John A. Eddy

March 25th, 1931 to June 10th, 2009

"John A. Eddy, Solar Detective, Dies at 78"

by Bruce Weber

June 18th, 2009

The New York Times

John A. Eddy, a solar astronomer who studied the history of the sun and demonstrated that it is not a constant star with a regular cycle of behavior but rather one that has periods of anomaly, died June 10 in Tucson, where he lived. He was 78.

The cause was cancer, his wife, Barbara, said.

In 1976, Dr. Eddy published an article in the journal Science in which he confirmed the speculative and largely unknown observations of 19th-century astronomers that for seven decades, from 1645 to 1715, the surface of the sun was inordinately calm, with the magnetic storms that often roil it — as indicated by the presence of sunspots — peculiarly absent.

Dr. Eddy called the peaceful interlude the Maunder Minimum, after E. W. Maunder, an English scientist who, along with a German, Gustav Spörer, first noted the presumed anomaly in the 1890s.

"I have re-examined 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," Dr. Eddy wrote.

His research consisted largely of digging into historical documents — including accounts of telescopic observations going back to Galileo; reports of the aurora borealis from centuries past; visual observations of sunspots recorded in Asia and historical descriptions of the appearance of the sun's corona during solar eclipses — all pointing with overwhelming coincidence, if not outright scientific proof, to the same conclusion.

But lastly, Dr. Eddy found confirmation of his findings in measurements of the concentration of the radioactive isotope carbon-14 found in tree rings, which is known to correlate with solar activity. The carbon-14 evidence also indicated earlier periods of solar quiescence, before the first telescopic observance of sunspots, including a period from 1450 to 1540, which Dr. Eddy called the Spörer Minimum.

Full article here:

http://philosophyofscienceportal.blogspot.com/2009/06/deceased-john-eddy.html