Jack Eddy died recently. Numerous articles and obituaries have credited him with discovering, and christening as "the Maunder Minimum" the period 1645-1715 when virtually no sunspots were seen (here is
Nature,
Telegraph,
Wikipedia). The conventional wisdom seems to be that the historical sunspot data was vaguely known but not widely accepted, until he came along, proved it really happened and coined the name "Maunder Minimum" in his 1976 paper. But is this really true? One of my sources suggested recently that there may be more to this story that meets the eye. He was an active researcher in this area at the time (and remains so) and says he remembers the term as being in widespread use prior to that paper. He even used the term himself in 1977 as if it were a well known expression. So I did a bit of investigation.
Let's look first at the conventional wisdom. Eg from the Telegraph's obit:
"While many contemporary scientists were sceptical about the reliability of these observations, Eddy reinvestigated sunspots in the light of Spörer's and Maunder's work, and concluded that every two centuries or so there was an interruption to the 11-year cycle. He christened the period 1645-1715 "the Maunder Minimum". "
And Wikipedia:
"he identified a 70-year period from 1645 to 1715 as a time when solar activity all but stopped. [...] which he called the Maunder Minimum"
(the
MM page also repeatedly credits him with its discovery)
Now, Eddy himself certainly acknowledged (
in an interview with Spencer Weart) that other scientists (specifically Maunder and Spörer) had known about the sunspot data, but argued that "in science the proper credit for something goes not necessarily to the first person who thinks of it, or writes about it but to the one who can convince his colleagues and the doubting world that it's true". However, he very specifically claims the name as his own:
"I also, deliberately chose the title of the paper in Science, calling it simply the "The Maunder Minimum." I knew nobody would know what that was."
I was therefore rather surprised to find that a simple google search finds the term "Maunder Minimum" used no fewer than three times in the
Introduction to a conference proceedings, dating from August 1975 - almost a full year before the famous Science paper appeared. Indeed, the author of this article (
E. N. Parker) refers precisely to the 1645-1715 interval as "the 70 year minimum (sometimes called the Maunder Minimum)" without any attribution or other hint that this might have been a recent neologism. He also refers to coronal and auroral observations which back up the sunspot evidence for anomalous solar behaviour at this time. Eddy was not at this meeting but a colleague of his from NCAR (Gilman) did attend and even has a brief comment, following the Introduction, which refers to some of his work with Eddy concerning the sun's rotation rate at around that same period. There are no formal references to any work by Eddy anywhere in the entire conference proceedings that I can find.
It gets curiouser. In
the same interview with Weart, Eddy specifically credits Gene Parker with introducing him to Maunder's work - this is the very same E. (Eugene) N. Parker who gave that introductory presentation in 1975 and talked about "the 70 year minimum (sometimes called the Maunder Minimum)". Contrary to Eddy's claim, I'm sure that Parker, and all the other scientists at that conference, would have known exactly what "The Maunder Minimum" referred to when Eddy's paper appeared!
None of this is intended to belittle Eddy's contribution of linking the sunspots to other data and putting it all on a firmer footing. But it seems clear that the basic phenomenon - and the name - was fairly well known (at least in the relevant research community) prior to his paper. Perhaps the story has grown a little during the numerous retellings on the after-dinner circuit he seems to have enjoyed. I think it may be time for a bit of Wikipedia editing...
I haven't found an earlier ref than 1975 to the "Maunder Minimum", but I am equipped with nothing more than google, so maybe someone else can do better...(I did see a dodgy ref in 1968 in German but it seems to be a typo).
Update 7/07/09I hadn't bothered to click on it as I has assumed it must post-date the famous 1976 paper, but in fact this paper by Eddy, Gilman and Trotter "
Solar rotation during the Maunder Minimum" predates the famous Science paper by several months! Dated Jan 1976 (only submitted Dec 1975 - how's that for a fast turnaround) it refers to Eddy 1976 as being in press.
It is also notable that in the 1976 paper, Eddy specifically christens the Spörer minimum (1460-1550) with the phrases "The earlier minimum, which we may call the Spörer minimum" and "which I have called the Spörer minimum". It is pretty clear that he named the Spörer minimum, and this contrasts strongly with the manner in which he refers to the Maunder minimum.
