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The war of the currents was a series of events surrounding the introduction of competing electric power transmission systems in the late 1880s and early 1890s. It grew out of two lighting systems developed in the late 1870s and early 1880s; arc lamp street lighting running on high-voltage alternating current (AC), and large-scale low-voltage direct current (DC) indoor incandescent lighting ...
Painting of a Copper Age walled settlement, Los Millares, Spain The Chalcolithic or Copper Age is the transitional period between the Neolithic and the Bronze Age. [1] It is taken to begin around the mid-5th millennium BC, and ends with the beginning of the Bronze Age proper, in the late 4th to 3rd millennium BC, depending on the region.
The Westinghouse company installed thirty more AC-lighting systems within a year, and by the end of 1887 it had 68 alternating current power stations compared to 121 DC-based stations Edison had installed over seven years. [20] This competition with Edison led, in the late 1880s, to what became known as the "war of currents". Thomas Edison and ...
Chalcolithic (or "Eneolithic", "Copper Age") Ancient history (The Bronze and Iron Ages are not part of prehistory for all regions and civilizations who had adopted or developed a writing system.) Bronze Age; Iron Age; Late Middle Ages. Renaissance; Early modern history; Modern history. Industrial Age (1760–1970) Machine Age (1880–1945) Age ...
Jōmon pottery, Japanese Stone Age Trundholm sun chariot, Nordic Bronze Age Iron Age house keys Cave of Letters, Nahal Hever Canyon, Israel Museum, Jerusalem. The three-age system is the periodization of human prehistory (with some overlap into the historical periods in a few regions) into three time-periods: the Stone Age, the Bronze Age, and the Iron Age, [1] [2] although the concept may ...
The second world war saw tremendous advances in the field of electronics; especially in radar and with the invention of the magnetron by Randall and Boot at the University of Birmingham in 1940. Radio location , radio communication and radio guidance of aircraft were all developed at this time.
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Reconstruction of Ötzi's copper axe (c. 3300 BCE). The Copper Age, also called the Eneolithic or the Chalcolithic Age, has been traditionally understood as a transitional period between the Neolithic and the Bronze Age, in which a gradual introduction of the metal (native copper) took place, while stone was still the main resource utilized.