flat. But this hasn't happened.

ROBERT: What might dark matter be? There are several options and no consensus. 

WENDY: Dark matter could be a number of things. It could be exotic particles, left over from the early formation of the universe. It could be failed stars [i.e., nonluminous brown dwarfs, star-like bodies whose low mass is insufficient to sustain thermonuclear reactions]. It could be neutron stars or black holes, although that doesn't seem to work.

ROBERT: How much dark matter have astronomers found relative to the critical density?

WENDY: We estimate that the total amount of matter in the universe is something like thirty percent of what would be required to achieve the critical density--most of it is dark matter; visible matter is only a small component of that. So, if our universe is at the critical density, then there's an extra seventy percent unaccounted for. 

ROBERT: So what about that extra seventy percent?
ANDREI: Recent observations suggest that it may be in the form of a cosmological constant, which is actually vacuum energy--

LEON: Spooky matter. 

ROBERT: Didn't Einstein say that the cosmological constant was his greatest mistake?

ANDREI: Yes.

ROBERT: Einstein imagined a cosmological constant as sort of a universal fudge factor, which he needed as a repelling force--of unknown origin--to balance the attractive force of gravitation, to prevent the universe from collapsing. 

WENDY: Einstein did his work before we recognized the expansion of the universe.

FRANK: Einstein's equations clearly show that the universe had to be expanding. He did not accept his own equations, and so he adapted them to make the universe the way he wanted it philosophically. 

ROBERT: So he put in a cosmological constant to balance gravity, to keep the universe on an even keel. What happened to the cosmological constant?

ANDREI: Many people tried to understand what the interpretations of this cosmological constant could be. The conclusion was that it was the energy of empty space, of the vacuum. Empty space, as strange as it sounds, may still have some energy density hidden in it. This is not forbidden by the laws of physics, so people tried to measure it. Well, this is the first kind of cosmological measurement where we are trying to calculate this energy of nothing, and it seems that is it not exactly zero. Although we can't be sure of the exact percentage right now, it looks like we may have the missing seventy percent of matter in this hidden state.

ROBERT: We talk as if the universe has a spring to it--a springiness, as well as a spookiness, to the universe. 

FRANK: If the cosmological constant were there, it would be pushing the universe apart faster and faster. 

ROBERT: And that's what the data seem to show--that the expansion rate of the universe has been increasing over time.

WENDY: Yes. If you take the recent data at face value, that's what you'd conclude. 

FRANK: In fact, I'm very dubious about taking the data at face value. 

WENDY: We're working on the frontier, and we should stress that. These are very difficult measurements, and it will take a while before they're conclusive.

ROBERT: But isn't this recent data a major surprise? Astronomers seemed to like the notion of a harmonious universe finely balanced between rapid dissipation and compaction. But instead of showing what you might expect--that is, that the expansion is gradually slowing, because of the effects of gravity--the data seem to indicate that the expansion is actually getting faster and faster. How do you determine that?

WENDY: What happens is that we can look back in time. As we look farther away in distance, we are looking farther back in time. The more distant the object, the earlier the moment.

ROBERT: You're looking at history. 

WENDY: Yes. And when we look locally--out to about sixty million light-years, say--we can see clearly that the universe is expanding. As we look farther out, we continue to see this expansion, and if we look back far enough, we should be able to see what the universe was doing early in its history. So if there's sufficient matter generating sufficient gravity, the universe will have been slowing down--decelerating over time because of gravity. However, if there is this cosmological constant, then the universe's expansion would actually be accelerating, and as a result the objects that we see further back will be dimmer than they would be if there were no acceleration. So what astronomers have done is to compare supernovae [i.e., very bright stars that exploded at the end of their lifetimes] in the far distant universe with those in the nearby universe. And the distant supernovae do appear dimmer than you would expect if there hadn't been an acceleration of the expansion. 

ROBERT: That's remarkable. Now, Leon, regarding the end of the universe, one phenomenon that physicists look for is the possible decay of stable elementary particles, such as protons.

LEON: The lifetime of a proton? At the moment, we don't know what it is, but we do have a limit to it. 

ROBERT: Meaning that it's not less than such-and-such?

