Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site kontron.UUCP Path: utzoo!linus!philabs!prls!amdimage!amdcad!amd!pesnta!pertec!kontron!cramer From: cramer@kontron.UUCP (Clayton Cramer) Newsgroups: net.astro Subject: Re: StarDate: July 8 The Solar Corona Message-ID: <406@kontron.UUCP> Date: Wed, 24-Jul-85 18:46:59 EDT Article-I.D.: kontron.406 Posted: Wed Jul 24 18:46:59 1985 Date-Received: Sun, 28-Jul-85 06:50:24 EDT References: <320@utastro.UUCP> <713@lsuc.UUCP> Organization: Kontron Electronics, Irvine, CA Lines: 58 > dipper@utastro.UUCP (Debbie Byrd) writes: > > July 8 The Solar Corona > > > > On today's date in the year 1842, there was a total eclipse of the > > sun. It became famous for some of the earliest scientific descriptions > > of the sun's corona. > > > > The reason there were no earlier scientific descriptions is that the > present visible (excited) form of the corona has only existed since about > that time, or perhaps a few decades previously. Apparently the sun's > level of activity tends to change at intervals on the order of a century, > and the present level is exceptionally high. > > Periods of high activity are characterized by the presence of sunspots > and the appearance of auroras. (Whether there is always a (2x11)-year cycle > when there are sunspots is unknown due to the scarcity of pre-telescopic > sunspot observations.) But even in past periods of high activity there are > no descriptions of eclipses resembling the way they appear now with the corona. > The present level, as I said, must therefore be exceptionally high. > > In periods of low activity there are almost no sunspots at all. This most > recently happened from 1645 to 1715. (There were then almost no auroras > in Scandinavia where they are now commonplace.) This may be why, when Schwabe > described the 11-year sunspot cycle about 1840, he was not believed at first. > When he was seen to be correct, scientists fell into believing that it had > always been that way, rather than that Schwabe had observed something new, > and the 1645-1715 "Maunder minimum" had to be rediscovered more than once > in historical records (Halley, Newton...) before IT was believed. > > Anyway, the 1645-1715 period coincides with the coldest part of the "Little > Ice Age", when places like Britain had what we here call a winter. Evidence > is that this is not a coincidence, and therefore the present global temperature > is unusually high (but may stay that way in future due to man's CO2 output). > > My source for all this is the article "The Case of the Missing Sunspots", > by John A. Eddy, in Scientific American, May 1977, p.80. Eddy was the > second rediscoverer, after Maunder (mentioned above). Anyone know of > further developments since then? > > Mark Brader I just *know* I'm going to get flamed for this. When I was a kid (about 8 or 9), I became very interested in the subject of the sunspot period. I grabbed the birth years of 100 randomly selected Nobel laureates and plotted them versus sun spot records. Fifty per cent of the Nobel laureates were born in the 20% of the years when sun spot activity was at its lowest. Of course, only being 8 or 9, I didn't have a sufficient grasp of statistics to do a more detailed analysis, nor quite the skills to get a Federal grant to study this issue. :-) Makes you wonder if the explosion of knowledge and technology in the last few centuries might be connected to the increase in solar activity? Just a thought. When the above ideas revolutionize biophysics, I'm sure I won't get any credit for sparking it.:-)