RESEARCH BASE
Search 3,721 documents across 34 fields — every claim tier-rated by evidence
3,633 are the core, quality-scored corpus (34 lettered sections — see How We Work); the remaining 88 are cross-corpus synthesis documents (68 InterDocs, 12 Connections, 8 Theories) also indexed here.
149 results for "mass extinction" — page 4 of 8
E_2_13 — Paleocene-Eocene Thermal Maximum
The Paleocene-Eocene Thermal Maximum (PETM) — approximately 55.8 million years ago — was the most extreme rapid warming event of the past 66 million years and is widely studied as a deep-time analog for modern anthropoge
E_2_12 — Great Oxygenation Event
The Great Oxygenation Event (GOE) — approximately 2.4–2.1 billion years ago — was one of the most transformative events in Earth's history: the first permanent rise of free molecular oxygen (O₂) in the atmosphere, from n
E_2_02 — Toba Supervolcano and the 74,000 BP Genetic Bottleneck
Approximately 74,000 years ago, the Toba supervolcano on the island of Sumatra (modern Indonesia) produced the largest volcanic eruption in the last 2 million years: a VEI-8 (Volcanic Explosivity Index maximum) event tha
E_4_26 — Younger Dryas Impact Evidence: A Comprehensive Review
The Younger Dryas Impact Hypothesis (YDIH) proposes that one or more extraterrestrial objects (comet or asteroid fragments) struck or exploded over the Earth approximately 12,900 years ago (12.9 ka BP), triggering the Yo
E_4_09 — Magnetic Pole Reversals and the Laschamp Event
Earth's magnetic field periodically undergoes geomagnetic reversals — events in which the north and south magnetic poles swap polarity. This has occurred at least 183 times in the last 83 million years, with the last ful
E_4_16 — Cosmogenic Isotope Dating: Beryllium-10 and Exposure Ages
Cosmogenic nuclide dating (also called cosmogenic exposure dating or terrestrial cosmogenic nuclide, TCN, dating) is a geochronological method that determines how long a rock surface has been exposed at or near Earth's s
E_1_04 — Complete Meteor & Asteroid Impact Catalog: Earth's Full Bombardment History
This document examines Complete Meteor & Asteroid Impact Catalog: Earth's Full Bombardment History, a topic within the Cataclysms and Chronology research area. Key areas of investigation include Theia Giant Impact (~4.51
E_1_01 — The Younger Dryas Impact Hypothesis (YDIH)
This document examines The Younger Dryas Impact Hypothesis (YDIH), a topic within the Cataclysms and Chronology research area. Notable findings include: Greenland ice-core data confirm rapid cooling at onset and abrupt w
E_1_15 — Uranium-Thorium Dating: Methodology and Applications in Deep Time
Uranium-thorium (U-Th) dating, also called uranium-series disequilibrium dating, is a radiometric technique that measures the decay of ²³⁴U to ²³⁰Th (half-life: ~245,620 years) in materials such as speleothems (cave form
E_1_09 — Solar Storms and Miyake Events
The Sun periodically releases enormous bursts of energy — coronal mass ejections (CMEs) and solar proton events (SPEs) — that interact with Earth's magnetosphere and can have devastating consequences for technology-depen
ZG_2_06 — Historical Linguistics and Language Family Classification
Historical linguistics is the scientific study of how languages change over time, how they are related to each other, and how they can be grouped into language families descended from common ancestors. The discipline's c
TH_05 — The Water-Carbon-Chirality Triple Lock
Life appears to need three separate lucky breaks: water, with all its strange life-friendly quirks; carbon, the one atom flexible enough to build living molecules; and a curious one-handedness, where life uses only "left
Q_1_12 — Conformal Cyclic Cosmology: Penrose's Vision of Eternal Recurrence
Conformal Cyclic Cosmology (CCC), proposed by Roger Penrose in 2005, envisions the universe as an infinite sequence of "aeons" — each beginning with a Big Bang-like event and ending in an infinitely expanded, cold state
Q_4_05 — Modified Gravity Theories
Modified gravity theories propose that the observed discrepancies between luminous matter and gravitational dynamics — traditionally attributed to dark matter — instead result from a breakdown or modification of Newtonia
Q_4_16 — Chandrasekhar Limit: White Dwarf Physics and Stellar Death
The Chandrasekhar limit — approximately 1.4 solar masses ($1.4 \, M_\odot$) — is the maximum mass of a stable white dwarf star, the dense remnant left after a low- or intermediate-mass star (initial mass up to ~8 $M_\odo
Q_4_18 — Spectroscopy: Principles, Methods, and Applications
Spectroscopy — the study of the interaction between matter and electromagnetic radiation — is one of the most powerful and versatile analytical methods in all of science. From Joseph von Fraunhofer's discovery of dark ab
Q_4_21 — Chromatography: Separation Science from Tswett to Modern Proteomics
Chromatography — the separation of mixtures by differential partitioning between a stationary phase and a mobile phase — is the most widely used analytical technique in chemistry, biology, and medicine. Mikhail Tswett (U
Q_4_32 — The Fundamental Constants: Physics, Life, and Mathematics
The universe runs on numbers — and not arbitrary ones. A small set of fundamental constants, mostly dimensionless, determines every property of matter, energy, space, and time. Change any of them by a fraction and atoms
Q_2_13 — Interstellar Medium, Dust, and Nebulae
The space between stars is far from empty — the interstellar medium (ISM) is a complex, dynamic ecosystem of gas, dust, magnetic fields, and cosmic rays that pervades galaxies and plays a central role in stellar birth, d
Q_2_08 — Quasars and Active Galactic Nuclei
Quasars (quasi-stellar objects) and active galactic nuclei (AGN) are the most luminous persistent objects in the universe, powered by accretion of matter onto supermassive black holes (SMBHs, 10⁶–10¹⁰ M☉) at galaxy cente
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