Caltech professor Sean Carroll is a world-class explainer of physics and cosmology. In The Big Picture: On the Origins of Life, Meaning and the Universe Itself, he turns his explanatory power toward a broader set of ideas. Fundamental physics, specifically the Core Theory (reality = fermion stuff + boson fields) and quantum mechanics, serves as Carroll’s scientific starting point while poetic naturalism captures his philosophical perspective. Tying these ends together becomes the job of Bayesian probability and emergence. As the subtitle suggests, Professor Carroll sets up an ambitious project and he succeeds on most, but perhaps not all, points.
One pivotal word enables that reconciliation between all the different stories: emergence. Like many magical words, it’s extremely powerful but also tricky and liable to be misused in the wrong hands…A naturalist believes that human behavior emerges from the complex interplay of the atoms and forces that make up individual human beings.
Carroll’s is a straightforward take on naturalism; the universe consists only of natural phenomena described by natural laws that we come to know through observation. The poetic modifier refers to the different but consistent descriptions of the world provided by humanity’s dedicated areas of study. As he builds the case for poetic naturalism, Carroll argues that our best descriptions of the universe come at two levels: underlying reality understood imperfectly through observation and emergent reality understood, with improving accuracy, by natural sciences, arts and philosophy. The combined effect of these two levels allows for a balance between the determinism of physical laws and the flexibility brought about by abduction and a dedication to seek the best explanations across different contexts.
A poetic naturalist has another way out: something is “real” if it plays an essential role in some particular story of reality that, as far as we can tell, provides an accurate description of the world within its domain of applicability…Not everything is real, even by this permissive standard. Physicists used to believe in the “luminiferous aether”…There is no domain in which our best description of the world invokes the concept of luminiferous aether; it’s not real.
As expected, The Big Picture shines in its description of the Core Theory, the Big Bang, the lower entropy history of the universe and quantum mechanics. Carroll’s easy use of helpful diagrams and illustrative metaphors reflect the depth to which he has studied these topics. It is at these moments that the reader is clearly in the presence of master. Less poetic and more Wikipedia-like are Carroll’s descriptions of the biology bits he considers necessary to round out his argument. Thankfully, there is plenty of excellent popular science describing evolution that Carroll relies on for adequate if not a bit utilitarian effect. However, the descriptions of molecular biology largely lack subtlety reading like a digestible textbook and forays into moral philosophy stretch to reach 101 levels. Still, he does manage the occasional helpful analogy in these areas as well.
Deciding how to be good isn’t like solving a math puzzle, or discovering a new fossil. It’s like going out to dinner with a group of friends. We think about what we want for our individual selves, talk to others about their desires and how we can work together, and reason about how to make it happen.
Whatever his limitations may with respect to biology and philosophy, the sum total of Carroll’s argument in favor of poetic naturalism is compelling. Readers wanting a deeper appreciation for fundamental physics and how it integrates with other fields of study, scientific and otherwise, to produce meaning for the dedicated naturalist are unlikely to do any better than The Big Picture.