Superseded theories in science
This list catalogs well-accepted theories in science and pre-scientific
Some theories are discarded in their entirety, such as the replacement of the phlogiston theory by energy and thermodynamics. Some theories known to be incomplete or in some ways incorrect are still used. For example, Newtonian classical mechanics is accurate enough for practical calculations at everyday distances and velocities, and it is still taught in schools. The more complicated relativistic mechanics must be used for long distances and velocities nearing the speed of light, and quantum mechanics for very small distances and objects.
Some aspects of discarded theories are reused in modern explanations. For example, miasma theory proposed that all diseases were transmitted by "bad air". The modern germ theory of disease has found that diseases are caused by microorganisms, which can be transmitted by a variety of routes, including touching a contaminated object, blood, and contaminated water. Malaria was discovered to be a mosquito-borne disease, explaining why avoiding the "bad air" near swamps prevented it. Increasing ventilation of fresh air, one of the remedies proposed by miasma theory, does remain useful in some circumstances to expel germs spread by airborne transmission, such as SARS-CoV-2.[1]
Some theories originate in, or are perpetuated by, pseudoscience, which claims to be both scientific and factual, but fails to follow the scientific method. Scientific theories are testable and make falsifiable predictions.[2] Thus, it can be a mark of good science if a discipline has a growing list of superseded theories, and conversely, a lack of superseded theories can indicate problems in following the use of the scientific method. Fringe science includes theories that are not currently supported by a consensus in the mainstream scientific community, either because they never had sufficient empirical support, because they were previously mainstream but later disproven, or because they are preliminary theories also known as protoscience which go on to become mainstream after empirical confirmation. Some theories, such as Lysenkoism, race science or female hysteria have been generated for political rather than empirical reasons and promoted by force.
Discarded theories
Biology
- Spontaneous generation – a principle regarding the spontaneous generation of complex life from inanimate matter, which held that this process was a commonplace and everyday occurrence, as distinguished from univocal generation, or reproduction from parent(s). Falsified by an experiment by Louis Pasteur: where apparently spontaneous generation of microorganisms occurred, it did not happen on repeating the process without access to unfiltered air; on then opening the apparatus to the atmosphere, bacterial growth started.[3]
- Mendelian genetics, combined in the modern synthesis which finds that genes in the form of DNA are the primary way parental characteristics are passed to descendants. Discoveries in epigenetics have shown that in some very limited ways, the life experiences of organisms can affect the development of their children.[4]
- Vitalism – the theory that living things are alive because of some "vital force" independent of matter, as opposed to because of some appropriate assembly of matter. It was gradually discredited by the rise of organic chemistry, biochemistry, and molecular biology, fields that failed to discover any "vital force." Friedrich Wöhler's synthesis of urea from ammonium cyanate was only one step in a long road, not a great refutation.[5][6]
- fetal origins of adult disease, genomic imprinting).
- atomic theory.
- Baer's laws of embryology.
- Telegony– the theory that an offspring can inherit characteristics from a previous mate of its mother's as well as its actual parents, often associated with racism.
- Out of Asia theory of human origin – The majority view is of a recent African origin of modern humans, although a multiregional origin of modern humans hypothesis has much support (which incorporates past evidence of Asian origins).
- Scientific racism – the theory that humanity consists of physically discrete superior or inferior races. Rendered obsolete by Human evolutionary genetics and modern anthropology.[9]
- Mendelian genetics, classical genetics, Boveri–Sutton chromosome theory – first genetic theories. Not invalidated as such, but subsumed into molecular genetics.
Chemistry
- unit of energy still used for nutritionin some countries.
- Classical elements – All matter was once thought composed of various combinations of classical elements (most famously air, earth, fire, and water). Antoine Lavoisier finally refuted this in his 1789 publication, Elements of Chemistry, which contained the first modern list of chemical elements.
- Electrochemical dualism – the theory that all molecules are salts composed of basic and acidic oxides
- Lavoisier's work on oxidation.
- Point 2 of Dalton's Atomic Theory was rendered obsolete by discovery of isotopes, and point 3 by discovery of subatomic particles and nuclear reactions.
- Radical theory – the theory that organic compounds exist as combinations of radicals that can be exchanged in chemical reactions just as chemical elements can be interchanged in inorganic compounds.
- Vitalism – See section on Biology.
