For What Reasons Could A Theory Be Changed Or Replaced? Check All That Apply.

Explanation of some aspect of the natural world which can be tested and corroborated

For broader coverage of this topic, see Theory.

A scientific theory is an caption of an aspect of the natural world and universe that has been repeatedly tested and corroborated in accord with the scientific method, using accepted protocols of ascertainment, measurement, and evaluation of results. Where possible, theories are tested nether controlled conditions in an experiment.^{[1] [2]} In circumstances not amenable to experimental testing, theories are evaluated through principles of abductive reasoning. Established scientific theories take withstood rigorous scrutiny and embody scientific knowledge.^[3]

A scientific theory differs from a scientific fact or scientific constabulary in that a theory explains "why" or "how": a fact is a elementary, bones observation, whereas a law is a statement (oft a mathematical equation) about a relationship between facts. For example, Newton's Law of Gravity is a mathematical equation that can be used to predict the attraction betwixt bodies, only information technology is not a theory to explain how gravity works.^[iv] Stephen Jay Gould wrote that "...facts and theories are dissimilar things, non rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts."^[v]

The significant of the term scientific theory (often contracted to theory for brevity) as used in the disciplines of science is significantly different from the common vernacular usage of theory.^{[6] [note 1]} In everyday speech, theory can imply an explanation that represents an unsubstantiated and speculative guess,^[6] whereas in science information technology describes an caption that has been tested and is widely accepted equally valid.^{[1] [ii] [three]}

The force of a scientific theory is related to the diversity of phenomena information technology can explicate and its simplicity. As additional scientific testify is gathered, a scientific theory may be modified and ultimately rejected if it cannot be fabricated to fit the new findings; in such circumstances, a more authentic theory is then required. Some theories are so well-established that they are unlikely ever to be fundamentally changed (for example, scientific theories such as evolution, heliocentric theory, cell theory, theory of plate tectonics, germ theory of disease, etc.). In certain cases, a scientific theory or scientific law that fails to fit all data tin can still exist useful (due to its simplicity) every bit an approximation under specific conditions. An example is Newton'due south laws of movement, which are a highly authentic approximation to special relativity at velocities that are pocket-size relative to the speed of low-cal.^{[ citation needed ]}

Scientific theories are testable and make falsifiable predictions.^[seven] They describe the causes of a particular natural phenomenon and are used to explain and predict aspects of the concrete universe or specific areas of research (for case, electricity, chemistry, and astronomy). As with other forms of scientific knowledge, scientific theories are both deductive and inductive,^[8] aiming for predictive and explanatory power. Scientists apply theories to further scientific cognition, equally well as to facilitate advances in technology or medicine.

Types [edit]

Albert Einstein described two types of scientific theories: "Effective theories" and "principle theories". Constructive theories are constructive models for phenomena: for example, kinetic theory. Principle theories are empirical generalisations such as Newton'due south laws of movement.^[ix]

Characteristics [edit]

Essential criteria [edit]

Typically for whatever theory to be accepted within most academia there is 1 uncomplicated criterion. The essential criterion is that the theory must be observable and repeatable. The aforementioned criterion is essential to prevent fraud and perpetuate science itself.

The tectonic plates of the earth were mapped in the 2nd one-half of the 20th century. Plate tectonic theory successfully explains numerous observations about the Globe, including the distribution of earthquakes, mountains, continents, and oceans.

The defining characteristic of all scientific knowledge, including theories, is the power to make falsifiable or testable predictions. The relevance and specificity of those predictions make up one's mind how potentially useful the theory is. A would-exist theory that makes no appreciable predictions is not a scientific theory at all. Predictions not sufficiently specific to be tested are similarly not useful. In both cases, the term "theory" is not applicative.

A body of descriptions of cognition can be called a theory if it fulfills the following criteria:

• It makes falsifiable predictions with consequent accuracy across a broad expanse of scientific enquiry (such every bit mechanics).
• Information technology is well-supported by many independent strands of evidence, rather than a single foundation.
• It is consequent with preexisting experimental results and at to the lowest degree as accurate in its predictions as are any preexisting theories.

These qualities are certainly true of such established theories as special and full general relativity, breakthrough mechanics, plate tectonics, the modern evolutionary synthesis, etc.

