The below introduction “The next Grand Solar Minimum, Cosmic Rays and Earth Changes (an introduction)” contains an overview on the connection between sunspot numbers, cosmic rays, climate and tectonic activity. At the end of the text, I added an instruction on how to observe sunspots using a telescope of binoculars. This also reveals a problem with historic optical sunspot records when they are compared to modern sunspot records, meaning with the technology of roughly before the 1900s. When we today observe sunspots on online monitors using space based high-end equipment including filters, keep in mind, that until a hundert years ago, only the larger and darker sunspot were registered and recorded at all.
The telescopes available from the 1610s onwards were rather rudimentary optical devices, using hand polished lenses made from hand-blown glass. Galileo and Kepler had 8x magnifications at their disposal without any achromatic correction. Galileo was finally able to improve his design to 23x but only with a 16 mm objective. Even cheap modern binoculars are superior to this. Thus, tables for historic visual sunspot counts should be regarded in historic context of solar activity only when they are calibrated with proxies for solar activity such as BE10 and C14 measurements.
So far this year – until the end of Feb 2018 – we had only one sunspot group with sunspots dark and large enough to be easily visible with a simple telescopes. (See the projection from 2-23 below). So, as far as visually recorded sunspot numbers are concerned, we could momentarily be at levels comparable to the Dalton of even the Maunder Minimum.
Space weather Live.com has already list 25 sunspot regions in 2018.
Christoph Scheiner and a fellow Jesuit scientist trace sunspots in Italy in about 1625. Illustration from Rosa Ursina by Christoph Scheiner. p. 150. Scanned from original at Houghton Library, Harvard University. Call # GC6.Sch256.630r
The next Grand Solar Minimum, Cosmic Rays and Earth Changes (an introduction) https://abruptearthchanges.com/2018/0…