Paris, Descartes, Newton, and the Void Bradley “Peanut” McCoy AAPT Summer meeting 2020  Doesn’t it always start with Aristotle  University of Paris 1277 Condemnations Outline  Descartes Over-reaches  Newton Non Fingos “In a void, no one could say why a thing once set in motion should stop anywhere; for why should it stop there rather than here? So that a thing will either be at rest or Outline must be moved ad infinitum, unless something more powerful gets in its way.

- Aristotle from Physics, Book IV section 8 University of Paris 1277 Condemnations

Condemned belief, punishable by excommunication:

“That God could not move the heavens with rectilinear motion; and the reason is that a vacuum would remain.” University of Paris 1277 Condemnations

Religious objection – There must be no limits on God’s power. “There is no real difference between space and corporeal substance…It is a contradiction to suppose there is such a thing as a vacuum, i.e. that in which there is nothing whatsoever. The impossibility of a vacuum, in the philosophical sense of ‘that in which there is no substance whatsoever’, is clear from the fact that there’s no Outline difference between the extension of a space or internal place and the extension of a body.”

- Rene Descartes from Principles of Philosophy (1644) Cartesian dualism – everything is either matter or mind

“It’s easy to see from all this that celestial matter is not different from terrestrial matter.” Outline - Rene Descartes from Principles of Philosophy (1644) “In the beginning he [God] created matter, along with its motion and rest; and now, merely by regularly letting things run their course, he preserves the same amount of motion and rest in the material universe as he put there in the beginning.” Outline - Rene Descartes from Principles of Philosophy (1644)

Religious objection – Materialist, God not active in the universe “1. Absolute, true, and mathematical time, in and of itself and of its own nature, without reference to anything external, flows uniformly... 2. Absolute space, of its own nature without reference to anything external, always remains homogeneousOutline and immovable… 3. Place is the part of space that a body occupies, and it is, depending on the space, either absolute or relative.”

- Isaac Newton from Principia, Scholium (1687) “He [God] endures always and is present everywhere, and by existing always and everywhere he constitutes duration and space. Since each and every particle of space is always, and each and every indivisible moment of duration is everywhere, certainly the makerOutline and lord of all things will not be never or nowhere.” - Isaac Newton from Principia, General Scholium (1687)  The concept of a vacuum was debated on philosophical grounds long before it was scientifically observable.  Key breakthrough: distinction between matter and Conclusions the space that it occupies  Religious response: Catholic church balked at theological claims made by scientists and philosophers, remaining neutral on existence or not of vacuum.