Other criteria [edit]

In addition, scientists adopt to piece of work with a theory that meets the following qualities:

• It tin can be subjected to minor adaptations to business relationship for new data that do not fit information technology perfectly, as they are discovered, thus increasing its predictive capability over time.^[10]
• It is among the most parsimonious explanations, economical in the use of proposed entities or explanatory steps as per Occam'south razor. This is because for each accepted explanation of a miracle, there may be an extremely big, perhaps even incomprehensible, number of possible and more complex alternatives, because one can e'er burden failing explanations with ad hoc hypotheses to foreclose them from being falsified; therefore, simpler theories are preferable to more complex ones because they are more testable.^{[eleven] [12] [13]}

Definitions from scientific organizations [edit]

The United states of america National Academy of Sciences defines scientific theories as follows:

The formal scientific definition of theory is quite different from the everyday meaning of the give-and-take. It refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence. Many scientific theories are so well established that no new show is likely to alter them essentially. For example, no new evidence volition demonstrate that the Earth does not orbit around the Sun (heliocentric theory), or that living things are not fabricated of cells (prison cell theory), that matter is not composed of atoms, or that the surface of the Earth is not divided into solid plates that take moved over geological timescales (the theory of plate tectonics)...One of the almost useful properties of scientific theories is that they can be used to make predictions about natural events or phenomena that take non all the same been observed.^[14]

From the American Association for the Advancement of Science:

A scientific theory is a well-substantiated explanation of some attribute of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. The theory of biological evolution is more than "just a theory". It is as factual an explanation of the universe equally the atomic theory of matter or the germ theory of affliction. Our agreement of gravity is nonetheless a piece of work in progress. Only the phenomenon of gravity, similar evolution, is an accepted fact.

Note that the term theory would not be advisable for describing untested merely intricate hypotheses or fifty-fifty scientific models.

Germination [edit]

The scientific method involves the proposal and testing of hypotheses, by deriving predictions from the hypotheses near the results of future experiments, then performing those experiments to run into whether the predictions are valid. This provides evidence either for or against the hypothesis. When enough experimental results accept been gathered in a detail area of inquiry, scientists may propose an explanatory framework that accounts for every bit many of these equally possible. This explanation is also tested, and if it fulfills the necessary criteria (run across above), so the explanation becomes a theory. This tin accept many years, equally it tin be difficult or complicated to assemble sufficient evidence.

Once all of the criteria have been met, it volition be widely accepted by scientists (encounter scientific consensus) as the best bachelor explanation of at least some phenomena. Information technology will have made predictions of phenomena that previous theories could not explain or could non predict accurately, and it will have resisted attempts at falsification. The strength of the prove is evaluated by the scientific community, and the well-nigh important experiments will have been replicated by multiple independent groups.

Theories practice not have to exist perfectly authentic to exist scientifically useful. For instance, the predictions fabricated by classical mechanics are known to exist inaccurate in the relativistic realm, but they are virtually exactly correct at the comparatively depression velocities of mutual man experience.^[sixteen] In chemistry, there are many acid-base theories providing highly divergent explanations of the underlying nature of acidic and basic compounds, but they are very useful for predicting their chemical beliefs.^[17] Like all knowledge in scientific discipline, no theory can always be completely certain, since it is possible that future experiments might conflict with the theory's predictions.^[eighteen] Withal, theories supported by the scientific consensus take the highest level of certainty of any scientific knowledge; for example, that all objects are subject to gravity or that life on World evolved from a common ancestor.^[nineteen]

Acceptance of a theory does not require that all of its major predictions be tested, if it is already supported by sufficiently strong evidence. For example, certain tests may exist unfeasible or technically difficult. Equally a effect, theories may make predictions that have not yet been confirmed or proven incorrect; in this instance, the predicted results may exist described informally with the term "theoretical". These predictions can be tested at a later time, and if they are wrong, this may pb to the revision or rejection of the theory.

Modification and improvement [edit]

If experimental results opposite to a theory's predictions are observed, scientists start evaluate whether the experimental pattern was audio, and if so they confirm the results by contained replication. A search for potential improvements to the theory then begins. Solutions may require minor or major changes to the theory, or none at all if a satisfactory explanation is found inside the theory's existing framework.^[xx] Over time, as successive modifications build on acme of each other, theories consistently better and greater predictive accuracy is achieved. Since each new version of a theory (or a completely new theory) must have more predictive and explanatory power than the last, scientific noesis consistently becomes more accurate over time.

If modifications to the theory or other explanations seem to be insufficient to account for the new results, so a new theory may be required. Since scientific knowledge is usually durable, this occurs much less unremarkably than modification.^[18] Furthermore, until such a theory is proposed and accustomed, the previous theory will be retained. This is because it is nonetheless the best bachelor caption for many other phenomena, equally verified by its predictive power in other contexts. For example, it has been known since 1859 that the observed perihelion precession of Mercury violates Newtonian mechanics,^[21] but the theory remained the best explanation available until relativity was supported by sufficient evidence. Besides, while new theories may be proposed by a single person or past many, the cycle of modifications somewhen incorporates contributions from many unlike scientists.^[22]

Afterward the changes, the accustomed theory will explain more than phenomena and accept greater predictive power (if it did not, the changes would non be adopted); this new explanation volition then be open to farther replacement or modification. If a theory does not require modification despite repeated tests, this implies that the theory is very accurate. This likewise means that accepted theories go on to accumulate evidence over time, and the length of fourth dimension that a theory (or any of its principles) remains accepted oftentimes indicates the force of its supporting evidence.

