Living in a physical world V. Maintaining temperature

摘要

Little else in our immediate world varies as much as the thermal loads that we terrestrial organisms face. Too often we find ourselves too hot, too cold, too well illuminated by sunlight, too exposed to an open sky, or in too great contact with hot or cold solid or liquid substrata. Thermal loads vary in time scale as well as in magnitude. Air temperatures and radiative regimes change over every time scale relevant to their operation, from seconds to years, at the least; in addition both soil and water temperatures may be far from constant. Variation may be as regular as night following day or it may be predictable only in a general statistical sense. Terrestrial life - and sometimes even aquatic life - is rife with thermal challenges.