An interview with Steven Weinberg
Justification of striving
TSR: Obviously there’s a higher science return from physics. Is there a higher return in terms of things we can touch, feel, and see? We like the Hubble pictures. Can we say, “That’s making my life better” about something comparable out of physics research?
Weinberg: The aim of the kind of work I do is not to make life better. I hope to make it more interesting. I talk to a lot of groups that are not scientists. I was talking to someone who invited to me to give a talk. I named various topics and the one that he went for was “The Mystery of Dark Energy”. People are fascinated by that.
TSR: Maybe we’ll come up with a use for dark energy?
Weinberg: I don’t think so. I think cosmology, the study of the universe in the large, in a way has an unfair advantage over other branches of physics, because it does appeal to people in a way that, say, particle physics doesn’t. Even in particle physics, people have been fascinated by quarks and antimatter. I think it does make life more interesting for a lot of people. It’s something that at a certain level can only be done with government money.
TSR: If it’s at bottom amusement and entertainment, shouldn’t we let the science TV programs pay for the science they do rather than support it from the government?
Weinberg: Well, we won’t get real science that way. We know what we’ll get. Look at the science TV programs.
TSR: But if that’s the main justification, are we buying too much science?
Weinberg: I don’t say that’s the main justification. That’s a justification. There are a number of justifications. One justification is that people find it interesting. Another justification is, as R. R. Wilson said, in effect, something that makes our civilization worthwhile. It’s something we’ve accomplished and contributed to the march of history. I think that’s really the most fundamental one. Then there’s all the other ones that we point to that we don’t really care about, that are real—when I say “we” I am talking now about the working scientists—the spinoffs. It’s certainly true. The money goes into these experiments like the Large Hadron Collider that is going to be going on the air next year. In my field of elementary particle physics, that’s where large amounts of money go. That spending actually produces economic value not from the knowledge that’s gained, but from the experience of pushing the technology to do the experiments.
TSR: Right. The “Grand Challenge”.
Weinberg: This is true of the space program too. I can quote a number of examples from elementary particle physics. The most obvious one is the World Wide Web, which was invented by particle physicists as a means of sharing data between laboratories. There are other examples. It is generally true that pushing the state of the art generally does produce economic spinoffs. That’s also an argument for the space program.
But it’s not specifically an argument for the manned spaceflight program. In fact, I would say, exactly the opposite. The technology required to do science in space without having people involved is just the kind of technology that’s useful on Earth. It’s the technology of computers and robotics. I gave a talk at IBM about just this issue. One of the people in the audience said, “The hell with robotics—it’s computer programming where it really has a big effect.”
Whereas having people in the loop is precisely what eliminates the necessity of having such elaborate computer program and robotics. Instead, what you do is you develop the technology of keeping people alive in space, which is not a useful technology for any purpose except for keeping people alive in space! I would say from the point of technological spinoffs, that’s a real argument for doing basic science. It applies to particle physics. It applies to unmanned space science. It applies less so to manned spaceflight.
NASA and species survival
TSR: The universe is a dangerous place; we may get another asteroid strike like the one that killed the dinosaurs.
Weinberg: That’s another place where NASA should be spending more money. Monitoring our Earth environment. I don’t know that NASA cut back on that because it never spent money on that. I think that we should have an active program of telescopes on Earth or in space—I don’t know which is needed—but government supported. It’s not basic science, but it’s important to the survival of Mankind to monitor the environment and get enough of an advanced word of anything really dangerous heading our way so that we can begin to take steps to protect ourselves. That’s something I’d like to see NASA money spent on. In one area where NASA has spent money and has cut way back is surveillance of the Earth—studying climate change. I spoke to someone here at University of Texas to someone who studies climate change. She was complaining bitterly about the cutbacks. It turns out she wasn’t talking hundreds of millions of dollars for space satellites, she was talking about hundreds of thousands of dollars for remote sensing on Earth which has been cut back. That’s just absolutely crazy. By the standards of NASA, it’s chump change.
TSR: Every thirty years the amount of heat that humanity produces doubles. We’ve been doing this for hundreds of years. Right now our waste heat is about 0.01% of the solar flux—about one hour’s worth of solar flux per year. If it doubles thirteen more times, that would be as much as entire solar flux. That could be in 400 years.
Weinberg: As you know, Freeman Dyson though that was the ultimate limiting factor on any civilization was the ability to get rid of waste heat. He expected that when we find really advanced civilizations what we would find is—
TSR: —the Dyson Sphere. They would capture all of their energy, but we would see their heat.
Weinberg: That’s interesting that we are only thirteen 30-year periods away from that. Thirteen doublings. I don’t know.
TSR: Not from the Dyson Sphere. We could just move a little off into low Earth orbit and put up a Mylar sheet and still have plenty of coolness right nearby.
Weinberg: Yes. Well, I always am suspicious when people talk about e-foldings and then they say, “With only 20 e-foldings—” There was that infamous example of the Club of Rome. They anticipated that the trends that were going on would continue and everything would go to Hell in n years. I don’t remember what n was.
TSR: 30. In the year 2000 everything would be terrible.