Unification [edit]

In some cases, ii or more theories may be replaced by a single theory that explains the previous theories as approximations or special cases, analogous to the manner a theory is a unifying explanation for many confirmed hypotheses; this is referred to equally unification of theories.^[23] For example, electricity and magnetism are at present known to be 2 aspects of the same phenomenon, referred to equally electromagnetism.^[24]

When the predictions of dissimilar theories appear to contradict each other, this is also resolved by either farther evidence or unification. For example, concrete theories in the 19th century unsaid that the Sun could not have been called-for long plenty to allow certain geological changes as well as the development of life. This was resolved past the discovery of nuclear fusion, the chief energy source of the Sun.^[25] Contradictions tin also be explained as the result of theories approximating more than cardinal (not-contradictory) phenomena. For example, diminutive theory is an approximation of quantum mechanics. Current theories describe three separate key phenomena of which all other theories are approximations;^[26] the potential unification of these is sometimes called the Theory of Everything.^[23]

Instance: Relativity [edit]

In 1905, Albert Einstein published the principle of special relativity, which soon became a theory.^[27] Special relativity predicted the alignment of the Newtonian principle of Galilean invariance, also termed Galilean relativity, with the electromagnetic field.^[28] Past omitting from special relativity the luminiferous aether, Einstein stated that time dilation and length contraction measured in an object in relative move is inertial—that is, the object exhibits constant velocity, which is speed with direction, when measured by its observer. He thereby duplicated the Lorentz transformation and the Lorentz contraction that had been hypothesized to resolve experimental riddles and inserted into electrodynamic theory as dynamical consequences of the aether's backdrop. An elegant theory, special relativity yielded its own consequences,^[29] such as the equivalence of mass and free energy transforming into one another and the resolution of the paradox that an excitation of the electromagnetic field could be viewed in one reference frame every bit electricity, but in another as magnetism.

Einstein sought to generalize the invariance principle to all reference frames, whether inertial or accelerating.^[30] Rejecting Newtonian gravitation—a central forcefulness acting instantly at a distance—Einstein presumed a gravitational field. In 1907, Einstein'due south equivalence principle implied that a gratuitous fall within a uniform gravitational field is equivalent to inertial movement.^[30] By extending special relativity's effects into three dimensions, general relativity extended length contraction into space contraction, conceiving of 4D space-time as the gravitational field that alters geometrically and sets all local objects' pathways. Even massless energy exerts gravitational motility on local objects by "curving" the geometrical "surface" of 4D space-time. Withal unless the energy is vast, its relativistic effects of contracting space and slowing time are negligible when merely predicting motion. Although general relativity is embraced as the more explanatory theory via scientific realism, Newton's theory remains successful as merely a predictive theory via instrumentalism. To summate trajectories, engineers and NASA still uses Newton's equations, which are simpler to operate.^[18]

Theories and laws [edit]

Both scientific laws and scientific theories are produced from the scientific method through the formation and testing of hypotheses, and tin predict the beliefs of the natural earth. Both are typically well-supported past observations and/or experimental evidence.^[31] However, scientific laws are descriptive accounts of how nature will comport under certain atmospheric condition.^[32] Scientific theories are broader in telescopic, and give overarching explanations of how nature works and why it exhibits certain characteristics. Theories are supported by evidence from many unlike sources, and may contain one or several laws.^[33]

A common misconception is that scientific theories are rudimentary ideas that will eventually graduate into scientific laws when enough information and evidence accept been accumulated. A theory does not change into a scientific law with the accumulation of new or better evidence. A theory will e'er remain a theory; a law will e'er remain a law.^{[31] [34] [35]} Both theories and laws could potentially be falsified by countervailing evidence.^[36]

Theories and laws are besides distinct from hypotheses. Unlike hypotheses, theories and laws may be simply referred to as scientific fact.^{[37] [38]} Still, in science, theories are unlike from facts fifty-fifty when they are well supported.^[39] For example, evolution is both a theory and a fact.^{[half dozen]}

Near theories [edit]

Theories as axioms [edit]

The logical positivists thought of scientific theories as statements in a formal linguistic communication. Commencement-guild logic is an example of a formal language. The logical positivists envisaged a similar scientific language. In addition to scientific theories, the linguistic communication too included observation sentences ("the sun rises in the east"), definitions, and mathematical statements. The phenomena explained by the theories, if they could non exist directly observed by the senses (for example, atoms and radio waves), were treated as theoretical concepts. In this view, theories role as axioms: predicted observations are derived from the theories much like theorems are derived in Euclidean geometry. Yet, the predictions are and then tested confronting reality to verify the predictions, and the "axioms" can exist revised equally a directly event.

