Monday, March 15, 2010

Nikola Tesla's Alternating Current

Nikola Tesla's Alternating Current: Serbian inventor, Nikola Tesla, is often overlooked when examining the historical development of electrification. Having secured nearly 300 patents over the course of his life, it was clear that Tesla had a profound impact on the Second Industrial Revolution. Beginning in the 1880s, large-scale electrification efforts were underway in the United States. Thomas Edison supplied New York City with its first electric grid while George Westinghouse discovered the utility of copper as an electrical conductor. But it was Tesla who devised the theoretical basis for alternating current (AC), which made long-distance electrical transmission possible. Tesla's work, however, ignited an intellectual debate with Edison over what constituted the most efficient way to distribute electricity. Edison advocated a direct current (DC) system of electrical transmission, which called for a constant level of voltage throughout the grid. Tesla criticized Edison's DC system by citing the amount of electricity that went to waste while sustaining a constant level of voltage. In an AC system, transformers represented cost-effective devices for converting high transmission voltages into low utilization voltages. This idea, along with successful installations of AC power at Niagara Falls and Chicago, effectively ended the debate of AC versus DC systems.

Monday, March 1, 2010

Marcus Garvey Goes Back to Africa?

Marcus Garvey Goes Back to Africa?: In August 1914, when the guns of World War I erupted, Marcus Garvey founded the Universal Negro Improvement Association (UNIA). Unlike the National Association for the Advancement of Colored People (NAACP), which originated five years earlier and primarily addressed African-American issues, the UNIA sought to uplift African peoples from around the world. As time progressed, the association started a weekly newspaper called The Negro World and various black-owned corporations (e.g. - Black Star Line) that operated in the economic sectors of trade, transportation, and manufacturing. Even though the UNIA managed most of its businesses from the United States, Garvey pushed for an increased emphasis on Africa. By the mid-1920s, he attempted to organize a Pan-African movement for the repatriation of African-Americans in Liberia. Its ultimate objective was to develop basic infrastructure such as roads, schools, and factories in an effort to resettle the country. Ironically, Garvey never made it to Africa and the Liberia program had to be abandoned due to unforeseen conflicts with American capitalistic designs, such as the Firestone Company's interest in Liberian rubber plantations.