This is a lovely video of the San Francisco sky for a year. According to the YouTube description,
A camera installed on the roof of the Exploratorium museum in San Francisco captured an image of the sky every 10 seconds. From these images, I created a mosaic of time-lapse movies, each showing a single day. The days are arranged in chronological order. My intent was to reveal the patterns of light and weather over the course of a year.
More information on the project site: http://www.murphlab.com/ahots
It is also a very clear illustration of how day length changes symmetrically over the year. All of the days are synchronized, starting and ending at the same time. So you can see that some days are much shorter and longer than others, and that sunrise and sunset happen a little earlier or later than the previous one. The exact times of sunrise and sunset depend on our latitude here in the Bay Area.
So… how does this connect back to resource efficient infrastructure?
Knowledge of the sun’s movement and its position in the sky at any given date and time are fundamental to energy efficient building design and the thermal and visual comfort of the building’s occupants.