The phrase "the received view of theories" is used to describe this approach. Terms usually associated with it are "linguistic" (because theories are components of a language) and "syntactic" (because a language has rules near how symbols can exist strung together). Problems in defining this kind of language precisely, due east.g., are objects seen in microscopes observed or are they theoretical objects, led to the effective demise of logical positivism in the 1970s.

Theories as models [edit]

The semantic view of theories, which identifies scientific theories with models rather than propositions, has replaced the received view as the dominant position in theory conception in the philosophy of science.^{[40] [41] [42]} A model is a logical framework intended to represent reality (a "model of reality"), similar to the way that a map is a graphical model that represents the territory of a urban center or country.^{[43] [44]}

In this approach, theories are a specific category of models that fulfill the necessary criteria (see above). One can use linguistic communication to describe a model; nonetheless, the theory is the model (or a collection of similar models), and not the description of the model. A model of the solar system, for instance, might consist of abstruse objects that represent the sun and the planets. These objects have associated backdrop, east.g., positions, velocities, and masses. The model parameters, e.chiliad., Newton's Law of Gravitation, decide how the positions and velocities change with time. This model can and then be tested to come across whether it accurately predicts hereafter observations; astronomers can verify that the positions of the model'south objects over time match the actual positions of the planets. For almost planets, the Newtonian model'due south predictions are accurate; for Mercury, it is slightly inaccurate and the model of general relativity must be used instead.

The give-and-take "semantic" refers to the fashion that a model represents the real globe. The representation (literally, "re-presentation") describes particular aspects of a phenomenon or the manner of interaction amongst a prepare of phenomena. For instance, a scale model of a business firm or of a solar system is clearly not an bodily firm or an actual solar system; the aspects of an bodily business firm or an actual solar arrangement represented in a scale model are, but in certain express ways, representative of the actual entity. A scale model of a firm is not a house; but to someone who wants to learn nearly houses, coordinating to a scientist who wants to sympathize reality, a sufficiently detailed scale model may suffice.

Differences betwixt theory and model [edit]

Several commentators^[47] take stated that the distinguishing characteristic of theories is that they are explanatory too equally descriptive, while models are but descriptive (although nevertheless predictive in a more limited sense). Philosopher Stephen Pepper besides distinguished between theories and models, and said in 1948 that general models and theories are predicated on a "root" metaphor that constrains how scientists conjecture and model a phenomenon and thus go far at testable hypotheses.

Engineering practice makes a distinction between "mathematical models" and "concrete models"; the cost of fabricating a physical model can exist minimized past first creating a mathematical model using a reckoner software parcel, such every bit a estimator aided design tool. The component parts are each themselves modelled, and the fabrication tolerances are specified. An exploded view drawing is used to lay out the fabrication sequence. Simulation packages for displaying each of the subassemblies allow the parts to be rotated, magnified, in realistic item. Software packages for creating the bill of materials for construction allows subcontractors to specialize in associates processes, which spreads the cost of manufacturing machinery amid multiple customers. See: Computer-aided applied science, Computer-aided manufacturing, and 3D printing

Assumptions in formulating theories [edit]

An assumption (or axiom) is a statement that is accepted without evidence. For example, assumptions can exist used as bounds in a logical argument. Isaac Asimov described assumptions as follows:

...it is incorrect to speak of an supposition as either true or false, since at that place is no fashion of proving it to be either (If at that place were, it would no longer be an assumption). Information technology is better to consider assumptions equally either useful or useless, depending on whether deductions fabricated from them corresponded to reality...Since we must start somewhere, we must have assumptions, only at least let u.s. have every bit few assumptions as possible.^[48]

Certain assumptions are necessary for all empirical claims (e.chiliad. the assumption that reality exists). However, theories practice not generally make assumptions in the conventional sense (statements accepted without bear witness). While assumptions are ofttimes incorporated during the formation of new theories, these are either supported past bear witness (such as from previously existing theories) or the evidence is produced in the grade of validating the theory. This may be as simple as observing that the theory makes authentic predictions, which is evidence that any assumptions made at the outset are correct or approximately correct under the weather tested.

Conventional assumptions, without evidence, may exist used if the theory is but intended to employ when the assumption is valid (or approximately valid). For example, the special theory of relativity assumes an inertial frame of reference. The theory makes accurate predictions when the supposition is valid, and does non make accurate predictions when the assumption is non valid. Such assumptions are oft the signal with which older theories are succeeded by new ones (the general theory of relativity works in non-inertial reference frames as well).

