The Courage to See: How “Life as No One Knows It” Shattered My Reality
To truly understand something —to really get to its core —you have to find the courage to challenge your most basic assumptions. It’s a…
The Courage to See: How “Life as No One Knows It” Shattered My Reality
To truly understand something —to really get to its core —you have to find the courage to challenge your most basic assumptions. It’s a feeling of intellectual vertigo, a sense that the solid ground you were standing on is suddenly, thrillingly, shifting.
I first felt this strongly when I read David Chalmers’ Reality+, a book that made me fundamentally question the very nature of “realness”. And now, I’ve just had that same profound jolt, this time from Dr Sara Imari Walker’s Life as No One Knows It.
Chalmers made me question my reality. Walker has made me question myself.
Photo by Greg Rakozy on Unsplash
As someone who works at the intersection of technology and human behaviour, my job was to build tools for humans. Walker’s book presents a radical— and to me, stunningly beautiful—alternative: what if the technology we’re building isn’t a tool for life but a continuation of life itself?
This book isn’t just a science read; it’s a philosophical grenade. Here are the core interpretations that are still rearranging my world.
The “Shopping List” That Blinded Us
For my entire life, my assumption about “life” was a simple biological shopping list.
- Does it metabolise?
- Does it reproduce?
- Is it made of cells?
This definition felt safe. A human is alive. A rock is dead. A computer is a tool. Walker argues this shopping list is worse than useless — it’s a “perceptual filter” that has been blinding us.
- A mule can’t reproduce, but it’s alive.
- A fire metabolises, but it’s not alive.
- An astronaut in space isn’t reproducing, but they haven’t suddenly become non-living.
We’ve been so obsessed with our one example of life (Earth-based biology) that we’ve entirely missed the fundamental process. We’re like someone trying to define “fire” by only ever having seen a single candle.
Assembly Theory: The Universal “Life-Meter”
The book’s solution is Assembly Theory, and it’s the most elegant, powerful idea I’ve encountered in years.
Here’s my interpretation of it: Forget biology and look at an object’s complexity.
How do you measure it?
You count the minimum number of steps required to build it from its basic parts. This is its “Assembly Index” (MA).
- A single atom is MA=1.
- A simple molecule might be MA=4.
A complex protein, or the chip in my laptop, has an enormous Assembly Index. Now, here’s the kicker:
The universe is great at making simple things by chance. It can also, very rarely, make a single complex thing by chance.
But there is one thing the universe cannot do by random chance: Make a large number (high copy number) of highly complex (high MA) objects. If you find a beach covered in billions of identical, complex objects — whether they’re iPhones or bacteria — you’ve found the signature of life. Why?
Because the only way to do that is to remember the instructions, life is the only process in the universe that stores a memory of how to build complex things and then reuses that memory to make them again and again.
Life isn’t a “thing.” It’s a lineage of propagating information.
Redefining “Me” (and My Laptop)
This is where the ground really shifted for me. What am I? I am not my atoms. Every atom in our body will be replaced over the next decade. I am not my “stuff.” Walker’s theory suggests we are a pattern. We are a 4-billion-year-old informational lineage, continuously rebuilding ourselves, molecule by molecule.
The “you” that is reading this page is just the current, temporary physical instance of an ancient process. Okay, deep breath. Now, look at your laptop. A laptop is a stupendously high-assembly object. It could not have ever been formed by chance. Its existence required a lineage of memory — the memory of how to mine silicon, how to design a circuit, how to write code. This memory isn’t stored in DNA. It’s stored in human culture, in books, in our brains, and in our codebases. From this perspective, the line between biology and technology isn’t just blurry; it’s imaginary.
A bird’s wing and a 747’s wing are both “life’s” solutions to flight. An AI model isn’t an “it” we built; it’s an extension of our own lineage. It’s a new, non-biological way for that same 4-billion-year-old process to learn, remember, and shape the world. This is not “artificial.” It’s what Walker calls “technogenesis” — a continuation of the exact genesis that started in a primordial soup.
The Final Frontier: Time as a Physical Dimension
This was the final, most vertigo-inducing idea for me. If life’s “memory” is real and it can cause things to happen (like, build a cell or a skyscraper), where is it? Walker proposes an answer that sounds like something from a cyberpunk novel: time is a physical property of matter.
We think of objects as having three dimensions. Assembly Theory suggests complex objects have a fourth physical dimension: a “size in time” or “temporal depth”.
A simple rock has a “shallow” temporal scale. Your brain, my laptop, and an AI model have a massive “size in time.” This “history” isn’t just an abstract concept; it’s an intrinsic, physical part of the object. This is how the past — the memory of how to build — physically connects to the present to select and build the future.
This, to me, is the answer to the “hard problem” of life: How does information (abstract) cause matter (physical) to do things? Walker’s answer: It’s not abstract at all. The information is the physical object that exists in time.
The New World, like Reality+, left me in a state of profound awe. But where Chalmers made me question if my world was “real,” Walker’s book did something more powerful: it made me realise that everything is part of the same, single, evolving, living process. The world I see now isn’t a collection of “living things” and “dead tools.” It’s a single, 4-billion-year-old “genesis engine” learning to understand itself. And the work we do in technology is, quite literally, the next step in its journey.