LEON: That's right. Protons seem to be much more stable than theorists would like. They'd like to see one decay, but they haven't.2

{FOOTNOTE}2 The lowest estimate for the half-life of a proton (the time it would take half of a given amount of protons to decay) is not less than 10^31 years (and rising in recent experiments)--or a thousand billion billion times the current age of the universe.{/FOOTNOTE} 

ROBERT: So that would indicate that protons, at least, will exist for a very long time, if not forever. 

LEON: Well, the lightest particles are supposed to be stable, so electrons ought to be around forever, however long that is. But to return to the expansion rate--I think scientists are driven by the notion that they want the mass of the universe to be equal to the critical density. 

WENDY: If the universe does not have enough mass (or density), it will continue to expand forever. If the mass (or density) is large enough, the expansion will be halted and the universe will ultimately collapse. The critical mass (density) is the mass (density) between the two [where the universe will just barely continue expanding forever, but at an ever slowing rate--i.e., flat universe].

LEON: The inflationary people like Omega to equal 1. 

ROBERT: What is Omega?

FRANK: Omega is the symbol representing the density parameter in the universe; it's the ratio of the amount of matter actually present to the critical density. 

ROBERT: OK. So if Omega is 1, then the universe is at the critical density.

LEON: But in order to get Omega to equal 1, they have constructed a fantastic cocktail. They say, "OK, there are stars, that's part of it. Then there's dark matter, which would include dark stars, planets, and exotic particles. Maybe we'll find some of those exotic particles in our accelerators." And even with all this dark matter, they still don't have enough matter to achieve the critical density, so they seize on Einstein's blunder, the cosmological constant.

WENDY: The other important point to make is that when you calculate what that cosmological constant should be, it's much bigger than what's being observed. The natural value is smaller than you would infer from calculating it. 

ROBERT: Andrei, how does Omega, the density parameter, relate to the multi-universe theory of chaotic inflationary cosmology?

ANDREI: What we've been talking about is the energy density in [the observable] universe. The multi-universe picture is somewhat different. The question goes back to where and how the universe began. Our new picture of it is inflationary cosmology--an extremely fast expansion of the universe in a kind of vacuumlike state, driven by a specific form of energy called a scalar field. The energy of this scalar field had the same kind of outward force as Einstein's cosmological constant. As it slowly decreased, some quantum fluctuations in this scalar field were responsible for later galaxy formation. But what inflation also predicts is that sometimes these quantum fluctuations become so large that they increase the local body of this cosmological constant, so to speak. And by increasing it, they make the universe [in that local region] expand exponentially faster. These events are also exponentially improbable, but once you jump, you are exponentially rewarded by [a vast amount] of new space, which you get. 

ROBERT: And each one of those exponentially improbable jumps can breed a new and different universe? 

ANDREI: Right. 

ROBERT: Frank, how can multiple universes be compatible with your Omega Point--your theory that the universe will come back to a final singularity and just before that everyone will be resurrected? Won't we get lost?

FRANK: Well, multiple universes directly contradict the Omega Point. If Andrei is right, then I am wrong. That's the way physics is. If one of us is right, then one of us is wrong. 

ROBERT: Of course, you both could be wrong. In fact, the only thing we know for sure is that you both can't be right. 

FRANK: Yes. It's interesting that we now have theorists and experimentalists on each side. I keep whirling around. The data will eventually correct all of us. But if the expansion of the universe is accelerating, then of course the universe will never come back to a final singularity. I think it's something of a misnomer to call that a Big Crunch, or a "fry," as Nancey termed it, because that's looking at the universe from an anthropocentric point of view. 

ROBERT: That's what it looks like to me.

FRANK: If humans were there, building things, that's what it would look like, but we have to remember--

ROBERT: If you were there, what would you see? 

FRANK: If I were there, I would be vaporized and tossed into nonexistence. But that's if I were there at what we call in computer science the lowest level of implementation [i.e., in the flesh].

ROBERT: You'd never get caught like that.

