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.
RADAR is a system that uses radio waves to determine and map the location, direction, and/or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations and terrain. A transmitter emits radio waves, which are reflected by the target and detected by a receiver, typically in the same location as the transmitter. Although the radio signal returned is usually very weak, radio signals can easily be amplified, so radar can detect objects at ranges where other emissions, such as sound or visible light, would be too weak to detect. Radar is used in many contexts, including meteorological detection of precipitation, air traffic control, police detection of speedingtraffic, and by the military.
The term RADAR was coined in 1941 as an acronym for Radio Detection and Ranging. This acronym of American origin replaced the previously used British abbreviation RDF (Radio Direction Finding). The term has since entered the English language as a standard word, radar, losing the capitalization in the process.
Deep Impact is a NASAspace probe designed to study the composition of the interior of the cometTempel 1. At 5:52 UTC on July 4, 2005, one section of the Deep Impact probe successfully impacted the comet's nucleus, excavating debris from the interior of the nucleus. Photographs of the impact showed the comet to be more dusty and less icy than expected. The impact generated a large, bright dust cloud that obscured the hoped-for view of the impact crater.