Daily Nature and Science News and Headlines. Prehistoric Time Line, Geologic Time Scale, Photos, Facts, Maps, and More. Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history.
A lot has happened in that time. Earth formed and oxygen levels rose in the foundational years of the Precambrian. The productive Paleozoic era gave rise to hard-shelled organisms, vertebrates, amphibians, and reptiles. Dinosaurs ruled the Earth in the mighty Mesozoic. And 64 million years after dinosaurs went extinct, modern humans emerged in the Cenozoic era. Human Brain Facts and Answers. By Disabled World - 2008-10-19 Questions answers and facts relating to the human brain and the study of the brain organ including the spinal cord.
What is the Brain? The brain is the center of the nervous system in animals. All vertebrates, and the majority of invertebrates, have a brain. Some "primitive" animals such as jellyfishes and starfishes have a decentralized nervous system without a brain, while sponges lack any nervous system at all. In vertebrates, the brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing, balance, taste, and smell. The human brain controls the central nervous system by way of the cranial nerves and spinal cord, the peripheral nervous system and regulates virtually all human activity. The brain controls both involuntary, or "lower," actions, such as heart rate, respiration, and digestion.
Brain Facts and Figures: How long is the spinal cord and how much does it weigh? How much does the brain weigh? A. Interactive 3D model of Solar System Planets and Night Sky. Astronomy Magazine - Interactive Star Charts, Planets, Meteors, Comets, Telescopes. Photopic Sky Survey. Prehistory. Prehistory (meaning "before history", or "before knowledge acquired by investigation", from the Latin word for "before," præ, and historia) is the span of time before recorded history or the invention of writing systems.
Prehistory refers to the period of human existence before the availability of those written records with which recorded history begins. More broadly, it can refer to all the time preceding human existence and the invention of writing. The notion of "prehistory" began to surface during the Enlightenment in the work of antiquarians who used the word 'primitive' to describe societies that existed before written records. The first use of the word prehistory in English, however, occurred in the Foreign Quarterly Review in 1836. The occurrence of written materials (and so the beginning of local "historic times") varies generally to cultures classified within either the late Bronze Age or within the Iron Age. Definition Stone Age Paleolithic uninhabited. Norse mythology.
An undead völva, a Scandinavian seeress, tells the spear-wielding god Odin of what has been and what will be in Odin and the Völva by Lorenz Frølich (1895) For the practices and social institutions of the Norse pagans, see Norse paganism Norse mythology, or Scandinavian mythology, is the body of mythology of the North Germanic people stemming from Norse paganism and continuing after the Christianization of Scandinavia and into the Scandinavian folklore of the modern period.
The northernmost extension of Germanic mythology, Norse mythology consists of tales of various deities, beings, and heroes derived from numerous sources from both before and after the pagan period, including medieval manuscripts, archaeological representations, and folk tradition. Most of the surviving mythology centers on the plights of the gods and their interaction with various other beings, such as humanity and the jötnar, beings who may be friends, lovers, foes and/or family members of the gods. Sources