Science cards in WikiCards

WikiCards has 599 Science cards in its base set: 12 Legendary, 34 Epic, 139 Rare, 325 Uncommon and 89 Common. The strongest are Moon, Lyme disease, Bill Gates. Each card is a real Wikipedia article, with its photo credit and licence below it.

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599 cards

Moon
LegendaryAttack 100
The Moon is the only natural satellite of Earth.
Photo Gregory H. Revera, CC BY-SA 3.0
Lyme disease
LegendaryAttack 97
Lyme disease, also known as Lyme borreliosis, is a tick-borne disease caused by species of Borrelia bacteria, transmitted by…
Photo Photo by Scott Bauer., Public domain
Bill Gates
LegendaryAttack 97
William Henry Gates III is an American businessman and philanthropist.
Photo Bogdan Hoyaux / European Union, CC BY 4.0
Higgs boson
EpicAttack 97
The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics…
Photo CERN for the ATLAS and CMS Collaborations, CC BY-SA 3.0
Hubble Space Telescope
EpicAttack 96
The Hubble Space Telescope is a space telescope that was launched into low Earth orbit in 1990 and remains in operation.
Photo NASA, Public domain
Traditional Chinese medicine
RareAttack 96
Traditional Chinese medicine is an alternative medical practice drawn from traditional medicine in China.
Photo Félix An, CC BY 4.0
Alzheimer's disease
EpicAttack 95
Alzheimer's disease is a neurodegenerative disease and is the most common cause of dementia, accounting for around 60–70% of…
Photo Garrondo, Public domain
Major depressive disorder
EpicAttack 95
Major depressive disorder, also known as clinical depression, is a mental disorder characterized by at least two weeks of…
Photo GoldenArtists, CC BY-SA 4.0
Renewable energy
RareAttack 95
Renewable energy is energy made from renewable natural resources that are replenished on a human timescale.
Photo kallerna, CC BY-SA 4.0
David Hume
RareAttack 94
David Hume was a Scottish philosopher, historian, economist and essayist who is known for his highly influential system of…
Photo Allan Ramsay, Public domain
Friedrich Hayek
RareAttack 93
Friedrich August von Hayek was an Austrian economist and philosopher.
Photo The original uploader was DickClarkMises at English Wikipedi, CC BY-SA 3.0
Underwater diving
UncommonAttack 93
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the…
Photo U.S. Navy photo by Senior Chief Mass Communication Specialis, Public domain
Unmanned aerial vehicle
RareAttack 93
An unmanned aerial vehicle, or unmanned aircraft system, commonly known as an aerial drone or simply drone, is an aircraft…
Photo Lt. Col. Leslie Pratt, Public domain
Economics
RareAttack 93
Economics is a social science that studies the production, distribution, and consumption of goods and services.
Photo www.elbpresse.de, CC BY-SA 4.0
Arthur Schopenhauer
EpicAttack 92
Arthur Schopenhauer, also known as the “Philosopher of Pessimism”, was a German philosopher and writer.
Photo Johann Schäfer, Public domain
Immanuel Kant
LegendaryAttack 92
Immanuel Kant was a German philosopher.
Photo Johann Gottlieb Becker (1720-1782), Public domain
Mathematics
LegendaryAttack 92
Mathematics is a field of knowledge concerned with abstract concepts such as numbers, geometric shapes, sets, functions, and…
Photo Attributed to Meliacin Master, Public domain
History of computing hardware
UncommonAttack 92
The history of computing hardware spans developments from early devices used for simple calculations to today's complex…
Photo Unknown author Unknown author, Public domain
Metaphysics
EpicAttack 92
Metaphysics is the branch of philosophy that examines the basic nature or most fundamental structure of reality.
Photo Aristotle, Public domain
Children's literature
UncommonAttack 92
Children's literature or juvenile literature includes stories, books, magazines, and poems that are created for children.
Photo Smith, Jessie Willcox, 1863-1935 (artist); L. Prang & Co. (p, Public domain
Nicolaus Copernicus
EpicAttack 91
Nicolaus Copernicus was a Renaissance polymath who formulated a model of the universe that placed the Sun rather than Earth…
Photo Unknown author Unknown author, Public domain
White dwarf
RareAttack 91
A white dwarf is a very dense type of star: in an Earth-sized volume, it packs a mass that is comparable to the Sun.
Photo NASA, ESA, H. Bond (STScI), and M. Barstow (University of Le, Public domain
Galaxy
EpicAttack 91
A galaxy is a physical system of stars, planetary systems, stellar remnants, substellar objects, interstellar gas, dust, and…
Photo The Hubble Heritage Team (AURA/STScI/NASA) NASA Headquarters, Public domain
Text messaging
UncommonAttack 91
Text messaging, or texting, is the act of composing and sending electronic messages, typically consisting of alphabetic and…
Photo Miss Puzzle, CC BY-SA 4.0
Translation
UncommonAttack 91
Translation, in reference to language, is the communication of the meaning of a source-language text by means of an…
Photo Unknown author Unknown author, Public domain
Prison
RareAttack 91
A prison, also known as a jail, gaol, penitentiary, detention center, correction center, correctional facility, or remand…
Photo Joshua Jebb, Public domain
Aluminium
EpicAttack 90
Aluminium or aluminum is a chemical element; it has symbol Al and atomic number 13.
Photo Unknown author Unknown author, CC BY 3.0
C. V. Raman
RareAttack 90
Chandrasekhara Venkata Raman was an Indian physicist known for his work in the field of light scattering.
Photo Nobel Foundation, Public domain
Ecology
UncommonAttack 90
Ecology (from Ancient Greek οἶκος 'house' and -λογία 'study of') is the natural science which studies the interactions…
Photo Thompsma, CC BY 3.0
Variable star
UncommonAttack 90
A variable star is a star whose brightness as seen from Earth changes systematically with time.
Photo ESO/M. Montargès et al., CC BY 4.0
Big Bang
EpicAttack 90
The Big Bang is a physical theory that describes how the universe expanded from an early state of high density and…
Photo NASA/WMAP Science Team, Public domain
Speed of light
EpicAttack 90
The speed of light is the speed of electromagnetic waves.
Photo LucasVB, Public domain
Music
EpicAttack 90
Music is the arrangement of sound to create some combination of form, harmony, melody, rhythm, or otherwise expressive…
Photo NASA, Public domain
Blood transfusion
UncommonAttack 90
Blood transfusion is the process of transferring blood products into a person's circulation intravenously.
Photo Erythrozytenkonzentrat.jpg : Pflegewiki-User Würfel derivati, CC BY-SA 3.0
Vaccine
UncommonAttack 90
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease.
Photo Photo Credit: James Gathany Content Providers(s): CDC, Public domain
Alexander Graham Bell
EpicAttack 90
Alexander Graham Bell was a Scottish-born Canadian-American inventor, scientist, and engineer who is credited with patenting…
Photo Unknown author Unknown author, CC0
COVID-19 vaccination in the United States
UncommonAttack 90
The COVID-19 vaccination campaign in the United States was a mass immunization campaign for the COVID-19 pandemic in the…
Photo US Centers for Disease Control and Prevention . Take a scree, Public domain
Riemann hypothesis
EpicAttack 90
In mathematics, the Riemann hypothesis is the conjecture that the Riemann zeta function has its zeros only at the negative…
Photo No machine-readable author provided. Conscious assumed (base, CC BY-SA 3.0
Steam locomotive
RareAttack 90
A steam locomotive, also known as an iron horse, is a type of locomotive that provides the force to move itself and other…
Photo PTG Dudva, CC BY-SA 3.0
Snooker
RareAttack 89
Snooker is a cue sport played on a rectangular billiards table covered with a green cloth called baize, with six pockets…
Photo DmitryYakunin, CC BY-SA 3.0
Zhiyi
UncommonAttack 89
Zhiyi also called Tiantai Dashi and Zhizhe, was a Chinese Buddhist monk, philosopher, meditation teacher, and exegete.
Photo Bamse, CC BY-SA 3.0
Louis Pasteur
RareAttack 89
Louis Pasteur was a French chemist, pharmacist, and microbiologist renowned for his discoveries of the principles of…
Photo Paul Nadar, Public domain
Rain
UncommonAttack 89
Rain or rainfall is a form of atmospheric precipitation composed of droplets of water aerosols that have condensed from…
Photo W.carter, CC0
Universe
EpicAttack 89
The universe comprises all of existence: all forms of matter and energy in space and time, and the structures they form…
Photo NASA and the European Space Agency., Public domain
Conscience
UncommonAttack 89
A conscience is a cognitive process that elicits emotion and rational associations based on an individual's moral philosophy…
Photo Vincent van Gogh, Public domain
Botany
UncommonAttack 89
Botany, also called plant science, is the branch of natural science and biology that studies the growth, reproduction and…
Photo W.A. Djatmiko ( Wie146 ), CC BY-SA 3.0
Computer
LegendaryAttack 89
A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations.
Photo M. Weik, Public domain
Laser
RareAttack 89
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of…
Photo ESO/A. Ghizzi Panizza ( www.albertoghizzipanizza.com ), CC BY 4.0
Spacetime
RareAttack 89
In physics, spacetime, or the space-time continuum, is a mathematical model that fuses the three dimensions of space and the…
Photo NASA, Public domain
Petroleum
EpicAttack 89
Petroleum, also known as crude oil or simply oil, is a natural resource that appears as a yellowish-black liquid chemical…
Photo Nefronus, CC0
Scientific Revolution
RareAttack 89
The Scientific Revolution of the 16th and 17th centuries in Europe was an irreversible break with the natural philosophy…
Photo Godfrey Kneller, Public domain
Cloud
RareAttack 88
In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, ice crystals, or other…
Photo NASA/Expedition 40 crew member, Public domain
Ibn Battuta
RareAttack 88
Ibn Battuta was a Maghrebi Muslim traveller, explorer, and scholar from Tangier, Morocco.
Photo Léon Benett, Public domain
Ice
RareAttack 88
Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 °C, 32 °F, or 273.15 K.
Photo Sharon Mollerus, CC BY 2.0
International law
UncommonAttack 88
International law, also known as public international law and the law of nations, is the set of rules, norms, legal customs…
Photo J.-H. Janßen, CC0
Intellectual property
RareAttack 88
Intellectual property is a category of property that includes intangible creations of the human intellect.
Photo Stephen Woolverton, CC BY-SA 3.0
Johannes Kepler
RareAttack 88
Johannes Kepler was a German polymath who was an astronomer, mathematician, astrologer, natural philosopher and music…
Photo August Köhler [1], Public domain
C. S. Lewis
LegendaryAttack 88
Clive Staples Lewis was a British author, literary scholar and Anglican lay theologian.
Photo John S. Murray, Public domain
Alchemy
EpicAttack 88
Alchemy is an ancient branch of natural philosophy, a philosophical and protoscientific tradition that was once practised in…
Photo Unknown author Unknown author, Public domain
Music theory
RareAttack 88
Music theory is the study of theoretical frameworks for understanding the practices and possibilities of music.
Photo Unknown author Unknown author, Public domain
Hildegard of Bingen
EpicAttack 88
Hildegard of Bingen, also known as the "Sibyl of the Rhine", was a German Benedictine abbess and polymath, active during the…
Photo Unknown author Unknown author, Public domain
Intellectual disability
RareAttack 88
Intellectual disability, also disorder of intellectual development and known as learning difficulty, is a generalized…
Photo A1C Justin Veazie, Public domain
Liquid-crystal display
UncommonAttack 88
A liquid-crystal display is a flat-panel display or other electronically modulated optical device that uses the…
Photo Béotien lambda, CC BY-SA 3.0
Mir
RareAttack 88
Mir was a space station operated in low Earth orbit from 1986 to 2001, first by the Soviet Union and later by the Russian…
Photo NASA, Public domain
Wilhelm Wundt
UncommonAttack 88
Wilhelm Maximilian Wundt was a German physiologist, philosopher, professor, and one of the fathers of modern psychology.
Photo Unknown author Unknown author, Public domain
Marie Curie
LegendaryAttack 87
Maria Salomea Skłodowska Curie, better known as Marie Curie, was a Polish and naturalised-French physicist and chemist.
Photo Henri Manuel, Public domain
Saturn
LegendaryAttack 87
Saturn is the sixth planet from the Sun, and is the second largest planet in the Solar System, after Jupiter.
Photo NASA / JPL-Caltech / SSI / color composite by Gordan Ugarkov, Public domain
Formation and evolution of the Solar System
UncommonAttack 87
The formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a…
Photo NASA/JPL-Caltech, Public domain
Lexus IS
RareAttack 87
The Lexus IS is a compact executive car sold by Lexus, a luxury division of Toyota, since 1998.
Photo Elise240SX, CC BY-SA 4.0
Alfred North Whitehead
UncommonAttack 87
Alfred North Whitehead was an English mathematician and philosopher.
Photo unknown, Public domain
Air conditioning
RareAttack 87
Air conditioning, often abbreviated as A/C or air con, is the process of removing heat from an enclosed space to achieve a…
Photo Dinkun Chen, CC BY-SA 4.0
Early modern period
RareAttack 87
The early modern period, c.
Photo Gerard ter Borch, Public domain
Pandemic
UncommonAttack 87
A pandemic is an epidemic of an infectious disease that has a sudden increase in cases and spreads across a large region…
Photo Maryland GovPics, CC BY 2.0
Geology
UncommonAttack 87
Geology is a branch of natural science concerned with the Earth and other astronomical bodies, the rocks of which they are…
Photo Tomascastelazo, CC BY-SA 3.0
World Wide Web
LegendaryAttack 87
The World Wide Web is a global interconnected information system that enables content sharing over the Internet.
