Today's post is about a thought experiment that's been capturing my fancy a lot recently. In this experiment, we conceive of the entire Universe around us as nothing more (or less) than a massive simulation. We suppose that "somewhere" there's a computer whose memory banks model the precise state of every sub-atomic particle in the Cosmos. To make things simple let's assume that time and space are quantized, and more generally that the rules of physics are amenable to such a simulation.

Now imagine that we're outside observers, sitting in "somewhere" and watching this simulation run. First of all, it's important to remember that what we're watching is just a bunch of patterns of bits flitting through the simulation's memory. As an illustration, suppose that each particle is tracked by a data structure containing its position, velocity, and other state. Looking at a snapshot of this data at a particular instant in time it would be very difficult to discern objects such as a table or a tree or a person. Such concepts are largely irrelevant, if not totally nonsensical, when viewed from the sub-atomic vantage point.

Which gets to the real value of the thought experiment. Our brains are evolved to identify and interact with "objects" at the scale that's relevant to our survival, so we tend to over-value distinctions at that scale. For example in trying to understand the biological world it's quite natural to think about individual animals as units of Darwinian evolution. However when we get around to studying how ideas move through our society (i.e. memetics), our processing apparatus struggles because there are no readily available "objects" to form the basis of our model.

In light of this thought experiment, the line between biological and memetic evolution has blurred considerably in my mind. From the simulation's perspective, both are just different mechanisms by which patterns of data seem to be propagating themselves through time. Both rely on chaotic processes to explore enormous potential spaces of patterns, and utilize natural selection to gradually drive increasing sophistication. The details of how the patterns are persisted and copied are quite different when viewed from the human brain's default paradigm, but on a larger (or smaller?) scale the distinctions boil down to implementation details.

Instead of considering these to be distinct processes I now think of them as merely two manifestations of what I call Nature's Algorithm. It seems that, whether it's simulated or not, our Universe is built upon rules that irresistibly move towards increasingly complex self-replicating patterns. I strongly suspect that the particular implementations of evolution we happen to see are themselves accidents, part of a meta-evolutionary process by which nature discovers its own tools. If this were indeed how Reality works, the implications would be profound; but even if it's utterly wrong, the thought experiment is a useful way to remind yourself of your brain's scale-based blind spots.

18 Oct 2011 | Tags: Memetics

Home Page  |  Science: A Masterpiece of Evolution »