All articles starting with H

Holocentric chromosome

Holocentric chromosome (holokinetic, diffuse centromere): a chromosome with kinetochore activity along nearly its whole length, tolerating fragmentation; evolved independently at least 13 times in plants and animals, first described 1935.

Holocephali

Holocephali, also known as holocephalans, is a subclass of cartilaginous fish containing the chimaeras, or ghost sharks, with upper jaws fused to the skull and a fossil record reaching back almost 360 million years.

Oct 21, 2026

Holochilus

Holochilus (marsh rats) is a genus of large, semiaquatic, herbivorous sigmodontine rodents in open wetlands across South America, from northern South America to central Argentina, with six or more recognized species and a complex taxonomic history.

Oct 21, 2026

Holodiscus discolor

Holodiscus discolor, oceanspray or creambush (Rosaceae), a deciduous arching shrub native from British Columbia to Mexico, with creamy white flower sprays, four varieties, fire-adapted, valuable to native bees.

Holodomor

Holodomor (Голодомор), the man-made famine of 1932–1933 in Soviet Ukraine under Stalin, caused by forced collectivization and grain requisition; killed at least 4 million; recognized as genocide by Ukraine, disputed internationally.

Holodomor genocide question

The Holodomor genocide question debates whether the 1932-1933 Soviet-induced famine in Ukraine (Holodomor, Голодомор) constitutes genocide under the 1948 UN Convention or a crime against humanity, centering on intent, Lemkin's four-stage account, and post-2022 state recognition.

Holofernes

Holofernes (Ὀλοφέρνης) is the Assyrian army commander in the Book of Judith who besieges Bethulia and is beheaded by the widow Judith; not attested historically, he became a major subject in European art and literature.

Oct 22, 2026

Holographic acoustic tweezers

Holographic acoustic tweezers are devices that use holographically shaped sound radiation forces to trap and move multiple particles without contact, first demonstrated in 2018 by Asier Marzo and Bruce Drinkwater.

Holographic dark energy

Holographic dark energy (HDE) is a class of cosmological models in which dark energy's density is set by the holographic principle, proposed by Miao Li in 2004.

Holographic imaging

Holographic imaging, also known as millimeter-wave holographic imaging, records a wave's interference pattern to preserve amplitude and phase, reconstructing 3D images for security screening and sensing.

Holographic interference microscopy

Holographic interference microscopy is a coherent optical technique applying holographic interferometry to microscopy, quantitatively measuring nearly transparent phase objects like living cells, recovering optical phase with nanometer-scale axial sensitivity.

Holographic interferometry

Holographic interferometry is an optical technique that reveals small changes in an object's shape or refractive index as fringe patterns, used in nondestructive testing and vibration analysis.

Holographic microscopy

Holographic microscopy is a label-free imaging technique that reconstructs the 3D structure of transparent specimens from interference patterns, yielding quantitative phase maps of living cells.

Holographic optical elements

Holographic optical elements (HOEs) are volume holograms used as thin, flat optical components that can replace lenses, prisms, and mirrors, notably in augmented reality displays.

Holographic optical tweezers

Holographic optical tweezers (HOTs) are an optical manipulation technique in which a computer-generated hologram splits a single laser beam into hundreds of traps in 3D, invented by Eric Dufresne and David Grier in 1997.

Holographic principle

The holographic principle, also known as holographic duality, is a conjecture in quantum gravity holding that a spacetime region's physics, including gravity, is fully described by its boundary.

Holographic QCD

Holographic QCD, also called the AdS/QCD correspondence, is a theoretical framework using gauge/gravity duality to study non-perturbative quantum chromodynamics, with applications to neutron stars and the quark-gluon plasma.

Oct 22, 2026

Holographic quantum error-correcting code

A holographic quantum error-correcting code is a quantum code encoding bulk degrees of freedom of a hyperbolic space onto its boundary, modeled on the AdS/CFT correspondence.

Holographic reconstruction

Holographic reconstruction is a computational imaging method that numerically recovers an object's amplitude and phase from recorded holograms, applied across optical, electron, and X-ray imaging, where the recovered phase carries quantitative information invisible to ordinary cameras.

Holographic recording

Holographic recording stores a complete light wavefront, amplitude and phase together, by exposing a photosensitive medium to the interference of object and reference waves; it enables 3D imaging, security holograms, and data storage.

Holographic tomography

Holographic tomography is a label-free optical imaging method that reconstructs the 3D refractive index of transparent specimens by combining holographic phase measurements from many illumination angles.

Holographic weapon sight

A holographic weapon sight, also called a holographic sight, is an electro-optic firearm sight using a laser-illuminated hologram to project a reticle, introduced commercially in 1996.

Holographic will

Holographic will, or holograph will: a will written and signed entirely in the testator's own handwriting, valid without witnesses in about half of US states, of Roman origin, recognized broadly in civil law jurisdictions like France.

Holography

Holography is a technique for recording and reconstructing the complete light field of an object, capturing both amplitude and phase of light to produce three-dimensional holograms.

Hololive Dreams

hololive Dreams (holodori, ホロドリ) is hololive production's first official smartphone game, a free-to-play rhythm & RPG by COVER and QualiArts launched July 23, 2026 on iOS, Android, and Steam, with 50+ talents, 150+ songs, and Dream Park building.

Hololive Production (ホロライブプロダクション)

Hololive Production (ホロライブプロダクション) is COVER Corporation's VTuber agency, uniting the hololive and HOLOSTARS groups plus Indonesia and English branches; 78 VTubers, 95.2 million YouTube subscribers, TSE Growth-listed since 2023.

HoloMatic

HoloMatic (禾多科技) was a Beijing-based autonomous-driving supplier founded by Ni Kai in 2017, which developed driver-assistance and parking solutions for Chinese automakers before its core divisions were dissolved in August 2024.

Holometabolism

Holometabolism (complete metamorphosis, Holometabola/Endopterygota) is insect development through egg, larva, pupa, and adult stages, seen in nearly 90% of insect species including beetles, flies, bees, and butterflies, controlled by ecdysone, juvenile hormone, chinmo, broad, and E93.

Holomorphic function

A holomorphic function, also called a complex analytic function, is a complex-valued function differentiable at every point of an open set, the central object of complex analysis.