Science (from the Latin scientia, meaning "knowledge" or "knowing") is the effort to discover, and increase human understanding of how the physical world works. Using controlled methods, scientists collect data in the form of observations, records of observable physical evidence of natural phenomena, and analyze this information to construct theoretical explanations of how things work. Knowledge in science is gained through research. The methods of scientific research include the generation of hypotheses about how natural phenomena work, and experimentation that tests these hypotheses under controlled conditions. The outcome or product of this empirical scientific process is the formulation of theory that describes human understanding of physical processes and facilitates prediction.
Lavoisier says, "... the impossibility of separating the nomenclature of a science from the science itself is owing to this, that every branch of physical science must consist of three things: the series of facts which are the objects of the science, the ideas which represent these facts and the words by which these ideas are expressed."
A broader modern definition of science may include the natural sciences along with the social and behavioral sciences, as the main subdivisions of science, defining it as the observation, identification, description, experimental investigation, and theoretical explanation of phenomena. However, other contemporary definitions still place the natural sciences, which are closely related with the physical world's phenomena, as the only true vehicles of science.
History of science
Main article: History of science
While empirical investigations of the natural world have been described since antiquity (for example, by Aristotle, Theophrastus and Pliny the Elder), and scientific methods have been employed since the Middle Ages (for example, by Ibn al-Haytham, Abu Rayhan Biruni and Roger Bacon), the dawn of modern science is generally traced back to the early modern period, during what is known as the Scientific Revolution of the 16th and 17th centuries. The Greek word for science is 'επιστήμη', deriving from the verb 'επίσταμαι', which literally means 'to know'.
History of usage of the word science
Well into the eighteenth century, science and natural philosophy were not quite synonymous, but only became so later with the direct use of what would become known formally as the scientific method, which was earlier developed during the Middle Ages and early modern period in Europe and the Middle East (see History of scientific method). Prior to the 18th century, however, the preferred term for the study of nature was natural philosophy, while English speakers most typically referred to the study of the human mind as moral philosophy. By contrast, the word "science" in English was still used in the 17th century to refer to the Aristotelian concept of knowledge which was secure enough to be used as a sure prescription for exactly how to do something. In this differing sense of the two words, the philosopher John Locke in An Essay Concerning Human Understanding wrote that "natural philosophy [the study of nature] is not capable of being made a science".
By the early 1800s, natural philosophy had begun to separate from philosophy, though it often retained a very broad meaning. In many cases, science continued to stand for reliable knowledge about any topic, in the same way it is still used in the broad sense (see the introduction to this article) in modern terms such as library science, political science, and computer science. In the more narrow sense of science, as natural philosophy became linked to an expanding set of well-defined laws (beginning with Galileo's laws, Kepler's laws, and Newton's laws for motion), it became more popular to refer to natural philosophy as natural science. Over the course of the nineteenth century, moreover, there was an increased tendency to associate science with study of the natural world (that is, the non-human world). This move sometimes left the study of human thought and society (what would come to be called social science) in a linguistic limbo by the end of the century and into the next.
Through the 19th century, many English speakers were increasingly differentiating science (meaning a combination of what we now term natural and biological sciences) from all other forms of knowledge in a variety of ways. The now-familiar expression “scientific method,” which refers to the prescriptive part of how to make discoveries in natural philosophy, was almost unused during the early part of the 19th century, but became widespread after the 1870s, though there was rarely total agreement about just what it entailed. The word "scientist," meant to refer to a systematically-working natural philosopher, (as opposed to an intuitive or empirically-minded one) was coined in 1833 by William Whewell. Discussion of scientists as a special group of people who did science, even if their attributes were up for debate, grew in the last half of the 19th century. Whatever people actually meant by these terms at first, they ultimately depicted science, in the narrow sense of the habitual use of the scientific method and the knowledge derived from it, as something deeply distinguished from all other realms of human endeavor.
By the twentieth century, the modern notion of science as a special brand of information about the world, practiced by a distinct group and pursued through a unique method, was essentially in place. It was used to give legitimacy to a variety of fields through such titles as "scientific" medicine, engineering, advertising, or motherhood. Over the 1900s, links between science and technology also grew increasingly strong.
Distinguished from technology
By the end of the century, it is arguable that technology had even begun to eclipse science as a term of public attention and praise. Scholarly studies of science have begun to refer to "technoscience" rather than science or technology separately. Meanwhile, such fields as biotechnology and nanotechnology are capturing the headlines. One author has suggested that, in the coming century, "science" may fall out of use, to be replaced by technoscience or even by some more exotic label such as "techknowledgy."
