LIFE AS NO ONE KNOWS IT - SARA IMARI WALKER

A mind fuck. Typically, I avoid pop-science stuff. It tends to dumb really, really complex things down to simple explanations, which makes people feel like they really understand what is being discussed, which then get used to make conclusions in other realms. Quantum physics is the most obvious example of this, there are no shortage of new age books that seek to explain the world or buttress their argument with “quantum physics” when their understanding of QP comes from pop-science books. But, I heard this book was good and mind-bending so I decided to pick it up. Walker is trying to do two things in this book, map out theory as to what constitutes life from a physics angle. This would help us recognize alien life that is very, very different than us. Secondly, and relatedly, she wants to explore how life here on earth began and if/how life could be created under other circumstances. The answer given in this book is pretty unique (at least to me), and it involves a new scientific theory called “Assembly Theory.” AT proposes that every object in the universe has two properties, an assembly index and a copy number, that can be combined to tell us an object’s assembly number, which in turn (if it’s over 15) can tell us whether or not something is evidence of life. Important to say that the assembly number does not say the object itself is alive, necessarily, but whether or not something alive was involved in its creation, since a lot of really complex objects means that something was selected for them and that something must be alive. Very interesting and heady stuffy, especially if you really consider what this means about very complicated hyper-objects, which Walker points out are quite large in “time” (another complex idea in the book is that an object’s size in time is a material property of the object, not merely a metaphor) in the sense that their assembly requires so many different points of selection. As she puts it in the book, “”matter,” “information,” “causation,” “computation,” “complexity,” and “life,” assembly theory is an attempt to see all of these as the same thing.” It’s something I think I’ll be thinking about for a while and try to apply to different areas of thought, much like the new age people I complained about at the top of this review. The book also includes parts about the history of this line of thinking as well as current experiment to try to build life from scratch here on earth. I found these parts less compelling. Likewise, I went to go look up a scientific paper that Walker had published in Nature that explains Assembly Theory in more technical terms and I found it really helpful. Sometimes the book is too light on the science and too interested in the color and background. Either way, a fascinating way to look at the world.