Photo Liamd967, CC BY-SA 4.0
John Dewey
RareAttack 87
John Dewey was an American philosopher, psychologist, and educational reformer.
Photo Underwood & Underwood, Public domain
Helicopter
RareAttack 87
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors.
Photo Fly45yt, CC BY 4.0
Morse code
EpicAttack 87
Morse code is a telecommunications method which encodes text characters as standardized sequences of two different signal…
Photo Hp.Baumeler, CC BY-SA 4.0
Life expectancy
RareAttack 87
Human life expectancy is a statistical measure of the estimate of the average remaining years of life at a given age.
Photo Lady3mlnm, CC0
Multilingualism
RareAttack 87
Multilingualism is the use of more than one language, either by an individual speaker or by a group of speakers.
Photo Ashraf Hendricks, CC BY 4.0
Tornado outbreak of March 29–31, 2022
CommonAttack 87
Between March 29–31, 2022, a line of strong to severe thunderstorms and multiple supercells swept through portions of the…
Photo TropicalAnalystwx13, CC BY-SA 4.0
Thomas Edison
LegendaryAttack 86
Thomas Alva Edison was an American inventor and businessman known for his work on the incandescent light bulb, the…
Photo Louis Bachrach, Bachrach Studios , restored by Michel Vuijls, Public domain
Radiocarbon dating
RareAttack 86
Radiocarbon dating is a method for determining the age of an object containing organic material by using the properties of…
Photo Unknown author Unknown author, Public domain
Engineering
RareAttack 86
Engineering is the practice of systematically applying natural science and mathematics to design and improve systems…
Photo Nicolás Pérez, CC BY-SA 3.0
Museum
UncommonAttack 86
A museum is an institution dedicated to displaying and preserving culturally or scientifically significant objects.
Photo LuisCG11, CC BY-SA 4.0
Passport
UncommonAttack 86
A passport is a formal travel document issued by a government that certifies a person's identity and nationality for…
Photo Normadic at English Wikipedia , User:Quistnix , बिजय पोख्रेल, CC BY-SA 4.0
Supermassive black hole
RareAttack 86
A supermassive black hole is the largest type of black hole, with its mass being on the order of hundreds of thousands, or…
Photo Event Horizon Telescope, CC BY 4.0
Cantor's first set theory article
CommonAttack 86
Cantor's first set theory article contains Georg Cantor's first theorems of transfinite set theory, which studies infinite…
Photo Unknown author Unknown author, Public domain
Henri Poincaré
UncommonAttack 86
Jules Henri Poincaré was a French mathematician, theoretical physicist, engineer, and philosopher of science.
Photo Unknown author Unknown author, Public domain
Marshall McLuhan
RareAttack 86
Herbert Marshall McLuhan was a Canadian philosopher whose work is among the cornerstones of the study of media theory.
Photo Josephine Smith, Public domain
Tourism
UncommonAttack 86
Tourism is travel for pleasure, and the commercial activity of providing and supporting such travel.
Photo Terabass, CC BY-SA 3.0
Sundial
UncommonAttack 86
A sundial is a horological device that tells the time of day when direct sunlight shines by the apparent position of the Sun…
Photo Wilson44691, Public domain
Medicine
RareAttack 86
Medicine is the science and practice of caring for patients, managing the diagnosis, prognosis, prevention, treatment and…
Photo Luke Fildes, Public domain
George Berkeley
UncommonAttack 86
George Berkeley, known as Bishop Berkeley, was an Anglo-Irish philosopher, writer, and clergyman who is regarded as the…
Photo John Smibert, Public domain
Cinderella
EpicAttack 86
Cinderella is a folk tale with thousands of variants that are told throughout the world.
Photo Otto Kubel, Public domain
Analgesic
RareAttack 86
An analgesic, also called an antalgic, painkiller, or pain reliever, is any member of the group of drugs used for pain…
Photo KGM007, Public domain
Palaeography
UncommonAttack 86
Palaeography or paleography is the study and academic discipline of historical writing systems.
Photo William Shakespeare and unknown scribe, Public domain
Palace
UncommonAttack 86
A palace is a large residence, often serving as a royal residence or the home for a head of state or another high-ranking…
Photo Tim Adams, CC BY-SA 4.0
Battleship
RareAttack 85
A battleship was a heavily armored large warship with a main battery consisting of large guns, designed to serve as a…
Photo PH1 Jeff Hilton, Public domain
Enrico Fermi
RareAttack 85
Enrico Fermi was an Italian and naturalized-American physicist, renowned for being the creator of the world's first…
Photo Department of Energy-Office of Public Affairs, restored by Y, Public domain
Theatre
UncommonAttack 85
Theatre or theater is a collaborative form of performing art that uses live performers, usually actors, to present…
Photo Lafayette Photo, London, Public domain
James Watson
EpicAttack 85
James Dewey Watson was an American molecular biologist, geneticist, and zoologist.
Photo Newspaper Enterprise Association, Public domain
Meteorology
UncommonAttack 85
Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena, with a focus on weather…
Photo NASA, Public domain
Rapid transit
RareAttack 85
Rapid transit, mass rapid transit or rail rapid transit and commonly referred to as metro, is a type of high-capacity public…
Photo LERK, CC BY-SA 4.0
Logarithm
RareAttack 85
In mathematics, the logarithm of a number is the exponent by which another fixed value, the base, must be raised to produce…
Photo Richard F. Lyon, CC BY-SA 3.0
Mini Hatch
RareAttack 85
The Mini is a supermini car which has been made since April 2001.
Photo Alexander-93, CC BY-SA 4.0
Car
EpicAttack 85
A car, or an automobile, is a motor vehicle with wheels.
Photo ModelTMitch, Public domain
Transistor
RareAttack 85
A transistor is a semiconductor device used to amplify or switch electrical signals and power.
Photo Ulfbastel, CC BY-SA 3.0
Stainless steel
RareAttack 85
Stainless steel is an iron-based alloy that contains chromium, making it resistant to rust and corrosion.
Photo W.carter, CC BY-SA 4.0
Binoculars
UncommonAttack 85
Binoculars or field glasses is an optical instrument made of a pair of identical refracting telescopes mounted side-by-side…
Photo Andreas Klehr, CC BY-SA 4.0
Long jump
UncommonAttack 85
The long jump is a track and field event in which athletes combine speed, strength and agility in an attempt to leap as far…
Photo Clément Bucco-Lechat, CC BY-SA 3.0
Paul Dirac
RareAttack 84
Paul Adrien Maurice Dirac was an English theoretical physicist who is considered to be one of the founders of quantum…
Photo Nobel Foundation, Public domain
Robert Hooke
RareAttack 84
Robert Hooke was an English polymath who was active as a physicist, astronomer, geologist, meteorologist, and architect.
Photo Mary Beale, Public domain
Domestication
UncommonAttack 84
Domestication is a multi-generational mutualistic relationship in which an animal species, such as humans or leafcutter…
Photo Nedih Limani, CC BY-SA 3.0
James Clerk Maxwell
RareAttack 84
James Clerk Maxwell was a Scottish physicist and mathematician who was responsible for the classical theory of…
Photo Unknown author Unknown author, Public domain
Astronomy
RareAttack 84
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos.
Photo Produced By: Cassini Imaging Team, Image Credit: NASA/JPL-Ca, Public domain
Messier 87
RareAttack 84
Messier 87 is a supergiant elliptical galaxy in the constellation Virgo that contains several trillion stars.
Photo en:NASA , en:STScI , en:WikiSky, Public domain
Galen
RareAttack 84
Aelius Galenus or Claudius Galenus, often anglicized as Galen or Galen of Pergamon, was a Roman and Greek physician…
Photo Georg Paul Busch (engraver), Public domain
Atmosphere of Earth
RareAttack 84
The atmosphere of Earth consists of a layer of mixed gas that is retained by gravity, surrounding the Earth's surface.
Photo NASA Earth Observatory, Public domain
Mile
RareAttack 84
The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit…
Photo Christine Matthews, CC BY-SA 2.0
Gravity
RareAttack 84
In physics, gravity, also known as gravitation or a gravitational interaction, is a fundamental interaction, which may be…
Photo NASA, ESA, and the Hubble Heritage Team (STScI/AURA), Public domain
Emergency medical services
UncommonAttack 84
Emergency medical services, also known as ambulance services, pre-hospital care, or paramedic services, are emergency…
Photo Scott L from Los Angeles, United States of America, CC BY-SA 2.0
Energy
RareAttack 84
Energy (from Ancient Greek ἐνέργεια 'activity') is the quantitative property that is transferred to a body or to a physical…
Photo Colin, CC BY-SA 3.0
Humphry Davy
UncommonAttack 84
Sir Humphry Davy, 1st Baronet was a British chemist and inventor who invented the Davy lamp and an early form of arc lamp.
Photo Thomas Phillips, Public domain
Michelson–Morley experiment
UncommonAttack 84
The Michelson–Morley experiment was an attempt to measure the motion of the Earth relative to the luminiferous aether, a…
Photo Case Western Reserve University, Public domain
Scientific diving
CommonAttack 84
Scientific diving is the use of underwater diving techniques by scientists to perform work underwater in the direct pursuit…
Photo Viv Hamilton, CC BY-SA 3.0
Public transport
UncommonAttack 84
Public transport refers to forms of transport made available for use by the general public.
Photo MaedaAkihiko, CC BY-SA 4.0
Military history
UncommonAttack 84
Military history is the study of armed conflict in the history of humanity, and its impact on the societies, cultures, and…
Photo MatthiasKabel, CC BY-SA 3.0
Loudspeaker
UncommonAttack 84
A loudspeaker is a combination of one or more speaker drivers, an enclosure, and electrical connections.
Photo Svjo, CC BY-SA 3.0
Music industry
UncommonAttack 84
The music industry are individuals and organizations that earn money by writing songs and musical compositions, creating and…
Photo Fred Lyon fred@fredlyon.com, CC BY-SA 3.0
Presbyterianism
EpicAttack 84
Presbyterianism is a historically Reformed Protestant tradition named after its form of church government by representative…
Photo Hellouser321, CC BY-SA 4.0
Hipparchus
UncommonAttack 84
Hipparchus was a Greek astronomer, geographer, and mathematician.
Photo William Henry Smyth, Public domain
Hypnosis
RareAttack 84
Hypnosis is a human condition involving focused attention, reduced peripheral awareness, and an enhanced capacity to respond…
Photo André Brouillet, Public domain
William James
RareAttack 84
William James was an American philosopher and psychologist.
Photo Notman Studios (photographer), Public domain
Hadith
RareAttack 83
Hadith is the Arabic word for a 'report' or an 'account [of an event]' and refers to the Islamic oral tradition of anecdotes…
Photo Bakkouz at Arabic Wikipedia, Public domain
Electricity
RareAttack 83
Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge.
Photo mattbuck ( category ), CC BY-SA 4.0
Exercise
UncommonAttack 83
Exercise or working out is physical activity that enhances or maintains fitness and overall health.
Photo Marc van Woudenberg, CC BY-SA 2.0
Leukemia
RareAttack 83
Leukemia is a group of blood cancers that usually begin in the bone marrow and produce high numbers of abnormal blood cells.
Photo Makysm, CC0
Transformer
RareAttack 83
In electrical engineering, a transformer is a passive component that transfers electrical energy from one electrical circuit…
Photo Raimond Spekking, CC BY-SA 4.0
Henri Bergson
UncommonAttack 83
Henri-Louis Bergson was a French philosopher who was influential in the traditions of analytic philosophy and continental…
Photo Henri Manuel, Public domain
Steam engine
RareAttack 83
A steam engine is a heat engine that performs mechanical work using steam as its working fluid.
Photo Petar Milošević, CC BY-SA 4.0
Claude Shannon
EpicAttack 83
Claude Elwood Shannon was an American polymath who was a mathematician, electrical engineer, computer scientist…
Photo Unknown author Unknown author, CC BY 2.0
Space exploration
UncommonAttack 83
Space exploration is the physical investigation of outer space by uncrewed robotic space probes and through human…
Photo Project Apollo Archive, Public domain
Ambulance
UncommonAttack 83
An ambulance is a medically equipped vehicle used to transport patients to treatment facilities, such as hospitals.
Photo AleWi, CC BY-SA 4.0
Integrated circuit
RareAttack 83
An integrated circuit, also known as a microchip or simply chip, is a compact assembly of electronic circuits formed from…
Photo cole8888, https://flickr.com/photos/187597251@N05/ (aka Cole, CC BY-SA 2.0
Maxwell's equations
EpicAttack 83
Maxwell's equations are a set of coupled partial differential equations that describe how electric and magnetic fields are…
Photo FF-UK, CC BY-SA 4.0
Refrigeration
UncommonAttack 83
Refrigeration is the artificial cooling of a space, substance, or system to lower and/or maintain its temperature below the…
Photo N-Lange.de, CC BY-SA 4.0
Electric power transmission
UncommonAttack 83
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an…
Photo Varistor60, CC BY-SA 4.0
Shot put
RareAttack 83
The shot put is a track and field event involving "putting" a heavy spherical ball, the shot, as far as possible.
Photo Kastom, CC BY-SA 3.0
William Herschel
UncommonAttack 82
Frederick William Herschel was a German–British astronomer and composer.
