Posts Tagged 'heliocentrism'

Copernicus and the Lutherans

Luther's room where he engaged in 'table talk' over meals with his students

It never ceases to amaze how scientific myths manage to get recycled ad nauseam. We have all heard the absurd myth that people once believed the earth was flat, but then (since characters are involved) there is the more mischievous myth that the Protestant Reformers, Luther and Calvin, vehemently opposed Copernicus. In truth, you will find nothing in their writings, their letters, their sermons or any other productions where Copernicus is even mentioned. But, amazingly, in textbooks you will find that “Luther attacked Copernicus” (Berman and Evans, Exploring the Cosmos).

I recently read a comment stating that Martin Luther called Copernicus “the fool who will turn the whole science of astronomy upside down” and that Copernicus found it difficult to get his work published by the University at Wittenberg, and that his supporters found it difficult to get or retain jobs there.

You will search in vain within the large corpus of Luther’s works to find the abovementioned quote, or anything like it. If anyone has the candour to give a reference it will finally be traced back to an entry in the Tischreden or ‘table talk’, which contains a lot of highly entertaining but doubtless embellished and spurious material that purports to be things Luther said at the dinner table. These sayings were written down by dinner guests decades later and are practically worthless as a historical source.

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Galileo’s vain ambition

Galileo’s Dialogue concerning the Two Chief World Systems (1632), which argues for the superiority of the heliocentric Copernican over the geocentric Ptolemaic system, is a classic straw man argument. By 1632, astronomers had all but abandoned the Ptolemaic system, which had become untenable in the light of the evidence from telescopes for more than 20 years, which showed, for example, that Mercury and Venus orbited the sun. By that late stage, the majority of astronomers had adopted the geo-heliocentric model, such as that of Tycho Brahe, which had all the planets (other than earth) orbiting the sun, and the sun and the moon in orbit around the earth. Adapted to include a rotating earth, it was indistinguishable from the Copernican system on the basis of empirical observations of our ‘solar system’ from the vantage point of a terrestrial observer.

The Tychonic system was still highly regarded until the end of the seventeenth century when Newton’s discovery of principles of gravitation, and their application to the solar system, caused it to be abandoned as an explanation of reality, though it continues to this day as an elegant method for generating the terrestrial observer’s view of the motions of heavenly bodies in our solar system, for example in planetarium projectors.

So, Galileo was incapable of making a case in favour of Copernican heliocentrism over against the majority view of Tychonic geo-heliocentrism based on observation of the sun, moon and planets, and he could not do so based on physical principles as he rejected the idea of gravitation beyond the earth’s atmosphere and had never bothered to read up on Kepler’s laws of planetary motion, which had been sitting on his bookshelf for over 20 years. He also believed that no practicable terrestrial experiments could establish whether the earth was in motion, for he says in his foreword “all experiments practicable upon the earth are insufficient measures for proving its mobility, since they are indifferently adaptable to an earth in motion or at rest.” Thus he deliberately contrived to make his case using the artifice of a straw man argument, with not even a mention of the then chiefest of the world systems, the Tychonic model.

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