Archelaus (philosopher) Archelaus (philosopher) Archelaus (; ; fl. 5th century BCE) was an Ancient Greek philosopher, a pupil of Anaxagoras, and may have been a teacher of Socrates. He asserted that the principle of motion was the separation of hot from cold, from which he endeavoured to explain the formation of the Earth and the creation of animals and humans. Archelaus was a philosopher of the Ionian School, called "Physicus" from having been the first to teach natural philosophy at Athens. This statement of Diogenes Laërtius, is contradicted by Clement of Alexandria, but the two may be reconciled by supposing that Archelaus
Hot tub energy efficiency of portable hot tubs (late 2006). California's portable electric hot tub listing include R values of thermal insulation, and standby watts. Hot tub covers have been shown to reduce most of the evaporative losses from the pool when not in use. With this component of heat loss being 70% a cover with even a small R-value is able to achieve as much as a 75% reduction in heating costs when used as opposed to leaving the water surface exposed. There are several different types of spa covers. Some covers are better for insulation and therefore are lighter on