A review of the science book “The Big Picture: On The Origins Of Life, Meaning And The Universe Itself” by Sean Carroll
Carroll is a theoretical physicist at the California Institute of Technology and an award winner for writing science books. As the title suggests, this book is hugely ambitious with a vast and complicated subject matter. At 440 pages, it is probably longer than it needs to be and at points is a struggle to comprehend, but what makes the work so readable is the breaking of the material into 50 chapters, each of which is sub-divided into sections of a few pages at a time, plus Carroll’s clear exposition and, of course, the sheer fascination of the material itself.
The core message of the book is that there is something called “the core theory” which asserts that everything consists of particles (such as electrons, protons and neutrons) and forces (such as the strong and weak nuclear forces and electromagnetism) that arise out of fields (such as the Higgs field). He offers a very brief and very simple explanation of quantum mechanics that the core theory describes and predicts, while admitting that actually nobody really understands quantum mechanics. Carroll is clear that “there is only one world, the natural world, operating according to the laws of physics” and describes his position as “poetic naturalism” which asserts that “there is only one, unified, physical world, but many useful ways of talking about it”.
So existence, whether at the levels of the sub-atomic world, our human-size world, or the whole universe itself can be explained completely and only by physics. There is no need or case for any metaphysical or supernatural concepts such as God, life-force, soul, spirits, afterlife, miracles, magic, physic powers and the like. He accepts that there is still a great deal we do not know, but argues that we can only achieve knowledge through science. Those who argue otherwise have to provide evidence for the existence of metaphysical concepts and crucially explain how the metaphysical impacts the physical and can contradict the laws of physics with forces or processes that cannot be detected.
As far as the origin of the universe is concerned, Carroll conventionally subscribes totally to the Big Bang model, “an extraordinarily successful theory of the evolution of the observable universe”, but distinguishes this from the Big Bang itself, which he tells us is “a hypothetical moment that we know almost nothing about”. He explains that the Big Bang is “a moment in time, not a location in space” and underlines that “the Big Bang doesn’t actually mark the beginning of the universe; it marks the end of our theorectical understanding”. Eventually he concludes: “What is the world really? It is a quantum wave function. At least until a better theory comes along”.
As far as the origin of life is concerned, Carroll admits that we do not know how life on Earth originated and how life outside Earth might originate. There are all sorts of theories, taking the cell as the basic unit of life and hypothesising about metabolism-first or replication-first processes. He is convinced that “There is no reason to think that we won’t be able to figure out how life started”. Meanwhile the truth is that we do not have a single agreed-upon definition that clearly seperates things that are ‘alive’ from things that are not. NASA has a working definition but it may be that, in the future, we find something beyond Earth yet cannot be sure whether it constitutes life or not. He quotes one Nobel laureate as defining life as “nothing but a free electron looking for a place to rest”.
As far as the origin of meaning is concerned, Carroll is clear than meaning cannot come from God (because there is no supreme being in a purely physical universe) and cannot come from the universe (because this simply runs according to impersonal underlying laws), so “it’s up to you, me, and every other person to create meaning and purpose for ourselves”. He quotes one geochemist as suggesting that “the purpose of life is to hydrogenerate carbon dioxide” but, more usefully, in a concluding chapter entitled “Existential Therapy”, he offers “Ten Considerations” which includes the advice: “Whenever we ask ourselves whether something matters, the answer has to be found in whether it matters to some person or persons. We take the word and we attach value to it, an achievement of which we can be justly proud.”
So, in short, this is a challenging, but ultimately liberating, read. It underlines how much we know and how much more we do not know about our universe and how responsibility for understanding it and living a moral life in it are matters for us as humans and cannot be found in any supernatural or metaphysical externality.