Metrication in the United States There are no U.S. customary units for electric current, potential difference, or charge since these concepts were developed after the international adoption of metric in science. The metric units ampere, volt, ohm and coulomb are the only units used. The SI term hertz has replaced the term "cycles per second" as a unit of frequency. Energy is often measured in watt hours, BTUs, therms or calories rather than the SI joule. Residential and commercial electrical energy use is metered and billed in kilowatt hours, kW·h, as in most metric countries. Force measurements regularly use the pound instead of the SI
The Civil Wars: A Tree Is Best Measured When It Is Down The Civil Wars: A Tree Is Best Measured When It Is Down the CIVIL warS: a tree is best measured when it is down is an opera created in the early 1980s by director Robert Wilson to music by Philip Glass, David Byrne, Gavin Bryars and others. The vast five-act work has never been performed whole. Originally, "The Civil Wars" was conceived as a single daylong piece of music theatre to accompany the 1984 Summer Olympics. Six different composers from six different countries were to compose sections of Wilson's text inspired by the American Civil War. After initial premieres in