Weinberg: Things that double for a while after a while stop doubling. But in fact, the real problem is not the heat produced by human being but the effect of human beings on the atmosphere in preventing the Earth from re-radiating its heat into space. The greenhouse effect. That’s the serious problem we have now.
TSR: It can’t be too bad. Doesn’t radiation go up as the fourth power of temperature?
Weinberg: Well, I haven’t done any of these calculations. Yes, of course that’s true.
TSR: So we won’t end up Venus, probably.
Weinberg: No. No, we won’t end up as Venus. But we may end up as the Congo. We may lose Florida and Venice and Bangladesh and so on. That would be a great tragedy.
TSR: Suppose we do keep on our current economic expansion and population expansion. Should we stop when the Earth gets full or should we work on expanding into the nearby cool airless desert—the Moon and LEO—and become maybe a 35-trillion-person species instead of a six-billion?
Weinberg: It’s certainly possible. I wouldn’t object. But I think the question is premature. Much closer to us than Mars or the Moon is an area we haven’t expanded into: Antarctica. Compared to Mars, Antarctica is heaven. Right now I don’t think we’d even be capable of setting up an economically self-supporting colony in Antarctica. Maybe we could. Certainly there’s no economic pressure to do so. I wouldn’t begin to think about colonies on Mars before I saw that Antarctica was getting crowded.
TSR: Or under the sea or people living on airships that were permanently fly through the jet stream. Do we want to have an insurance policy against species extinction?
Weinberg: That’s a better argument for Mars. It’s possible. We’re not capable of setting up an economically self-supporting colony on Mars. When we are capable of doing so, I think you’d make a good case for doing it. I think we ought to when we’re capable of doing it. We’re not now. I think the idea of a lifeboat is worth consideration.
TSR: So you would send more on basic space research as opposed to sending someone.
Weinberg: Yes. Certainly sending someone now serves no purpose.
Prevent the end of the world
Weinberg: There are so many things we could do if you think about, for instance, the need for a lifeboat. There are so many things we could do to prevent the ship from sinking that we’re not doing for want of money. One of the things I mentioned is surveillance of the Earth’s environment for asteroids hitting us.
The other great danger we face is cataclysmic nuclear war. What we should do to avoid that is to spend anything it takes to control nuclear materials. There is a program—the Nunn-Lugar program—which aimed at controlling nuclear materials in the former Soviet Union. It has been consistently underfunded. Now, I would rather spend money on that than anything including space—including science!
TSR: Fully fund that first.
Weinberg: I think that there is a real danger. I mean, the greatest danger facing us on Earth is cataclysmic nuclear war. I think both the nuclear forces of Russia and America are not intended for that purpose, but they are configured for that.
Weinberg: They are—and the Russians, the more their forces are degraded by the decay of their military establishment, the more they put them on a hair-trigger basis. And I think—you know—you ask me, “What is the chance that by an unintended misinterpretation of what’s happening, the Russians launch nuclear weapons at us in the next 20 years?”
TSR: More likely than an asteroid strike?
Weinberg: I would say, maybe even—with the present situation, with the lack of control, with our really—
TSR: Is this poor monitoring and poor systems that were developed forty years ago?
Weinberg: I would say more likely than not. I am terrified of it.
Weinberg: I think if things don’t improve—I think there’s also a chance that things will improve. But I—
TSR: So you are not heartened by President George Bush Sr.’s taking our nuclear missile off of a hair trigger and the fact that the Russians haven’t been spending so much on keeping their nuclear arsenal up to date?
Weinberg: I’m terrified by the fact they’re not spending money on keeping it up to date. It means they’re not spending money on things that would give them the assurance that they could ride out a first strike and still retaliate, which is the greatest source of stability. And I think that they’re not spending money on security that they should spend. There was a discussion of having a center in Moscow that would monitor missile launches on both sides.
Weinberg: And that was never funded. I think the Congress and the President—not just this president, but all presidents—have been criminally careless with this issue. And only a few people like Sam Nunn. And there’s a defense expert named Bruce Blair. It’s a really serious problem.
TSR: Would the best thing for human spaceflight be to cut off government funding so it can learn to be efficient and cost effective?
Weinberg: No. There are some things only government can do. You cannot be efficient and cost effective doing things that cannot possibly earn a profit. No, there are public goods and private goods.
TSR: The Google guys have just paid for a Moon rover with private money. We’re only about 40-50 years behind the public space program.
Weinberg: If you said that private support would now be relied on for basic physics and for space-based astronomy, I think you’d see them come to an end. They’re too expensive and I don’t think it would work. It’s true that ground-based astronomy still continues largely privately funded. In the 19th century, the best science was privately funded science. Conceivably we could make a transition to privately funded science across the board. I think one of the things we would need for that is a steeply graduated income tax together with a charitable deduction. We are going in the opposite direction. We’re going toward a flatter tax with limited charitable deductions. It is exactly the wrong direction to go.
One of the glories of American society is the fact that our universities, museums, opera companies, and churches operate without government support, many of them operate without federal support. We have lots of universities that operate without any government support. In a way they keep the government supported universities healthy because they provide a standard. The University of Texas I think would be a much worse place if it weren’t for places like Stanford and Harvard.
TSR: Right. Keeping us competing. Well, thank you for very much for granting this interview.
Weinberg: I enjoyed it.