Physiology seemed like a grab-bag of random processes which no one really understands. If you understand a physiological process—congratulations, that idea probably doesn’t transfer much to other domains. You just know how humans—and maybe closely related animals—do the thing. At least, that’s how I felt. (These sentiments tend to feel sillier when spelled out.)
I haven't totally changed my mind. But I do know that it's nice to look down at my hand and be able to pop through multiple understandings of my body. I start with the circulatory system and I might imagine how oxygenated hemoglobin turns bright red, tracing the flow back down to my median cubital vein (where blood is drawn). My mind’s eye flickers as I imagine the peripheral nervous system and its reflex arcs, wondering at the preconditions which trigger spinal short-circuits (and at what preprocessing is done to customize the reflex to the situation). Another flicker and I see the muscles and joints and their lubricants and connectives; gazing through flesh at my ulna and remembering the repetitive stress injury which once tormented me…
>The semicircular canals track changes in your head’s orientation. The otoliths track which way is down. But why not just combine them? Why did they evolve to be separate?
Here’s an idea.
The body is completely obsessed with inferring its state of poisonedness, and uses inner ear orientation sensors to help infer this. This is why car / sea / VR sickness exist. Since inferring poisonedness quickly is important, so it can start forcing itself to throw up, having two sensors is better because.. it’s more.. fault-tolerant? Not sure. But maybe there’s something here.