Science refers to any coherently organized system of knowledge attained by verifiable observation or logical vindication. The New Oxford American Dictionary describes 'science' as follows:
the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment: [e.g.,] the world of science and technology. [Also] a particular area of this: [e.g.,] veterinary science | the agricultural sciences. [Also] a systematically organized body of knowledge on a particular subject: [e.g.,] the science of criminology 
Webster's Third New International Dictionary, Unabridged offers the following:
accumulated and accepted knowledge that has been systematized and formulated with reference to the discovery of general truths or the operation of general laws : knowledge classified and made available in work, life, or the search for truth : comprehensive, profound, or philosophical knowledge; especially : knowledge obtained and tested through use of the scientific method. [Also] such knowledge concerned with the physical world and its phenomena 
We can divide sciences to two main branches:
- Abstract sciences, such as mathematics
- Empirical sciences, such as all natural and social sciences — by 'empirical' we mean "originating in or relying or based on factual information, observation, or direct sense experience usually as opposed to theoretical knowledge"
In abstract sciences, the method of vindication is logical proof. In empirical sciences, the validation of hypotheses and theories requires both confirmation by empirical observations and the absence of disconfirmation by such observations.
Abstract sciences, like mathematics, provide tools for empirical sciences. Mathematics as a whole is vital to the sciences — indeed, major advances in mathematics have often led to major advances in other sciences. Certain aspects of mathematics are indispensable for the formation of hypotheses, theories, and laws, both in discovering and describing how things work (natural sciences) and how people think and act (social sciences).
Empirical science is an attempt to explain our observations. Scientists maintain that scientific investigation must adhere to the scientific method, a process for evaluating empirical knowledge that explains observable events in nature as results of natural causes.
Fields of empirical science are commonly classified along two major lines:
- 1 Etymology
- 2 Early history of science
- 3 Modern science
- 4 Scientific method
- 5 Philosophy of science
- 6 Mathematics and the scientific method
- 7 Significance of science
- 8 Where science is practiced
- 9 Science and social concerns
- 10 Scientific literature
- 11 Fields of science
- 12 Scientific institutions
The word science comes from the Latin word scientia for knowledge, which in turn comes from scio - I know. The Indo-European root means to discern or to separate, akin to Sanskrit chyati, he cuts off, Greek schizein, to split, Latin scindere, to split. From the Middle Ages to the Enlightenment, science or scientia meant any systematic or exact recorded knowledge. Science therefore had the same sort of very broad meaning that philosophy had at that time. In some languages, including French, Spanish, Portuguese, and Italian, the word corresponding to science still carries this meaning.
From classical times until the advent of the modern era, philosophy was divided into natural philosophy and moral philosophy. In the 1800s, the term natural philosophy gradually gave way to the term natural science. Natural science was gradually specialized to its current domain, which typically includes the physical sciences and biological sciences. The social sciences, inheriting portions of the realm of moral philosophy, are currently also included under the auspices of science to the extent that these disciplines use empirical methods. As currently understood, moral philosophy still retains the study of ethics, regarded as a branch of philosophy and one of the three classical normative sciences.
Early history of science
The earliest recorded scientific practices can be traced back to Egypt in North-East Africa. Isaac Asimov (a Russian-born American author) in his book Biographical Encyclopaedia of Science and Technology reports that science is a gift from Ancient Africa to the modern world. Imhotep (an Egyptian priest) was the first recorded person to practice Medicine. The earlest scientific centre could possibly have been the Library of Alexandria in Egypt (North-East Africa), where many notable early scientists like Euclid and Heron of Alexandria came to study. The Greeks also practiced science in its early forms but the oldest trace of science still lies in Egypt.
In century 21, the following definition of Science is suggested :
Science is kind of knowledge, activity and notations, based on concepts that have all the six properties below:
S1. Applicability: Each concept has the limited range of validity, distinguishable from the empty set.
