Science (from Latin scientia, meaning "knowledge") is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
From classical antiquity through the 19th century, science as a type of knowledge was more closely linked to philosophy. In the West, the term natural philosophy encompassed fields of study that are currently associated with disciplines such as classical physics, astronomy and medicine and was a precursor of modern natural sciences (life science and physical science). In the 17th and 18th centuries, scientists increasingly sought to formulate knowledge in terms of laws of nature. Over the centuries, the term science became associated with the scientific method, a systematic way of studying the natural world and particularly in the 19th century, multiple distinguishing characteristics of contemporary modern science began to take shape.
Modern science is typically divided into three major branches that consist of the natural sciences (e.g. biology, chemistry, physics), which study nature in the broadest sense; the social sciences (e.g. psychology, sociology, economics), which study individuals and societies; and the formal sciences (e.g. mathematics, logic, theoretical computer science), which study abstract concepts. There is disagreement, however, on the formal sciences being a science as they do not rely on empirical evidence. Disciplines that use science, such as engineering and medicine, are described as applied sciences.
Science is related to research and is commonly organized by academic and research institutions as well as government agencies and companies. The practical impact of scientific research has led to the emergence of science policies that seek to influence the scientific enterprise by prioritizing the development of commercial products, armaments, health care, and environmental protection.
The geology of the Grand Canyon area
exposes one of the most complete sequences of rock
anywhere, representing a period of nearly 2 billion years of the Earth
's history in that part of North America
. The major sedimentary rock
layers exposed in the Grand Canyon
and in the Grand Canyon National Park
area range in age from 200 million to nearly 2 billion years old. Most were deposited in warm, shallow seas
and near ancient, long-gone sea shores. Both marine and terrestrial sediments are represented, including fossilized sand dunes
from an extinct desert
Uplift of the region started about 75 million years ago in the Laramide orogeny, a mountain-building event that is largely responsible for creating the Rocky Mountains to the east. Accelerated uplift started 17 million years ago when the Colorado Plateaus (on which the area is located) were being formed. In total these layers were uplifted an estimated 10,000 feet (3000 m) which enabled the ancestral Colorado River to cut its channel into the four plateaus that constitute this area. But the canyon did not start to form until 5.3 million years ago when the Gulf of California opened up and thus lowered the river's base level (its lowest point) from that of large inland lakes to sea level.
Direct current-generated plasma (violet) enhances the growth of carbon nanotubes in this laboratory-scale PECVD apparatus. Plasma-enhanced chemical vapor deposition processes utilize plasma to enhance chemical reaction rates. PECVD processing allows deposition at lower temperatures, which is often critical in the manufacture of semiconductors. The red color in the picture is black-body radiation.
Michio Kaku (Kanji: 加来 道雄) (born January 24, 1947 in the United States) is a Japanese American theoretical physicist, tenured professor, and co-creator of string field theory, a branch of string theory.
Dr. Kaku is the author of several scholarly, Ph.D.-level textbooks and has had more than 70 articles published in physics journals covering topics such as superstring theory, supergravity, supersymmetry, and hadronic physics. He is also known as an author of popular science books, including the best-sellers Beyond Einstein, Visions, Hyperspace, and Parallel Worlds, and the host of several radio shows, as well as being a popular figure in science television shows due to his accessible approach to the layman on explaining complex physics.
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