Steven Weinberg: Interview


Steven Weinberg is a theoretical physicist at the University of Texas at Austin. He was awarded the Nobel Prize in physics for his work on the theory of electroweak unification. He is the author of the best-selling books "The First Three Minutes" (about the very early universe), and "Dreams of a Final Theory" (about the quest for a unified theory of physics.)

QUESTION: Over the past decade, many physicists have been making an association between their science and "the mind of God". What do you think of this association being made?

DR. WEINBERG: It makes me nervous when physicists use the word "God" loosely, as talking about the laws of nature as the mind of God, or even Einstein's famous remarks about God playing dice with the cosmos. I think mostly they're just using the word "God" in the metaphorical sense.

By "God" most of them simply mean the laws of nature, the principles that govern everything. And, well, there's nothing wrong with the metaphor, I suppose, but the word "God" is charged with so much meaning, it carries so much historical freight, and I think one ought to be careful about how one uses it.

QUESTION: Why do you think so many physicists in recent years have made such an association?

DR. WEINBERG: It is true that this use of the word "God," this metaphorical use of the word "God" comes naturally to physicists. Theologian Paul Tillich said once that he thought that physicists were the only scientists that found it comfortable to talk about God.

The aim of physics, or at least one branch of physics, is after all to find the principles that explain the principles that explain the principles that explain everything we see in nature, to find the ultimate rational basis of the universe. And that gets fairly close in some respects to what people have associated with the word "God." But I think it is still very different. And I wouldn't refer to the laws of nature as the mind of God, or call anything discovered by physicists the ‘God this’ or the ‘God that’. It's a word that has a lot of punch to it.

QUESTION: Why do you think that over the last decade there has been a whole flurry of books about physics and the mind of God?

DR. WEINBERG: Well, I think the public is generally interested in the deeper meanings of science. I think it's natural that the latest elementary particle raises questions such as what is its mass, what is its charge, et cetera. But that isn't even so interesting -- the point is what does it mean? And if by using words like "God" you can give an impression of some deep spiritual meaning, well, that's naturally going to attract public interest.

QUESTION: For many physicists throughout history - people like Copernicus, Kepler, Newton - God was an inspiration in their scientific work. If God could inspire Newton, do you think it's not legitimate that God could in some way be an inspiration for physicists today?

DR. WEINBERG: Newton's ideas about God - and in fact, Newton's ideas about science - are difficult for a modern to get in tune with. As John Maynard Keynes said, he wasn't the first modern scientist, he was the last of the magicians.

Newton, as I understand it from what I've read about him, thought that the world was a puzzle set here for us to decipher, and that you could decipher it by understanding the chronology of the Book of Daniel, or you could decipher it by studying the motions of the planets in the solar system. I don't know if I feel that way about the world. I find it hard to think that the world was set here as a puzzle for me to decipher.

It's true that for some scientists in the past, and even today, their interest in God is part of their interest in nature, and the two go together. For others they run very much in opposite directions. Laplace is famous for his remark to Napoleon, "Sire, I have no need of that hypothesis," when Napoleon asked him what place God had in his picture of the solar system.

For some scientists their scientific work and their religion have been quite opposite and incompatible. Darwin, I believe, lost his attachment to the faith of his childhood as a result of his development of the theory of evolution. So different folks go different ways.

QUESTION: You have written that the more comprehensible the universe becomes the more pointless it seems. Could you explain what you mean by that?

DR. WEINBERG: Years ago I wrote a book about cosmology, and near the end I tried to summarize the view of the expanding universe and the laws of nature. And I made the remark - I guess I was foolish enough to make the remark - that the more the universe seems comprehensible the more it seems pointless. And that remark has been quoted more than anything else I've ever said. It's even in Bartlett's Quotations. I think it's been the truth in the past that it was widely hoped that by studying nature we will find the sign of a grand plan, in which human beings play a particularly distinguished starring role. And that has not happened. I think that more and more the picture of nature, the outside world, has been one of an impersonal world governed by mathematical laws that are not particularly concerned with human beings, in which human beings appear as a chance phenomenon, not the goal toward which the universe is directed. And for some this has no effect on their religion. Their religion never looked for any kind of point in nature. For others this is appalling, the idea that all of the stars and galaxies and atoms are going about their business, and it's just by accident that here on this solar system the peculiar chemical properties of DNA acting over billions of years have produced these people who have been able to talk and look around and enjoy life. For some people that picture is antithetical to the view of nature and the world that their religion had given them.