Photo Lemuel Francis Abbott, Public domain
Louis Agassiz
UncommonAttack 82
Jean Louis Rodolphe Agassiz was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's…
Photo William Shaw Warren, Public domain
Motorcycle
RareAttack 82
A motorcycle is a two or three-wheeled motor vehicle steered by a handlebar from a saddle-style seat.
Photo Devanand.j, CC BY-SA 4.0
Solar energy
UncommonAttack 82
Solar energy is the radiant energy from the Sun's light and heat, which can be harnessed using a range of technologies such…
Photo NASA/Terry Virts, Public domain
Georg Cantor
UncommonAttack 82
Georg Ferdinand Ludwig Philipp Cantor ( KAN-tor; German: [ˈɡeːɔʁk ˈfɛʁdinant ˈluːtvɪç ˈfɪlɪp ˈkantoːɐ̯]; 3 March [O.S.
Photo Unknown author Unknown author, Public domain
Road
UncommonAttack 82
A road is a thoroughfare from one place to another, primarily used for movement of traffic.
Photo Ermell, CC BY-SA 4.0
Blue
RareAttack 82
Blue is one of the three primary colours in the RGB colour model, as well as in the RYB colour model.
Photo NOAA-JMA, CC BY 4.0
Brain injury
UncommonAttack 82
Brain injury, also known as brain damage or neurotrauma, is the destruction or degeneration of brain cells.
Photo James Heilman, MD, CC BY-SA 3.0
Imperial units
RareAttack 82
The imperial system of units, imperial system or imperial units is the system of units first defined in the British Weights…
Photo Nico Hogg, CC BY 2.0
Anxiety disorder
RareAttack 82
Anxiety disorders are a group of mental disorders characterized by significant and uncontrollable feelings of anxiety and…
Photo Edvard Munch, Public domain
Public administration
UncommonAttack 82
Public administration, also known as public policy and administration or public management, is the implementation of public…
Photo Terry Monrad, Public domain
Voyager program
RareAttack 82
The Voyager program is an American scientific program that employs two interstellar probes, Voyager 1 and Voyager 2.
Photo Don Davis, Public domain
B. F. Skinner
RareAttack 82
Burrhus Frederic Skinner was an American psychologist, behaviorist, inventor, and social philosopher.
Photo Silly rabbit, CC BY 3.0
Hovercraft
UncommonAttack 82
A hovercraft, also known as an air-cushion vehicle or ACV, is an amphibious craft capable of travelling over land, water…
Photo Thomas Philipp, CC BY-SA 3.0
International relations
UncommonAttack 82
International relations is an academic discipline.
Photo Tom Page, CC BY-SA 2.0
Carlos Slim
RareAttack 82
Carlos Slim Helú is a Mexican business oligarch, investor and philanthropist.
Photo Secretaría de Cultura Ciudad de México from México, CC BY 2.0
Jabir ibn Hayyan
UncommonAttack 82
Abū Mūsā Jābir ibn Ḥayyān, died c.
Photo Unknown author Unknown author, Public domain
Antenna
UncommonAttack 82
In radio-frequency engineering, an antenna or aerial is a structure used to convert alternating electric currents into radio…
Photo Adityamadhav83, CC BY-SA 4.0
Edward Bernays
RareAttack 82
Edward Louis Bernays was an Austrian-American pioneer in the field of public relations and propaganda, referred to in his…
Photo Bain News Service, Public domain
Calculator
RareAttack 82
A calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to…
Photo Mc681, CC BY-SA 4.0
Limestone
RareAttack 81
Limestone is a type of carbonate sedimentary rock which is the main source of the material lime.
Photo Fernando Domínguez Cerejido, CC BY-SA 4.0
Augustin-Jean Fresnel
UncommonAttack 81
Augustin-Jean Fresnel was a French civil engineer and physicist whose research in optics led to the almost unanimous…
Photo E Rosette after a painting by A Tardieu, Public domain
Robert Koch
UncommonAttack 81
Heinrich Hermann Robert Koch was a German physician and microbiologist.
Photo Unknown author Unknown author, Public domain
Barbara McClintock
UncommonAttack 81
Barbara McClintock was an American cytogeneticist who was awarded the 1983 Nobel Prize in Physiology or Medicine.
Photo Smithsonian Institution /Science Service; Restored by Adam C, Public domain
Timeline of chemistry
CommonAttack 81
This timeline of chemistry lists important works, discoveries, ideas, inventions, and experiments that significantly changed…
Photo haade, Public domain
Basalt
RareAttack 81
Basalt; US: buh-SALT) is an aphanitic extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in…
Photo James St. John, CC BY 2.0
Positivism
RareAttack 81
Positivism is a philosophical school that holds that all genuine knowledge is either true by definition or positive, the…
Photo Johan Hendrik Hoffmeister, Public domain
Image scanner
UncommonAttack 81
An image scanner is a device that optically scans images, printed text, handwriting, or an object and converts it to a…
Photo Santeri Viinamäki, CC BY-SA 4.0
Haber process
RareAttack 81
The Haber process, also called the Haber–Bosch process, is the main industrial procedure for the production of ammonia.
Photo The Nobel Foundation, Public domain
Mail
UncommonAttack 81
The mail, or post, is a system for physically transporting postcards, letters, and parcels.
Photo Chong Fat, Public domain
Vitamin
RareAttack 81
Vitamins are organic molecules that are essential to an organism in small quantities for proper metabolic function.
Photo Ragesoss, CC BY-SA 3.0
Microwave
UncommonAttack 81
Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared…
Photo GeorgeLouis ( talk ) ( Uploads ), CC BY 3.0
Plastic surgery
UncommonAttack 81
Plastic surgery is a surgical specialty involving restoration, reconstruction, or alteration of the human body.
Photo Gaspare Tagliacozzi - scanned by Google, Public domain
Exam
UncommonAttack 81
An examination, or test, is an educational assessment intended to measure a test-taker's knowledge, skill, aptitude…
Photo Albeiro Rodas - albeiror24@gmail.com, Public domain
Donald Knuth
RareAttack 81
Donald Ervin Knuth is an American computer scientist and mathematician.
Photo Alex Handy, CC BY-SA 2.0
Mass
RareAttack 81
Mass is an intrinsic physical quantity of a body which in modern physics is generally defined as the strength of an object's…
Photo Coyau, CC BY-SA 3.0
Polymer
RareAttack 81
A polymer is a substance or material that consists of very large molecules, or macromolecules, that are constituted by many…
Photo Yurko, CC BY-SA 3.0
Hallucination
RareAttack 81
A hallucination is a perception in the absence of an external context stimulus that has the compelling sense of reality.
Photo August Natterer, Public domain
Cooling tower
UncommonAttack 81
A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a…
Photo User:zootalures (Owen Cliffe), CC BY-SA 3.0
Random-access memory
RareAttack 80
Random-access memory is a form of electronic computer memory that can be read and changed in any order, typically used to…
Photo An-d, CC BY-SA 3.0
Maria Montessori
RareAttack 80
Maria Tecla Artemisia Montessori was an Italian physician and educator best known for her philosophy of education and her…
Photo Unknown author Unknown author, Public domain
Daihatsu Ayla
UncommonAttack 80
The Daihatsu Ayla is a city car designed by Daihatsu and manufactured by Astra Daihatsu Motor in Indonesia since 2013…
Photo オーバードライブ83, CC BY-SA 4.0
Acetic acid
RareAttack 80
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical…
Photo W. Oelen, CC BY-SA 3.0
Zodiac
EpicAttack 80
The zodiac is a belt-shaped region of the sky that extends approximately 8° north and south celestial latitude of the…
Photo Tauʻolunga, CC BY-SA 3.0
George Boole
UncommonAttack 80
George Boole was an English mathematician and philosopher often credited with revolutionizing logic by transforming it from…
Photo Unknown author Unknown author, Public domain
Sievert
UncommonAttack 80
The sievert is a derived unit in the International System of Units intended to represent the stochastic health risk of…
Photo Haruhiko Okumura, CC BY 2.0
Jet engine
UncommonAttack 80
A jet engine is a type of reaction engine, discharging a fast-moving jet of heated gas that generates thrust by jet…
Photo Shelley Gill, Public domain
Ahmad ibn Hanbal
UncommonAttack 80
Ahmad ibn Hanbal was an Arab jurist and founder of the Hanbali school who is widely recognized as the scholar who memorized…
Photo Sun'i, Public domain
Red blood cell
UncommonAttack 80
Red blood cells, referred to as erythrocytes in academia and medical publishing, also known as red cells, erythroid cells…
Photo BruceBlaus . When using this image in external sources it ca, CC BY 3.0
Lee de Forest
UncommonAttack 80
Lee de Forest was an American inventor, electrical engineer, and early pioneer in electronics of fundamental importance.
Photo The original uploader was Thbusch at English Wikipedia . Lat, Public domain
Sedimentary rock
UncommonAttack 80
Sedimentary rocks are types of rock formed by the cementation of sediments, i.e.
Photo Michael C. Rygel, CC BY-SA 3.0
Chemical reaction
UncommonAttack 80
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another.
Photo User:Nikthestunned (Wikipedia), CC BY-SA 3.0
Theft
UncommonAttack 80
Theft is the act of taking another person's property or services without that person's permission or consent with the intent…
Photo Paul Chocarne-Moreau, Public domain
Philipp Melanchthon
UncommonAttack 80
Philipp Melanchthon was a German Lutheran reformer, collaborator with Martin Luther, the first systematic theologian of the…
Photo Workshop of Lucas Cranach the Elder, Public domain
Duns Scotus
UncommonAttack 80
John Duns Scotus was a Scottish Catholic priest and Franciscan friar, university professor, philosopher and theologian.
Photo Justus van Gent / Pedro Berruguete, Public domain
Heat transfer
UncommonAttack 80
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal…
Photo The original uploader was Harroschmeling at German Wikipedia, CC BY-SA 3.0
Arius
UncommonAttack 80
Arius was a Cyrenaic presbyter and ascetic.
Photo Michael Damaskinos, Public domain
Hot air balloon
UncommonAttack 80
A hot air balloon is a lighter-than-air aircraft consisting of a bag, called an envelope, which contains heated air.
Photo Kropsoq, CC BY-SA 3.0
Vacuum
UncommonAttack 80
A vacuum is space devoid of matter.
Photo Hannes Grobe ( talk ), CC BY 3.0
Edward Thorndike
UncommonAttack 80
Edward Lee Thorndike (August 31, 1874 –August 9, 1949) was an American psychologist who spent nearly his entire career at…
Photo Unknown author Unknown author, Public domain
Inductor
UncommonAttack 80
An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a…
Photo Miguel, CC BY-SA 3.0
Steam turbine
UncommonAttack 80
A steam turbine or steam turbine engine is a machine or heat engine that extracts thermal energy from pressurized steam and…
Photo Siemens Pressebild, http://www.siemens.com, CC BY-SA 3.0
Visa requirements for Algerian citizens
UncommonAttack 80
Visa requirements for Algerian citizens are administrative entry restrictions by the authorities of other states placed on…
Photo Algerian Government, CC0
Particle accelerator
UncommonAttack 80
A particle accelerator is a machine that uses electromagnetic fields to propel ions to very high speeds and energies to…
Photo Fermilab, Reidar Hahn, Public domain
Wave
UncommonAttack 80
In mathematics and physical science, a wave is a propagating dynamic disturbance of one or more quantities.
Photo Roger McLassus, CC BY-SA 3.0
Oscilloscope
UncommonAttack 80
An oscilloscope is a type of electronic test instrument that graphically displays varying voltages of one or more signals as…
Photo Pittigrilli, CC BY-SA 4.0
Diplomacy
UncommonAttack 80
Diplomacy is the communication by representatives of state, intergovernmental, or non-governmental institutions intended to…
Photo You may select the license of your choice., CC BY-SA 3.0
Manifold
RareAttack 80
In mathematics, a manifold is a topological space that locally resembles Euclidean space near each point.
Photo User:RokerHRO, CC BY-SA 3.0
Ramanuja
UncommonAttack 79
Ramanuja, also known as Rāmānujācārya, was an Indian Hindu philosopher, guru and social reformer.
Photo Todayindian, CC BY-SA 3.0
Cirrus cloud
UncommonAttack 79
Cirrus is a genus of high-altitude cloud made of ice crystals.
Photo PiccoloNamek, CC BY-SA 3.0
Gastroenteritis
RareAttack 79
Gastroenteritis, also known as infectious diarrhea, is an inflammation of the gastrointestinal tract including the stomach…
Photo en:User:Graham Beards at en.wikipedia, CC BY 3.0
Hydropower
UncommonAttack 79
Hydropower, also known as water power or water energy, is the use of falling or fast-running water to produce electricity or…
Photo allen watkin from London, UK, CC BY-SA 2.0
Printing press
RareAttack 79
A printing press is a machine that applies pressure to transfer ink onto a surface made of paper, cloth, or a similar…
Photo International Printing Museum, CC0
Apostles in the New Testament
EpicAttack 79
In Christian theology and ecclesiology, the apostles, particularly the Twelve Apostles, were the primary disciples of Jesus…
Photo Leonardo da Vinci, Public domain
The arts
UncommonAttack 79
The arts, or creative arts, are a vast range of human practices involving creative expression, storytelling, and cultural…
Photo Gauguin, Paul (1848 - 1903) – Artist (French) Details on Goo, Public domain
Polyvinyl chloride
RareAttack 79
Polyvinyl chloride, alternatively poly, colloquially vinyl or polyvinyl, abbreviated PVC, is the world's third-most widely…
Photo LHcheM, CC BY-SA 3.0
Ecosystem
RareAttack 79
An ecosystem is a system formed by organisms in interaction with their environment, where the biotic and abiotic components…
Photo Richard Ling <wikipedia@rling.com>, CC BY-SA 3.0
Ignaz Semmelweis
RareAttack 79
Ignaz Philipp Semmelweis (German: [ˈɪɡnaːts ˈfɪlɪp ˈzɛml̩vaɪs]; Hungarian: Semmelweis Ignác Fülöp [ˈsɛmɛlvɛjs ˈiɡnaːts…
Photo József Borsos / Albert Doctor, Public domain
Gemstone
RareAttack 79
A gemstone is a piece of mineral crystal which, when cut or polished, is used to make jewelry or other adornments.
