Luke Blackstone Circulus Vitae aluminum, light-emitting diodes, glass, electronic and electromechanical devices, wooden spoon, tea kettle, rubber, clear acrylic sheet, leaf exterior: 15 ft. X 6 ft. X 4 in. interior: 32 in. X 28 in. X 22 in. 2005
Circulus Vitae is a Latin phrase meaning "cycle of lives" and was inspired by the name of the building, Silva, which means "a group of trees". The artwork connects the relationship between trees - as part of our environment and human breath - life. The mechanism in the lobby window refers to the human act of breathing. Every 4 seconds (a relaxed breathing rate), air is blown from two glass cylinders onto a leaf, which moves a tilt switch. This sends a signal to an electronic counter, which tallies the number of "breaths" taken over a period of a year. As the number increases, it is displayed in binary form via the red light-emitting diodes located behind the glass at the bottom of the window. Decimal numbers are etched into the glass to help convert the binary number system to the more familiar decimal number system. The window mechanism also controls light-emitting diodes that are mounted inside the exterior aluminum tubes. Each tube represents a binary digit. If a tube is illuminated, it is a "one". If it is not, then it is a "zero". By looking at which tubes are illuminated, it is possible to read the total number of breaths taken since the beginning of the year. Annual tree ring patterns, derived from native cedar, fir, and hemlock trees, are engraved into the tubes. At the end of the year, all 24 tubes will be illuminated and the wooden spoon will tap the glass cylindrical lungs, celebrating the beginning of a new year.