QUESTION: Do you believe then there is no overall point to the universe?

DR. WEINBERG: I believe that there is no point in the universe that can be discovered by the methods of science. I believe that what we have found so far, an impersonal universe in which it is not particularly directed toward human beings is what we are going to continue to find. And that when we find the ultimate laws of nature they will have a chilling, cold impersonal quality about them.

I don't think this means [however] there's no point to life. Usually the remark is quoted just as it stands. But if anyone read the next paragraph, they would see that I went on to say that if there is no point in the universe that we discover by the methods of science, there is a point that we can give the universe by the way we live, by loving each other, by discovering things about nature, by creating works of art. And that -- in a way, although we are not the stars in a cosmic drama, if the only drama we're starring in is one that we are making up as we go along, it is not entirely ignoble that faced with this unloving, impersonal universe we make a little island of warmth and love and science and art for ourselves. That's not an entirely despicable role for us to play.

QUESTION: What is your response to scientists like Paul Davies, who say they do see a point to the universe and they think that science itself supports that?

DR. WEINBERG: I think it's true that there is a mystery about nature which is not likely to be cleared up in any way that I can now foresee. That is, we can look forward to a theory which encompasses all existing theories, which unifies all the forces, all the particles, and at least in principle is capable of serving as the basis of an explanation of everything. We can look forward to that, but then the question will always arise, "Well, what explains that? Where does that come from?" And then we -- looking at -- standing at that brink of that abyss we have to say we don't know, and how could we ever know, and how can we ever get comfortable with this sort of a world ruled by laws which just are what they are without any further explanation?

And coming to that point which I think we will come to, some would say, well, then the explanation is God made it so. And I suppose that's a natural reaction to this dilemma. Unfortunately to me it seems quite unsatisfactory. Either by God you mean something definite or you don't mean something definite. If by God you mean a personality who is concerned about human beings, who did all this out of love for human beings, who watches us and who intervenes, then I would have to say in the first place how do you know, what makes you think so? And in the second place, is that really an explanation? If that's true, what explains that? Why is there such a God? It isn't the end of the chain of whys, it just is another step, and you have to take the step beyond that.

I think much more often, however, when a physicist says, "Well, then the explanation is God," they don't mean anything particular by it. That's just the word they apply. Einstein said that he didn't believe in a God who was concerned with human affairs, who intervenes in human life, but a God who was simply an abstract principle of harmony and order.

And so then I rather grieve that they use the word "God," because I do think one should have some loyalty to the way words are used historically, and that's not what people have historically meant by "God" - not an abstract principle of harmony and order. If that's all you mean by it, if God is practically synonymous with the laws of nature, then we don't need the word. Why not just say the laws of nature? It isn't that it's wrong, because after all G-O-D is just a set of letters of the alphabet, and you can let it mean anything you like. But if language is to be of any use to us, we ought to try to preserve the meanings of words, and "God" historically has not meant the laws of nature. It has meant an interested personality. And that's not something we're finding scientifically. It's not something for which I see any evidence.

QUESTION: Do you feel though that a similar question comes up with physics itself. If you and your colleagues find a "final theory", as you have called it, then you could also ask why that theory, why not some other theory? You still get an endless chain of whys.

DR. WEINBERG: We are facing the possibility that in finding a final theory we will have the question left to us: Why is this correct, and we might have no answer?

I think it is not going to be possible that the answer will be that this is the only logically possible set of laws of nature, because even now any physics graduate student could invent a set of laws of nature which don't describe the universe as we know it, but which are perfectly logically possible. So I don't think pure logic will ever lead to an explanation of the laws of nature. On the other hand, it may be that the laws of nature as we discover them, when we discover them, will turn out to be the unique, logically consistent set of laws that provide a universe rich enough to allow for the existence of life and people who ask about the laws of nature, so that at least there will be a kind of pleasing self-consistency about the situation.

QUESTION: There are people who say that the very particularity of the laws of physics means these laws are "fine tuned" to allow for the possibility of life evolving. They interpret this in a religious sense as meaning that the universe was in some sense designed to produce life.

DR. WEINBERG: I don't see any clear evidence that the laws of nature or the constants of nature as we know them are fine tuned to allow life. I mean, certainly the laws of nature do allow life. But I don't see anything clearly in them that looks like a spectacular coincidence. I'm not convinced by any of those arguments.