Photo Robert M. Lavinsky / Robert M. Lavinsky, CC BY-SA 3.0
Postage stamp
UncommonAttack 79
A postage stamp is a small piece of paper issued by a post office, postal administration, or other authorized vendors to…
Photo Nicagura Post Office. Stamp artist unknown, work more than 7, Public domain
Money
RareAttack 79
Money is any item or verifiable record that is generally accepted as payment for goods and services and repayment of debts…
Photo Avij ( talk · contribs ), Public domain
Pulsar
RareAttack 79
A pulsar is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic…
Photo NASA/CXC/SAO (X-Ray); NASA/JPL-Caltech (Infrared), Public domain
Plasma
RareAttack 79
Plasma is a state of matter that results from one of the other three classical states having undergone an appreciable degree…
Photo U.S. Air Force photo by Edward Aspera Jr., Public domain
David Hilbert
RareAttack 79
David Hilbert was a German mathematician and philosopher of mathematics and one of the most influential mathematicians of…
Photo Unknown author Unknown author, Public domain
Color
RareAttack 79
Color is the visual perception produced by the activation of the different types of cone cells in the eye caused by light.
Photo MichaelMaggs, CC BY-SA 3.0
Sense of smell
UncommonAttack 79
The sense of smell, or olfaction, is the special sense through which smells are perceived.
Photo David Ryckaert III, Public domain
Shopping center
UncommonAttack 79
A shopping center, shopping complex, shopping arcade, shopping plaza, or galleria, is a group of shops built together…
Photo Devjohnson, CC BY-SA 3.0
Glutamate receptor
UncommonAttack 79
Glutamate receptors are synaptic and non synaptic receptors located primarily on the membranes of neuronal and glial cells.
Photo Curtis Neveu, CC BY-SA 3.0
Electrochemistry
UncommonAttack 79
Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference…
Photo Sir John Barrow, 1st Baronet , 1764-1848, Public domain
Al-Biruni
UncommonAttack 79
Abu Reyhan Muhammad ibn Ahmad al-Biruni, known as Biruni, was a Khwarazmian Iranian polymath of the Islamic Golden Age.
Photo The original uploader was Romanm at Slovenian Wikipedia ., Public domain
Mayor of Bologna
CommonAttack 79
The mayor of Bologna is an elected politician who, along with the Bologna City Council, is accountable for the strategic…
Photo Francesco Pierantoni, CC BY 2.0
Cinematography
UncommonAttack 79
Cinematography (from Ancient Greek κίνημα 'movement' and γράφειν 'to write, draw, paint, etc.') is the art of motion picture…
Photo Sean P. Anderson from Dallas, TX, USA, CC BY 2.0
Yang Chen-Ning
RareAttack 78
Yang Chen-Ning also known as C.N.
Photo ENERGY.GOV, Public domain
Planetary nebula
UncommonAttack 78
A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red…
Photo Pablo Carlos Budassi, CC BY-SA 4.0
Metrology
UncommonAttack 78
Metrology is the scientific study of measurement.
Photo Jennifer Lauren Lee, for the U.S. National Institute of Stan, Public domain
Georges Lemaître
RareAttack 78
Georges Henri Joseph Édouard Lemaître was a Belgian Catholic priest, theoretical physicist, and mathematician who made major…
Photo Unknown author Unknown author, Public domain
Prehistory
RareAttack 78
Prehistory, sometimes referred to as pre-literary history, is the period of human history between the first known use of…
Photo Unknown author Unknown author, Public domain
Control of fire by early humans
UncommonAttack 78
The control of fire by early humans was a critical technology enabling the evolution of humans.
Photo Charles Robert Knight, Public domain
Planetary system
UncommonAttack 78
A planetary system consists of a set of non-stellar bodies which are gravitationally bound to and in orbit of a star or star…
Photo NASA Later versions were uploaded by WilyD at en.wikipedia ., Public domain
African Pygmies
UncommonAttack 78
The African Pygmies (or Congo Pygmies, variously also Central African foragers, African rainforest hunter-gatherers or…
Photo Kwamikagami, CC BY-SA 3.0
James Watt
RareAttack 78
James Watt (30 January 1736 – 25 August 1819) was a Scottish inventor, engineer and chemist who improved on Thomas…
Photo Carl Frederik von Breda, Public domain
Rugby sevens
UncommonAttack 78
Rugby sevens is a variant of rugby union in which teams are made up of seven players playing seven-minute halves, instead of…
Photo Like tears in rain, CC BY-SA 4.0
Machine
RareAttack 78
A machine is a thermodynamic system that uses power to apply forces and control movement to perform an action.
Photo Watertown Arsenal (Mass.), Public domain
Linus Torvalds
LegendaryAttack 78
Linus Benedict Torvalds is a Finnish and American software engineer who is the creator and lead developer of the Linux…
Photo Krd (photo) Von Sprat (crop/extraction), CC BY-SA 4.0
Lead service line
CommonAttack 78
A lead service line is a pipe made of lead which is used in potable water distribution to connect a water main to a user's…
Photo IntangibleArts, CC BY 2.0
Map projection
UncommonAttack 78
In cartography, a map projection is any of a broad set of transformations employed to represent the curved two-dimensional…
Photo Lord Nicolas the German (Donnus Nicholas Germanus), cartogra, Public domain
Telephone
RareAttack 78
A telephone, commonly shortened to phone, is a telecommunications device that enables two or more users to conduct a…
Photo Berthold Werner, CC BY-SA 3.0
Carl Benz
RareAttack 78
Carl Friedrich Benz was a German engine designer and automotive engineer.
Photo Unknown (same photo credited to various stock photo agencies, Public domain
Thomas Robert Malthus
UncommonAttack 78
Thomas Robert Malthus was an English economist, Christian priest, and scholar influential in the fields of political economy…
Photo John Linnell, CC BY 4.0
Fatty acid
UncommonAttack 78
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either…
Photo The original uploader was (Automated conversion) at English , CC BY-SA 3.0
Mercator projection
EpicAttack 78
The Mercator projection is a conformal cylindrical map projection first presented by Flemish geographer and mapmaker…
Photo Strebe, CC BY-SA 3.0
Brick
UncommonAttack 78
A brick is a type of building material used to build walls, pavements, and other elements in masonry construction.
Photo Andrewlister, Public domain
Convection
UncommonAttack 78
Convection is the transfer of heat through the physical movement of fluids, where warmer, less-dense material rises and…
Photo Prosthetic Head, CC BY-SA 4.0
Apollonius of Perga
UncommonAttack 78
Apollonius of Perga was an ancient Greek geometer and astronomer known for his work on conic sections.
Photo Giovanni Battista Memo, Public domain
Month
UncommonAttack 78
A month is a unit of time, used with calendars, that is approximately as long as a natural phase cycle of the Moon; the…
Photo Jacek Halicki, CC BY-SA 4.0
Frank Hawthorne
CommonAttack 78
Frank Christopher Hawthorne is an English-born Canadian mineralogist, crystallographer and spectroscopist.
Photo Xanon9, CC BY-SA 4.0
Sampling
UncommonAttack 78
In statistics, quality assurance, and survey methodology, sampling is the selection of a subset of individuals from within a…
Photo Dan Kernler, CC BY-SA 4.0
Hippocrates
RareAttack 77
Hippocrates of Kos, also known as Hippocrates II, named after his grandfather Hippocrates I was a Greek physician and…
Photo Unidentified engraver, Public domain
Isidor Rabi
UncommonAttack 77
Israel Isaac "Isidor" Rabi was an American physicist who received the Nobel Prize in Physics in 1944 "for his resonance…
Photo Nobel Foundation, Public domain
Tim Berners-Lee
EpicAttack 77
Sir Timothy John Berners-Lee, also known as TimBL, is an English computer scientist best known as the inventor of the World…
Photo Summit, CC BY 4.0
Wildlife conservation
UncommonAttack 77
Wildlife conservation refers to the practice of protecting wild species and their habitats in order to maintain healthy…
Photo Drew, Aaron D. - U.S. Fish & Wildlife Service, Public domain
Geomorphology
UncommonAttack 77
Geomorphology (from Ancient Greek γῆ 'earth', μορφή 'form' and λόγος 'study') is the scientific study of the origin and…
Photo DanHobley, CC BY-SA 4.0
Natural science
RareAttack 77
Natural science or empirical science is a branch of science concerned with the description, understanding, and prediction of…
Photo ESO/T. Preibisch, CC BY 4.0
Gregor Mendel
RareAttack 77
Gregor Johann Mendel was an Austrian biologist, meteorologist, mathematician, Augustinian friar and abbot of St.
Photo Unknown author Unknown author, Public domain
Thermometer
UncommonAttack 77
A thermometer is a device that measures temperature.
Photo Anonimski, CC BY-SA 3.0
Robert Millikan
UncommonAttack 77
Robert Andrews Millikan was an American experimental physicist who received the Nobel Prize in Physics in 1923 "for his work…
Photo Nobel foundation, Public domain
Jean-Baptiste Lamarck
UncommonAttack 77
Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck, often known simply as Lamarck, was a French naturalist…
Photo Charles Thévenin, Public domain
Consumer electronics
UncommonAttack 77
Consumer electronics, also known as home electronics, are electronic devices intended for everyday household use.
Photo Coolcaesar at English Wikipedia, CC BY-SA 3.0
James Hutton
UncommonAttack 77
James Hutton was a Scottish geologist, agriculturalist, chemical manufacturer, naturalist and physician.
Photo Henry Raeburn, Public domain
Business
EpicAttack 77
Business is the practice of making one's living or making money by producing or buying and selling products.
Photo Steve Daniels, CC BY-SA 2.0
Phenomenology
RareAttack 77
Phenomenology is a philosophical study and movement largely associated with the early 20th century that seeks to objectively…
Photo Unknown (Mondadori Publishers), Public domain
Light
RareAttack 77
Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye.
Photo User:Kelvinsong, CC0
Communications satellite
UncommonAttack 77
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a…
Photo Flickr user ideonexus, CC BY-SA 2.0
Printed circuit board
RareAttack 77
A printed circuit board, also known as a printed wiring board, is a laminated sandwich structure of conductive and…
Photo Raimond Spekking, CC BY-SA 4.0
Relay
UncommonAttack 77
A relay is an electrically operated switch.
Photo Raimond Spekking, CC BY-SA 4.0
Bonaventure
UncommonAttack 77
Bonaventure was an Italian Catholic Franciscan bishop, cardinal, scholastic theologian and philosopher.
Photo Claude François, Public domain
Colonization
UncommonAttack 77
Colonization or colonisation is defined as "the act or process of sending people to live in and govern another country".
Photo Universalis, CC BY-SA 4.0
PH
RareAttack 77
In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of aqueous solutions.
Photo Alvy16, CC BY 4.0
Equations of motion
UncommonAttack 77
In physics, equations of motion are equations that describe the behavior of a physical system in terms of its motion as a…
Photo nakulll, CC BY-SA 3.0
Corrosion
EpicAttack 77
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide.
Photo Thester11, CC BY-SA 3.0
Cerium
UncommonAttack 76
Cerium is a chemical element; it has symbol Ce and atomic number 58, and is a soft, ductile, and silvery-white metal that…
Photo Jurii, CC BY 3.0
Alfred Nobel
EpicAttack 76
Alfred Bernhard Nobel was a Swedish chemist, inventor, engineer, and businessman.
Photo Unknown author Unknown author, Public domain
Aerosol
UncommonAttack 76
An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas.
Photo Steve1941, CC BY-SA 4.0
Vinegar
RareAttack 76
Vinegar is an odorous aqueous solution of diluted acetic acid and trace compounds that may include flavorings or naturally…
Photo Georges Seguin ( Okki ), CC BY-SA 3.0
Antonie van Leeuwenhoek
UncommonAttack 76
Antonie Philips van Leeuwenhoek ( AHN-tə-nee vahn LAY-vən-hook, -⁠huuk; Dutch: [ˈɑntoːni vɑn ˈleːu.əˌɦuk] ; 24 October 1632…
Photo Jan Verkolje, Public domain
Moustache
UncommonAttack 76
A moustache or mustache is a growth of facial hair grown above the upper lip and under the nose of people, mostly men.
Photo Unknown author Unknown author, Public domain
USS Akron
UncommonAttack 76
USS Akron was a helium-filled rigid airship of the U.S.
Photo USN, Public domain
Seyfert galaxy
UncommonAttack 76
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasar host galaxies.