FRANK: What would happen is that as the universe contracts, things will get hotter and hotter. But it would be possible for [far advanced intelligence] to use the energy of contraction itself to build devices that survive the unlimited heat. So, from the point of view of a more reasonable timescale, the actual experiences that life would have between the resurrection and the final state would be literally infinite. Now, the reason I'm very dubious about an ever-expanding universe--besides the fact that it contradicts my theory--is that if you have an ever-expanding universe you will have black holes evaporating.3 Now, the problem with having black holes evaporating to completion is that it violates a fundamental law of quantum mechanics called unitarity. 

{FOOTNOTE}3 Black holes are the densest conceivable form of matter, formed by the gravitational collapse of large stars in their final stages. No imaginable force can stop their contraction and the gravitation force is so strong that not even light can escape. All the mass of a black hole is concentrated into a single point, called a singularity, where mass has no volume and space and time stop. Black holes were conceived by theory but confirmed by observation. It is believed that super-massive black holes, perhaps with the mass of a billion suns, sit in the center of galaxies. Black holes are thought to evaporate in a process known as Hawking radiation, but there is disagreement over whether or not they are immortal. {/FOOTNOTE} 

ROBERT: Nancey, is your theological perspective compatible with an infinitely growing universe and/or with an ultimately contracting universe?

NANCEY: You started out by asking why high school students, or people in general, should care about all of this. And what we're asking from a theological perspective is, Why should the human species care? Most of these scenarios are so far beyond what we can project for the longevity of Homo sapiens that they're irrelevant.

ROBERT: But they're not irrelevant to our conception of what human beings are and what our purpose may be in the cosmos.

FRANK: I've argued the very promise that we'll be blown back into existence [at the penultimate moment just before the Big Crunch].

NANCEY: Right. Frank's point of view is in fact relevant to that [why-should-we-care] question. But the more general questions raised in cosmology--about whether the universe is open and expanding or closed and contracting, or whatever--are fairly irrelevant to the human species.

ROBERT: Well, I disagree. Endtime cosmology may be irrelevant to what happens to us individually, but it may help classify, clarify, limit, enhance, or purge human purpose or position in the cosmos. If we define progress as progression toward truth, even nullification of human purpose or position would be progress. 

NANCEY: But if we simply cease to exist--literally go out of existence, without any trace left of us--it doesn't really matter how that happens, does it?

ROBERT: If we ultimately vanish and that, indeed, is the last out of the last game, then, sure, nothing else really matters. But the fact that we human beings may soon understand what actually happens at cosmology's ultimate end would mark us as unique beings--participants, in a way.4 And that, I think, may be terribly relevant. 

{FOOTNOTE}4 Lawrence Krauss and Glenn Starkman speculate in their article "The Fate of Life in the Universe" (Scientific American, November 1999) that about 100 trillion years from now, the last conventionally formed stars will wink out, that black holes will consume galaxies in about 1020 years (1030 years after the Big Bang) and that galactic black holes dissipate in about 1088 years. {/FOOTNOTE}

NANCEY: Well, yes, but that doesn't have any particular theological significance over and above what most of science does. Another way to ask the question is, What does all of this cosmology look like from God's point of view?

ROBERT: I won't ask Frank; I'll ask you.

NANCEY: I'm attracted to Andrei's conception of multiple universes, because one would be tempted to ask what happens to God if our little universe ceases to exist. Or, if it ceases to have any life in it, with whom would God interact? What's God going to do for the rest of eternity?

LEON: Unemployment. He will want to avoid that at all costs.

NANCEY: That's right.

FRANK: But what bothers me about Andrei's universe is that it seems to be a resurrection of the Steady State theory, in which on the largest possible scales nothing much happens. Everything is sort of constantly reproduced. 

ROBERT: Andrei, you've now had someone claim that your multiple universes are a God-sent remedy for God's own ennui and someone else allege that it's just the outmoded Steady State model dressed up in modern language. You're the man--what does it look like to you? 

ANDREI: First of all, I should perhaps take a more modest position and say that this is not my universe. This is the standard prediction of the standard inflationary theory, which is widely accepted by many cosmologists who actually work in this field.

LEON: Just because Frank is in the minority doesn't mean he's right.

FRANK: Nor does it mean I'm wrong. 

ROBERT: Andrei, are all of your universes, however many fractal bubbles there may be, the totality of reality?

