42,772 articles
Natural inflation
Natural inflation is a model of cosmic inflation in which the inflaton is a pseudo Nambu-Goldstone boson with a cosine potential, proposed by Freese, Frieman, and Olinto in 1990.
Natural kinds
Natural kinds are groupings of things that reflect the structure of the natural world rather than human interests, with chemical elements like H₂O as paradigm examples.
Natural linewidth
The natural linewidth is the irreducible width of a spectral line, caused by the finite lifetime of the atomic states involved and measured as the full width at half maximum.
Natural logarithm
The natural logarithm, also called the natural log, is the logarithm to the base e, written ln x; it is the inverse of the exponential function.
Natural nuclear fission reactor
A natural nuclear fission reactor is a uranium deposit where fission chain reactions occurred without human intervention, known only at Oklo, Gabon, about 2 billion years ago.
Natural number
A natural number, or positive integer, is one of the numbers 0, 1, 2, 3, and so on, depending on convention, used for counting and ordering.
Natural philosophy
Natural philosophy was the traditional term for the systematic study of nature, from antiquity until the nineteenth century, when William Whewell's 1833 word "scientist" replaced "natural philosopher".
Natural resource
A natural resource is any biological, mineral, or aesthetic asset afforded by nature without human intervention that can be used for benefit; classifications include renewable, non-renewable, and nondepletable.
Natural Resource Partners
Natural Resource Partners is an American diversified natural resource partnership, formed in 2002, that owns about 13 million acres of mineral rights and earns royalties without mining.
Natural Resources Defense Council
The Natural Resources Defense Council (NRDC) is an international nonprofit environmental organization that uses law and science to confront the climate crisis, founded in 1970.
Natural resources of India
The natural resources of India are the minerals, fossil fuels, water, land, and forests within the country that support its economy, coal being the principal mineral resource.
Natural satellite
A natural satellite, also called a planetary satellite or moon, is a celestial body that orbits a planet, dwarf planet, or other larger non-stellar body.
Natural science
Natural science, also known as the biological and physical sciences, is the branch of science that studies the natural world through observation and experiment, spanning physics, chemistry, and biology.
Natural transformation
A natural transformation, also called a morphism of functors, assigns to each object a morphism between two parallel functors' values, compatible with every morphism of the source category.
Natural units
Natural units, or the natural unit system, are measurement systems based on fundamental physical constants rather than units like the meter, used heavily in particle and atomic physics.
Naturalistic observation
Naturalistic observation is a research method that watches and records behavior in its real-world setting without manipulating any variable, yielding descriptions rather than causal conclusions.
Naturally occurring radioactive material
Naturally occurring radioactive material (NORM) is material whose radioactivity comes only from natural radionuclides, principally uranium and thorium series isotopes and potassium-40; when industry concentrates them, it is called TENORM.
Naturalness
Naturalness is a criterion in particle physics that a theory's parameters should not require extreme fine-tuning, underlying the Higgs hierarchy problem but called into question after the LHC found no expected new physics.
Nature
Nature is the material world and its processes considered independently of human artifice, and in philosophy the concept framing what counts as natural rather than artificial or supernatural.
Nature (journal)
Nature is a weekly international scientific journal publishing peer-reviewed research in all fields of science and technology, founded in London in 1869 and ranking among the most prestigious general-science journals.
Nature Communications
Nature Communications is a fully open access, multidisciplinary scientific journal published by Springer Nature. Launched in April 2010, it publishes research across the biological, physical, chemical, and social sciences.
Nature Genetics
Nature Genetics is a monthly peer-reviewed scientific journal publishing research in genetics and genomics, launched in April 1992 as the first of Nature's discipline-specific sister journals.
Nature Medicine
Nature Medicine is a monthly peer-reviewed medical journal published by Springer Nature that covers translational and clinical research, launched in January 1995 as an early sister journal of Nature.
Nature Methods
Nature Methods is a monthly peer-reviewed journal in Springer Nature's Nature Portfolio that publishes novel life-science methods, requiring strong validation and performance comparisons, with a 2024 impact factor of 32.1.
Nature Physics
Nature Physics is a monthly peer-reviewed scientific journal published by Springer Nature covering pure and applied physics, launched in October 2005 as part of the Nature portfolio.
Naum Akhiezer
Naum Akhiezer (Наум Ілліч Ахієзер) was a Soviet and Ukrainian mathematician who worked in approximation theory and the moment problem in Kharkiv, giving his name to the Akhiezer polynomials.
Nautical Almanac
The Nautical Almanac is an annual ephemeris published jointly by the US and UK Nautical Almanac Offices, giving mariners data for celestial navigation with a sextant.
Nautical chart
A nautical chart, also called a marine or navigation chart, is an official government-issued map for marine navigation, showing depths, hazards, and aids to seafarers.
Nautical mile
The nautical mile, historically called the admiralty mile, is a unit of length used in sea and air navigation, defined as exactly 1,852 meters and standardized in 1929; its speed companion is the knot.
Navajo Sandstone
The Navajo Sandstone is a light-colored, cross-bedded Jurassic sandstone deposited by ancient dunes across the Colorado Plateau, forming the slickrock cliffs of Zion National Park.