The term "assumption" is actually broader than its standard use, etymologically speaking. The Oxford English Dictionary (OED) and online Wiktionary indicate its Latin source as assumere ("accept, to take to oneself, adopt, usurp"), which is a conjunction of advertising- ("to, towards, at") and sumere (to take). The root survives, with shifted meanings, in the Italian assumere and Spanish sumir. The first sense of "assume" in the OED is "to take unto (oneself), receive, accept, adopt". The term was originally employed in religious contexts as in "to receive up into sky", especially "the reception of the Virgin Mary into sky, with body preserved from corruption", (1297 CE) just it was besides simply used to refer to "receive into association" or "adopt into partnership". Moreover, other senses of assumere included (i) "investing oneself with (an attribute)", (2) "to undertake" (especially in Law), (iii) "to take to oneself in appearance but, to pretend to possess", and (4) "to suppose a thing to be" (all senses from OED entry on "assume"; the OED entry for "assumption" is almost perfectly symmetrical in senses). Thus, "assumption" connotes other associations than the gimmicky standard sense of "that which is assumed or taken for granted; a supposition, postulate" (only the 11th of 12 senses of "assumption", and the tenth of 11 senses of "assume").

Descriptions [edit]

From philosophers of science [edit]

Karl Popper described the characteristics of a scientific theory as follows:^[vii]

1. It is easy to obtain confirmations, or verifications, for nearly every theory—if we look for confirmations.
2. Confirmations should count only if they are the outcome of risky predictions; that is to say, if, unenlightened by the theory in question, we should have expected an outcome which was incompatible with the theory—an effect which would have refuted the theory.
3. Every "proficient" scientific theory is a prohibition: it forbids certain things to happen. The more than a theory forbids, the ameliorate it is.
4. A theory which is not refutable by any conceivable consequence is non-scientific. Irrefutability is not a virtue of a theory (as people often recollect) only a vice.
5. Every 18-carat test of a theory is an try to falsify it, or to abnegate it. Testability is falsifiability; only there are degrees of testability: some theories are more than testable, more exposed to refutation, than others; they take, as it were, greater risks.
6. Confirming evidence should not count except when information technology is the result of a genuine examination of the theory; and this means that information technology can be presented as a serious but unsuccessful attempt to falsify the theory. (I now speak in such cases of "corroborating evidence".)
7. Some genuinely testable theories, when constitute to be fake, might still exist upheld by their admirers—for case by introducing post hoc (later on the fact) some auxiliary hypothesis or assumption, or by reinterpreting the theory post hoc in such a manner that it escapes refutation. Such a procedure is always possible, simply information technology rescues the theory from refutation only at the price of destroying, or at least lowering, its scientific status, past tampering with bear witness. The temptation to tamper can be minimized by first taking the fourth dimension to write down the testing protocol before embarking on the scientific work.

Popper summarized these statements by maxim that the central criterion of the scientific condition of a theory is its "falsifiability, or refutability, or testability".^[7] Echoing this, Stephen Hawking states, "A theory is a expert theory if it satisfies two requirements: It must accurately draw a large grade of observations on the footing of a model that contains just a few arbitrary elements, and it must brand definite predictions nearly the results of time to come observations." He also discusses the "unprovable simply falsifiable" nature of theories, which is a necessary consequence of inductive logic, and that "you can disprove a theory past finding even a single observation that disagrees with the predictions of the theory".^[49]

Several philosophers and historians of science have, however, argued that Popper's definition of theory equally a set of falsifiable statements is wrong^[50] because, as Philip Kitcher has pointed out, if 1 took a strictly Popperian view of "theory", observations of Uranus when first discovered in 1781 would take "falsified" Newton'south celestial mechanics. Rather, people suggested that another planet influenced Uranus' orbit—and this prediction was indeed eventually confirmed.

Kitcher agrees with Popper that "At that place is surely something right in the idea that a scientific discipline can succeed only if it can neglect."^[51] He also says that scientific theories include statements that cannot be falsified, and that good theories must also be artistic. He insists we view scientific theories equally an "elaborate collection of statements", some of which are not falsifiable, while others—those he calls "auxiliary hypotheses", are.

Co-ordinate to Kitcher, skilful scientific theories must accept 3 features:^[51]

1. Unity: "A science should exist unified…. Proficient theories consist of just one problem-solving strategy, or a pocket-sized family of problem-solving strategies, that can be applied to a broad range of problems."
2. Fecundity: "A great scientific theory, similar Newton'south, opens up new areas of research…. Because a theory presents a new style of looking at the earth, information technology can atomic number 82 u.s.a. to ask new questions, and and then to embark on new and fruitful lines of inquiry…. Typically, a flourishing science is incomplete. At any fourth dimension, it raises more questions than it can currently reply. But incompleteness is not vice. On the contrary, incompleteness is the mother of fecundity…. A adept theory should be productive; information technology should raise new questions and assume those questions can be answered without giving up its problem-solving strategies."
3. Auxiliary hypotheses that are independently testable: "An auxiliary hypothesis ought to exist testable independently of the particular problem it is introduced to solve, independently of the theory it is designed to save." (For example, the testify for the existence of Neptune is independent of the anomalies in Uranus'due south orbit.)

