Not a Fact Anymore
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How long did a fact last?

Lifespans of accepted claims

Compare the approximate span between a claim becoming established and the representative point when stronger evidence changed the record.

Catalogue median≈69.5 yearsAcross 228 quantitatively comparable entries
Shortest span≈2 yearsMars has a liquid metallic core with a radius of about 1,830 km.
Longest span≈2,297 yearsMalaria is caused by foul or unhealthy air rising from marshes.
Categories measured32Descriptive of this catalogue

These durations are approximate. Each quantitatively comparable entry keeps its human-readable historical ranges, while acceptedYear and timelineYear provide representative landmarks for ordering and comparison. A field or classroom can continue using an older view after contrary evidence appears, so these numbers are not exact dates of universal consensus. 69 entries are deliberately excluded from lifespan statistics because their acceptance boundary is too diffuse, their historical wording spans competing traditions, or a precise numerical duration would create false precision. Category comparisons describe this curated catalogue, not turnover rates for whole scientific fields.

The extremes

Shortest- and longest-lived claims

Shortest-lived

  1. Mars has a liquid metallic core with a radius of about 1,830 km.2021 → 2023 · Planetary Science≈2 years
  2. Thalidomide is safe to use during pregnancy.1957 → 1961 · Medicine≈4 years
  3. Quasars are unusual stars within or near the Milky Way.1958 → 1963 · Astronomy≈5 years
  4. Radioactivity is a chemical or molecular property that should change when a substance is heated, cooled, dissolved, or combined.1896 → 1902 · Physics≈6 years
  5. Dreams occur only during REM sleep.1955 → 1962 · Neuroscience≈7 years

Longest-lived

  1. Malaria is caused by foul or unhealthy air rising from marshes.400 BCE → 1897 · Medicine≈2,297 years
  2. Living organisms such as microbes can routinely arise spontaneously from nonliving matter under ordinary present-day conditions.350 BCE → 1861 · Biology≈2,211 years
  3. Most of a growing plant's dry mass comes from material absorbed from the soil.350 BCE → 1804 · Botany≈2,154 years
  4. Water is a fundamental element that cannot be decomposed into simpler substances.350 BCE → 1783 · Chemistry≈2,133 years
  5. Air is a single elemental substance.350 BCE → 1774 · Chemistry≈2,124 years

Compare categories

Medicine vs Astronomy

Choose any two subjects to compare their entries in this catalogue.

Medicine≈83 years46 entries · range ≈4 years to ≈2,297 years
Astronomy≈79.5 years26 entries · range ≈5 years to ≈1,960 years

Astronomy is ≈3.5 years shorter at the median in this catalogue.

By subject

Median lifespan by category

Sorted from the shortest median to the longest. Small categories can move sharply when a single entry is added, so the entry count is shown alongside each median.

CategoryEntriesMedian lifespanObserved range
Environmental Science1≈17 years—
Genetics13≈31 years≈12 years – ≈96 years
Cell Biology1≈37 years—
Psychology4≈38.5 years≈24 years – ≈75 years
Human Evolution8≈40 years≈12 years – ≈95 years
Neuroscience4≈40 years≈7 years – ≈115 years
Astrochemistry2≈41.5 years≈30 years – ≈53 years
Atmospheric Science3≈42 years≈39 years – ≈69 years
Ocean Science5≈45 years≈27 years – ≈205 years
Public Health5≈45 years≈35 years – ≈64 years
Biochemistry2≈47 years≈27 years – ≈67 years
Technology2≈48.5 years≈47 years – ≈50 years
Chemistry14≈58.5 years≈14 years – ≈2,133 years
Animal Behavior1≈60 years—
Cosmology2≈62.5 years≈55 years – ≈70 years
Archaeology5≈65 years≈45 years – ≈265 years
Physics22≈65 years≈6 years – ≈1,988 years
Planetary Science8≈69.5 years≈2 years – ≈110 years
Earth Science16≈79 years≈21 years – ≈269 years
Astronomy26≈79.5 years≈5 years – ≈1,960 years
Paleontology4≈79.5 years≈55 years – ≈146 years
Evolution4≈82 years≈9 years – ≈135 years
Medicine46≈83 years≈4 years – ≈2,297 years
Paleoclimate1≈84 years—
Ecology4≈98 years≈55 years – ≈120 years
Zoology4≈107.5 years≈72 years – ≈188 years
Biology8≈110 years≈15 years – ≈2,211 years
Virology1≈118 years—
Microbiology4≈118.5 years≈100 years – ≈140 years
Measurement3≈119 years≈71 years – ≈130 years
Materials Science3≈131 years≈54 years – ≈132 years
Botany2≈1,114.5 years≈75 years – ≈2,154 years

