According to Dearborn, "In Europe, where
the telescope was first invented and used, it informed them that sunspots
existed. There was a belief that the heavens were perfect, and frequently
people see only what they expect to see. So when they first saw sunspots,
they were amazed. They didn't really know what sunspots were, because they
didn't have the tools to measure the
were producing these things, but they definitely sparked curiosity."
There is some debate over which European was first to discover sunspots.
The credit is usually shared by Johann Goldsmid (known as Johannes Fabricius)
of Holland, Galileo Galilei of Italy, Christopher Scheiner of Germany, and
Thomas Herriot of England, all of whom claimed to have discerned sunspots
sometime in 1611. All four men observed sunspots through telescopes, and
made drawings of the changing shapes by hand, watching the spots traverse
the visible surface of the sun. These drawings were the first steps toward
Dave Dearborn talks about the development of the telescope
and viewing sunspots.
But these scientists could not agree on what
they were seeing. Some, like Galileo, believed that sunspots were part of
the sun itself, features like spots or clouds. But other scientists, especially
Scheiner, who was a Jesuit priest, believed the Catholic Church's doctrine
that the heavens were perfect, representing the divine perfection of God.
This doctrine is often seen as an extension of Aristotle's view of the heavens
as ideal and unchanging. To admit that the sun had spots or blemishes that
moved and changed would be to undermine that perfection! So Scheiner argued
that the spots he and Galileo were seeing must be planets or moons orbiting
the sun, and he interpreted his observations in the light of that argument.
Perhaps less entangled in the doctrine of
the period, Galileo made a breakthrough. By observing the sun closely over
a period of several weeks, Galileo noticed the shape of the sunspots became
foreshortened as they approached the edge of the visible sun. He realized
that this would only happen if the spots were objects on the surface of
the sun, and not if they were spherical planets or moons passing before
the sun. So he concluded that the spots must be on the surface. Though he
admitted that he was unsure what the spots were, he suggested that they
could be clouds.