Photo NASA, Andrew S. Wilson (University of Maryland); Patrick L. , Public domain
Geophysics
UncommonAttack 76
Geophysics is a physical science concerned with the processes and properties of Earth and its surrounding space environment…
Photo CharlesC, CC BY-SA 3.0
Pelvis
RareAttack 76
The pelvis is the lower part of an anatomical trunk, between the abdomen and the thighs, together with its embedded skeleton.
Photo Henry Vandyke Carter, Public domain
$Diffraction$
Diffraction
UncommonAttack 76
Diffraction is the deviation of waves from straight-line propagation due to an obstacle or through an aperture, without any…
Photo Wisky, CC BY-SA 3.0
Joseph Banks
UncommonAttack 76
Sir Joseph Banks, 1st Baronet was an English naturalist, botanist, and patron of the natural sciences.
Photo Joshua Reynolds, Public domain
Electrical connector
UncommonAttack 76
Components of an electrical circuit are electrically connected if an electric current can run between them through an…
Photo Bretwa, CC BY-SA 4.0
Read-only memory
UncommonAttack 76
Read-only memory is a form of non-volatile memory used in computers and other electronic devices.
Photo Simon A. Eugstera, CC BY-SA 3.0
Galactic Center
RareAttack 76
The Galactic Center is the barycenter of the Milky Way and a corresponding point on the rotational axis of the galaxy.
Photo 2MASS/G. Kopan, R. Hurt, Public domain
Igneous rock
UncommonAttack 76
Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic.
Photo USGS, Public domain
John Dalton
UncommonAttack 76
John Dalton was an English chemist, physicist, and meteorologist whose work laid the foundations of modern atomic theory and…
Photo Thomas Phillips, Public domain
Luck
UncommonAttack 76
Luck is a phenomenon or belief that humans may associate with experiencing improbable events, especially improbably positive…
Photo Phyzome under the GFDL., CC BY-SA 3.0
Electromagnet
UncommonAttack 76
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current.
Photo MikeRun, CC BY-SA 4.0
William Harvey
UncommonAttack 76
William Harvey was an English physician who made influential contributions to anatomy and physiology.
Photo After Daniël Mijtens, Public domain
Paul Samuelson
UncommonAttack 76
Paul Anthony Samuelson was an American economist who was the first American to win the Nobel Memorial Prize in Economic…
Photo Gotfryd, Bernard, photographer, Public domain
Market failure
UncommonAttack 76
In neoclassical economics, market failure is a situation in which the allocation of goods and services by a free market is…
Photo CEphoto, Uwe Aranas, CC BY-SA 3.0
Edsger W. Dijkstra
UncommonAttack 76
Edsger Wybe Dijkstra was a Dutch computer scientist, programmer, mathematician, and science essayist.
Photo Hamilton Richards, CC BY-SA 3.0
Steamship
UncommonAttack 76
A steamship, often referred to as a steamer, is a type of steam-powered vessel, typically ocean-faring and seaworthy, that…
Photo Herbythyme, CC BY-SA 4.0
Metallicity
UncommonAttack 76
In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium.
Photo NASA, The Hubble Heritage Team, STScI, AURA, Public domain
Ionization
UncommonAttack 76
Ionization or ionisation is the process by which an atom or a molecule acquires a negative or positive charge by gaining or…
Photo Pavel.shyshkouski, CC BY-SA 4.0
Lawn mower
UncommonAttack 76
A lawn mower is a device utilizing one or more revolving blades to cut a grass surface to an even height.
Photo Staff Sgt. Brian Jopek, Public domain
Physics beyond the Standard Model
UncommonAttack 76
Physics beyond the Standard Model is the theoretical developments needed to explain the deficiencies of the Standard Model…
Photo Lucas Taylor / CERN, CC BY-SA 3.0
Chinese units of measurement
UncommonAttack 76
Chinese units of measurement, known in Chinese as the shìzhì, are the traditional units of measurement of the Han Chinese.
Photo cafecatKate from (optional), CC BY-SA 2.0
Dye
UncommonAttack 76
A dye is a colored substance that is soluble in some solvent; by contrast pigments are insoluble or nearly so in all…
Photo Brian Jeffery Beggerly, CC BY 2.0
Air traffic control
UncommonAttack 76
Air traffic control is a service provided by ground-based air traffic controllers who direct aircraft on the ground and…
Photo Yatrik Sheth, CC BY 2.0
Bleach
RareAttack 76
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color from fabric…
Photo Adina Firestone, CC BY-SA 2.0
Magnetism
UncommonAttack 76
Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel…
Photo Maciej J. Mrowinski, CC BY-SA 4.0
Gottlob Frege
UncommonAttack 76
Friedrich Ludwig Gottlob Frege was a German philosopher, logician, and mathematician.
Photo Unknown author Unknown author, Public domain
Police car
UncommonAttack 76
A police car is an emergency vehicle used by police for transportation during patrols and responses to calls for service.
Photo Raymond Wambsgans, CC BY 2.0
Whiskers
UncommonAttack 75
Whiskers, also known as vibrissae, are specialized sensory hairs that help most species of mammals sense their environment.
Photo Sleddog116 at en.wikipedia, CC BY 3.0
Sound
RareAttack 75
Sound is a phenomenon in which pressure disturbances propagate through an elastic material medium.
Photo Infrogmation of New Orleans, CC BY-SA 3.0
Mica
RareAttack 75
Micas are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily…
Photo Pascal Terjan from London, United Kingdom, CC BY-SA 2.0
Scientific American
UncommonAttack 75
Scientific American, informally abbreviated SciAm or sometimes SA, is an American popular science magazine.
Photo Artist Posters, Public domain
Satellite navigation
UncommonAttack 75
Satellite navigation or satellite positioning is the use of satellites for navigation or geopositioning.
Photo U.S. Air Force, Public domain
Heat treating
UncommonAttack 75
Heat treating is a group of industrial, thermal and metalworking processes used to alter the physical, and sometimes…
Photo Ichudov, CC BY-SA 3.0
Wheel
RareAttack 75
A wheel is a rotating component intended to turn on an axle bearing.
Photo Bybbisch94, Christian Gebhardt, CC BY-SA 4.0
Paper money
UncommonAttack 75
Paper money, often referred to as a note or a bill, is a type of negotiable promissory note that is payable to the bearer on…
Photo Unknown author Unknown author, Public domain
Analytical chemistry
UncommonAttack 75
Analytical chemistry is the branch of chemistry concerned with the development and application of methods to identify the…
Photo Hey Paul from Sacramento, CA, USA, CC BY 2.0
Colloid
UncommonAttack 75
A colloid is a mixture in which one substance, consisting of microscopically dispersed insoluble particles, is suspended…
Photo Yasrena, CC BY-SA 4.0
Oceanography
UncommonAttack 75
Oceanography (from Ancient Greek ὠκεανός 'ocean' and γραφή 'writing'), also known as oceanology, sea science, ocean science…
Photo Robert Simmon, NASA. Minor modifications by Robert A. Rohde , Public domain
Demography
UncommonAttack 75
Demography (from Ancient Greek δῆμος 'people, society' and -γραφία 'writing, drawing, description') is the statistical study…
Photo Max Roser from OurWorldinData.org, CC BY 4.0
Tillage
UncommonAttack 75
Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and…
Photo Wikideas1, CC0
Locomotive
UncommonAttack 75
A locomotive is a rail vehicle that provides the motive power for a train.
Photo Max Thum, CC BY-SA 4.0
Fernand Braudel
UncommonAttack 75
Fernand Paul Achille Braudel was a French historian.
Photo Jerry Bauer, Public domain
Charcoal
RareAttack 75
Charcoal is a lightweight black residue made of carbon that is produced by strongly heating wood in minimal oxygen to remove…
Photo Dati Bendo, European Commission, CC BY 4.0
Industrial robot
UncommonAttack 75
An industrial robot is a robot used for manufacturing.
Photo KUKA Roboter GmbH, Bachmann, Public domain
Aryabhata
RareAttack 75
Aryabhata or Aryabhata I was the first of the major mathematician-astronomers and early physicist from the classical age of…
Photo Cpjha13, CC BY-SA 4.0
Muhammad al-Bukhari
UncommonAttack 75
Abū ʿAbd Allāh Muḥammad ibn Ismāʿīl ibn Ibrāhīm al-Juʿfī al-Bukhārī, commonly known as al-Bukhārī, was a 9th-century Muslim…
Photo Unknown author Unknown author, CC0
Potential energy
UncommonAttack 75
In physics, potential energy is the energy of an object or system due to the body's position relative to other objects, or…
Photo Penny Mayes, CC BY-SA 2.0
Stress
UncommonAttack 75
In continuum mechanics, stress is a physical quantity that describes forces present during deformation.
Photo Nevit Dilmen, CC BY-SA 3.0
Exchange rate
UncommonAttack 75
In finance, an exchange rate is the rate at which one currency will be exchanged for another currency.
Photo Emilian Robert Vicol from Com. Balanesti, Romania, CC BY 2.0
Chainsaw
RareAttack 75
A chainsaw is a portable handheld power saw that cuts with a set of teeth attached to a rotating chain driven along a guide…
Photo kallerna, CC BY-SA 3.0
Pipe
UncommonAttack 75
A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey…
Photo Syced, CC0
Debye model
UncommonAttack 75
In thermodynamics and solid-state physics, the Debye model is a method developed by Peter Debye in 1912 to estimate phonon…
Photo Unknown author Unknown author, Public domain
Lathe
UncommonAttack 75
A lathe is a machine tool that rotates a workpiece about an axis of rotation to perform various operations such as cutting…
Photo Glenn McKechnie, CC BY-SA 3.0
Diogenes
EpicAttack 74
Diogenes the Cynic, also known as Diogenes of Sinope, was an ancient Greek philosopher during the period of Classical…
Photo Unknown author Unknown author, Public domain
Promethium
UncommonAttack 74
Promethium is a generally synthetic chemical element; it has symbol Pm and atomic number 61.
Photo Oak Ridge National Laboratory, Public domain
Jöns Jacob Berzelius
UncommonAttack 74
Jöns Jacob Berzelius was a Swedish chemist.
Photo John Way [1], Public domain
Water cycle
UncommonAttack 74
The water cycle is a biogeochemical cycle that involves the continuous change in form of water on, above and below the…
Photo Hayley Corson-Dosch, Cee Nell, Rachel Volentine, Althea Arch, Public domain
Creation myth
UncommonAttack 74
A creation myth or cosmogonic myth is a type of cosmogony, a symbolic narrative of how the world began and how people first…
Photo James Tissot, Public domain
Heinrich Hertz
UncommonAttack 74
Heinrich Rudolf Hertz was a German physicist who first conclusively proved the existence of the electromagnetic waves…
Photo Robert Krewaldt, Kaiserplatz 16, Bonn, Public domain
Decimal
UncommonAttack 74
A decimal system is a numeral system that uses ten as its radix.
Photo User:Hr.hanafi, CC BY-SA 3.0
Router
UncommonAttack 74
A router is a computer and networking device that forwards data packets between computer networks, including internetworks…
Photo The original uploader was Redfox hq at Romanian Wikipedia ., CC BY 3.0
Metalworking
UncommonAttack 74
Metalworking is the process of shaping and reshaping metals in order to create useful objects, parts, assemblies, and large…
Photo Airman Eric S. Garst, Public domain
Gustave Eiffel
RareAttack 74
Alexandre Gustave Eiffel was a French civil engineer.
Photo Nadar, Public domain
Cybernetics
RareAttack 74
Cybernetics is the transdisciplinary study of circular causal processes such as feedback and recursion, where the outcomes…
Photo Baango, CC BY-SA 4.0
Metallurgy
UncommonAttack 74
Metallurgy is a domain of material science and engineering that studies the physical and chemical behavior of metallic…
Photo Allen Drebert, Public domain
Eclipse
UncommonAttack 74
An eclipse is an astronomical event which occurs when an astronomical object or spacecraft is temporarily obscured, by…
Photo Luc Viatour, CC BY-SA 3.0
Hydrology
UncommonAttack 74
Hydrology (from Ancient Greek ὕδωρ 'water' and -λογία 'study of') is the scientific study of the movement, distribution, and…
Photo Michal Klajban, CC BY-SA 4.0
Metric system
RareAttack 74
A system of measurement is a frame in which physical qualities can be quantified with numbers.
Photo Martinvl, CC BY-SA 3.0
Alfred Wegener
UncommonAttack 74
Alfred Lothar Wegener was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher.
Photo Unknown author Unknown author, Public domain
Inverse function
UncommonAttack 74
In mathematics, the inverse function of a function f is a function that undoes the operation of f.
Photo Jim.belk at English Wikipedia, Public domain
Radio broadcasting
UncommonAttack 74
Radio broadcasting is the transmission of signals, especially audio, to receivers using radio waves over a wide area.
Photo Alex Brasetvik, CC BY-SA 3.0
Design of experiments
UncommonAttack 74
The design of experiments, also known as experimental design, refers to the construction of procedures that attempt to…
Photo Robiminer, CC BY-SA 3.0
Soyuz
UncommonAttack 74
Soyuz is a series of spacecraft which has been in service since the 1960s, having made more than 140 flights.
Photo CactiStaccingCrane, CC0
Blood sugar level
UncommonAttack 74
The blood sugar level, blood sugar concentration, blood glucose level, or glycemia is the measure of glucose concentrated in…
Photo Jakob Suckale, Michele Solimena, CC BY 3.0
Japanese writing system
RareAttack 74
The modern Japanese writing system uses a combination of logographic kanji, which are adopted Chinese characters; and…
Photo User:Hatukanezumi, Public domain
Su Song
UncommonAttack 73
Su Song, courtesy name Zirong, was a Chinese polymathic scientist and statesman who lived during the Song dynasty.