ANDREI: That's a very hard question. Our discussions here are using the language of normal particles. Meanwhile, over the last fifteen years or so, we've started to learn that maybe nature should be discussed in terms of string theory, and this could produce quite unexpected outcomes. For example, suppose that our universe is collapsing and it comes to a state of singularity, a single point, which would mean the end of everything. From the point of view of string theory, it could mean the beginning of a different phase.

ROBERT: String theory being that minuscule, vibrating strings are the fundamental stuff underlying all energy, matter and forces, including gravity--

ANDREI: Yes, instead of the universe consisting of pointlike objects, it fundamentally consists of these extremely tiny stringlike objects. And when the universe is collapsing, the question is whether the collapse is the end of everything or just the end of the stage where you can easily apply the old pre-string theory. Now, with string theory, when you come close enough to this point of singularity, you see there is no singularity. There are some people who call this pre-Big Bang theory. My point is that when we speak about the end of the universe as a whole, we can run into trouble if we use simple language rather than the mathematical models of physics. 

ROBERT: Nancey, cosmologists are now talking about the beginning and the end of the universe--things that theologians have talked about for thousands of years. Doesn't that excite you?

NANCEY: Yes, it does, because it gets people thinking about human destiny and raises the sorts of questions that religion sets out to answer. But most of what's being said here is genuinely irrelevant to what Christians have been saying over the centuries, because Christians are talking about the way this whole universe, however the physicists describe it, is going to be transformed afterward. 

ROBERT: And that afterward would occur when?

NANCEY: Well, that's not clear. The scriptures, which are all we've got to go on, speak about last things in highly imaginative picture language and don't set out any chronology of events. The Bible doesn't tell us how long the human race is going to last--a million years, or a thousand years, or whatever. It just tells us that it's all going to end up good. And we have rich, literary descriptions of what that goodness consists of. But no account of the time line.

ROBERT: Does this all sound pretty good to you, Leon?

LEON: Sounds wonderful, though it's somewhat above my salary level. But it seems to me that we have a working theory of the origin of the universe that is somewhat consistent with the data. We have lots of things we have to learn about it, and we will learn them. Our progress has been very good, and in a hundred years from now, maybe the Theory of Everything will tell us how the universe began and how the laws of physics dictated this particular expansion and brought us eventually to galaxies and stars and one inconsequential solar system, with one minor planet out of whose oceans we crawled. If all of this emerges from the Theory of Everything, that theory also ought to be able to predict the conditions at the end of the physical universe. Humanity will not be around to bear witness to it, because all kinds of rather unpleasant things will happen first. 

ROBERT: That's the standard model, if you will, of current cosmology.

LEON: That's the standard model. But I don't think that means we should be discouraged, because everything we've created--our institutions, our passions, our loves, our enthusiasms--will continue for the unforeseeable future. 

ROBERT: Wendy, do you ever think about theological issues when you're looking at photographs and data from the heavens?

WENDY: I think when you look at the heavens, it's hard not to have a sense of wonder and amazement that we live in a universe that we can describe by physical laws, and we can ask questions and make predictions about its origin and ultimate state. I agree with Leon; ultimately we may come to a theory that will allow us to describe those things. I don't like the name--the Theory of Everything--because it will describe only a particular set of things and will have to be linked to other unsolved problems, such as consciousness.

ROBERT: Do you discuss these issues with theologians or people interested in the nature of consciousness or religion?

WENDY: Yes, I do. It's an area where there's still room to interpret things as you would like to interpret things. And so we ask them, What came before? Where were the laws of physics? What was the universe? Science doesn't offer an answer to those questions, but what's interesting is that we're at a point where we can come to these questions in very different ways. 

ROBERT: Project forward a hundred years. It's not quite Frank's Omega Point, but genetic engineering has enabled us to reconvene. Will there be a final theory of what will happen at the end of the universe?

FRANK: I think there will be. Obviously, I'm going to think that we'll have moved toward acceptance of the Omega Point theory. The reason is that Andrei and his colleagues are inventing new forces in physics to accomplish his inflation mechanism, whereas tried-and-tested physics--actual forces that Leon has seen in the lab--leads inexorably to the Omega Point theory. The known laws of physics are sufficient to tell us what the future of the universe will be. If the universe were to expand forever, then black-hole evaporation would give rise to a violation of a very fundamental law of quantum mechanics. I'm sure that can't happen. That's why I'm confident that the universe will expand to a maximum size and then contract into a final singularity. 