There are some things that are quite mysterious in our understanding of nature as we know it now. There is a constant called the "cosmological constant", which if I didn't know anything I would make an estimate of what its magnitude would be just on the basis of guess work from what I know about the laws of nature. The correct value is less than that estimated value by something like 120 orders of magnitude. That looks like some kind of fine tuning. And we don't know. It may be that that number is simply zero, and it's zero for some fundamental reason that we will discover. And so it isn't fine tuned. It's also possible that the universe is bigger and more complicated than we had thought, and that what we call the universe, is just part of the universe, and that what we call the laws of nature differ from one part to another, and that we are living in a part of the universe where what we call the laws of nature, including the value of this constant, allow life to appear. In that case we wouldn't imagine that any supernatural agency fine tuned the laws and constants to make us possible, any more that we imagine that a supernatural agency arranged that the Earth had a temperature which allows life. Out there, there are doubtless millions of planets in the galaxy, and we live on one that allows life. That doesn't imply to me that it has been specially arranged to allow life.

QUESTION: In some sense do you think this quest for a "final theory" of physics -- a theory that would unite all the forces of nature under one unified umbrella -- in some sense is that like a religious quest? Is it like a quest for the ultimate source of order and creation, which is one aspect of God in traditional Judeo-Christianity?

DR. WEINBERG: I think a lot of intellectual energy over the centuries has gone into religious matters. Think of all the monks devoting themselves to fine points of theological doctrine -- monks and rabbis and bonzes and Moabs, imams, down through the years devoting so much talent and energy to questions of theology. In a way science provides an alternative way of using your mind. This is something else where you can use human intelligence. It has several advantages. It has the advantage that we have ways of finding out we're wrong about things. I've had that experience in my life -- most scientists have -- of having a theory that I thought was bound to right shown to be wrong by experiments -- its a very cleansing experience.

We scientists also have ways of coming to solutions about things. There are things about which now there is universal agreement as compared with the situation in theology. So in a way the same kind of intellectual activity goes on in science as has historically been devoted to religion. But I think with several distinct advantages.

QUESTION: When you die, does any little part of you hope that you might be proved wrong, that there ultimately might be something beyond the pointlessness you see in the universe?

DR. WEINBERG: Science cannot give us what religion gives those who believe in it. Science can't give us the consolation of knowing that when we die we are going to continue in some sense to exist. It leaves us with a much bleaker view of our own future.

Religion can provide that consolation -- and I think that must have been over many millennia one of the driving forces behind religion -- the fact that it allows us to think that we will continue after death. But for that reason we ought to be suspicious of it, because we ought to be suspicious of anything that is so satisfying that it might after all just be wishful thinking.

QUESTION: What do you think about this new dialogue between science and religion that’s taking place now?

DR. WEINBERG: I know there's been a lot of talk about a reconciliation between science and religion, of ending the old conflict. And in a way it's a good thing. Certainly science in trying to get public support doesn't need to have a conflict with religion going on at the same time. In another sense I tend to deplore it. I think that part of the historical mission of science has been to teach us that we are not the playthings of supernatural intervention, that we can make our own way in the universe, and that we have to find our own sense of morality. We have to find our own sense of what we should love. And I would hate to have those gains made by science vitiated by a misguided reconciliation with religious life.

QUESTION: What do you make of the fact that perhaps the greatest scientist of this century - Albert Einstein - used to talk so often about God and physics?

DR. WEINBERG: Often people talking about science and religion point to the example of Einstein as a deeply religious scientist, but who has certainly seen as far into the laws of nature as any of us. And I think that's really quite wrong. I think that Einstein in his famous remarks about God not playing dice with the cosmos, and wanting to find out whether God had any choice in the way he created the world, was using the word "God" quite metaphorically. He said in a more serious vein that he did not believe in a god who intervened in human affairs, to whom it made sense to pray. For him God was an abstract principle of harmony and order. There have been deeply religious physicists, but I don't think you can count Einstein as one of them.

QUESTION: Do you think religion has value?

DR. WEINBERG: I think there's much to be said on both sides of that. I mean, certainly religion has produced great art. Where would architecture be without the great cathedrals and wonderful Japanese temples, and mosques.

On the moral side, however, I'm less sure about it. Certainly good causes have sometimes been mobilized under the banner of religion, but you find the opposite I think more often the case. It's more often been the motivation for us to kill each other - not only for people of one religion to kill those of another, but even within religions. After all, it was a Moslem who killed Sadat. It was a devout Jew who killed Rabin. It was a devout Hindu who killed Gandhi. And this has been going on for centuries and centuries.