- Nascent state refers to the form of a chemical element (or sometimes compound) in the instance of their liberation or formation. Often encountered are atomic oxygen (Onasc) and nascent hydrogen (Hnasc), and chlorine (Clnasc) or bromine (Brnasc).[12]
- Polywater, a hypothesized polymer form of water, the properties of which actually arose from contaminants such as sweat
Physics
- Emission theory of vision – the belief that vision is caused by rays emanating from the eyes was superseded by the intro-mission approach and more complex theories of vision.
- Newtonian physics.
- Ptolemy's law of refraction, replaced by Snell's law.
- Luminiferous aether – failed to be detected by the sufficiently sensitive Michelson–Morley experiment, made obsolete by Einstein's work.
- Joule's work.
- Contact tension– a theory on the source of electricity.
- Gottfried Leibniz's elementary and limited early formulation of the principle of conservation of energy.
- "Purely generation of voltage differences.
- Emitter theory – another now-obsolete theory of light propagation.
- voltaic cell to be a new type of force acting on the charges generated merely from contact of the electrodes. Michael Faradaylater correctly explained the active agent was chemical reactions.
- Balance of nature – superseded by catastrophe theory and chaos theory.
- Progression of atomic theory
- Democritus, the originator of atomic theory, held that everything is composed of atoms that are indestructible. His claim that atoms are indestructible is not the reason it is superseded—as it was later scientists who identified the concept of atoms with particles, which later science showed are destructible. Democritus' theory is superseded because of his position that several kinds of atoms explain pure materials like water or iron, and characteristics that science now identifies with molecules rather than with indestructible primary particles. Democritus also held that between atoms, an empty space of a different nature than atoms allowed atoms to move. This view on space and matter persisted until Einstein described spacetime as being relative and connected to matter.
- John Dalton's model of the atom, which held that atoms are indivisible and indestructible (superseded by nuclear physics) and that all atoms of a given element are identical in mass (superseded by discovery of atomic isotopes).[13]
- Plum pudding model of the atom—assuming the protons and electrons were mixed together in a single mass
- Rutherford model of the atom with an impenetrable nucleus orbited by electrons
- Bohr model with quantized orbits
- Electron cloud model following the development of quantum mechanics in 1925 and the eventual atomic orbitalmodels derived from the quantum mechanical solution to the hydrogen atom
Astronomy and cosmology
- Ptolemaic system – superseded by Nicolaus Copernicus' heliocentric model.
- Geocentric universe– superseded by Copernicus
- Copernican system - superseded by Tychonic system
- barycentric coordinates.
- Aristotelian Dynamics of the celestial spheres superseded by the Elliptic orbit and Kepler's laws of planetary motion
- Tychonic system – superseded by Newton's laws of motion
- Luminiferous aether theory
- Static Universe theory[14]
- expanding universe was in a steady state, and had no beginning. It was a competitor of the Big Bangmodel until evidence supporting the Big Bang and falsifying the steady state was found.
Geography and climate
- Buenaventura River
- Flat Earth theory, generally known to be false among educated people in various ancient and medieval societies
- Terra Australis, which technically is Antarctica, but the original idea was based on an unproven belief that land in the Northern hemisphere must have a Southern counterpart for balance.
- Hollow Earth theory
- The Open Polar Sea, an ice-free sea once supposed to surround the North Pole
- Rain follows the plow – the theory that human settlement increases rainfall in arid regions (only true to the extent that crop fields evapotranspirate more than barren wilderness)
- Island of California – the theory that California was not part of mainland North America but rather a large island
- Pre-modern effects of global warming)
- Climatic determinism
- Topographic determinism
- Moral geography
- Cultural acclimatization
- Global cooling
- Drainage divides as always being made up by hills and mountains.
- Ancient and medieval concepts surrounding the antipodes, including the related theories of antichthones and the alleged existence of a torrid zone[a]
Geology
- Abiogenic petroleum origin – While some petroleum or natural gas is almost certainly abiogenic, the vast majority has origins as living organisms
- uniformitarianism and neocatastrophism
- Cryptoexplosion craters, now discarded in favour of impact craters and ordinary volcanism.
- Flood geology replaced by modern geology and stratigraphy
- Neptunism replaced by plutonism and volcanism
- Granitization, a discredited alternative to a magmatic origin of granites
- Monoglaciation, the idea that the Earth had a single ice age, replaced by polyglaciation, the idea that the Earth has gone through several periods of widespread ice cover.[17]
- Oscillation theory of land-level rise and subsidence during deglaciation
- The following were superseded by plate tectonics:
- Elevation crater theory
- Expanding Earth theory (superseded by subduction)
- Contracting Earth
- Geosyncline theory
- Haarman's Oscillation theory
- Various Lemuria
Psychology
- Pure behaviorist explanations for language acquisition in infancy, falsified by the study of cognitive adaptations for language.[18]
Medicine
- Theory of the four bodily humours (see also Four temperaments)
- Heroic medicine – a therapeutic method derived from the belief in bodily humour imbalances as the cause of ailments.