Photo Su Song, Public domain
Computer hardware
RareAttack 73
Computer hardware, commonly shortened to hardware, includes the physical parts of a computer, such as the central processing…
Photo Retro-Computing Society of Rhode Island, CC BY-SA 3.0
Hydrochloric acid
RareAttack 73
Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride.
Photo W. Oelen, CC BY-SA 3.0
Gaudapada
UncommonAttack 73
Gauḍapāda, also referred as Gauḍapādācārya, was an early medieval era Hindu philosopher and scholar of the Advaita Vedanta…
Photo Ashok Prabhu, CC BY-SA 3.0
Chaitanya Mahaprabhu
RareAttack 73
Chaitanya Mahaprabhu, born Vishvambhara Mishra, was an Indian Hindu saint from Bengal and the founder of Gaudiya Vaishnavism.
Photo Unknown author Unknown author, Public domain
Ivan Pavlov
UncommonAttack 73
Ivan Petrovich Pavlov (Russian: Иван Петрович Павлов, IPA: [ɪˈvan pʲɪˈtrovʲɪtɕ ˈpavləf] ; 26 September [O.S.
Photo Unknown author Unknown author, Public domain
Electricity generation
UncommonAttack 73
Electricity generation is the process of generating electric power from sources of primary energy.
Photo Siemens, CC BY-SA 3.0
Carina Nebula
UncommonAttack 73
The Carina Nebula or Eta Carinae Nebula is a large, complex area of bright and dark nebulosity in the constellation Carina…
Photo Harel Boren, CC BY-SA 4.0
Harold Urey
UncommonAttack 73
Harold Clayton Urey was an American physical chemist who conducted pioneering work on isotopes.
Photo Flickr: ENERGY.GOV - Unknown photographer. Restored by Creat, Public domain
Cepheid variable
UncommonAttack 73
A Cepheid variable is a type of variable star that pulsates radially, varying in both diameter and temperature.
Photo NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/, Public domain
Sofya Kovalevskaya
UncommonAttack 73
Sofya Vasilyevna Kovalevskaya (Russian: Софья Васильевна Ковалевская; born Korvin-Krukovskaya; 15 January [O.S.
Photo Unknown author Unknown author, Public domain
Mineralogy
UncommonAttack 73
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical…
Photo Jordens_inre.svg : Original Mats Halldin Vectorization: Chab, CC BY 3.0
Xunzi
UncommonAttack 73
Xunzi, born Xun Kuang, was a late Warring States period Confucian Chinese philosopher, often ranked as the third great…
Photo Unknown author Unknown author, Public domain
Inclined plane
UncommonAttack 73
An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with…
Photo Coyau, CC BY-SA 3.0
Wolfgang Pauli
UncommonAttack 73
Wolfgang Ernst Pauli was an Austrian theoretical physicist and a pioneer of quantum mechanics.
Photo Nobel foundation, Public domain
Louis de Broglie
UncommonAttack 73
Louis Victor Pierre Raymond, 7th Duc de Broglie was a French theoretical physicist and aristocrat known for his…
Photo Unknown author Unknown author, Public domain
Void
UncommonAttack 73
Cosmic voids are vast spaces between filaments, which contain very few or no galaxies.
Photo NASA, ESA, and E. Hallman (University of Colorado, Boulder), Public domain
Immunology
UncommonAttack 73
Immunology is a branch of biology and medicine that covers the study of immune systems in all organisms.
Photo National Institutes of Health (NIH), Public domain
Cardiopulmonary bypass
UncommonAttack 73
Cardiopulmonary bypass or heart-lung machine, also called the pump or CPB pump, is a machine, operated by a cardiac…
Photo Jerry Hecht, Public domain
Hermann Weyl
UncommonAttack 73
Hermann Klaus Hugo Weyl was a German mathematician, theoretical physicist, logician and philosopher.
Photo ETH Zürich, CC BY-SA 3.0
Switch
UncommonAttack 73
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an…
Photo en:User:ArnoldReinhold, CC BY-SA 3.0
Semiconductor device
UncommonAttack 73
A semiconductor device is an electronic component that relies on the electronic properties of a semiconductor material for…
Photo Nimal udayanga 12, CC BY-SA 4.0
William Henry Bragg
UncommonAttack 72
Sir William Henry Bragg was a British X-ray crystallographer who uniquely shared a Nobel Prize with his son Lawrence Bragg –…
Photo Nobel foundation, Public domain
John Logie Baird
UncommonAttack 72
John Logie Baird was a Scottish inventor, electrical engineer and innovator who demonstrated the world's first mechanical…
Photo Unknown author Unknown author, Public domain
Sodium chloride
RareAttack 72
Sodium chloride , is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions.
Photo Didier Descouens, CC BY-SA 4.0
Minor planet
UncommonAttack 72
A minor planet, according to the International Astronomical Union, is an astronomical object in direct orbit around the Sun…
Photo NASA/Johns Hopkins University Applied Physics Laboratory/Sou, Public domain
Remote control
UncommonAttack 72
A remote control, also known colloquially as a remote or clicker, is an electronic device used to operate another device…
Photo Evan-Amos, Public domain
Paper
RareAttack 72
Paper is a thin sheet of matted cellulose fibers.
Photo Meganbeckett27, CC BY-SA 3.0
Calipers
UncommonAttack 72
Calipers or callipers are an instrument used to measure the linear dimensions of an object or hole; namely, the length…
Photo Simon A. Eugster, CC BY-SA 3.0
Albert Bandura
UncommonAttack 72
Albert Bandura was a Canadian-American psychologist and professor of social science in psychology at Stanford University…
Photo bandura@stanford.edu, CC BY-SA 4.0
Electronics
RareAttack 72
Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create…
Photo DustyDingo, Public domain
Theorem
UncommonAttack 72
In mathematics and formal logic, a theorem is a statement that has been proven, or can be proven.
Photo Brews ohare, CC BY-SA 3.0
Analysis
UncommonAttack 72
Analysis is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding…
Photo Adriaen van Ostade, Public domain
Mycology
UncommonAttack 72
Mycology is the branch of biology concerned with the study of fungi, including their taxonomy, genetics, biochemical…
Photo JJ Harrison ( https://www.jjharrison.com.au/ ), CC BY-SA 3.0
Henry Cavendish
UncommonAttack 72
Henry Cavendish was an English experimental and theoretical chemist and physicist.
Photo George Wilson, Public domain
G. H. Hardy
RareAttack 72
Godfrey Harold Hardy was an English mathematician, known for his achievements in number theory and mathematical analysis.
Photo Unknown author Unknown author, Public domain
Astrophysics
UncommonAttack 72
Astrophysics is a science that applies the methods and principles of physics and chemistry in the study of astronomical…
Photo Dodd, Mead and Company, Public domain
Aquatic therapy
CommonAttack 72
Aquatic therapy refers to treatments and exercises performed in water for relaxation, fitness, physical rehabilitation, and…
Photo NPS Photo, Public domain
Foam
UncommonAttack 72
Foam is a two-phase material system and a type of dispersed media, consisting of gas cells dispersed in a continuous liquid…
Photo Frank Luca frankluca, CC0
Roberto Assagioli
CommonAttack 72
Roberto Assagioli was an Italian psychiatrist in the fields of humanistic and transpersonal psychology.
Photo Maspez, CC0
Whirlpool Galaxy
UncommonAttack 71
The Whirlpool Galaxy, also known as Messier 51a or NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2…
Photo NASA and European Space Agency, Public domain
Cumulus cloud
UncommonAttack 71
Cumulus clouds are clouds that have flat bases and are often described as puffy, cotton-like, or fluffy in appearance.
Photo PiccoloNamek, CC BY-SA 3.0
Traditional medicine
UncommonAttack 71
Traditional medicine refers to the knowledge, skills, and practices rooted in the cultural beliefs of various societies…
Photo Marco Schmidt [1], CC BY-SA 3.0
Pierre Curie
RareAttack 71
Pierre Curie was a French physicist and chemist, and a pioneer in crystallography and magnetism.
Photo Dujardin, Public domain
Molecular cloud
UncommonAttack 71
A molecular cloud, sometimes called a stellar nursery if star formation is occurring within, is a type of interstellar cloud…
Photo NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hub, Public domain
Brazilian passport
UncommonAttack 71
Brazilian passport is the official document for foreign travel issued by the Ministry of Foreign Affairs, through the…
Photo Casa da Moeda do Brasil, CC BY-SA 4.0
Inch
UncommonAttack 71
The inch is a unit of length in the British Imperial and the United States customary systems of measurement.
Photo MJCdetroit at English Wikipedia, Public domain
Epithelium
UncommonAttack 71
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix.
Photo US Government, Public domain
Assembly line
UncommonAttack 71
An assembly line, often called progressive assembly, is a manufacturing process where the unfinished product moves in a…
Photo DearEdward from New York, NY, USA, CC BY 2.0
Amalgam
UncommonAttack 71
An amalgam is an alloy of mercury with another metal.
Photo Robert M. Lavinsky, CC BY-SA 3.0
Electric generator
UncommonAttack 71
In electricity generation, a generator, also called an electric generator, electrical generator, and electromagnetic…
Photo NRC, Public domain
White blood cell
RareAttack 71
White blood cells, also called immune cells or immunocytes, are cells of the immune system that are involved in protecting…
Photo BruceBlaus . When using this image in external sources it ca, CC BY 3.0
Simple machine
UncommonAttack 71
A simple machine is a mechanical device that changes the direction or magnitude of a force.
Photo Foster, Ellsworth D., ed; Hughes, James L. (James Laughlin), Public domain
Blazar
UncommonAttack 71
A blazar is an active galactic nucleus with a relativistic jet – a jet composed of ionized matter traveling at nearly the…
Photo NASA and The Hubble Heritage Team (STScI/AURA), Public domain
Lock and key
UncommonAttack 71
A lock is a mechanical or electronic fastening device that is released by a physical object, by supplying secret…
Photo Trougnouf, CC BY 4.0
Cast iron
UncommonAttack 71
Cast iron is a class of iron–carbon alloys with a carbon content of more than 2% and silicon content around 1–3%.
Photo Abob Bob, CC BY 2.0
Knot
UncommonAttack 71
A knot is an intentional complication in cordage which may be practical or decorative, or both.
Photo Unknown author Unknown author, Public domain
Wilhelm Röntgen
RareAttack 70
Wilhelm Conrad Röntgen was a German experimental physicist who produced and detected electromagnetic radiation in a…
Photo Erwin Hanfstaengl, Public domain
Photometry
CommonAttack 70
In astronomy, photometry, from Greek photo- and -metry, is a technique used in astronomy that is concerned with measuring…
Photo NASA, Public domain
Dwarf galaxy
UncommonAttack 70
A dwarf galaxy is a small galaxy composed of about 1,000 up to several billion stars, as compared to the Milky Way's 100–400…
Photo NASA/Ames Research Center, Public domain
Horticulture
UncommonAttack 70
Horticulture is the science and art of growing ornamental plants, flowers, as well as fruits, vegetables, and other…
Photo MBart0525, CC0
Fahrenheit
EpicAttack 70
The Fahrenheit scale is a temperature scale based on one proposed in 1724 by the physicist Daniel Gabriel Fahrenheit.
Photo Stilfehler, Public domain
Peter Gustav Lejeune Dirichlet
UncommonAttack 70
Johann Peter Gustav Lejeune Dirichlet was a German mathematician.
Photo Unknown author Unknown author, Public domain
Geodetic datum
UncommonAttack 70
A geodetic datum or geodetic system is a global datum reference or reference frame for unambiguously representing the…
Photo Cosmo1976, CC BY 3.0
Electrical wiring
UncommonAttack 70
Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards…
Photo BatManFascination at English Wikipedia, CC BY 3.0
Stefan Banach
UncommonAttack 69
Stefan Banach was a Polish mathematician who is generally considered one of the 20th century's most important and…
Photo nieznany/unknown, Public domain
Earth science
UncommonAttack 69
Earth science or geoscience includes all fields of natural science related to planet Earth.
Photo DirkvdM, CC BY-SA 3.0
Ink
UncommonAttack 69
Ink is a gel, sol, or solution that contains at least one colorant, such as a dye or pigment, and is used to color a surface…
Photo Hannes Grobe ( talk ), CC BY 3.0
Scissors
UncommonAttack 69
Scissors or shears are hand-operated cutting tools that consist of a pair of pivoting blades whose sharpened edges slide…
Photo Doggerelblogger, CC BY-SA 4.0
Theoretical physics
UncommonAttack 69
Theoretical physics is a branch of physics that uses mathematical models and abstractions of physical objects and systems to…
Photo AllenMcC., CC BY-SA 3.0
University Academy 92
CommonAttack 69
University Academy 92 is a higher education institution based in Greater Manchester, England, offering undergraduate degrees…
Photo Creator: Jody Hartley, CC0
Niels Henrik Abel
UncommonAttack 69
Niels Henrik Abel was a Norwegian mathematician who made pioneering contributions in a variety of fields.
