The narwhal, or narwhale ( Monodon monoceros), is a medium-sized toothed whale that possesses a large "tusk" from a protruding canine tooth. It lives year-round in the Arctic waters around Greenland, Canada, and Russia. It is one of two living species of whale in the Monodontidae family, along with the beluga whale. The narwhal males are distinguished by a long, straight, helical tusk, which is an elongated upper left canine. The narwhal was one of many species described by Carl Linnaeus in his publicatio..
The Mars Society is a space-advocacy non-profit organization dedicated to promoting the human exploration and settlement of the planet Mars. Inspired by "The Case for Mars" conferences which were hosted by The Mars Underground at the University of Colorado Boulder and established by Dr. Robert Zubrin and many others in 1998, the organization works to educate the public, the media and government on the benefits of Mars exploration and the importance of planning for a Earth-to-Mars mission in the coming dec..
History (from Greek ἱστορία, historia, meaning "inquiry, knowledge acquired by investigation") is the study of the past, specifically how it relates to humans. It is an umbrella term that relates to past events as well as the discovery, collection, organization, and presentation of information about these events. The term includes cosmic, geologic, and organic history, but is often generically implied to mean human history. Scholars who write about history are called . Events occurring prior to wr..
Zinc, in commerce also spelter, is a chemical element; it has the symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is 2. Zinc is the 24th most abundant element in the Earth's crust and has five stable . The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest mineable amounts are found in Australia, A..
A circle is a simple closed shape in Euclidean geometry. It is the set of all points in a plane that are at a given distance from a given point, the centre; equivalently it is the curve traced out by a point that moves so that its distance from a given point is constant. The distance between any of the points and the centre is called the radius.
Tamil Nadu ( ; ); literally The Land of Tamils or Tamil Country is one of the 29 states of India. Its capital and largest city is Chennai (formerly known as Madras). Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by the union territory of Puducherry and the states of Kerala, Karnataka, and Andhra Pradesh. It is bounded by the Eastern Ghats on the north, by the Nilgiri, the Anamalai Hills, and Kerala on the west, by the Bay of Bengal in the east, by the Gulf of Mannar and..
Barricade, from the French barrique (barrel), is any object or structure that creates a barrier or obstacle to control, block passage or force the flow of traffic in the desired direction. Adopted as a military term, a barricade denotes any improvised field fortification, most notably on the city streets during urban warfare.
