Thermal information is not differentiated in our memory; rather it is retained as a quality, or underlying tone, associated with the whole experience of the place. It contributes to our sense of the particular personality, or spirit, that we identify with that place. In remembering the spirit of a place, we can anticipate that if we return, we will have the same sense of comfort or relaxation as before.
There is an underlying assumption that the best thermal environment never needs to be noticed, and that once an objectively "comfortable" thermal environment has been provided, all of our thermal needs will have been met. The use of all of our extremely sophisticated environmental control systems is directed to this one end—to produce standard comfort zone conditions.
Textbooks on water-system engineering state that supply mains are generally installed on the north side of the street in the Northern Hemisphere and on the south side in the Southern Hemisphere, so that the sun will warm them. In both hemispheres they are supposed to be on the east side of north-south streets, on the premise that the afternoon sun is warmer than the morning sun.
The predicted mean vote (PMV) was developed by Povl Ole Fanger at Kansas State University and the Technical University of Denmark as an empirical fit to the human sensation of thermal comfort. It was later adopted as an ISO standard. It predicts the average vote of a large group of people on the a seven-point thermal sensation scale where:
These days I am more interested in the reverse case [of Da Vinci's helicopter]: ideas that could have worked many centuries before they actually appeared. The economist Alex Tabarrok calls these “ideas behind their time”
Curious minds want to know why these ideas appeared so late — and whether there might be anything that would prevent delays in future. One explanation is that the ideas aren’t as simple as they appear.
The bicycle is not as straightforward an invention as it seems. To move from ox-hauled cart to human-powered bicycle requires smooth-rolling wheel bearings, which in turn need precisely engineered bearing balls. Modern steel ball bearings were not patented until the late 1700s, and demand from the 19th-century bicycle industry helped to improve their design.