La plénitude du vide – Trinh Xuan Thuan

Thoughts: Discovered among the stacks of the Marc Favreau branch of the Montreal Library, I read La plénitude du vide as part of an ongoing effort to expose myself to more French. The book traces humanity’s evolving understanding of emptiness or nothingness, from the invention of the number zero, to Aristotle’s notion that nature abhors a vacuum, to the idea of aether, through which light was thought to travel in the void of space, all the way up to modern understandings of vacuum energy and quantum foam, before circling back to a discussion of ideas of void and emptiness in several Eastern religions. Though the subject matter may play a significant role in my preference (I’m currently reading another book of his in which entropy, complexity and emergence figure prominently), among the francophone authors whose works I’ve read so far, I enjoy Trinh Xuan Thuan’s writing the most.

(The notes below are not a summary of the book, but rather raw notes - whatever I thought, at the time, might be worth remembering.)

Trinh Xuan Thuan. 2016. La plénitude du vide. Albin Michel.

I. Le vide mathématique

• 39: to check out eventually, perhaps: Al-Khwarizmi’s Livre de l’addition et de la soustraction d’après le calcul des Indiens (or however it’s customarily translated in English - roughly 9th century) - introduced the hindu numeral system to the Arab world

II. L’horreur du vide

III. Du vide et de l’éther

IV. Le vide quantique

• 162-164: the Casimir effect: virtual particles are always popping in and out of existence, and they can interact with objects before they disappear. If two extremely thin sheets of metal are placed very close together in a vaccuum, the only virtual particles that can form between them are particles with a wavelength that’s a multiple of the distance between the two sheets. But outside of these two sheets, particles of any wavelength may come into existence. Because more particles can interact with the sheets from the outside than from the inside, the two sheets experience a force that pushes them toward each other.

V. L’univers naît du vide

• 169: “Les changements de phase sont toujours accompagnés par une perte ou un gain de symétrie” - “Phase changes are always accompanied by a loss or gain of symmetry”
  • 197: e.g. in water vapor, water molecules can be oriented in any direction (360º symmetry in all three dimensions), but in liquid water, the hydrogen atoms of water molecules tend to be oriented toward the oxygen atoms of nearby molecules - since they can no longer be be oriented any which way, this is a loss of symmetry
  • 197: phase transitions often lead to changes in complexity: when water goes from its liquid to its solid phase, the orientations of water molecules are now strictly determined, creating crystal structures - a loss of symmetry. Such crystal structures enable the formation of much more complex structures, like snowflakes
• 204: It’s believed that once the universe cooled below 10^15K, certain symmetries of the Higgs field were broken, causing it to “crystallize” undergoing a phase transition similar to that of water freezing
  • 205: above these temperatures, the weak nuclear force and the electromagnetic force are equivalent, and are known as the “electroweak” force - it’s only at lower temperatures that equations for each force begin to provide different answers for calculations.
  • 206-207: it’s predicted that above temperatures of 10^28K, the electroweak force and the strong nuclear force will behave with a similar symmetry, becoming a single, “electronuclear” force
  • 207-208: and it’s possible that at even higher temperatures, gravity is unified with the electronuclear force. If we can demonstrate this symmetry, it would be evidence in favour of the Grand Unified Theory
• 274-275: Thuan identifies the Tao Te King (Livre de la Voie et de la Vertu) and the Tchouang-Tseu as two foundational texts of Taoism. The Tao Te King is fairly short