Astronomy Intelligent Design

Galileo’s contemporary science opponents made a lot of sense

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People who got their education from the village atheist may be surprised to learn that much opposition to the Copernican (heliocentric) theory of our solar system was not religious but scientific. A man named Johann Georg Locher summed up contemporary science-driven arguments against the Sun-centred solar system, in favour of an Earth-centred one:

Locher argued that Copernicus was wrong about Earth circling the Sun, and that Earth was fixed in place, at the centre of the Universe, like Ptolemy said. But Locher was making no religious argument. Yes, he said, a moving Earth messes with certain Biblical passages, like Joshua telling the Sun to stand still. But it also messes with certain astronomical terms, such as sunrise and sunset. Copernicans had work-arounds for all that, Locher said, even though they might be convoluted. What Copernicans could not work around, though, were the scientific arguments against their theory. Indeed, Locher even proposed a mechanism to explain how Earth could orbit the Sun (a sort of perpetual falling – this decades before Isaac Newton would explain orbits by means of perpetual falling), but he said it would not help the Copernicans, on account of the other problems with their theory.

What were those problems? A big one was the size of stars in the Copernican universe. Copernicus proposed that certain oddities observed in the movements of planets through the constellations were due to the fact that Earth itself was moving. Stars show no such oddities, so Copernicus had to theorise that, rather than being just beyond the planets as astronomers had traditionally supposed, stars were so incredibly distant that Earth’s motion was insignificant by comparison. But seen from Earth, stars appear as dots of certain sizes or magnitudes. The only way stars could be so incredibly distant and have such sizes was if they were all incredibly huge, every last one dwarfing the Sun. Tycho Brahe, the most prominent astronomer of the era and a favourite of the Establishment, thought this was absurd, while Peter Crüger, a leading Polish mathematician, wondered how the Copernican system could ever survive in the face of the star-size problem.

Christopher Graney, “Opposition to Galileo was scientific, not just religious” at Aeon

It took generations to straighten out enough issues that the Sun-centred solar system made sense to science-minded people. Graney wrote a book on this topic in 2015: Setting Aside All Authority: Giovanni Battista Riccioli and the Science Against Copernicus in the Age of Galileo. The true history is a warning to thoughtful people to avoid popular science written by the village atheist; he knows just enough to get it all wrong.

4 Replies to “Galileo’s contemporary science opponents made a lot of sense

  1. 1
    Truthfreedom says:

    If the Universe is so ‘imperfect’
    And Nature is so ‘imperfect’
    And we are ‘imperfect’ beings…
    -Where did you get the idea of perfection?

  2. 2

    Brahe’s comments make perfect sense. The problem wasn’t with the logic, it was with the measurement. Blurry telescope optics (and the blurring or twinkling of the atmosphere) made stars look like blobs through the telescope, when in fact, they should have been points. So the argument vanished with better telescopes. Well, let’s be fair, Brahe didn’t even have a telescope, all his observations were naked eye–maybe like me, he just needed glasses.

  3. 3
    kairosfocus says:

    RS, Brahe’s precision helped his successor, Kepler. In optics, a “point” source will create a diffraction pattern which will spread out on an image screen or sensor array such as the retina. It took centuries to sort out the required optical theory. It was in what, the 1830’s that parallax of stars was directly measured. It was from 1912 or so on that a magnitude vs spectral class plot revealed the main sequence and opened up understanding of the mass luminosity law etc. Relativity was then needed to work out the implications for H-rich gravitationally collapsing balls of gas kept up by radiation pressure i/l/o fusion as energy release mechanism. This last is itself quite a strange concept: light exerting a pressure. c 1615 – 30 was an odd window in time. KF

  4. 4
    Fasteddious says:

    Several years ago Scientific American had a piece acknowledging that the geocentric model was still valid long after Galileo. A model with the sun going around the earth and everything else going around the sun was equivalent to the heliocentric system. Think relativity of location in an uncertain cosmos. (I think I got that right.) Not until stellar parallax was measured – long after Galileo – did it become clear that the Earth indeed revolved around the sun.

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