I think in many respects religion is a dream - a beautiful dream often. Often a nightmare. But it's a dream from which I think it's about time we awoke. Just as a child learns about the tooth fairy and is incited by that to leave a tooth under the pillow - and you're glad that the child believes in the tooth fairy. But eventually you want the child to grow up. I think it's about time that the human species grew up in this respect.

It seems to me that with or without religion good people will behave well and bad people will do evil things. But for good people to do evil things, that takes religion.

QUESTION: Some people would claim that the same criticisms you've just raised about religion could also apply to science, that science has given us many great things, but there have also been appalling things done in the name of science. For instance, government testing of syphilis on black people.

DR. WEINBERG: I think there's been great harm done by using some of the discoveries of science. But I think there's a profound difference between the role of science in this respect and that of religion. Science merely amplifies the capabilities of human beings. Science gives us the ability to do ill and to do good more than we had, and to question science in this respect is like questioning whether people ought to have two hands or just one, because with two hands they could do more evil than they can with just one.

Carl Popper has made the point that although people have done terrible things using the fruits of science, no one has ever gone to war on behalf of a scientific principle, or exterminated whole populations because they disagreed on a point of science.

QUESTION: People have, however, gone to war WITH the fruits of science, and in fact have killed millions of people with the fruits of science - atomic bombs, land mines, and so on - things that we would not have had without the technology that comes out of science. Does that suggest there should be moral considerations about how we use science -- and perhaps religious people could have a role to play in determining the uses of science?

DR. WEINBERG: Certainly science, because of its ability to increase our capacities to do things, raises terrible risks for us all. If it were possible to undiscover nuclear fission, I would be very happy to undiscover it, because of the risks that it puts us all under. And I think it's ridiculous to imagine that science should just proceed without any moral guidance as to the kinds of things which are going to be done with the discoveries of science. I mean, just because a scientist is capable of wrecking the Earth, there is no reason why he should be allowed to do that. Of course not.

What we need is a moral sense which can govern the way we use the fruits of science, in the same way we need a moral sense that governs the way we use our own two hands. Where is the moral sense to come from? Well, I don't think it really does much good to look to religion for it, because in fact although today's religions teach much that is very good in the way of moral teachings, I think these really reflect rather than inspire the moral evolution of human beings. After all, going back to the example of slavery, there was nothing in the teachings of any of the great world religions historically that was hostile to the institution of slavery. I mean, Christianity was not against slavery. Judaism was not against it. Islam was not against it. In some cases they prohibited slavery for their own co-religionists, but they never were against enslaving people who belonged to other religions. Gradually over the centuries human beings have turned away from slavery. And the religions now reflect that change in moral judgment. I don't think they're responsible for it. I think they simply reflect it.

I think there is no reason why people of good will can't see what has to be done and what should not be done without the aid of religion. And considering the role of religion today in causing people all over the world to murder each other, it would probably be better done without it.

QUESTION: You said there was some specific point you wanted to make. What was that?

DR. WEINBERG: In my experience most physicists are not particularly religious. A few are - no question about it. But most are not. In fact, I would say they're not so much irreligious as simply uninterested in this subject. They don't know enough or think enough about religion to qualify as atheists. And but I think that's not so limited to physicists. In my experience many Americans think of religion as important, and want to do whatever they can to support it. But if you ask them what they themselves believe, you'll find they're very uncertain about their religious beliefs. They don't actually accept the theology of their official church.

One piece of evidence I give for this is the fact that I have very good friends who belong to religious denominations whose teaching is that since I don't accept their teaching I am damned for all eternity. And you would think that these friends would try to convert me. But they never do. Now, you could explain this in various ways. It may be that they really don't like me very much and are just as glad to see me damned for all eternity -- that's a possible explanation. But another explanation which I tend to think is more likely is that although they know what their church teaches and they give lip service to it, they really don't believe that if you don't follow that particular form of worship you're damned for all eternity. And when you talk to them about what they believe they're likely to say something like this: "That I think there is a great mystery; we don't know what it's all about. Who knows what's going to happen when we die? Who knows whether there's a heaven or hell? I was born into this faith. I think it's important to have a faith, therefore I will continue to attach myself to this faith." But it really is pretty much what Susan Sontag a long time ago called "piety without content." They believe in religion more than they believe in what religion teaches.

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