Across time

Lifespan distributions by century of change

Each row groups entries by the century containing their representative change year, then shows how those lifespans are distributed.

<25 years25–49 years50–99 years100–249 years250+ years
16th century5 entries · median ≈1,433 years
250+ years: 5
17th century7 entries · median ≈1,478 years
25–49 years: 150–99 years: 1250+ years: 5
18th century10 entries · median ≈842.5 years
25–49 years: 150–99 years: 2100–249 years: 2250+ years: 5
19th century34 entries · median ≈73.5 years
<25 years: 425–49 years: 1050–99 years: 8100–249 years: 6250+ years: 6
20th century149 entries · median ≈65 years
<25 years: 1925–49 years: 4250–99 years: 45100–249 years: 37250+ years: 6
21st century23 entries · median ≈42 years
<25 years: 725–49 years: 550–99 years: 4100–249 years: 7

Explore every lifespan

Acceptance → change

Search the catalogue and sort it from the shortest-lived claims to the longest. The explorer starts with Chemistry as a manageable sample; choose All categories to see the full catalogue. Bar length represents lifespan and is capped at 250 years so modern short-lived claims remain visible; the printed dates and duration always show the full approximate span.

Showing all 228 entries

Kept out of the rankings

Entries not assigned a quantitative lifespan

These remain part of the catalogue, but their acceptance boundary is too diffuse, contested, or historically mixed for a defensible single-number lifespan.