The Bohr model of the atom, like many ideas in the history of science, was at first prompted by and later partially disproved by experiment.
The scientific method seeks to explain the events of nature in a reproducible way, and to use these reproductions to make useful predictions. It is done through observation of natural phenomena, and/or through experimentation that tries to simulate natural events under controlled conditions. It provides an objective process to find solutions to problems in a number of scientific and technological fields.
Based on observations of a phenomenon, a scientist may generate a model. This is an attempt to describe or depict the phenomenon in terms of a logical physical or mathematical representation. As empirical evidence is gathered, a scientist can suggest a hypothesis to explain the phenomenon. This description can be used to make predictions that are testable by experiment or observation using the scientific method. When a hypothesis proves unsatisfactory, it is either modified or discarded.
While performing experiments, Scientists may have a preference for one outcome over another, and it is important that this tendency does not bias their interpretation. A strict following of 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 a thorough peer review of the experimental results as well as conclusions of a study. Once the experiment results are announced or published, an important cross-check can be the need to validate the results by an independent party.
Once a hypothesis has survived testing, it may become adopted into the framework of a scientific theory. This is a logically reasoned, self-consistent model or framework for describing the behavior of certain natural phenomena. A theory typically describes the behavior of much broader sets of phenomena than a hypothesis—commonly, a large number of hypotheses can be logically bound together by a single theory. These broader theories may be formulated using principles such as parsimony (e.g., "Occam's Razor"). They are then repeatedly tested by analyzing how the collected evidence (facts) compares to the theory. When a theory survives a sufficiently large number of empirical observations, it then becomes a scientific generalization that can be taken as fully verified.
Despite the existence of well-tested theories, science cannot claim absolute knowledge of nature or the behavior of the subject or of the field of study due to epistemological problems that are unavoidable and preclude the discovery or establishment of absolute truth. Unlike a mathematical proof, a scientific theory is empirical, and 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 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 Newtonian law of gravitation is a famous example of an established law that was later found not to be universal—it does 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 excellent 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 a more comprehensive theory.
Data from the famous Michelson–Morley experiment
Mathematics is essential to many sciences. One 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 extensive use of mathematics and mathematical models. Calculus may be the branch of mathematics most often used in science, but virtually every branch of mathematics has applications in science, including "pure" areas such as number theory and topology. Mathematics is fundamental to the understanding of the natural sciences and the social sciences, many of which also rely heavily on statistics.
Statistical methods, comprised of mathematical techniques for summarizing and exploring data, allow scientists to assess the level of reliability and the range of variation in experimental results. Statistical thinking also plays a fundamental role in many areas of science.
Computational science applies computing power to simulate real-world situations, enabling a better understanding of scientific problems than formal mathematics alone can achieve. According to the Society for Industrial and Applied Mathematics, computation is now as important as theory and experiment in advancing scientific knowledge.
Whether mathematics itself is properly classified as science has been a matter of some debate. 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 an experimental test of its theories and hypotheses. Mathematical theorems and formulas are obtained by logical derivations which presume axiomatic systems, rather than the combination of empirical observation and logical reasoning that has come to be known as the scientific method. In general, mathematics is classified as formal science, while natural and social sciences are classified as empirical sciences.
Philosophy of science
Velocity-distribution data of a gas of rubidium atoms, confirming the discovery of a new phase of matter, the Bose–Einstein condensate.
Main article: Philosophy of science
The philosophy of science seeks to understand the nature and justification of scientific knowledge. It has proven difficult to provide a definitive account of the scientific method that can decisively serve to distinguish science from non-science. Thus there are legitimate arguments about exactly where the borders are, leading to the problem of demarcation. There is nonetheless a set of core precepts that have broad consensus among published philosophers of science and within the scientific community at large.
Science is reasoned-based analysis of sensation upon our awareness. As such, the scientific method cannot deduce anything about the realm of reality that is beyond what is observable by existing or theoretical means. When a manifestation of our reality previously considered supernatural is understood in the terms of causes and consequences, it acquires a scientific explanation.
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. Science is the branch of knowledge dealing with people and the understanding we have of our environment and how it works.
There are different schools of thought in the philosophy of scientific method. Methodological naturalism maintains that scientific investigation must adhere to empirical study and independent verification as a process for properly developing and evaluating natural explanations for observable phenomena. Methodological naturalism, therefore, rejects supernatural explanations, arguments from authority and biased observational studies. Critical rationalism instead holds that unbiased observation is not possible and a demarcation between natural and supernatural explanations is arbitrary; it instead proposes falsifiability as the landmark of empirical theories and falsification as the universal empirical method. Critical rationalism argues for the ability of science to increase the scope of testable knowledge, but at the same time against its authority, by emphasizing its inherent fallibility. It proposes that science should be content with the rational elimination of errors in its theories, not in seeking for their verification (such as claiming certain or probable proof or disproof; both the proposal and falsification of a theory are only of methodological, conjectural, and tentative character in critical rationalism). Instrumentalism rejects the concept of truth and emphasizes merely the utility of theories as instruments for explaining and predicting phenomena.