S2. Verifiability: In the terms of the already accepted concepts, some specific experiment with some specific result, that confirms the concept, can be described.
S3. Refutability: In the terms of the concept, some specific experiment with some specific result, that negates the concept, can be described.
S4. Self-consistency: No internal contradictions of the concept are known.
S5. Principle of correspondence: If the range of validity of a new concept intersects the range of validity of another already accepted concept, then, the new concept either reproduces the results of the old concept, or indicates a way to refute the old concept. (For example, the estimate of the range of validity of the old concept may be wrong.)
S6. Pluralism: Mutually-contradictive concepts may coexist; if two concepts satisfying S1-S5 have some common range of validity, then, in this range, the simplest of them has priority.
Such a definition is expected to simplify the distinguishing of science from pseudoscience, rejecting all the projects of the perpetual motion machines and gravitsapas by just the correspondence principle. Also, all the religions can be distinguished from Sicence due to the lack of the refutability.
Scientists use model to refer to a description of something, specifically one which can be used to make predictions that can be tested by experiment or observation. A hypothesis is a contention that has been neither well supported nor yet ruled out by experiment. A theory, in the context of science, is a logically self-consistent model or framework for describing the behavior of a certain natural phenomena. A theory typically describes the behavior of much broader sets of phenomena than a hypothesis — commonly, a large number of hypotheses may be logically bound together by a single theory. A physical law or law of nature is a universal statement based on a sufficiently large number of empirical observations that it is taken as fully confirmed.
The scientific method provides an objective process to find solutions to problems in a number of scientific and technological fields. Often scientists have a preference for one outcome over another, and it is important that this preference does not bias their interpretation. The scientific method attempts to minimize the influence of a scientist's bias on the outcome of an experiment. This can be achieved by correct experimental design, and thorough peer review of experimental design as well as conclusions of a study.
Empirical scientists can not claim absolute knowledge. Unlike a mathematical proof, a confirmed scientific theory is always open to falsification, if new evidence is presented. Even the most basic and fundamental theories may turn out to be imperfect if new observations are inconsistent with them. Critical to this process is making every relevant aspect of research publicly available, which permits peer review of published results, and also allows ongoing review and repeating of experiments and observations by multiple researchers operating independently of one another. Only by fulfilling these expectations can it be determined how reliable the experimental results are for potential use by others.
Isaac Newton's law of gravitation and Newton's second law are famous examples of established laws that were later found not to be universal - they do not hold in experiments involving motion at speeds close to the speed of light or in close proximity of strong gravitational fields. Outside these conditions, Newton's Laws remain an practical model of motion and gravity. Since general relativity accounts for all the same phenomena that Newton's Laws do and more, general relativity is now regarded as the accepted theory.
Philosophy of science
The philosophy of science seeks to understand the nature and vindication of scientific knowledge, and its ethical implications. It has proven difficult to provide a definitive account of the scientific method that can decisively serve to demarcate science from non-science. Thus there are legitimate arguments about exactly where the borders are. There is nonetheless a set of core precepts that have broad consensus among published philosophers of science and within the scientific community at large. (see: Problem of demarcation)
Resting on reason and logic, along with other guidelines such as Ockham's Razor, which states a principle of parsimony, scientific theories are formulated and the most promising theory is selected after analysing the collected evidence. Some of the findings of science can be very counter-intuitive. Atomic theory, for example, implies that a granite boulder which appears a heavy, hard, solid, grey object is actually a combination of subatomic particles with none of these properties, moving very rapidly in space where the mass is concentrated in a very small fraction of the total volume. Many of humanity's preconceived notions about the workings of the universe have been challenged by new scientific discoveries. Quantum mechanics, particularly, examines phenomena that seem to defy our most basic postulates about causality and fundamental understanding of the world around us.