Like other definitions of theories, including Popper's, Kitcher makes information technology clear that a theory must include statements that have observational consequences. But, similar the observation of irregularities in the orbit of Uranus, falsification is only one possible effect of observation. The production of new hypotheses is another possible and equally of import outcome.

Analogies and metaphors [edit]

The concept of a scientific theory has as well been described using analogies and metaphors. For example, the logical empiricist Carl Gustav Hempel likened the structure of a scientific theory to a "complex spatial network:"

Its terms are represented by the knots, while the threads connecting the latter correspond, in part, to the definitions and, in function, to the fundamental and derivative hypotheses included in the theory. The whole system floats, as information technology were, in a higher place the plane of observation and is anchored to it by the rules of interpretation. These might be viewed as strings which are not part of the network but link certain points of the latter with specific places in the plane of ascertainment. By virtue of these interpretive connections, the network can part equally a scientific theory: From sure observational information, nosotros may arise, via an interpretive string, to some signal in the theoretical network, thence proceed, via definitions and hypotheses, to other points, from which another interpretive string permits a descent to the plane of observation.^[52]

Michael Polanyi fabricated an analogy betwixt a theory and a map:

A theory is something other than myself. It may be set out on paper every bit a system of rules, and it is the more truly a theory the more completely it can be put down in such terms. Mathematical theory reaches the highest perfection in this respect. Simply fifty-fifty a geographical map fully embodies in itself a set of strict rules for finding one's way through a region of otherwise uncharted feel. Indeed, all theory may be regarded as a kind of map extended over space and time.^[53]

A scientific theory tin can as well exist thought of as a book that captures the fundamental information about the world, a book that must exist researched, written, and shared. In 1623, Galileo Galilei wrote:

Philosophy [i.eastward. physics] is written in this g volume—I mean the universe—which stands continually open to our gaze, but it cannot be understood unless one first learns to encompass the linguistic communication and translate the characters in which it is written. It is written in the language of mathematics, and its characters are triangles, circles, and other geometrical figures, without which it is humanly impossible to understand a single word of it; without these, i is wandering effectually in a dark labyrinth.^[54]

The book metaphor could also be applied in the following passage, by the contemporary philosopher of science Ian Hacking:

I myself adopt an Argentine fantasy. God did non write a Book of Nature of the sort that the old Europeans imagined. He wrote a Borgesian library, each book of which is every bit brief as possible, yet each book of which is inconsistent with every other. No volume is redundant. For every book there is some humanly attainable bit of Nature such that that volume, and no other, makes possible the comprehension, prediction and influencing of what is going on…Leibniz said that God chose a earth which maximized the variety of phenomena while choosing the simplest laws. Exactly and so: but the best way to maximize phenomena and have simplest laws is to accept the laws inconsistent with each other, each applying to this or that but none applying to all.^[55]

In physics [edit]

In physics, the term theory is generally used for a mathematical framework—derived from a small gear up of basic postulates (normally symmetries—similar equality of locations in infinite or in time, or identity of electrons, etc.)—that is capable of producing experimental predictions for a given category of concrete systems. A good case is classical electromagnetism, which encompasses results derived from guess symmetry (sometimes called gauge invariance) in a course of a few equations chosen Maxwell'south equations. The specific mathematical aspects of classical electromagnetic theory are termed "laws of electromagnetism," reflecting the level of consistent and reproducible bear witness that supports them. Inside electromagnetic theory generally, there are numerous hypotheses well-nigh how electromagnetism applies to specific situations. Many of these hypotheses are already considered to exist adequately tested, with new ones always in the making and maybe untested. An instance of the latter might be the radiation reaction strength. As of 2009, its effects on the periodic motility of charges are detectable in synchrotrons, just only equally averaged effects over fourth dimension. Some researchers are at present because experiments that could observe these furnishings at the instantaneous level (i.e. not averaged over time).^{[56] [57]}

Examples [edit]

Note that many fields of inquiry do not accept specific named theories, e.yard. developmental biology. Scientific knowledge outside a named theory can still have a high level of certainty, depending on the amount of bear witness supporting it. Also annotation that since theories draw evidence from many fields, the categorization is not absolute.

• Biology: cell theory, theory of evolution (modern evolutionary synthesis), abiogenesis, germ theory, particulate inheritance theory, dual inheritance theory, Immature–Helmholtz theory, opponent process, cohesion-tension theory
• Chemistry: standoff theory, kinetic theory of gases, Lewis theory, molecular theory, molecular orbital theory, transition state theory, valence bond theory
• Physics: atomic theory, Large Bang theory, Dynamo theory, perturbation theory, theory of relativity (successor to classical mechanics), quantum field theory
• World scientific discipline: Climate change theory (from climatology),^[58] plate tectonics theory (from geology), theories of the origin of the Moon, theories for the Moon illusion
• Astronomy: Self-gravitating system, Stellar evolution, solar nebular model, stellar nucleosynthesis

Notes [edit]

1. ^ Quote: "The formal scientific definition of theory is quite dissimilar from the everyday pregnant of the word. It refers to a comprehensive caption of some aspect of nature that is supported by a vast trunk of evidence."

