# John A. Eddy

John Allen Eddy (March 25, 1931 – June 10, 2009) was an American astronomer who in 1976 published a landmark paper in Science titled "The Maunder Minimum" where, using the Nineteenth Century works of Edward W. Maunder and Gustav Spörer, he identified a 70-year period from 1645 to 1715 as a time when solar activity all but stopped.

## Quotes

* "It has long been though that the sun is a constant star of regular and repeatable behavior. Measurements of the radiative output, or solar constant, seem to justify the first assumption, and the record of periodicity in sunspot numbers is taken as evidence of the second. Both records, however, sample only the most recent history of the sun."
* "I have reexamined the contemporary reports and new evidence which has come to light since Maunder's time and conclude that this 70-year period was indeed a time when solar activity all but stopped. This behavior is wholly unlike the modern behavior of the sun which we have come to accept as normal, and the consequences for solar and terrestrial physics seem to me profound."
* "The reality of the 'Maunder Minimum' and its implications of basic solar change may be but one more defeat in our long and losing battle to keep the sun perfect, or, if not perfect, constant, and if inconstant, regular. Why we think that sun should be any of these when other stars are not is more a question for social than for physical science."
* “I am most indebted to E N Parker for calling my attention to Maunder's papers, and for personal encouragement in all the work reported here.”
* "It would seem that Maunder and Sporer were right and that most of the rest of us have been wrong. As is often the case in the onrush of modern science, we had too quickly forgotten the past, forgotten the less-than-perfect pedigree of the sunspot cycle and the fact that it too once came as a surprise. We had adopted a kind of solar uniformitarianism, contending that the modern behavior of the sun represented the normal behavior of the sun over a much longer span of time."
* "The Maunder minimum corresponds almost precisely with the coldest excursion of the 'little ice age', a period of unusual cold in Europe from the 16th century through the early 19th century. In the coldest extremes of that period the average temperature was about one degree Celsius colder than it is now, according to the British climatologist Hubert H. Lamb. In that period the Alpine glaciers advanced farther than they had since the last major glaciation 15,000 years ago. In that period too the Norse colony in southwestern Greenland perished to a man, cut off from the rest of the world by pack ice that year after year failed to thaw."
* "We had adopted a kind of solar uniformitarianism," solar physicist John (Jack) Eddy suggested in retrospect. "As people and as scientists we have always wanted the Sun to be better than other stars and better than it really is."
* Regarding the claims of Maunder and Sporer: "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."
* "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."
* "But my reasons for taking this less-traveled road were many. One is the inevitable thrill of discovery when you wander into new areas. More importantly, you also avoid the danger of being too comfortable in too narrow a niche. I truly believe the sayings that there is no hope for the satisfied man and that without fear there is no learning. Entering a new field with a degree in another is not unlike Lewis and Clark walking into the camp of the Mandans. You are not one of them. They distrust you. Your degree means nothing and your name is not recognized. You have to learn it all from scratch, earn their respect, and learn a lot on your own. But I also think that many of the most significant discoveries in science will be found not in but between the rigid boundaries of the disciplines: the terra incognita where much remains to be learned. It's not a place that's hidebound by practice and ritual. I have always tried to keep moving between fields of study and it shows up, I think, in my vitae."
* "When we have observed the Sun most intensively, its behavior may have been unusually regular and benign."
* "Were God to give us, at last, the cable, or patch-cord that links the Sun to the Climate System it would have on the solar end a banana plug, and on the other, where it hooks into the Earth—in ways we don’t yet know—a Hydra-like tangle of multiple 24-pin parallel computer connectors. It is surely at this end of the problem where the greatest challenges lie."

## References

* 1 2 3 4 5 Eddy, J.A., "The Maunder Minimum", Science 18 June 1976: Vol. 192. no. 4245, pp. 1189 - 1202, PDF Copy
* 1 2 "The Case of the Missing Sunspots"; Scientific American, May 1977, volume 236, issue 5, pages 80-92
* ↑ Changing Sun, Changing Climate? by Spencer Weart
* 1 2 3 Interview with Jack Eddy, April 21, 1999: In Michigan by phone, conducted by Spencer Weart
* ↑ The Sun: A Biography by David Whitehouse, page 225.
* ↑ NASA EOS Project Science Office: The Earth Observer January/February 2004, Vol. 16, No. 1, Page 4