A pregnant woman's intense sights, fears, desires, or imagination can physically mark or deform the developing fetus.Premodern medicine, especially elaborated in the 17th century → 18th centuryA thrown projectile continues moving after release because the surrounding air rushes around it and supplies the continuing external push.An influential Aristotelian explanation of projectile motion in antiquity and medieval natural philosophy → 14th-century impetus mechanicsA vast southern continent must exist to balance the large landmasses of the Northern Hemisphere.Ancient geographical speculation revived strongly in Renaissance and early-modern European cartography → 18th-century Pacific explorationAdult human heart-muscle cells are permanently post-mitotic and are never replaced.Much of the 20th century → Late 20th century–2000sAdult mammalian brains cannot produce new neurons.Late 19th–mid-20th century → 1960s–1990sAir and other gases are weightless because they naturally rise or disappear.Antiquity through the 17th century → 17th–18th centuriesArteries normally carry pneuma or air rather than blood.Erasistratean and related Hellenistic physiology, 3rd century BCE → 2nd century CE in Galenic physiologyBase metals are immature or imperfect forms of metal that naturally ripen toward gold, and alchemical processes can accelerate that maturation.Influential medieval and early-modern alchemical metallogenesis → 17th–19th centuriesBlack-hole solutions were widely regarded as mathematical idealizations rather than realistic outcomes of gravitational collapse in nature.Especially influential from the 1930s into the 1960s → 1960s–1970sBodily changes acquired through use, disuse, or environmental conditions were widely thought to be inherited and to direct evolutionary change.Early 19th century–early 20th century → 1880s–1930sBone is primarily a structural and mineral-regulating organ, not an endocrine organ that signals to distant tissues.20th-century physiology before the endocrine role of bone was established → Late 20th century–2000sBreast milk is menstrual blood redirected to the breasts and transformed after childbirth.Ancient Greek and Galenic reproductive medicine through premodern medical teaching → 18th–19th centuries, with modern endocrine physiology later completing the explanationBrown adipose tissue was thought to disappear after infancy or to have little physiological importance in normal adults.Mid to late 20th century → 2000sChickens were first domesticated in the Indian subcontinent.20th century–2022 → 2022Corals were commonly classified with plants or “plant-like” marine growths rather than animals.Early-modern natural history through the mid-18th century → 1720s–1750sDinosaurs were treated as an entirely extinct group, separate from living birds.19th century–late 20th century → 1970s–1990sDire wolves were close relatives of gray wolves within the genus Canis.1858–2021, despite a separate-genus proposal in 1918 → 2021; refined in 2026Early tetrapods grew slowly or moderately, like modern amphibians; rapid juvenile growth evolved later with amniotes.Late 20th century–2022 → 2022Earthquakes are generated mainly by subterranean winds, gases, fire, explosions, or related volcanic processes.Ancient and early-modern natural philosophy; multiple competing subterranean theories → 19th–20th centuriesEuropean mecC-MRSA lineages arose during the modern antibiotic era because medical or veterinary antibiotic use selected for methicillin resistance.2011–2022 → 2022Every patient having a heart attack should receive supplemental oxygen, even when blood oxygen is normal.20th century–early 21st century → 1970s–2010sFibonacci leaf spirals were an ancient pattern inherited from the earliest leafy land plants.Late 20th–early 21st century → 2023Food webs were expected to depend ultimately on photosynthetic primary production powered by sunlight.Before the discovery of hydrothermal-vent ecosystems → 1977–early 1980sGermany's Ries and Steinheim craters were formed at the same time by a binary asteroid impact.1960s–2022 → 2022, after earlier challengesHeavenly bodies are made from a special incorruptible substance called aether or quintessence, rather than the matter found on Earth.Aristotelian cosmology from the 4th century BCE through the Renaissance → 17th–19th centuriesImagination, reason, and memory are located in particular fluid-filled ventricles or 'cells' of the brain.Late-antique and medieval cell doctrine from the 4th–5th centuries CE → 17th–18th centuriesImmune tolerance was thought to prevent self-directed immune reactions from becoming a major cause of disease.Early 20th century–1950s → 1940s–1960sLive birth was treated as a defining feature of mammals, making reports of egg-laying mammals difficult to reconcile with Mammalia.European zoology before monotreme reproduction was resolved → Early 19th century–1880sLiving organisms were generally expected to require a continuous supply of free oxygen to survive and grow.Late 18th–mid-19th century generalization in physiology and biology → 1861–1870sLong-lived dense planetary rings can survive only inside their parent body’s Roche limit.late 20th century–2023 → 2023Luxuriant tropical rainforest was widely taken as evidence that the underlying soil was exceptionally fertile and could remain highly productive after clearing.19th–early 20th-century exploration and colonial agriculture → 1930s–mid-20th centuryMammalian spinal evolution was a simple transition from reptile-like side-to-side bending in early synapsids to mammal-like up-and-down bending.Long-standing textbook model before 2021 → 2021Mars became dry mainly because its ancient surface water escaped into space.Late 20th century–2021 → 2021Metals are composed from sulfur and mercury principles in different proportions and qualities.Medieval Arabic and Latin alchemy, especially 12th–16th centuries → 17th–18th centuriesNanotyrannus fossils are juvenile