Mathematics and the scientific method
Mathematics is essential to many sciences. The most important function of mathematics in science is the role it plays in the expression of scientific models. Observing and collecting measurements, as well as hypothesizing and predicting, often require mathematical models and extensive use of mathematics. Mathematical branches most often used in science include calculus and statistics, although virtually every branch of mathematics has applications, even "pure" areas such as number theory and topology. Mathematics is most prevalent in physics, but less so in chemistry, biology, and some social sciences.
Some thinkers see mathematicians as scientists, regarding physical experiments as inessential or mathematical proofs as equivalent to experiments. Others do not see mathematics as a science, since it does not require experimental test of its theories and hypotheses, although some theorems can be disproved by contradiction through finding exceptions. (More specifically, mathematical theorems and formulas are obtained by logical derivations which presume axiomatic systems, rather than a combination of empirical observation and method of reasoning that has come to be known as scientific method.) In either case, the fact that mathematics is such a useful tool in describing the universe is a central issue in the philosophy of mathematics.
- Further information: Eugene Wigner, The Unreasonable Effectiveness of Mathematics in the Natural Sciences
Richard Feynman said "Mathematics is not real, but it feels real. Where is this place?", while Bertrand Russell quipped, in allusion to the abstraction inherent in the axiomatic method, that "Mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true."
Mathematics cannot be considered pure science as everything that is mathematically correct may not be physically or practically correct. It is a tool to study various fields of science and to effectively pursue the scientific method.
Significance of science
|…science is about real things that happen in the world; science tries to provide a coherent understanding of these things; our specific observations must be placed in a more general framework to be understood; interpretations are often based on pictorial models; we often use instruments and measurements to augment our observations; a genuinely coherent picture often leads to predictions of new observations, which serve as tests of how correct our present interpretation is.
The underlying goal or purpose of using science in our society and individuals is to produce useful models of reality. People can form hypotheses based on observations that they make in the world. By analyzing a number of related hypotheses, scientists can form general theories. These theories benefit society or human individuals who make use of them. For example, Newton's theories of physics allow us to predict various physical interactions, from the collision of one moving billiard ball with another, to trajectories of space shuttles and satellites. Relativity can be used to calculate the effects of our sun's gravity on a mass light-years away. The social sciences allow us to predict (with limited accuracy for now) things like economic turbulence and also to better understand human behavior and to produce useful models of society and to work more empirically with government policies. Chemistry and biology together have transformed our ability to use and predict chemical and biological reactions and scenarios. In modern times though, these segregated scientific disciplines (notably the latter two) are more often being used together in conjunction to produce more complete models and tools. One goal of science is to explain and utilize multiple known phenomena with one theory or set of theories.
Science is not a source of subjective value judgments, though it can certainly speak to matters of ethics and public policy by pointing to the likely consequences of actions. 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.
For a large part of recorded history, science had little bearing on people's everyday lives. Scientific knowledge was gathered for its own sake, and it had few practical applications. However, with the dawn of the Industrial Revolution in the 18th century, this rapidly changed. Today, science has a profound effect on the way we live, largely through technology—the use of scientific knowledge for practical purposes.
Some forms of technology have become so well established that it is easy to forget the great scientific achievements that they represent. The refrigerator, for example, owes its existence to a discovery that liquids take in energy when they evaporate, a phenomenon known as latent heat. The principle of latent heat was first exploited in a practical way in 1876, and the refrigerator has played a major role in maintaining public health ever since (see Refrigeration). The first automobile, dating from the 1880s, made use of many advances in physics and engineering, including reliable ways of generating high-voltage sparks, while the first computers emerged in the 1940s from simultaneous advances in electronics and mathematics.
Other fields of science also play an important role in the things we use or consume every day. Research in food technology has created new ways of preserving and flavoring what we eat (see Food processing). Research in industrial chemistry has created a vast range of plastics and other synthetic materials, which have thousands of uses in the home and in industry. Synthetic materials are easily formed into complex shapes and can be used to make machine, electrical, and automotive parts, scientific and industrial instruments, decorative objects, containers, and many other items.
