EDDY: Yes, on a mountain top, and it looked very astronomical, and going up there sounded like a real adventure. I got into it that way. I think the lesson I learned there, again, was never to be dissuaded when you first step into another discipline. Because as soon as I asked the archaeologists about it, and the anthropologists, they would tell me right away that there's absolutely no point in looking at it. That it had been there too long, and too many people had looked at it already and learned all there was to know. And this notion of astronomy and sky-oriented alignment wasn't going to work out anyway. I have since learned that when you venture into something new - even in your own field - you're always going to he told that it's not possible, or unnecessary, or someone else has already been there. And you never should be dissuaded. So that was a really good learning experience for me.

EDDY: Right, Gene Parker was an occasional visitor at the High Altitude Observatory in Boulder. He's from the University of Chicago, as anyone who listens to this knows. I remember him coming there in the late 1950s and giving a colloquium on his wild idea that there was a solar wind, before that was accepted by anyone. I remember the unanimous reaction of the solar physicists to his idea: what a ridiculous notion that was -- a wind blowing charged particles out of the Sun. It reinforces what I said earlier: that new ideas, if they are worth anything, will always be met by a knee-jerk rejection on the part of the disciplinary experts. It also tells something about Gene, who was never afraid of stepping into new things. Later, in the early 1970s, he called Maunder's early papers to my attention: did I know about this thing in the past? (I did not.) Because he knew I had an interest in history. I don't know just why he told me. He may have known that at that time I was cautiously and with some prejudice digging back into the history of sun weather relations, which is another story.

WEART: That's of the sunspot cycle story?

EDDY: The 11-year sunspot cycle and correlations with it, which I was very negative about.

WEART: You thought, as most people did, that it was an impossible thing.

EDDY: I had been taught that while the Sun indeed affects the upper and outer atmosphere of the Earth, purported connections with the troposphere and weather and climate were uniformly wacky and to be distrusted. I still believe that to some extent, for there is a hypnotism about cycles that seems to attract people. It draws all kinds of creatures out of the woodwork. The claims that were made for associations between weather events and the Sun I thought were pretty preposterous. One of those that turned up was this notion that Gene told me about. About the work of Walter Maunder 100 years before, when he had thought that there was a prolonged period of time in the 1600s when the Sun wasn't so active.

That really piqued my curiosity, and I began digging into it. The trail was, initially, purely historical, initiated by Gene Parker telling me about Maunder, and driven by my prejudice of trying to find examples from the past that would disprove, once and for all, the notion of strong sun-weather relations. A devout negativism on this subject was the gospel at the High Altitude Observatory anyway and the catechism that I had been taught and had taught to others. And although I was indeed an acolyte, I was trying to examine the early origins of Sun-weather claims, like unrolling and deciphering the Dead Sea scrolls of solar physics. But it was mostly a love of history that took me down the trail.

EDDY: It was entirely sunspots at first. I wanted to check these original records, so I did that as much as I could, and the NASA editorial job enabled me to do that. Then, when that came together, I began to look around for other ways that there might be for checking on it -- that Maunder and Sporer didn't have. I knew I would face an uphill battle convincing my colleagues about the reality of the Maunder Minimum if it leaned entirely on accounts from so long ago. Why should you trust someone in the 1600s when we are so much smarter and know so much more now? As scientists, we're trained to discount what one finds in old books, I think. You know science does, of necessity, have to look at things through a rather narrow window of time, because most of what earlier generations believed has been replaced by something else. Some things may be of interest for historical reasons, like whether Galileo was left-handed, or Niels Bohr thought this or that, but usually not for practical or applied ones. And I thought there ought to be some way to check on what Maunder, and earlier, Sporer, had claimed.

EDDY: So when I read Maunder's and Sporer's claims from the 1890's that several hundred years before that the sun had behaved strangely for seventy years, it seemed almost preposterous. And in the long-standing traditions of the High Atltitude Observatory, where I had been trained, it needed to be shot at, even after all these years, and dismissed once and for all. So I set out to demonstrate that what Maunder had claimed was really nonsense. I felt I could do that by applying other tests that Maunder didn't have: like our better understanding of aurorae and so on. And so I tried them. And every one I tried seemed to confirm what Maunder and Sporer had said.

WEART: I see. So you really started by trying to make it go away.

EDDY: I started by trying to make it go away, mostly because of a prejudice about sun-weather relationships, and what I thought was true about the sun. In time I realized that there was a more profound and philosophical message in the Maunder Minimum: that people want the Sun to be more constant and regular than perhaps it is. The connection with carbon-14 I think was the clinching thing. I had become certain enough on the basis of historical records, and aurorae, and the Chinese sunspot records, and the absence of the corona (or what seemed to me the absence of the corona at that time, or a very, very minimum corona). Even though none of these lines of evidence might have been strong enough to make the case-to convict a criminal in court-the combination of them all pointing the same way was to me more than convincing. It was like the strength that can be found in thread or string when enough strands are woven together. That's what finally convinced me and I was ready to publish the paper. And then I looked into the carbon-14 thing, learned more and more about that and found this DeVries anomaly that the carbon-14 people had found long after Maunder was gone. It was coincident in time with the Maunder Minimum and of the right sense-that is, what one would expect to happen to carbon-14 production were the Sun unusually inactive for 70 years.

You're the first person who has mentioned that name [DeVries] to me in many years Spencer. It fit together so well, and I think has since. The ensuing work on Beryllium 10 from polar ice cores has also helped confirm the Maunder Minimum. When I die, I'll think that's one thing that I did that I'll feel absolutely certain about. That the Sun really does go through prolonged period of anomalous behavior, and will again some day.

EDDY: They were, but they were also very skeptical about the sun-weather connections that had been proposed.

WEART: Because so much nonsense had been written about it.

EDDY: Exactly. And they were also disdainful about the solar constant. The solar constant was to most solar physicists a joke. It was like saying, "I'm doing my thesis on the solar plexus, or suntan lotion" something. It had so little to do with what they saw as the really exciting parts of the sun. At the High Altitude Observatory anyway there was this obsession with radiative transfer theory, under non-thermodynamic equilibrium conditions. I can't imagine anything duller, but that somehow had almost everyone obsessed. That was what you worked on. Or else you'd work on longstanding but prosaic features such as flares or faculae or prominences. These other things that had to do with the Earth were considered a bit beneath an astronomer and certainly an astrophysicist, and were best left to the amateurs, or maybe to someone at the fringe. So the possible climate connection with the Maunder Minimum was also kind of a blow to me.

Jack Eddy http://www.aip.org/history/climate/eddy_int.htm