What is Emergence? Some scientists nowadays have revitalized this already old idea, according to which, when one climbs the ladders of complexity, from elementary particles to galaxies and amebas to humankind, new properties appear. “The whole is more than the sum of its parts,” they say. Some among them even refer to a specific effect of the whole on the parts: Do not our conscious decisions change what the neurons in our brain do, thereby justifying our free will?
Going beyond the old scientific ideal of reductionism, this revival of emergence augurs a revolution to come, somewhat similar to that which occurred when Galileo argued for the inversion of the old cosmology to adopt the Copernican point of view. Here thus the return of the three protagonists of the famous book of Galileo, brought up to date: Sagredo, Simplicio, and Salviata. Each day during a certain spring in Paris, they go to Saint Germain des Près, the museum of the Conservatoire des Arts et Métiers, and so forth. They meet there famous scientists, such as James Clerk Maxwell, Charles Darwin, Ilya Prigogine, or Roger Sperry. With them, they discuss emergence in their respective disciplines. By listening to them, one can measure the formidable challenges of this new debate for science and philosophy and better understand phenomena as various as the shape of molecules, the workings of the brain, or, perhaps more importantly, the nature of time.
Rudolf Carnap, “Logical Foundations of the Unity of Science,” in International Encyclopedia of Unified Science, vol. 1, ed. Otto Neurath, Rudolf Carnap and Charles Morris (Chicago, il: University of Chicago Press, 1938).
From1906, the practice of dating rocks by measuring their radioactivity and isotopic composition led to consolidating and specifying these estimates. The most recent measurements using such methods put the age of the earth at 4.57 billion years.
See Ernst Mayr, Evolution and the Diversity of Life (Cambridge: Belknap Press, 1976).