Alongside these achievements, science has also brought about technology that helps save human life. The kidney dialysis machine enables many people to survive kidney diseases that would once have proved fatal, and artificial valves allow sufferers of coronary heart disease to return to active living. Biochemical research is responsible for the antibiotics and vaccinations that protect us from infectious diseases, and for a wide range of other drugs used to combat specific health problems. As a result, the majority of people on the planet now live longer and healthier lives than ever before.
However, technology can also have a negative impact in human affairs. Over the last hundred years, some of the technological advances that make life easier or more enjoyable have proved to have unwanted and often unexpected long-term effects. Industrial and agricultural chemicals pollute the global environment, even in places as remote as Antarctica, and city air is contaminated by toxic gases from vehicle exhausts (see Pollution). The increasing pace of innovation means that products become rapidly obsolete, adding to a rising tide of waste (see Solid Waste Disposal). Most significantly of all, the burning of fossil fuels such as coal, oil, and natural gas releases into the atmosphere carbon dioxide and other substances known as greenhouse gases. These gases have altered the composition of the entire atmosphere, producing global warming and the prospect of major climate change in years to come.
Science has also been used to develop technology that raises complex ethical questions. This is particularly true in the fields of biology and medicine (see Medical Ethics). Research involving genetic engineering, cloning, and in vitro fertilization gives scientists the unprecedented power to bring about new life, or to devise new forms of living things. At the other extreme, science can also be used to generate technology that is deliberately designed to harm or to kill, like chemical and biological warfare, and also nuclear weapons, by far the most destructive weapons that the world has ever known.
Science is a useful tool. It is a growing body of understanding that allows us to contend more effectively with our surroundings and to better adapt and evolve as a social whole as well as independently. As all tools, science may also be used to create harmful technology, or technology with harmful side effects. This issue connected to applied science and technology is not an issue of science, but a question of ethics and politics.
Where science is practiced
For a large part of recorded history, science had little bearing on people's everyday lives. Scientific knowledge was gathered for its own sake, and it had few practical applications. However, with the dawn of the Industrial Revolution in the 18th century, this rapidly changed.
Today, science has a profound effect on the way we live, largely through technology—the use of scientific knowledge for practical purposes. Thus science is practiced formally, in universities and other scientific institutes and it has become a solid vocation in academia. However, informally many more people who are not associated with any university or research institute practice science in their daily life. As people involved in the field of science education often argue that the process of science is performed by all individuals as they learn about their world. For example, science is often practiced by amateurs, who typically engage in the observational part of science.
Workers in corporate research laboratories also practice science, although their results are often deemed trade secrets and not published in public journals. Corporate and university scientists often cooperate, with the university scientists focusing on basic research and the corporate scientists applying their findings to a specific technology of interest to the company. Although generally this method of co-operation has benefited both the advancement of science and the corporations, it has also in some cases lead to ethical problems, when the results arrived at in the course of research have had a negative aspect for the financing corporation. A classical example is the history of health research related to smoking.
Science is also practiced in many other places to achieve specific goals. For example:
- Quality control in manufacturing facilities (for example, a microbiologist in a cheese factory ensures that cultures contain the proper species of bacteria)
- Obtaining and processing crime scene evidence (forensics)
- Monitoring compliance with environmental laws
- Performing medical tests to help physicians evaluate the health of their patients
- Investigating the causes of a disaster (such as a bridge collapse or airline crash)
A basic understanding of science and technology has become indispensable for anyone living in a developed country, whether in an urban or rural area, because technology – a product of science – has become an important part of peoples' lives. Science education aims at increasing common knowledge about science and widening social awareness. The process of learning science begins early in life for many people; school students start learning about science as soon as they acquire basic language skills, and science is always an essential part of curriculum. Science education is also a very vibrant field of study and research. Learning science requires learning its language, which often differs from colloquial language. For example, the terminology of the physical sciences is rich in mathematical jargon, and that of biological studies is rich in Latin names. The language used to communicate science is rich in words pertaining to concepts, phenomena, and processes, which are initially alien to children.
