Pressure is the Problem

摘要

The basic problem in sending humans down to great depths, or even relatively modest depths, is simple: We were designed, or evolved, to function best under a fairly rigid set of specifications. These include sea level pressure, specific body temperature, correct breathing gas mixture, light levels, and so forth. On this planet, the greatest extreme of physical topography is approximately 14 miles. The tallest mountain is approximately seven miles up and the bottom of the Marianas Trench is, coincidently, just over seven miles down. We can't go to the top of Mount Everest the way we were born-naked, freezing, needing oxygen at a greater pressure than found there, and we certainly can't go the bottom of the ocean in our natural state. If we stray too far from our sea level design specs, the results can range from uncomfortable to fatal.