Book Review: “Setting Aside All Authority” by Christopher M. Graney

The book “Setting Aside All Authority” comprises 10 chapters, 270 pages. The last half of the book is largely made up of two appendices: (A) the first English translation of Monsignor Francesco Ingoli’s essay to Galileo (disputing the Copernican system on the eve of the Inquisition’s condemnation of it in 1616) and (B) excerpts from the Italian Jesuit astronomer Giovanni Battista Riccioli’s reports on his experiments with falling bodies. The book is published by the University of Notre Dame, 2015.

Cover of the book. The cover image is taken from Riccioli’s New Almagest (1651). Note the heliocentric system (top left) compared to the Tychonic hybrid geocentric system (bottom right).

The main thesis of the book challenges the notion that around the time of Galileo, and the beginning of the Copernican revolution, opponents of the heliocentric worldview, championed by Galileo, were primarily motivated by religion or dictates from the authority of the Roman Catholic Church.

The author, Christopher M. Graney, uses newly translated works by anti-Copernican writers of the time to demonstrate that they predominantly used scientific arguments and not religion in their opposition to the Copernican system. Graney argues that it was largely a science-versus-science debate, rather than church authority-versus-science as often incorrectly portrayed.

In the 1651, the Jesuit Giovanni Battista Riccioli published his book the New Almagest wherein he outlined 77 arguments against the Copernican system (pro-geocentrism) and 49 arguments in favour of it. Most arguments against the Copernican heliocentric system could be answered, at that time, but Riccioli, using the then available telescopic observations of the size of stars, was able to construct a powerful scientific argument that the pro-Copernican astronomers could not answer without an appeal to the greatness of God.

Graney largely uses Riccioli’s New Almagest, which argues in favour not of the Ptolemaic system but of the hybrid Tychonic system, where the Earth is immobile at the centre of the universe, the sun, the moon and the stars circle the earth; but the planets circle the sun. Riccioli built on the work of the Danish astronomer Tycho Brahe, and built a strong scientific case against the heliocentric system, at least through the middle of the seventeenth century, which was several decades after the advent of the telescope.

The main two arguments presented in the book, both scientific, are the size of stars and the effect on falling bodies.

Falling bodies

If the earth were rotating, then a falling body should hit a point on the surface of the earth at a definite distance from a vertical line to the surface, if dropped vertically. The same argument could be made for cannon balls fired in different directions on the earth’s surface. These type of discussions and arguments carried on for a century, and even Isaac Newton got involved. What we now know as the Coriolis force, a ‘fictitious’ force, resulting from the rotation of the planet on the fired or dropped objects could not be measured with the required precision in the 17th century.

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