Due to the growing economic value of technology and industrial research, the economy of any modern country depends on its state of science and technology. The governments of most developed and developing countries therefore dedicate a significant portion of their annual budget to scientific and technological research. Many countries have an official science policy, and many undertake large-scale scientific projects—so-called "big science". The practice of science by scientists has undergone remarkable changes in the past few centuries. Most scientific research is currently funded by government or corporate bodies. These relatively recent economic factors appear to increase the incentive for some to engage in fraud in reporting the results of scientific research , often termed scientific misconduct. Occasional instances of verified scientific misconduct, however, are by no means solely modern occurrences. (see also: Junk science)
Science has become so pervasive in modern societies that it is generally considered necessary to communicate the achievements, news, and dreams of scientists to a wider populace. This need is fulfilled by an enormous range of scientific literature. While scientific journals communicate and document the results of research carried out in universities and various other institutions, science magazines cater to the needs of a wider readership. Additionally, science books and magazines on science fiction ignite the interest of many more people. A significant fraction of literature in science is also available on the World Wide Web; most reputable journals and newsmagazines maintain their own websites. A growing number of people are being attracted towards the vocation of science popularization and science journalism.
Fields of science
Science is broadly sub-divided into the categories of abstract sciences, natural sciences and the social sciences. There are also related disciplines that are grouped into interdisciplinary and applied sciences, such as engineering and health science. Within these categories are specialized scientific fields that can include elements of other scientific disciplines but often possess their own terminology and body of expertise. Examples of diverse scientific specialities include Linguistics, archaeology, forensic psychology, materials science, microbiology, nuclear physics, information science, cognitive science, computer science and paleontology.
Learned societies for the communication and promotion of scientific thought and experimentation have existed since the Renaissance period. The oldest surviving institution is the Accademia dei Lincei in Italy. National Academy of Sciences are distinguished institutions that exist in a number of countries, beginning with the British Royal Society in 1660 and the French Académie des Sciences in 1666.
International scientific organizations, such as the International Council for Science, have since been formed to promote co-operation between the scientific communities of different nations. More recently, influential government agencies have been created to support scientific research, including the National Science Foundation in the U.S.
Other prominent organizations include:
- "science n." The New Oxford American Dictionary, second edition. Ed. Erin McKean. Oxford University Press, 2005. Oxford Reference Online. Oxford University Press.
- "science." ‘’Webster's Third New International Dictionary, Unabridged’’. Merriam-Webster, 2002
- "empirical." Webster's Third New International Dictionary, Unabridged. Merriam-Webster, 2002.
- The Oxford English Dictionary defines science as:
- The state of fact of knowing; knowledge or cognizance of something specified or implied; also, with wider reference, knowledge (more or less extensive) as a personal attribute. (Now only theological and philosophical.)
- Knowledge acquired by study; acquaintance with or mastery of any department of learning. Also (plural) (a person's) various kinds of knowledge. b) Trained skill
- A particular branch of knowledge or study; a recognized department of learning. b) Contradistinguished from art....d)A craft, trade or occupation requiring trained skill. (obs.)
- In a more restricted sense: A branch of study which is concerned either with a connected body of demonstrated truths or with observed facts systematically classified and more or less colligated by being brought under general laws, and which includes trustworthy methods for the discovery of new truth within its own domain.
- The kind of knowledge or of intellectual activity of which the various sciences are examples....In modern use, chiefly: The sciences (in sense 4) as distinguished from other departments of learning; scientific doctrine or investigation.... b) In modern use, often treated synonymous with 'Natural and Physical Science,' and thus restricted to those branches of study that relate to the phenomena of the material universe and their laws, sometimes with implied exclusion of pure mathematics.