NANCEY: I'm intrigued by the fact that Frank's book is attacked as vehemently by theologians as it is by scientists. 

FRANK: Not by Wolfhart Pannenberg, the famous German theologian.

NANCEY: Quite right. But I'm not sure whether to judge cosmological theories on the basis of their theological acceptance or rejection. This is not something that a theologian can speak to--unless, of course, the end of the world in my sense of the term comes sooner than a hundred years from now, but I doubt it. 

ANDREI: If we want to understand the end of everything, then we should first understand the end of each and every one of us. In particular, we need to understand the nature of consciousness, which has been outside the bounds of our discussion. I do think that scientists must attack the problem of consciousness much more seriously than they do right now, and not insist that in order to describe consciousness the only thing we need to know is how to describe electrons and protons, and so forth.

ROBERT: Closer to Truth oscillates between cosmology and consciousness, because these are the two critical questions of human understanding.

ANDREI: First of all, I don't think that the universe as a whole is going to collapse. Second, it seems to have little practical consequence for us personally, because our part of the universe must disappear one way or another. And this may require that we consider other things, ideas that Nancey thinks about. After all, even all the multi-universes may still not be the whole thing. What about our perception of the universe, our consciousness, our life? From my perspective, these are much more difficult phenomena to understand than the universe, and perhaps, in some specific sense, may encompass it.

WENDY: As a scientist, I can't predict the future, other than anticipating continued incremental solutions to many of these unsolved problems. I don't know what the timescale will be for solving them; it may be a hundred years, it may be a thousand years. If I were to take a guess, the question of how the universe will end may be one of the questions we will debate for a long time, because I think we're getting to the point where many of these ideas can't be tested--where you can propose theories or make predictions that aren't amenable to scientific test. However, we're now addressing questions that it wasn't even possible to conceive of a hundred years ago. Our ideas about the universe have changed that dramatically, and I think we'll continue to learn dramatic things about the universe. 

LEON: I'm close to that. At the moment, if you take all the data and the best synthesis, the expansion will continue, entropy will increase, heat will die. On the other hand, in a hundred years, if our educational system improves, we'll have thousands of brilliant scientists who will think hard about this question, so that maybe there will be some alternatives. There are already fragmentary ideas about totally different alternatives for the future. 

ROBERT: So you want to make a lot more Wendy Freedmans.

LEON: I'm in favor of that.

ANDREI: There are some theories about the possibility of creating a universe in a laboratory. And that's not science fiction.

LEON: Be very careful.

FRANK: It involves laws of physics that have never been seen. 

LEON: One of the things we're leaving out is the scientific design of human evolution. This growing knowledge of our biology is going to have an impact on all facets of our understanding, including how much we find out about the universe. It's unforeseeable, so I'm not going to say any more about it.


ROBERT: CONCLUDING COMMENT

THE fate of the universe: it's the question that makes you take a deep breath. Current theories seem clear enough. Either there is enough matter for gravity to reverse the universe's expansion and cause the Big Crunch, compacting everything back into a singularity, or there is not enough matter, and the universe will expand forever, evaporating into nothingness. The latest data not only supports the unstoppable expansion but also suggests an accelerating expansion. Space, it seems, has some spring to it, increasing the outward rush. And just when we think we cannot be any more astonished, cosmologists whack us again, this time with multiverses--perhaps an infinite number of universes, each bringing forth new universes, continually, endlessly, all of them somehow coexisting in the totality of reality. Remember what Einstein said about the universe: "Make it as simple as possible, but not simpler." Cosmological problems are overwhelming, but I'm oddly preoccupied with something else. How is it that we humans have such vast understanding after only a few thousand years of historical consciousness and a scant few hundred years of effective science? Maybe it's still too early in the game? Maybe answers have been with us all along. Some say that the more we learn about the universe, the more pointless it becomes. Not me. The further we look, the closer we get to truth.

*******************

About this Program  |  HyperForum  |  Transcript  |  Watch the Show  | Show Feedback