References [edit]

1. ^ ^{a b} National Academy of Sciences (US) (1999). Scientific discipline and Creationism: A View from the National University of Sciences (2nd ed.). National Academies Press. p. 2. doi:10.17226/6024. ISBN978-0-309-06406-iv. PMID 25101403.
2. ^ ^{a b} "The Structure of Scientific Theories". The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University. 2016.
3. ^ ^{a b} Schafersman, Steven D. "An Introduction to Science".
4. ^ July 2017, Alina Bradford-Live Science Contributor 29. "What Is a Scientific Theory?". livescience.com . Retrieved 2021-01-17 .
5. ^ The Devil in Dover,
6. ^ ^{a b c} "Is Evolution a Theory or a Fact?". National Academy of Sciences. 2008. Archived from the original on 2009-09-07.
7. ^ ^{a b c} Popper, Karl (1963), Conjectures and Refutations, Routledge and Kegan Paul, London, UK. Reprinted in Theodore Schick (ed., 2000), Readings in the Philosophy of Science, Mayfield Publishing Visitor, Mountain View, Calif.
8. ^ Andersen, Hanne; Hepburn, Brian (2015). "Scientific Method". In Edward N. Zalta (ed.). The Stanford Encyclopedia of Philosophy.
9. ^ Howard, Don A. (23 June 2018). Zalta, Edward N. (ed.). The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University – via Stanford Encyclopedia of Philosophy.
10. ^ "Even theories change". Understanding Scientific discipline . Retrieved 2021-02-12 .
11. ^ Alan Bakery (2010) [2004]. "Simplicity". Stanford Encyclopedia of Philosophy. California: Stanford University. ISSN 1095-5054.
12. ^ Courtney A, Courtney Thou (2008). "Comments Regarding "On the Nature Of Science"". Physics in Canada. 64 (3): 7–8. arXiv:0812.4932.
13. ^ Elliott Sober, Let's Razor Occam's Razor, pp. 73–93, from Dudley Knowles (ed.) Explanation and Its Limits, Cambridge University Press (1994).
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15. ^ Hooke, Robert (1635–1703). Micrographia, Observation Xviii.
16. ^ Misner, Charles Due west.; Thorne, Kip S.; Wheeler, John Archibald (1973). Gravitation, p. 1049. New York: W. H.Freeman and Company. ISBN 0-7167-0344-0.
17. ^ Come across Acid–base reaction.
18. ^ ^{a b c} "Chapter 1: The Nature of Science". www.project2061.org.
19. ^ See, for example, Common descent and Prove for common descent.
20. ^ For example, run into the commodity on the discovery of Neptune; the discovery was based on an apparent violation of the orbit of Uranus every bit predicted by Newtonian mechanics. This explanation did not require whatever modification of the theory, only rather modification of the hypothesis that there were only seven planets in the Solar System.
21. ^ U. Le Verrier (1859), (in French), "Lettre de M. Le Verrier à M. Faye sur la théorie de Mercure et sur le mouvement du périhélie de cette planète", Comptes rendus hebdomadaires des séances de 50'Académie des sciences (Paris), vol. 49 (1859), pp. 379–83.
22. ^ For example, the mod theory of evolution (the modern evolutionary synthesis) incorporates significant contributions from R. A. Fisher, Ernst Mayr, J. B. Due south. Haldane, and many others.
23. ^ ^{a b} Weinberg Due south (1993). Dreams of a Final Theory: The Scientist's Search for the Ultimate Laws of Nature.
24. ^ Maxwell, J. C., & Thompson, J. J. (1892). A treatise on electricity and magnetism. Clarendon Press series. Oxford: Clarendon.
25. ^ "How the Sunday Shines". www.nobelprize.org.
26. ^ The strong force, the electroweak force, and gravity. The electroweak force is the unification of electromagnetism and the weak forcefulness. All observed causal interactions are understood to take place through ane or more than of these three mechanisms, although most systems are far too complicated to account for these except through the successive approximations offered past other theories.
27. ^ Albert Einstein (1905) "Zur Elektrodynamik bewegter Körper Archived 2009-12-29 at the Wayback Motorcar", Annalen der Physik 17: 891; English translation On the Electrodynamics of Moving Bodies by George Barker Jeffery and Wilfrid Perrett (1923); Another English translation On the Electrodynamics of Moving Bodies by Megh Nad Saha (1920).
28. ^ Schwarz, John H (Mar 1998). "Contempo developments in superstring theory". Proceedings of the National Academy of Sciences of the United States of America. 95 (6): 2750–57. Bibcode:1998PNAS...95.2750S. doi:ten.1073/pnas.95.six.2750. PMC19640. PMID 9501161.