Photo Johan Gørbitz, Public domain
Scaffolding
UncommonAttack 69
Scaffolding, also called scaffold or staging, is a temporary structure used to support a work crew and materials to aid in…
Photo Felalo, CC BY-SA 4.0
Photocopier
UncommonAttack 69
A photocopier is a machine that makes copies of documents and other visual images onto paper or plastic film quickly and…
Photo Solomon203, CC BY-SA 3.0
Carolus Clusius
CommonAttack 69
Charles de l'Écluse, L'Escluse, or Carolus Clusius, seigneur de Watènes, was an Artois doctor and pioneering botanist…
Photo Attributed to Jacob de Monte, Public domain
Escape velocity
UncommonAttack 69
In celestial mechanics, escape velocity or escape speed is the minimum speed needed for an object to escape from contact…
Photo STS115_Atlantis_undock_ISS.jpg : NASA derivative work: The H, Public domain
Paul Preston
UncommonAttack 69
Sir Paul Preston CBE is an English historian and Hispanist, biographer of Francisco Franco, and specialist in Spanish…
Photo Museu d'Història de Catalunya (fotògraf: Pep Parer), CC BY 3.0
Ashok Seth
CommonAttack 68
Ashok Seth is an Indian interventional cardiologist, credited with the performance of over 50,000 angiograms and 20,000…
Photo Mohd Waseem Ansari, CC BY-SA 4.0
Recreation
UncommonAttack 68
Recreation is an activity of leisure, often done for enjoyment, amusement, or pleasure and are considered to be "fun".
Photo Marcos André Cropped by uploader to remove watermark., CC BY 2.0
Theodolite
UncommonAttack 68
A theodolite is a precision optical instrument for measuring angles between designated visible points in the horizontal and…
Photo en:User:Rolypolyman - Photo taken and uploaded by contributo, CC BY-SA 3.0
Starburst galaxy
UncommonAttack 68
A starburst galaxy is one undergoing an exceptionally high rate of star formation, as compared to the long-term average rate…
Photo NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hub, Public domain
Irving Langmuir
UncommonAttack 68
Irving Langmuir was an American chemist, physicist, and metallurgical engineer.
Photo Unknown author Unknown author, Public domain
Combine harvester
UncommonAttack 68
The modern combine harvester, also called a combine, is a machine designed to harvest a variety of cultivated seeds.
Photo Wikideas1, CC0
Honda Fury
CommonAttack 68
The Honda Fury was the first production chopper from a major motorcycle manufacturer.
Photo Dbratland, CC BY 3.0
Rudolf Diesel
UncommonAttack 68
Rudolf Christian Karl Diesel was a German inventor and mechanical engineer.
Photo Unknown author Unknown author, Public domain
Child prodigy
UncommonAttack 68
A child prodigy is, technically, a child under the age of 10 who produces meaningful work in some domain at the level of an…
Photo anonymous, Public domain
Radio galaxy
UncommonAttack 68
A radio galaxy is a galaxy with giant regions of radio emission extending well beyond its visible structure.
Photo Martijn Oei, CC BY-SA 4.0
William Gilbert
UncommonAttack 68
William Gilbert, also known as Gilberd, was an English physician, physicist and natural philosopher.
Photo Unknown author Unknown author, Public domain
Signal-to-noise ratio
UncommonAttack 68
Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level…
Photo Dtrx, CC BY-SA 4.0
USCGC Morgenthau
CommonAttack 68
The USCGC Morgenthau, was the eighth of twelve 378-foot dual-powered turbine/diesel Hamilton-class high endurance cutters…
Photo USCG, Public domain
Feldspar
UncommonAttack 67
Feldspar ( FEL-spar; sometimes spelled felspar) is a group of rock-forming aluminium tectosilicate minerals, also containing…
Photo PaleoNeolitic, CC BY 4.0
Fishing industry
CommonAttack 67
The fishing industry includes any industry or activity that takes, cultures, processes, preserves, stores, transports…
Photo Robert K. Brigham, Public domain
Harley-Davidson FL
UncommonAttack 67
Harley-Davidson FL is a model designation used for Harley-Davidson motorcycles since 1941, when F referred to the new large…
Photo Piero at Dutch Wikipedia, CC BY-SA 3.0
Volume
UncommonAttack 67
Volume is a measure of regions in three-dimensional space.
Photo No machine-readable author provided. Batty~commonswiki assum, Public domain
Voltage
UncommonAttack 67
Voltage, also known as potential difference, electric pressure, or electric tension, is the difference in electric potential…
Photo Lead holder, CC BY-SA 3.0
Particle
UncommonAttack 67
In the physical sciences, a particle is a separate part of a larger system.
Photo William M. Plate Jr., Public domain
Virgo Cluster
UncommonAttack 67
The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly away in the Virgo constellation.
Photo Credit: RubinObs/NOIRLab/SLAC/NSF/DOE/AURA, CC BY 4.0
Joseph Fourier
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Jean-Baptiste Joseph Fourier was a French mathematician and physicist born in Auxerre, Burgundy and best known for…
Photo Julien-Léopold Boilly, Public domain
Gustav Kirchhoff
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Gustav Robert Kirchhoff was a German physicist and mathematician who contributed to the fundamental understanding of…
Photo Unknown author Unknown author, Public domain
Johannes Diderik van der Waals
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Johannes Diderik van der Waals was a Dutch theoretical physicist who received the Nobel Prize in Physics in 1910 "for his…
Photo Unknown author Unknown author, Public domain
Oil drop experiment
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The oil drop experiment was performed by Robert A.
Photo Unknown author Unknown author, Public domain
Horse-drawn vehicle
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A horse-drawn vehicle is a wheeled vehicle pulled by horses to carry passengers or a load.
Photo Königliches Reichsministerium, Public domain
Wheelbarrow
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A wheelbarrow is a small hand-propelled load-bearing vehicle, usually with just one wheel, designed to be pushed and guided…
Photo Ildar Sagdejev ( Specious ), CC BY-SA 4.0
Barge
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A barge is typically a flat-bottomed boat which does not have its own means of mechanical propulsion.
Photo Diliff, CC BY-SA 3.0
Claude Bernard
UncommonAttack 66
Claude Bernard was a French physiologist.
Photo Unknown author Unknown author, Public domain
Chemical compound
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A chemical compound is a chemical substance composed of many identical molecules containing atoms from more than one…
Photo Roger McLassus, CC BY-SA 3.0
Osmosis
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Osmosis is the spontaneous net movement of solvent molecules through a selectively permeable membrane from a region of high…
Photo OpenStax, CC BY 4.0
André-Marie Ampère
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André-Marie Ampère was a French physicist and mathematician who was one of the founders of the science of classical…
Photo Ambroise Tardieu, Public domain
Image
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An image or picture is a visual representation.
Photo Olaf Simons, CC BY-SA 3.0
Louis Bachelier
UncommonAttack 66
Louis Jean-Baptiste Alphonse Bachelier was a French mathematician.
Photo Louis_jeune_.gif, Public domain
Head
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A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth…
Photo Bilby, CC BY 3.0
Elliptical galaxy
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An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image.
Photo NASA/ESA/Hubble Space Telescope, Public domain
Masonry
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Masonry is the craft of building a structure with stone, brick, concrete, or similar material, including mortar plastering…
Photo Jamain, CC BY-SA 3.0
Ladder
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A ladder is a vertical or inclined set of rungs or steps commonly used for climbing or descending.
Photo Wikideas1, CC0
Wire
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A wire is a flexible, round bar of metal.
Photo ClarkMills, CC BY-SA 3.0
Great Attractor
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The Great Attractor is a region of enhanced gravitational attraction in the local universe.
Photo ESA/Hubble Space Telescope & NASA, Public domain
Low Earth orbit
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A low Earth orbit is an orbit around Earth with a period of 128 minutes or less and an eccentricity less than 0.25.
Photo NASA/Scott Kelly, Public domain
Carl Gustav Jacob Jacobi
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Carl Gustav Jacob Jacobi was a German mathematician who made fundamental contributions to elliptic functions, dynamics…
Photo Unknown author Unknown author, Public domain
Thomas Corwin Mendenhall
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Thomas Corwin Mendenhall was an American autodidact physicist and meteorologist.
Photo Hell&Fischer Philadelphia, Public domain
Michel Devoret
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Michel Henri Devoret is a French–American physicist.
Photo Christian Ursilva from København, Danmark, CC BY-SA 4.0
Loan
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In finance, a loan is the tender of money by one party to another with an agreement to pay it back.
Photo Ibovec, CC BY-SA 3.0
Amiga 1200
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The Amiga 1200, or A1200, is a personal computer in the Amiga computer family released by Commodore International, aimed at…
Photo Jcassara86, CC BY-SA 4.0
$1,000 genome
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The $1,000 genome refers to an era of predictive and personalized medicine during which the cost of fully sequencing an…
Photo National Human Genome Research Institute (NHGRI) Web site ge, CC0
Arthur Cayley
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Arthur Cayley was an English mathematician who worked mostly on algebra.
Photo Herbert Beraud (1845–1896), Public domain
Home appliance
UncommonAttack 63
A home appliance, also referred to as a domestic appliance, an electric appliance or a household appliance, is a machine…
Photo Smoth 007 from Christchurch, New Zealand, CC BY-SA 2.0
Atari Program Recorder
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The Atari Program Recorder is Atari's dedicated magnetic-tape data storage device for the Atari 8-bit computers.
Photo TGB1718, Public domain
Boat
UncommonAttack 63
A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its…
Photo Kondicherry, CC BY-SA 3.0
Emile Berliner
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Emile Berliner was a German-American inventor and businessman who invented the lateral-cut flat disc record, also known as a…
Photo Unknown, Public domain
Euphoria
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Euphoria is a programming language created by Robert Craig of Rapid Deployment Software in Toronto, Ontario, Canada.
Photo Ricardo Silva Veloso, Public domain
Richard Dedekind
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Julius Wilhelm Richard Dedekind was a German mathematician who made important contributions to number theory, abstract…
Photo Unknown (Mondadori Publishers), Public domain
Palmitic acid
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Palmitic acid is a fatty acid with a 16-carbon chain.
Photo Milda 444, CC BY-SA 4.0
Poisk
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Poisk, also known as the Mini-Research Module 2, is a docking module of the International Space Station.
Photo NASA, Public domain
Connective tissue
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Connective tissue is biological tissue that is found in between other tissues in the body.
Photo Rollroboter, CC BY-SA 3.0
Pulley
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A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction…
Photo GK Bloemsma, CC BY-SA 3.0
Charles Hermite
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Charles Hermite was a French mathematician who studied analysis, number theory, and algebra.
Photo Eugène Pirou / Paul Dujardin, Public domain
Mirage
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A mirage is a naturally occurring optical phenomenon in which light rays bend via refraction to produce a displaced image of…
Photo Brocken Inaglory, CC BY-SA 3.0
Donald Lynden-Bell
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Donald Lynden-Bell CBE FRS was a British theoretical astrophysicist.
Photo Institute of Astronomy, University of Cambridge – Amanda Smi, CC BY-SA 4.0
Activator appliance
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Activator Appliance is an Orthodontics appliance that was developed by Viggo Andresen in 1908.
Photo Coronium, CC BY-SA 4.0
Machine press
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A forming press, commonly shortened to press, is a machine tool that changes the shape of a work-piece by the application of…
Photo Audrius Meskauskas ( Audriusa ), CC BY-SA 3.0
$Microfracture surgery$
Microfracture surgery
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Microfracture surgery is an articular cartilage repair surgical technique that works by creating tiny fractures in the…
Photo Henry Vandyke Carter, Public domain
Ampere
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The ampere, often shortened to amp, is the unit of electric current in the International System of Units.
Photo Hannes Grobe ( talk ), CC BY 3.0
Flyer 700/800/900 series
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The Flyer 700/800/900 series were a series of transit buses built in three generations by Western Flyer and its successors…
Photo Steve Morgan, CC BY-SA 3.0
Green flash
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The green flash and green ray are meteorological optical phenomena that sometimes occur transiently around the moment of…
Photo Brocken Inaglory, CC BY-SA 3.0
3C 273
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3C 273 is a quasar located at the center of a giant elliptical galaxy in the constellation of Virgo.
Photo Hubble ESA, CC BY 2.0
DB-Engines ranking
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The DB-Engines Ranking ranks database management systems by popularity, covering over 410 systems.
Photo Wikideas1 https://github.com/Vonng/dbrank?tab=readme-ov-file, CC0
Jeremiah Dixon
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Jeremiah Dixon was an English surveyor and astronomer best known for surveying the Mason–Dixon line with Charles Mason from…
Photo Illustrator unknown; published by Ginn and Company., Public domain
Hydrosphere
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The hydrosphere (from Ancient Greek ὕδωρ 'water' and σφαῖρα 'sphere') is the combined body of water found on, under, and…
Photo NASA , Apollo 11, Public domain
Megastructure
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A megastructure is a very large artificial object, although the limits of precisely how large vary considerably.
Photo Andreas Tille This image is the original work of Andreas Til, CC BY-SA 3.0
Jack Copeland
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Brian Jack Copeland is Professor of Philosophy at the University of Canterbury, Christchurch, New Zealand, and author of…
Photo Royal Society Te Apārangi, CC BY 3.0
Fred Gage
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Fred "Rusty" Gage is an American geneticist known for his discovery of stem cells in the adult human brain.
Photo Cmichel67, CC BY-SA 4.0
The Chronicles of Clovis
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The Chronicles of Clovis is the third volume of short stories by Saki, the pseudonym of Hector Hugh Munro.
Photo Saki, Public domain
Pascal
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The pascal is the unit of pressure in the International System of Units.
