|
Bronze Age
The Bronze Age was a historical period lasting from approximately 3300 to 1200 BC. It was characterized by the use of bronze, the use of writing in some areas, and other features of early urban civilization. The Bronze Age is the middle principal period of the three-age system, between the Stone Age, Stone and Iron Ages. Worldwide, the Bronze Age generally followed the Neolithic period, with the Chalcolithic serving as a transition. The Bronze Age is generally considered to have ended with the Late Bronze Age collapse, a time of widespread societal collapse between and 1150 BC. This collapse affected a large area of the Eastern Mediterranean, including North Africa and Southeast Europe, as well as the Near East, in particular History of Egypt, Egypt, Ancient Libya, eastern Libya, the Balkans, the Aegean Sea#History, Aegean, Anatolia, and the Caucasus. It was sudden, violent, and culturally disruptive for many Bronze Age civilizations, and it brought a sharp econom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegean Sea
The Aegean Sea ; tr, Ege Denizi (Greek language, Greek: Αιγαίο Πέλαγος: "Egéo Pélagos", Turkish language, Turkish: "Ege Denizi" or "Adalar Denizi") is an elongated embayment of the Mediterranean Sea between Europe and Asia. It is located between the Balkans and Anatolia, and covers an area of some 215,000 square kilometres. In the north, the Aegean is connected to the Marmara Sea and the Black Sea by the straits of the Dardanelles and the Bosphorus. The Aegean Islands are located within the sea and some bound it on its southern periphery, including Crete and Rhodes. The sea reaches a maximum depth of 2,639m to the west of Karpathos. The Thracian Sea and the Sea of Crete are main subdivisions of the Aegean Sea. The Aegean Islands can be divided into several island groups, including the Dodecanese, the Cyclades, the Sporades, the Saronic Islands, Saronic islands and the North Aegean islands, North Aegean Islands, as well as Crete and its surrounding islands. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egyptian Hieroglyphs
Egyptian hieroglyphs (, ) were the formal writing system used in Ancient Egypt, used for writing the Egyptian language. Hieroglyphs combined logographic, syllabic and alphabetic elements, with some 1,000 distinct characters.There were about 1,000 graphemes in the Old Kingdom period, reduced to around 750 to 850 in the classical language of the Middle Kingdom, but inflated to the order of some 5,000 signs in the Ptolemaic period. Antonio Loprieno, ''Ancient Egyptian: A Linguistic Introduction'' (Cambridge: Cambridge UP, 1995), p. 12. Cursive hieroglyphs were used for religious literature on papyrus and wood. The later hieratic and demotic Egyptian scripts were derived from hieroglyphic writing, as was the Proto-Sinaitic script that later evolved into the Phoenician alphabet. Through the Phoenician alphabet's major child systems (the Greek and Aramaic scripts), the Egyptian hieroglyphic script is ancestral to the majority of scripts in modern use, most prominently the Latin and Cyr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuneiform
Cuneiform is a logo-syllabic script that was used to write several languages of the Ancient Middle East. The script was in active use from the early Bronze Age until the beginning of the Common Era. It is named for the characteristic wedge-shaped impressions (Latin: ) which form its signs. Cuneiform was originally developed to write the Sumerian language of southern Mesopotamia (modern Iraq). Cuneiform is the earliest known writing system. Over the course of its history, cuneiform was adapted to write a number of languages in addition to Sumerian. Akkadian texts are attested from the 24th century BC onward and make up the bulk of the cuneiform record. Akkadian cuneiform was itself adapted to write the Hittite language in the early second millennium BC. The other languages with significant cuneiform corpora are Eblaite, Elamite, Hurrian, Luwian, and Urartian. The Old Persian and Ugaritic alphabets feature cuneiform-style signs; however, they are unrelated to the cuneiform lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesopotamia
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the Fertile Crescent. Today, Mesopotamia occupies modern Iraq. In the broader sense, the historical region included present-day Iraq and Kuwait and parts of present-day Iran, Syria and Turkey. The Sumerians and Akkadians (including Assyrians and Babylonians) originating from different areas in present-day Iraq, dominated Mesopotamia from the beginning of written history () to the fall of Babylon in 539 BC, when it was conquered by the Achaemenid Empire. It fell to Alexander the Great in 332 BC, and after his death, it became part of the Greek Seleucid Empire. Later the Arameans dominated major parts of Mesopotamia (). Mesopotamia is the site of the earliest developments of the Neolithic Revolution from around 10,000 BC. It has been identi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Writing
The history of writing traces the development of expressing language by systems of markings and how these markings were used for various purposes in different societies, thereby transforming social organization. Writing systems are the foundation of literacy and literacy learning, with all the social and psychological consequences associated with literacy activities. In the history of how writing systems have evolved in human civilizations, more complete writing systems were preceded by ''proto-writing'', systems of ideographic or early mnemonic symbols (symbols or letters that make remembering them easier). ''True writing'', in which the content of a linguistic utterance is encoded so that another reader can reconstruct, with a fair degree of accuracy, the exact utterance written down, is a later development. It is distinguished from proto-writing, which typically avoids encoding grammatical words and affixes, making it more difficult or even impossible to reconstruct the exac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry. The primary use of arsenic is in alloys of lead (for example, in car batteries and ammunition). Arsenic is a common n-type dopant in semiconductor electronic devices. It is also a component of the III-V compound semiconductor gallium arsenide. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, and insecticides. These applications are declining with the increasing recognition of the toxicity of arsenic and its compounds. A few species of bacteria are able to use arsenic compounds as respiratory metabolites. Trace quantities of arsenic are an essential dietary element in rats, ham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, opacity (optics), opacity, and lustre (mineralogy), luster, but may have properties that differ from those of the pure metals, such as increased strength or hardness. In some cases, an alloy may reduce the overall cost of the material while preserving important properties. In other cases, the mixture imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Alloys are defined by a metallic bonding character. The alloy constituents are usually measured by mass percentage for practical applications, and in Atomic ratio, atomic fraction for basic science studies. Alloys are usually classified as substitutional or interstitial alloys, depending on the atomic arrangement that forms the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smelting
Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal base behind. The reducing agent is commonly a fossil fuel source of carbon, such as coke—or, in earlier times, charcoal. The oxygen in the ore binds to carbon at high temperatures due to the lower potential energy of the bonds in carbon dioxide (). Smelting most prominently takes place in a blast furnace to produce pig iron, which is converted into steel. The carbon source acts as a chemical reactant to remove oxygen from the ore, yielding the purified metal element as a product. The carbon source is oxidized in two stages. First, the carbon (C) combusts with oxygen (O2) in the air to produce carbon monoxide (CO). Second, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
