The power of the sun has been known throughout human existence. The Greeks and Romans developed one of its first uses in architecture between the first and fourth century A.D. Greek bathhouses used large south facing openings to let the sun’s rays warm the baths. The Greek philosopher Socrates once wrote “In houses that look toward the south, the sun penetrates the portico in winter”(Southface). The Romans improved upon the Greek design by incorporating glass and a semi-translucent rock called mica into the openings to form windows that could allow the sun’s rays into the building and keep the heat from escaping. In the sixth century A.D., the Roman Empire added “sun rights” to its zoning codes because so many houses utilized sun rooms, a room of the house that was heated by the sun’s rays. Native Americans also used the sun’s energy. The Anasazi, who lived in current day New Mexico and Arizona, built adobe and sandstone homes into south facing cliff walls so that the winter sun would heat the rock, which would stay warm throughout the night. The basic understanding of the sun’s warming capabilities was used for centuries. However, in more recent years (starting with the mid 1800’s) the sun’s ability to provide heat has been overshadowed by the invention and refinement of photovoltaic technologies. During World War II, Americans looked for alternatives to fossil energy and were again intrigued by the power of the sun. Homes were retrofitted with roof-mounted solar water heaters, which utilized the suns rays to heat much of the water used in the home. In the early 1950’s, architect Frank Bridges designed the world’s first commercial office building to use solar water heating and passive design techniques. One of the biggest credits to the ingenuity and success of the building’s design is that it has been continuously operational since the time it was built. In recent years, there has again been an increased interest in the power of the sun. One of the most notable buildings of the 1990’s is 4 Times Square, which incorporated more energy efficient techniques than any other commercial skyscraper, including the ability to keep the temperature of the building within a comfort zone relying solely on passive technologies.