BBC Earth (Asia) - - Science -

Caused by mag­netic storms break­ing through the Sun’s sur­face, th­ese rel­a­tively cool patches ap­pear as black spots that seem to move across the Sun’s disc. They are some­times so large they can be seen with the naked eye through thin cloud or at sun­set. As such, their ex­is­tence has prob­a­bly been known about since pre­his­toric times, and Chi­nese as­tronomers kept records of them over 2,000 years ago.

How­ever, the true na­ture of sunspots only be­came clear with the ad­vent of mod­ern astron­omy in the early 17th Cen­tury. Be­lief in the An­cient Greek model of a per­fect Uni­verse was still wide­spread, mak­ing the very ex­is­tence of ‘blem­ishes’ on the Sun deeply con­tro­ver­sial. In 1611, the Je­suit scholar Christoph Scheiner in­sisted they were moons in or­bit around the oth­er­wise pris­tine Sun. Galileo was un­con­vinced, and ar­gued for clouds in the so­lar at­mos­phere.

The first per­son to show the sunspots were fea­tures on the Sun it­self was a Ger­man as­tronomer named Jo­hannes Fabri­cius. Us­ing a pin­hole cam­era, he ob­served clus­ters of sunspots for months, show­ing that they van­ished over the Sun’s western edge, then ap­peared again two weeks later on the other side. This con­firmed they were part of the Sun’s ro­tat­ing sur­face – and made Fabri­cius the first so­lar sci­en­tist. RM This is used in many tablets,

in­clud­ing as­pirin and parac­eta­mol, to bulk them out.

This is added dur­ing the man­u­fac­tur­ing process to help the var­i­ous pow­ders that make the tablet flow nicely to­gether.

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