ScienceScience (from scientia, Latin for "knowledge") has come to mean a body of knowledge, or a method of study devoted to developing this body of knowledge, concerning the universe gained through methodological observation and experimentation. The scientific method consists of different principles and procedures that are useful in acquiring scientific knowledge. Exactly what constitutes science and scientific methods are subjects studied by the philosophy of science. Implicit in science's devotion to acquiring knowledge about the universe is an assumption that there is a reality that exists independent of a mind (or minds) perceiving it. This view, realism, holds that the universe (atoms, animals, gravity, stars, wind, microbes, etc.) exists independent of our observation. Under this view, the (approximate) truth of scientific knowledge is taken at face value. Some of the findings of science under this view can be quite extraordinary to a non-scientific mind in light of every day common observation. Atomic theory, for example, implies that a granite boulder which appears as heavy, hard, solid, grey, etc. is actually a combination of subatomic particles with none of these properties, moving very rapidly in an area consisting mostly of empty space. Philosophers sometimes distinguish between the actual reality of things within the universe, which may or may not be fully perceivable by humans, and our perception of things within the universe. Immanuel Kant coined the phrases phenomena (the universe as humans experience it) and noumena (things-in-themselves). Realism, however, is not necessary to science. Instrumentalism, for example, posits that while entities, such as atoms, help explain and predict data from experiments, these entities do not necessarily exist. This approach is favored by some when it comes to committing to the ontological status of a scientific entity which may seem unobservable in principle. In contrast to Kant's views (and despite wide acceptance that human perception of phenomena is not necessarily an accurate reflection of the universe as it really is), most scientists assert that it is possible to understand and accurately explain (at least somewhat if not fully) the universe using the scientific method to hone accurate scientific theories and laws. Scientists point out that while some people criticise the basic ideas of science, it is science alone that has provided information on the mysteries of the atom, the cell, the solar system, and the observable universe. It is science alone that has provided knowledge to develop tens of thousands of technological advances in medicine, engineering, communications and beyond. No other system which claims to compete with science has ever actually succeeded in actually producing useful information about the physical world in which we live. Previous definitions of the term Until the Enlightenment, the word "science" (or its Latin cognate) meant any systematic or exact, recorded knowledge (and the word continues to be used in this sense sometimes). "Science" therefore had the same sort of very broad meaning that "philosophy" had at that time. There was a distinction between, for example, "natural science" and "moral science," which latter included what we now call philosophy, and this mirrored a distinction between "natural philosophy" and "moral philosophy." More recently, "science" has come to be restricted to what used to be called "natural science" or "natural philosophy," and further distinctions have been drawn within it, such as physical science, biological science, and social science. Fields of study are often distinguished in terms of hard sciences and soft science. Physics, chemistry, biology and geology are all forms of hard sciences. They rely solely on the scientific method. Studies of history and sociology are sometimes called "soft science". Mathematics is widely believed to be a science, but it is not. It is more closely related to Logic; it is not a science because it makes no attempt to gain empirical knowledge. However, mathematics is the universal language of all sciences. The term "science" is sometimes pressed into service for new and interdisciplinary fields that make use of scientific methods at least in part, and which in any case aspire to be systematic and careful explorations of their subjects, including computer science, library and information science, and environmental science. Mathematics and computer science reside under "Q" in the Library of Congress classification, along with all else we now call science. Scientific Models, Theories and Laws The terms "hypothesis", "model", "theory" and, "law" are often used incorrectly in colloquial speech. Scientists use the term model to mean a proposed account of something, specifically one which can be used to make predictions which can be tested by experiment or observation. Some models become a hypothesis, which refer to a contention that has not (yet) been well supported nor ruled out by experiment. They use theory to mean both the same thing as hypothesis and more established explanations, and law to mean a theory which has been so well confirmed that the probability of being refuted by experiment is very small. Some models are used to help our thinking. Most non-scientists are unaware that what scientists call "theories" are what most people call "facts". The general public loosely uses the word theory to refer to ideas that have no firm proof or support; in contrast, scientists usually use this word to refer only to ideas that have repeatedly withstood test. Thus, when scientists