Photo leapingllamas, CC BY 2.0
Reaction mechanism
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In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical reaction…
Photo Minhputintranohiocringe, CC BY-SA 4.0
Stephen J. Blackwood
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Stephen James Blackwood is a Canadian-American professor, academic, and social commentator.
Photo Personaggi, CC BY-SA 3.0
Léon Foucault
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Jean Bernard Léon Foucault was a French physicist who invented the Foucault pendulum, a device demonstrating the effect of…
Photo Bertall & Cie. Fizped, Public domain
Prism
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An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light.
Photo Kelvinsong, CC0
Irregular galaxy
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An Irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy.
Photo NASA, ESA, and The Hubble Heritage Team (STScI/AURA), Public domain
Nicolaus Otto
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Nicolaus August Otto was a German engineer who successfully developed the compressed charge internal combustion engine which…
Photo Unknown author Unknown author, Public domain
44-foot motor lifeboat
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The 44-foot motor lifeboat was the standard workhorse of the United States Coast Guard rescue boat fleet, designed in 1961…
Photo Lee Cannon from Bayville aka West Fenwick, DE, USA, CC BY-SA 2.0
Galaxy groups and clusters
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Galaxy groups and clusters are the largest known gravitationally bound objects to have arisen thus far in the process of…
Photo ESA/Hubble & NASA Acknowledgement: Judy Schmidt, CC BY 4.0
Conor Woodman
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Conor Thomas Patrick Woodman is an Irish author and broadcaster best known as the host of Scam City and Around the World in…
Photo Editorgr, CC BY-SA 4.0
Antistatic device
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An antistatic device is any device that reduces, dampens, or otherwise inhibits electrostatic discharge, or ESD, which is…
Photo Evan-Amos, Public domain
The Santa Fe New Mexican
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The Santa Fe New Mexican or simply The New Mexican is a daily newspaper published in Santa Fe, New Mexico.
Photo The Santa Fe New Mexican, Public domain
Facial disc
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In ornithology, the facial disc is the concave collection of feathers on the face of some birds, most notably owls…
Photo Stevie B, CC BY 2.0
Version 7 Unix
UncommonAttack 59
Version 7 Unix, also called Seventh Edition Unix, Version 7 or just V7, was an important early release of the Unix operating…
Photo Huihermit, CC0
ORP Ślązak
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ORP Ślązak is an offshore patrol vessel of the Polish Navy, formerly known as Gawron-class corvette.
Photo Żeglarz, CC BY-SA 4.0
Environmental chemistry
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Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places.
Photo Brylie Christopher Oxley, CC BY-SA 3.0
Traveller's cheque
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A traveller's cheque is a medium of exchange that can be used in place of the currency of a country.
Photo kln1985, Public domain
1913 United Kingdom tornado outbreak
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The 1913 United Kingdom tornado outbreak was an outbreak of tornadoes, particularly over England and Wales, on 27 October…
Photo Unknown (Life time: fl.1913), Public domain
CANape
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CANape is a software tool from Vector Informatik.
Photo Myrddin Lailoken, CC BY-SA 3.0
Ulf von Euler
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Ulf Svante von Euler was a Swedish physiologist and pharmacologist.
Photo Unknown author Unknown author, CC BY 4.0
Irrigation sprinkler
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An irrigation sprinkler is a device used to irrigate agricultural crops, lawns, landscapes, golf courses, and other areas.
Photo JJ Harrison ( https://www.jjharrison.com.au/ ) If you enjoy , CC BY-SA 3.0
Perseus Cluster
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The Perseus Cluster is a cluster of galaxies in the constellation Perseus.
Photo NASA/CXC/IoA/A.Fabian et al., Public domain
Confession of the Ethiopian Eunuch
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The confession of the Ethiopian eunuch is a variant reading in Acts 8:37, widely seen by textual critics to be a later…
Photo Pieter Lastman, Public domain
Magnetic tape
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Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film.
Photo Daniel P. B. Smith., CC BY-SA 3.0
Electromagnetic suspension
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Electromagnetic suspension is the magnetic levitation of an object achieved by constantly altering the strength of a…
Photo Antonín Ryska, CC BY-SA 4.0
Yuzuru Hiraga
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Vice Admiral Baron Yuzuru Hiraga was a career naval officer in the Imperial Japanese Navy, Doctor of Engineering and head of…
Photo Unknown author Unknown author, CC BY 4.0
Robert Preus
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Robert David Preus was an American Lutheran pastor, professor, author, and seminary president.
Photo Flobnitch7, CC0
Richard Pankhurst
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Richard Keir Pethick Pankhurst OBE was a British scholar who was a founding member of the Institute of Ethiopian Studies and…
Photo Unknown author Unknown author, Public domain
Andrew M. Stuart
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Andrew M.
Photo Bpp223, CC BY-SA 4.0
Photoinitiator
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In chemistry, a photoinitiator is a molecule that creates reactive species when exposed to radiation.
Photo Ligonauer, CC BY-SA 4.0
December 2009 lunar eclipse
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A partial lunar eclipse occurred at the Moon’s descending node of orbit on Thursday, 31 December 2009, with an umbral…
Photo Codybird, CC BY-SA 3.0
Ruler
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A ruler is an instrument used to make length measurements, whereby a length is read from a series of markings called "rules"…
Photo Geof, CC BY-SA 3.0
Dwingeloo 1
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Dwingeloo 1 is a barred spiral galaxy about 10 million light-years away from the Earth, in the constellation Cassiopeia.
Photo Ruslik0 , NASA, Public domain
Devarda's alloy
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Devarda's alloy is an alloy of aluminium, copper and zinc.
Photo Vano3333, CC BY-SA 4.0
Antiguan and Barbudan passport
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Antiguan and Barbudan passports are issued to nationals of Antigua and Barbuda for international travel.
Photo Mateusxw7, Public domain
Shanghai Ocean University
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Shanghai Ocean University is a public research university in Shanghai, China, dedicated to the study of aquaculture, marine…
Photo SHOU Media, CC BY-SA 4.0
Aviation insurance
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Aviation insurance is insurance coverage geared specifically to the operation of aircraft and the risks involved in aviation.
Photo United States Coast Guard, PA2 Sarah Foster-Snell, Public domain
Tipraland
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Tipraland is the name of a proposed state in India for the indigenous Tripuri people in the tribal areas of the Tripura…
Photo Banksboomer, CC BY-SA 4.0
Betty Grissom
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Betty Lavonne Grissom was the wife of American astronaut Gus Grissom, one of the Mercury Seven astronauts.
Photo NASA, Public domain
John Blenkinsop
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John Blenkinsop was an English mining engineer and an inventor of steam locomotives, who designed the first practical…
Photo 1829 author unknown, Public domain
McLaren M14A
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The McLaren M14A is a Formula One racing car built and raced by McLaren in the 1970 and 1971 World Championship.
Photo Pyrope, CC BY-SA 3.0
Tauc–Lorentz model
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The Tauc–Lorentz model is a mathematical formula for the frequency dependence of the complex-valued relative permittivity…
Photo Engiqueer, CC BY-SA 4.0
Luggage carrier
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A luggage carrier, also commonly called a rack, is a device attached to a bicycle to which cargo or panniers can be attached.
Photo The original uploader was AndrewDressel at English Wikipedia, CC BY-SA 3.0
Walking excavator
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The term walking excavator may apply to two different forms of heavy equipment, the historic walking power shovel or…
Photo Diane Klee (Menzi Muck AG Widnau), CC BY-SA 2.0
Gland
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A gland is a cell or an organ in an animal's body that produces and secretes different substances that the organism needs…
Photo Henry Vandyke Carter, Public domain
Boundary Treaty of 1970
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The Boundary Treaty of 1970 is a treaty between the United States and Mexico that settled all outstanding boundary disputes…
Photo Unknown author, Public domain
HM Prison Wayland
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HM Prison Wayland is a Category C men's prison, located near the village of Griston in Norfolk, England.
Photo Chelb, CC BY-SA 4.0
Nicola Winter
CommonAttack 50
Nicola Winter is a German reserve astronaut and former fighter pilot.
Photo Sebastiaan ter Burg from Utrecht, The Netherlands, CC BY 2.0
Electronic Diesel Control
CommonAttack 50
Electronic Diesel Control is a diesel engine fuel injection control system for the precise metering and delivery of fuel…
Photo Panoha, CC BY-SA 3.0
Stereographic map projection
CommonAttack 49
The stereographic projection, also known as the planisphere projection or the azimuthal conformal projection, is a conformal…
Photo Strebe, CC BY-SA 3.0
Lophophore
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The lophophore is a characteristic feeding organ possessed by four major groups of animals: the Brachiopoda, Bryozoa…
Photo TheAlphaWolf, CC BY-SA 3.0
Travan
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Travan is an 8 mm magnetic tape cartridge design developed by the 3M company, used for the storage of data in computer…
Photo Surv1v4l1st at English Wikipedia, Public domain
Fordite
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Fordite, also known as Detroit agate, Motor City agate, paint rock, or paint slag, is a lapidarist term for polished pieces…
Photo James St. John, CC BY 2.0
NGC 3077
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NGC 3077 is a small disrupted elliptical galaxy, a member of the M81 Group, which is located in the northern constellation…
Photo en:NASA , en:STScI , en:WikiSky, Public domain
B-type asteroid
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B-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group; the 'B' indicates…
Photo NASA/Goddard/University of Arizona, Public domain
John Rous
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John Rous was an English historian and antiquary, most noted for his Historia Regum Angliae, which describes ancient British…
Photo John Rous, Public domain
Gong Qihuang
CommonAttack 47
Gong Qihuang is a Chinese opticist and educator who is a professor and former president of Peking University.
Photo 中国新闻社, CC BY 4.0
Fire command vehicle
CommonAttack 46
A fire command vehicle, also called a fire chief car, battalion chief vehicle, fly car, or fire chief’s cruiser, is a…
Photo Peter Stehlik - PS-2507, CC BY 3.0
Shopping bag
CommonAttack 46
Shopping bags are medium-sized bags, typically around 10–20 litres in volume, that are used by shoppers to carry home their…
Photo Skeezix1000, CC BY-SA 3.0
Neutrophilia
CommonAttack 46
Neutrophilia is leukocytosis of neutrophils, that is, a high number of neutrophils in the blood.
Photo Dr Graham Beards, CC BY-SA 3.0
Honda JNC1 engine
CommonAttack 46
The Honda JNC1 engine is a bespoke 3.5-liter, twin-turbocharged V6 engine, designed and produced by Honda for the second…
Photo Nheyob, CC BY-SA 4.0
MAN SL202
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The MAN SL202 is a single-decker bus manufactured by MAN in Salzgitter, Germany between 1983 and 1993.
Photo Michael Heimerl, CC BY-SA 3.0
White box
CommonAttack 45
In computer hardware, a white box is a personal computer or server without a well-known brand name.
Photo TJRP, Public domain
HM Prison Thorn Cross
CommonAttack 45
HM Prison Thorn Cross is a Category D Adult Male Institution for males; it previously was for young men aged 18–25.
Photo Liverpoolpics, CC BY-SA 3.0
Spitz
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The spitz is a type of domestic dog including between 50 and 70 breeds depending on classification.
Photo The original uploader was Teuteul at French Wikipedia . Late, CC BY-SA 3.0
Julius Springer
CommonAttack 45
Julius Springer was a German publisher who founded the academic publishing house Springer Science+Business Media.
Photo Anonymous Unknown author, Public domain
Ford Crestline
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The Ford Crestline is an automobile which was produced by Ford in the United States for models years 1952 to 1954.
Photo Sicnag, CC BY 2.0
AC Greyhound
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The AC Greyhound is a 2+2 grand touring automobile made by AC Cars of Thames Ditton, Surrey, England.
Photo SG2012, CC BY 2.0
Accordion effect
CommonAttack 43
In physics, the accordion effect occurs when fluctuations in the motion of a traveling body cause disruptions in the flow of…
Photo Kiribat, CC0
USS Gladiator
CommonAttack 42
USS Gladiator was an Avenger-class mine countermeasures ship of the United States Navy, and is the third U.S.
Photo Mass Communication Specialist 3rd Class Mark Patterson II, Public domain
Precision engineering
CommonAttack 41
Precision engineering is a subdiscipline of electrical engineering, software engineering, electronics engineering…
Photo National Institute of Standards and Technology’s Manufacturi, Public domain
Bharat Nirman
CommonAttack 40
The Bharat Nirman Yojana was a flagship program launched in 2005 by the United Progressive Alliance government under the…
Photo Gopal Aggarwal from INDIA, CC BY 2.0
Majipa Lakhey
CommonAttack 40
Majipa Lakhey is a special lakhey in Nepalese folklore.
Photo Less than 3, CC BY 2.0
3.6m Devasthal Optical Telescope
CommonAttack 39
The 3.6m Devasthal Optical Telescope is a clear-aperture Ritchey–Chrétien telescope built by Aryabhatta Research Institute…
Photo Ajay Talwar, CC BY 4.0
Human Factors Analysis and Classification System
CommonAttack 34
The Human Factors Analysis and Classification System identifies the human causes of an accident and offers tools for…
Photo Doveroftke, CC BY-SA 4.0
Pent-roof combustion chamber
CommonAttack 33
The penta engine is an arrangement of the upper portion of the cylinder and valves that is common in internal combustion…
Photo Tennen-Gas, CC BY-SA 3.0