Which half? One day when I was a junior medical student, a very important Boston surgeon visited the school and delivered a great treatise on a large number of patients who had undergone successful operations for vascular reconstruction. At the end of the lecture, a young student at the back of the room timidly asked, "Do you have any controls?" Well the great surgeon drew himself up to his full height, hit the desk, and said, "Do you mean did I not operate on half of the patients?" The hall grew very quiet then. The voice at the back of the room hesitantly replied, "Yes, that's what I had in mind." Then the visitor's fist really came down as he thundered, "Of course not. That would have doomed half of them to their death!" God, it was quiet then, and one could scarcely hear the small voice ask, "Which half?" E.E. Peacock Jr., Seeing With Fresh Eyes science
Anasazi dwellings The Anasazi Indians of the southwestern United States were remarkably clever in choosing the sites for their cliff dwellings. They invariably chose locations shaded in the summer by an overhanging ledge of the cliff, but exposed to full sun all winter long. With their backs to the cliff, the dwellings were protected from the winter winds and also took advantage of the thermal mass of the earth to moderate the temperature flux. Lisa Heschong, Thermal Delight in Architecture Eaves and sun building