- Miasma theory of disease – the theory that diseases are caused by "bad air". No experimental support, and rendered obsolete by the germ theory of disease.
- Phrenology – a theory of highly localised brain function popular in 19th century medicine.
- Homeopathy – a theory according to which a disease can be cured by infinitesimal doses of the substance that caused it
- Eclectic medicine – transformed into alternative medicine, and is no longer considered a scientific theory
- Physiognomy, related to phrenology, held that inner character was strongly correlated with physical appearance
- periodontitis, and toothaches
Obsolete branches of enquiry
- Alchemy, which led to the development of chemistry
- Astrology, which led to the development of astronomy
- Phrenology, a pseudoscience
- Numerology, a pseudoscience
Theories now considered incomplete
These theories that are no longer considered the most complete representation of reality but remain useful in particular domains or under certain conditions. For some theories, a more complete model is known, but for practical use, the coarser approximation provides good results with much less calculation.
- Newtonian gravity.
- Classical electrodynamics is a very close approximation to quantum electrodynamicsexcept at very small scales and low field strengths.
- The Bohr model of the atom was extended by the quantum mechanical model of the atom.
- The formula known as hypersonic flow.[22]
- The once-popular cycle of erosion is now considered one of many possibilities for landscape evolution.[23]
- The theory of continental drift was incorporated into and improved upon by plate tectonics.
- Rational choice theory as a model of human behavior.
See also
- Pseudoscience
- Scientific theory
- Philosophy of science
- Protoscience
- Fringe science
- Pathological science
- Paradigm shift
- History of evolutionary thought
- Creation–evolution controversy
Lists
- List of common misconceptions, including those about scientific subjects
- List of discredited substances
- List of experiments
- List of topics characterized as pseudoscience
Notes
- ^ Antipodes and antichthones do literally exist as opposite points on the Earth and people who live on and around them, but do not have any of the unique properties ascribed to them by ancient or medieval authors.
References
- Washington Post.
- ^ 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 Company, Mountain View, Calif.
- ^ "Spontaneous generation | Examples & Experiments | Britannica".
- PMID 25917417.
- ISBN 978-0-7546-0881-3.
- ^ Bechtel, William; Williamson, Robert C. (1998). "Vitalism". In E. Craig (ed.). Routledge Encyclopedia of Philosophy. Routledge.
- ^ Havelock Ellis, Studies in the Psychology of Sex, vol. 5 p. 218
- ISBN 0-618-31938-7.
- ^ "AAA Statement on Race". American Anthropological Association. Retrieved December 15, 2018.
- ^ "germline theory". Glossary. NCBI.
- ^ Lefers, Mark. "germ-line theory". Glossary. Northwestern University. Retrieved February 28, 2012.
- ^ Jensen, William B. (1990). "Whatever Happened to the Nascent State?" (PDF). Bulletin for the History of Chemistry (5): 26–36. Retrieved May 6, 2017.
- ^ De Leon, Professor N. "Dalton's Atomic Theory". Chemistry 101 Class Notes. Indiana University Northwest. Retrieved August 26, 2013.
- ^ Rob Garner. "NASA's WFIRST Will Help Uncover Universe's Fate". Retrieved September 3, 2023.
- ISBN 978-1-921520-64-8.
- ^ An inland sea, the Eromanga Sea, did exist there in the Mesozoic, but not during any period of human history
- ^ Glacial Theory
- ^ Crain, Stephen and Diane C. Lillo-Martin (1999). An Introduction to Linguistic Theory and Language Acquisition. Oxford: Blackwell.
- ^ Steven Novella, MD. "Psychomotor Patterning". Retrieved October 16, 2014.
- ^ Aerodynamics: Selected Topics in the Light of Their Historical Development, book by Theodore Von Karman, 1954, Dover Publications, p10 and following pages Detailed discussion of Newton's sine-square law, invalidity in the general case and applicability at high supersonic speeds.
- S2CID 128907423.
External links
- Media related to Obsolete scientific theories at Wikimedia Commons