29. ^ See Tests of special relativity. As well, for example: Sidney Coleman, Sheldon L. Glashow, Catholic Ray and Neutrino Tests of Special Relativity, Phys. Lett. B405 (1997) 249–52, establish here [1]. An overview tin can exist plant hither.
30. ^ ^{a b} Roberto Torretti, The Philosophy of Physics (Cambridge: Cambridge Academy Printing, 1999), pp. 289–ninety.
31. ^ ^{a b} "Scientific Laws and Theories". Archived from the original on 2017-07-09.
32. ^ See the article on Physical police, for example.
33. ^ "Definitions of Fact, Theory, and Law in Scientific Work". 16 March 2016.
34. ^ "Harding (1999)".
35. ^ William F. McComas (30 December 2013). The Language of Science Instruction: An Expanded Glossary of Central Terms and Concepts in Science Education and Learning. Springer Science & Business concern Media. p. 107. ISBN978-94-6209-497-0.
36. ^ "What'south the Deviation Between a Scientific Hypothesis, Theory and Law?".
37. ^ Gould, Stephen Jay (1981-05-01). "Evolution as Fact and Theory". Discover. ii (5): 34–37.
38. ^ Further examples are hither [2], and in the article on Evolution every bit fact and theory.
39. ^ "Essay". ncse.com . Retrieved 25 March 2015.
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41. ^ Halvorson, Hans (2012). "What Scientific Theories Could Non Exist" (PDF). Philosophy of Science. 79 (ii): 183–206. CiteSeerXten.one.i.692.8455. doi:x.1086/664745. S2CID 37897853. Retrieved 14 February 2013.
42. ^ Frigg, Roman (2006). "Scientific Representation and the Semantic View of Theories" (PDF). Theoria. 55 (2): 183–206. Retrieved 14 February 2013.
43. ^ Hacking, Ian (1983). Representing and Intervening. Introductory Topics in the Philosophy of Natural Science. Cambridge Academy Press.
44. ^ Box, George East.P. & Draper, N.R. (1987). Empirical Model-Building and Response Surfaces. Wiley. p. 424
45. ^ Lorenzo Iorio (2005). "On the possibility of measuring the solar oblateness and some relativistic furnishings from planetary ranging". Astronomy and Astrophysics. 433 (1): 385–93. arXiv:gr-qc/0406041. Bibcode:2005A&A...433..385I. doi:10.1051/0004-6361:20047155. S2CID 1546486.
46. ^ Myles Standish, Jet Propulsion Laboratory (1998)
47. ^ For example, Reese & Overto (1970); Lerner (1998); too Lerner & Teti (2005), in the context of modeling homo beliefs.
48. ^ Isaac Asimov, Agreement Physics (1966) pp. four–5.
49. ^ Hawking, Stephen (1988). A Cursory History of Time . Runted Books. ISBN978-0-553-38016-3.
50. ^ Hempel. C.1000. 1951 "Problems and Changes in the Empiricist Benchmark of Meaning" in Aspects of Scientific Explanation. Glencoe: the Gratuitous Printing. Quine, W.V.O 1952 "Two Dogmas of Empiricism" reprinted in From a Logical Point of View. Cambridge: Harvard Academy Press
51. ^ ^{a b} Philip Kitcher 1982 Abusing Scientific discipline: The Instance Confronting Creationism, pp. 45–48. Cambridge: The MIT Printing
52. ^ Hempel CG 1952. Fundamentals of Concept Formation in Empirical Science. (Book two, #vii of Foundations of the Unity of Science. Toward an International Encyclopedia of Unified Science). University of Chicago Press, p. 36.
53. ^ Polanyi Yard. 1958. Personal Knowledge. Towards a Postal service-Critical Philosophy. London: Routledge & Kegan Paul, p. iv.
54. ^ Galileo Galilei, The Assayer, every bit translated by Stillman Drake (1957), Discoveries and Opinions of Galileo pp. 237–38.
55. ^ Hacking I. 1983. Representing and Intervening. Cambridge Academy Printing, p. 219.
56. ^ Koga J and Yamagiwa Grand (2006). Radiation reaction effects in ultrahigh irradiance laser pulse interactions with multiple electrons.
57. ^ [3] ^{[ expressionless link ]}
58. ^ Plass, Thou.North., 1956, The Carbon Dioxide Theory of Climatic Change, Tellus VIII, 2. (1956), pp. 140–54.

Further reading [edit]

• Sellers, Piers (August 17, 2016). "Space, Climate Alter, and the Real Meaning of Theory". The New Yorker . Retrieved August 18, 2016. , essay by British/American meteorologist and a NASA astronaut on anthopogenic global warming and "theory"

Source: https://en.wikipedia.org/wiki/Scientific_theory

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