The Body: A Guide for Occupants

As wondrous as the body is, it is also very strange. People can hear sounds because the ears contain very small and precisely shaped bones that transit the sound pulses to the auditory nerves. The digestive system relies on hydrochloric acid to dissolve foods, yet it doesn’t digest itself. The brain is the central processor of sensations, but it contains no sensory nerves of its own. 

Some body systems are stunningly precise, like the control of internal temperature and the processing of sensory inputs, but other systems are awkwardly jury-rigged, as with bipedal locomotion, which adds unusual strains to the spine, and delivery of babies, which puts an infant’s too-large head through a too-small birth canal. Sleep is absolutely vital, and people will die without it, but it also requires the sleeper to lie immobile for hours at a time, exposed to predation. 

Many of the strange aspects of the human body are simply mysteries not yet unraveled by science. The drop in fertility of recent decades, the mechanics of aging, and the true purpose of sleep appear strange largely because they are too complex to understand easily. It’s widely expected that these puzzles, like many others of recent decades, will succumb to the relentless progress of medicine. At that point, they will shift from the strange to the wondrous.