Martin Horky vs. Galileo

[lpetrich]

Who was Martin Horky?

He was a mathematician, physician, and student of astrology from Bohemia, what's now the western Czech Republic. In 1610, he was living in Bologna, Italy, in the home of astronomer Antonio Magini as that astronomer's assistant. In late April of that year, Galileo visited Bologna and demonstrated his telescope. Horky and Magini were less than impressed. Horky wrote a letter to Johannes Kepler stating that while Galileo's telescope worked miracles on Earthly objects, it also produced lots of stars that are not there. Or so he believed.

He wrote in more detail in his Brevissima peregrinatio contra Nuncium Sidereum (A very brief excursion against the Starry Messenger (published by Galileo)).

One of his arguments against the existence of Jupiter's moons was that since astrologers had already taken into account every celestial body that could have an Earthly influence, and since they did not use those moons, those moons must therefore have no purpose.

Galileo's friend John Wedderburn responded that those moons do have a purpose: to torment Horky, to confuse the astrologers, and to alarm the superstitious.

Horky also argued that Jupiter's moons were likely from flaws in the telescope, like our moon's surface features, and that Galileo's claiming to have discovered those moons was only because of his craving for money.

When Magini learned of this publication, he kicked Horky out of his house and told Galileo that he had nothing to do with that publication.


Johannes Kepler responded to Horky's letter by building his own telescope, and he observed Jupiter's moons with it. Kepler also made an innovation in telescope design that is still in use. Galileo had used a convex primary lens and a concave secondary one, because that gives an image with the correct orientation. Kepler, however, used a convex secondary one, and while it inverted the image, it also made possible greater magnification.


Sources:
Martin Horky
Letter from Martin Horky to Kepler, April, 1610
Martin Horky | Turtledove | FANDOM powered by Wikia
Martin Horký - Wikipedia (in Italian)
Galileo Galilei and the Roman Curia - Karl von Gebler - Google Books
Essays on Galileo and the History and Philosophy of Science - Stillman Drake - Google Books
 Johannes Kepler

 

[metacristi]

Horky could have argued at most, rationally I would say, that at that time there was not a clear cut theory of the apparatus (telescope) and light thus one should be not so sure of the celestial findings of Galileo (the theories usually come with auxiliary hypotheses, including about the measurement devices; sometimes we can have problems if the auxiliary hypotheses are not right, see for example Kauffman's experiences which seemed to contradict special relativity). Yet given that one could hardly deny the observations with the telescope at the Earth level it was of course more rational to safely minimize this problem (remaining open to it however, indeed the problem of the spherical aberration is in the same league; solved completely by Newton via his reflection telescope, which replaced the refraction telescope in the 18th century). But of course this kind of argument belong to the 20th century, impossible for Horky, extremely conservative even for the early 17th century, to even dream of it (the serious Academia itself was still strongly immersed in Aristotelianism even at the time when Newton started his University studies in Cambridge half a century later).

 

[lpetrich]

Here is what I think that he thought. He went from

Telescopes show stars that are not visible without them.

to

Since those stars are not visible without using a telescope, those stars must not be real stars but telescope artifacts.


Galileo's response to this telescope-artifact theory was to offer a big sum of money for anyone who can construct a telescope that makes Jupiter-moon artifacts only around Jupiter.

 

[Speakpigeon]

So some people are dumb and some people are bright.

Still, what strikes me in that story is how familiar it sounds. Some things never change. You could almost feel how Galileo must have been amused by Horky's attitude.
EB