Sunspots

Sunspots

Introduction of sunspots

dark spots on the Sun's surface

The ancient Chinese

record observations of sunspots in 165

European actronomers 

thoughts about sunspots

didn't believe spots were actually on the sun

reason for this thoughts

belief that the \"heavenly\"bodies were perfect

opinion about sunspots

The shadow hypotheis-something like shadows of planets crossing the Sun's face

Galileo's finding

the shape of sunspots weren't circular

the shape of sunspots changed

opinion of sunspots

因为seeming to change shape and no predicting changes所以觉得是a feature of the Sun and maybe cloud in the atmosphere

Other hypotheses

the spots were mountains and holes

Heinrich Schwabe's claim

study procedure

look for evidence for 17 years and keep track of and map the sunspots

finding

no planets

sunspots的消长是regular的，并且10y为一个cycle

breakthrough

Wolf

keep track of sunspots for 40y

go through old records from various observatories and put together a history of sunspot综合之前100年的

different from H S

pattern is 11y rather than 10y

It is the same amount of year as the fluctuation of geomagnetic 

Scientists in the later 19s

doing studies of possible relationship between the sun and the earth

the sunspots are magnetic field