refer to the theories of Biological evolution, electromagnetism, and relativity, they are referring to ideas that have survived considerable experimental testing. But there are exceptions, such as string theory, which seems to be a promising model but as yet has no empirical evidence to give it precedence over competing models. Especially fruitful theories that have withstood the test of time, and which predict and describe a very wide range of phenomenon, acquire the 'status' of a "law of nature". Most scientists believe that our descriptions of laws of nature are provisional. Theories are always open to revision if new evidence is provided. Newton's law of gravitation is a famous example of a theory falsified by experiments regarding motions at high speeds and in close proximity to strong gravitational fields. Outside of those conditions, Newton's Laws remain excellent accounts of motion and gravity. Because General Relativity accounts for all of the phenomena that Newton's Laws do, and more, General Relativity is regarded as our best account of gravitation, so far. Mathematics and the Scientific Method Science makes extensive use of Mathematics. Observing and collecting measurements often requires the use of mathematics; hypothesizing and predicting may require extensive use of mathematics. Mathematical branches often used in science include Calculus and Statistics. A form of systematic reasoning has been applied to mathematics itself at least since the time of Euclid. Many people see mathematicians as working scientifically; they regard physical experiments as inessential and argue that proofs figure equivalently in mathematics. Most do not, since mathematics does not require experimental test of its theories / hypotheses. Others observe that mathematics has no experimental tests (that do not involve mathematicians) for any of its results; mathematicians are both the investigators and the theoreticians. See: Eugene Wigner The Unreasonable Effectiveness of Mathematics. R.P. Feynman said "Mathematics is not real, but it feels real. Where is this place?". Philosophical Foundations of the Scientific Method One school of thought asserts that the scientific method (and science in general) relies upon basic axioms or "self-evident truths" such as internal consistency and realism. While it is true that many scientists believe these things and do assume them in their everyday work, the method itself does not rely on them: all such assumptions are just part of the hypotheses being tested, and many of them are subject to test as well. For example, one of the "common sense" ideas that scientists believed for a long time is that any measurable property of an object is something that exists in the object before it is measured, and our measurements are merely observations of that pre-existing condition; Quantum mechanics rejects this, because experiments have contradicted it. Some believe that scientific principles have been "solidly" established, beyond question, and are true. Some scientists themselves may indeed feel that way, having come to rely upon many of the results of science without having done all the experiments themselves; after all, one cannot expect every individual scientist to repeat hundreds of years' worth of experiments. Many scientists even encourage an attitude of skepticism toward claims that contradict the current state of scientific knowledge or some easy extrapolation from it; but that only means such claims must meet a higher burden before being accepted, not that they can never be accepted. In the extreme, some, including some scientists, may believe in this or that scientific principle, or even "science" itself, as a matter of faith in a manner similar to that of religious believers. However, neither science nor scientific method itself rely on faith; all scientific facts (i.e., measurements) and explanations (i.e., hypotheses or theories) are subject to test, and will eventually be rejected as the best available hypothesis when new evidence falsifying them is found. (See more under falsificationism. This is the reason that political, religious, or social enforcement of scientific convictions is inherently pernicious. Examples include the Roman Catholic Church's action against Galileo's non-Aristotelian discoveries about the behavior of the planets (they violated some prestigious, and ancient, philosophical speculation the Church had promoted to dogma), and Stalin's support for Lysenko's biological and genetic beliefs (what was wrong with standard genetics in Stalin's view is not clear; Lysenko was either a deliberate con man or incapable of understanding standard genetics in his day). Goals of science Despite popular impressions of science, it is not the goal of science to answer all questions, only those that pertain to physical reality. Scientists teach that science does not produce absolute and unquestionable truth. Rather, science consistently tests the currently best hypothesis about some aspect of the physical world, and when necessary revises or replaces it. Science is not a source of value judgements, though it can certainly speak to matters of ethics and public policy by pointing to the likely consequences of actions. However, science can't tell us which of those consequences to desire or which is 'best'. What one projects from the currently most reasonable scientific hypothesis onto other realms of interest is not a scientific issue, and the scientific method offers no assistance for those who wish to do so. Scientific justification (or refutation) for many things is, nevertheless, often claimed.