Science, pseudoscience and nonscience
Main articles: Cargo cult science, Fringe science, Junk science, Pseudoscience, and Scientific misconduct
Any established body of knowledge which masquerades as science in an attempt to claim a legitimacy which it would not otherwise be able to achieve on its own terms is not science; it is often known as fringe- or alternative science. The most important of its defects is usually the lack of the carefully controlled and thoughtfully interpreted experiments which provide the foundation of the natural sciences and which contribute to their advancement. Another term, junk science, is often used to describe scientific theories or data which, while perhaps legitimate in themselves, are believed to be mistakenly used to support an opposing position. There is usually an element of political or ideological bias in the use of the term. Thus the arguments in favor of limiting the use of fossil fuels in order to reduce global warming are often characterized as junk science by those who do not wish to see such restrictions imposed, and who claim that other factors may well be the cause of global warming. A wide variety of commercial advertising (ranging from hype to outright fraud) would also fall into this category. Finally, there is just plain bad science, which is commonly used to describe well-intentioned but incorrect, obsolete, incomplete, or over-simplified expositions of scientific ideas.
The status of many bodies of knowledge as true sciences, has been a matter of debate. Discussion and debate abound in this topic with some fields like the social and behavioural sciences accused by critics of being unscientific. Many groups of people from academicians like Nobel Prize physicist Percy W. Bridgman, or Dick Richardson, Ph.D.—Professor of Integrative Biology at the University of Texas at Austin, to politicians like U.S. Senator Kay Bailey Hutchison and other co-sponsors, oppose giving their support or agreeing with the use of the label "science" in some fields of study and knowledge they consider non-scientific, ambiguous, or scientifically irrelevant compared with other fields. Karl Popper denied the existence of evidence and of scientific method. Popper holds that there is only one universal method, the negative method of trial and error. It covers not only all products of the human mind, including science, mathematics, philosophy, art and so on, but also the evolution of life. He also contributed to the Positivism dispute, a philosophical dispute between Critical rationalism (Popper, Albert) and the Frankfurt School (Adorno, Habermas) about the methodology of the social sciences.
Historian Jacques Barzun termed science "a faith as fanatical as any in history" and warned against the use of scientific thought to suppress considerations of meaning as integral to human existence. Many recent thinkers, such as Carolyn Merchant, Theodor Adorno and E. F. Schumacher considered that the 17th century scientific revolution shifted science from a focus on understanding nature, or wisdom, to a focus on manipulating nature, i.e. power, and that science's emphasis on manipulating nature leads it inevitably to manipulate people, as well. Science's focus on quantitative measures has led to critiques that it is unable to recognize important qualitative aspects of the world. It is not clear, however, if this kind of criticism is adequate to a vast number of non-experimental scientifics fields like astronomy, cosmology, evolutionary biology, complexity theory, paleontology, paleoanthropology, archeology, earth sciences, climatology, ecology and other sciences, like statistical physics of irreversible non-linear systems, that emphasize systemic and historically contingent frozen accidents. Considerations about the philosophical impact of science to the discussion of the (or lack of) meaning in human existence are not suppressed but strongly discussed in the literature of science divulgation, a movement sometimes called The Third Culture.
The implications of the ideological denial of ethics for the practice of science itself in terms of fraud, plagiarism, and data falsification, has been criticized by several academics. In "Science and Ethics", the philosopher Bernard Rollin examines the ideology that denies the relevance of ethics to science, and argues in favor of making education in ethics part and parcel of scientific training.
The media and the scientific debate
The mass media face a number of pressures that can prevent them from accurately depicting competing scientific claims in terms of their credibility within the scientific community as a whole. Determining how much weight to give different sides in a scientific debate requires considerable expertise on the issue at hand. Few journalists have real scientific knowledge, and even beat reporters who know a great deal about certain scientific issues may know little about other ones they are suddenly asked to cover.
Psychologist Carl Jung believed that though science attempted to understand all of nature, the experimental method used would pose artificial, conditional questions that evoke only partial answers. Robert Anton Wilson criticized science for using instruments to ask questions that produce answers only meaningful in terms of the instrument, and that there was no such thing as a completely objective vantage point from which to view the results of science.