Today, the ever-evolving term "science" refers to the pursuit of knowledge, not the knowledge itself. It is often synonymous with "natural and physical science" and often restricted to those branches of study relating to the phenomena of the material universe and their laws. Although the term implies exclusion of pure mathematics, many university faculties include Mathematics Departments within their Faculty of Science. The dominant sense in ordinary use has a narrower use for the term "science." It developed as a part of science becoming a distinct enterprise of defining the "laws of nature"; early examples include Kepler's laws, Galileo's laws, and Newton's laws of motion. In this period it became more common to refer to natural philosophy as "natural science." Over the course of the 19th century, the word "science" became increasingly associated with the disciplined study of the natural world, including physics, chemistry, geology and biology. This sometimes left the study of human thought and society in a linguistic limbo, which was resolved by classifying these areas of academic study as social science. For example, psychology evolved from philosophy, and has grown into an area of study.
Currently, there are both "hard" (e.g. biological psychology) and "soft" science (e.g. social psychology) fields within the discipline. As a result, and as is consistent with the unfolding of the study of knowledge and development of methods to establish facts, each area of psychology employs a scientific method. Reflecting the evolution of the development of knowledge and established facts and the use of the scientific method, Psychology Departments in universities are found within: Faculty of Arts and Science, Faculty of Arts, and a Faculty of Science. Similarly, several other major areas of disciplined study and knowledge exist today under the general rubric of "science", such as formal science and applied science.
Nanotechnology comprises technological developments on the nanometer scale, usually 1 to 100 nm (1/1,000 µm, or 1/1,000,000 mm). A possible way to interpret this size is to take the width of a human hair, and imagine something ten thousand times smaller. The term has sometimes been applied to microscopic technology.
Nanotechnology is any technology which exploits phenomena and structures that can only occur at the nanometer scale, which is the scale of several atoms and small molecules. The United States's National Nanotechnology Initiative website defines nanotechnology as "the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications."
View of the Earth as seen by the Apollo 17 crew traveling toward the moon. This translunar coast photograph extends from the Mediterranean Sea area to the Antarctica south polar ice cap. This is toward the northeast. Earth, also known as Terra, and (mostly in the 19th century) Tellus, is the third-closest planet to the Sun. It is the largest of the solar system's terrestrial planets and the only planetary body that modern science confirms as harboring life. Scientific evidence indicates that the planet formed around 4.57 billion years ago, and shortly thereafter (4.533 billion years ago) acquired its single natural satellite, the Moon.