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Gutenberg, Johann

(Encyclopedia)Gutenberg, Johann go͞oˈtənbərg, Ger. yōˈhän go͞oˈtənbĕrk [key], c.1397–1468, German inventor and printer, long credited with the invention of a method of printing from movable type, inclu...

Miocene epoch

(Encyclopedia)Miocene epoch mīˈəsēn [key], fourth epoch of the Tertiary period in the Cenozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table), lasting from around 24.6 to 5.1 mill...

Aswan

(Encyclopedia)Aswan or Assuan both: äswänˈ, ăswănˈ [key], city (1986 pop. 190,579), capital of Aswan governorate, S Egypt, on the Nile River at the First Cataract. It is one of the driest cities in the world....

Mycenaean civilization

(Encyclopedia)Mycenaean civilization mīsēnēˈən [key], an ancient Aegean civilization known from the excavations at Mycenae and other sites. They were first undertaken by Heinrich Schliemann and others after 18...

writing

(Encyclopedia)writing, the visible recording of language peculiar to the human species. Writing enables the transmission of ideas over vast distances of time and space and is a prerequisite of complex civilization....

dating

(Encyclopedia)dating, the determination of the age of an object, of a natural phenomenon, or of a series of events. There are two basic types of dating methods, relative and absolute. In relative dating, the tempor...

dam

(Encyclopedia)dam, barrier, commonly across a watercourse, to hold back water, often forming a reservoir or lake; dams are also sometimes used to control or contain rockslides, mudflows, and the like in regions whe...

aluminum

(Encyclopedia)aluminum ălˌyo͞omĭnˈēəm [key], metallic chemical element; symbol Al; at. no. 13; at. wt. 26.98154; m.p. 660.37℃; b.p. 2,467℃; sp. gr. 2.6989 at 20℃; valence +3. Aluminum is a silver-white...

metamorphism

(Encyclopedia)metamorphism, in geology, process of change in the structure, texture, or composition of rocks caused by agents of heat, deforming pressure, shearing stress, hot, chemically active fluids, or a combin...

Cretaceous period

(Encyclopedia)Cretaceous period krĭtāˈshəs [key], third and last period of the Mesozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table), lasting from approximately 144 to 65 millio...