Symmetry Is Hard Wired in our Brains

According to Wilczek, symmetry is "Change without change" - the most powerful single principle underlying the laws of both aesthetics and physics. In Wilczek's books, he provides simple examples and a few mind bending ones (such as the symmetry involved in the strong nuclear force - the rules governing quarks). For some reason, he neglects the most common example of symmetry that is always quite literally right in our face. This is the ability of our perceptual system to recognize "objects" in the world - "things" that seem to be the same no matter how they are oriented, how far away they are, or how they are illuminated. Sometimes we only need to hear or smell the "thing" to "see" it in our minds. Anyone who has attempted to "teach" a computer to do anything like this knows how incredible this ability is. And it's totally natural, totally automatic. What's more all "higher" animals (maybe all living things) seem to have some version this capability - at least when it comes to recognizing "objects" that are relevant to their survival. One capability that does see universal among all living things is the ability to detect change - relevant change or what a physicist would call "symmetry breaking".

The ability to handle "change without change" is therefore hard wired into our brains, making recognition of symmetry a fundamental principle of existence, not just "consciousness". Thinking like Wilczek, we see that the dog that "looks like" the "same" dog, even though I never see her in exactly the same way, is really the same dog. My dog has something like the same capability, being able to pick me out of a crowd at considerable distance.

Of course, Zen will quibble about how our brains chop reality up into "objects" that have somewhat arbitrary definitions and boundaries, but the truly remarkable fact is that our brains get it right 99.99% of the time and do so automatically and effortlessly. Fully one third of the cortex of the brain is devoted to the visual component of this capability, giving us a clue as to its importance.

Wylczek provides another way of thinking about this. Symmetry underlies our ability to compress information about the world. The ultimate example is how the Standard Model can be written on a single sheet of paper but sums up everything we know about the laws governing ordinary matter and energy. Along these lines, we can see language as a tool for compressing everything we can know (or at least say) about the world. Our taste for symmetry acts on this "compression algorithm", making things "feel" like they are the "same" even when they are obviously different. For example, the woman who says "all men are the same" has obviously saved herself a lot of work, compressing everything she knows about men into five words. It is her built-in preference for symmetry that allows her to be believing this or at least saying this.

More on compression here.