Tyrannosaurus rex rather than a distinct small-bodied tyrannosaur.1999–2025 → 2025Natural background radiation is an important source of the spontaneous mutations that fuel evolution.1940s–1950s → 2010sNerves are hollow channels that transmit animal or psychic spirits between the brain and the body.Galenic neurophysiology and later animal-spirit theories → 17th–18th centuriesOnce adulthood is reached, the brain is permanently hardwired and cannot substantially reorganize.Late 19th–mid-20th century → 1960s–presentOpen-ocean regions rich in nitrate and phosphate were thought to contain enough iron that iron deficiency could not explain their low phytoplankton productivity.Mid-20th century–1980s, while iron limitation remained a recurring minority hypothesis → 1980s–1990sPlanetary and stellar configurations exert physical influences that can cause disease and should guide medical diagnosis, prognosis, and treatment.Mainstream late-medieval and early-modern European learned medicine → 17th–19th centuriesPlants were not understood to require a male reproductive contribution analogous to animal fertilization.Before the late-17th-century experimental establishment of plant sexuality → 1694 and the early 18th centuryProkaryotes were treated as one fundamental group, with organisms now called archaea classified among the bacteria.Mid-20th century–1970s → 1977–1990Pterosaurs remained relatively small through the Jurassic and only evolved much larger body sizes in the Cretaceous.Late 20th century–2022 → 2022Respiratory particles can be divided into “droplets” and “aerosols” using one fixed particle-size cutoff.20th century–2024 → 2024Sea sponges were often classified as plants or intermediate plant-like organisms rather than animals.Early-modern natural history through the 18th century → 18th–19th centuriesSecure human occupation of North America began only after the Last Glacial Maximum.late 20th century–2021 → 2021–2023Sleep is essentially a unitary, passive state produced by a general reduction of brain activity.Before EEG sleep staging and the discovery of REM sleep → 1930s–1950sSome shell-, bone-, or organism-shaped stones are generated inside rocks by mineral or 'plastic' forces rather than being the remains of once-living organisms.One important Renaissance and 17th-century explanation among several competing fossil theories → Late 17th–18th centuriesStars can be treated as essentially fixed stellar types rather than objects passing through connected evolutionary stages.Before modern stellar-structure and evolutionary astronomy → Late 19th–mid-20th centurySwallows disappear in winter because they become torpid and hibernate underwater or in pond mud rather than migrating long distances.A serious early-modern natural-history position, especially debated in the 17th–18th centuries → Late 18th–19th centuriesSynaptic transmission was widely expected to continue electrically across the junction between excitable cells.Late 19th–mid-20th century → 1921–1950sThe adult human lower jaw consists of two bones joined together at the chin.Galenic anatomy from the 2nd century CE → c. 1200 in medieval Islamic anatomy; later in Renaissance European anatomyThe Amazon rainforest was broadly a net carbon sink across the basin.Late 20th century–2021 → 2021The central nervous system has no conventional lymphatic vessels.Modern neuroanatomy before 2015 → 2015The Earth is flat, and its broad surface remains suspended because the air beneath it supports it.Several Presocratic natural philosophers in the 6th–5th centuries BCE → By the 4th century BCE in Greek learned astronomyThe equatorial 'torrid zone' is too hot for humans to inhabit.Influential classical and medieval European climatic geography → Late medieval–15th-century travel and explorationThe human uterus has seven chambers or cells, with different chambers associated with male, female, or intersex fetuses.Medieval learned anatomy, especially 13th–14th centuries → Early-to-mid 16th centuryThe lungs' primary function is to cool the heart and regulate its innate heat.Aristotelian and Galenic cardiorespiratory physiology → 17th–18th centuriesThe Moon’s youngest mare volcanism required a KREEP-rich mantle source enriched in heat-producing elements.1990s–2021 → 2021The planets and stars are carried around Earth by real nested celestial spheres.Ancient and medieval geocentric natural philosophy → Late 16th–17th centuriesThe space between stars contains no detectable material medium.Before the first spectroscopic detections of interstellar matter → 1904–1920sTitan’s outward tidal migration should be extremely slow because it orbits far from Saturn.1960s–2020 → 2020Transmissible infectious agents were expected to require DNA or RNA to store and propagate biological information.Mid-20th century–early 1980s → 1982–1997Vision occurs because visual rays or a visual power travels outward from the eyes to the object being seen.Influential ancient extramission traditions and much of the early medieval Latin West → 13th-century European optics after the Latin reception of Ibn al-HaythamVolcanic eruptions are driven by underground combustion or chemical fires involving substances such as sulfur, coal, or other combustible materials.Influential 17th–18th-century theories, with older roots → Late 18th–19th centuriesWhite light is a simple, uniform kind of light, while prisms and other transparent bodies create or modify the colors seen in a spectrum.Pre-Newtonian optical theories, especially 17th century → 1666–1672Widespread domestic-horse mobility was a major driver of the Yamnaya expansion into Europe around 3000 BCE.late 20th century–2021 → 2021–2024Woodpecker skulls protect the brain by acting as shock absorbers during pecking.Late 20th century–2022 → 2022Woody plants obtain their water mainly from soil and use water stored in bedrock only as an emergency reserve during severe drought.Long-standing soil-centered model before 2021 → 2021