{"https://codexery.com/optics-and-color/e/optics-and-color/focal-length/": {"t": "Focal length", "s": "Measure of how strongly an optical system bends light.", "i": "https://codexery.com/optics-and-color/img/optics-and-color/focal-length.webp", "c": "cmglee, chensiyuan · CC BY-SA 4.0"}, "https://codexery.com/scientists-and-mathematicians/e/scientists-and-mathematicians/christiaan-huygens/": {"t": "Christiaan Huygens", "s": "Dutch polymath who advanced optics, mechanics, and astronomy."}, "https://codexery.com/science-measurement/e/science-and-measurement/optical-telescope/": {"t": "Optical telescope", "s": "Instrument that gathers visible light to magnify distant objects.", "i": "https://codexery.com/science-measurement/img/science-and-measurement/optical-telescope.webp", "c": "NASA Goddard Space Flight Center from Greenbelt, MD, USA · Public domain"}, "https://codexery.com/historical-figures/e/artists/christopher-wren/": {"t": "Christopher Wren", "s": "English architect, astronomer, mathematician and physicist; master of English Baroque; rebuilt 52 churches after the Great Fire of London.", "i": "https://codexery.com/historical-figures/img/artists/christopher-wren.webp", "c": "Godfrey Kneller · via Wikipedia: Christopher Wren · Public domain"}, "https://codexery.com/astronomers-and-astrophysicists/e/astronomers-and-astrophysicists/giovanni-domenico-cassini/": {"t": "Giovanni Domenico Cassini", "s": "Giovanni Domenico Cassini, an Italian-French mathematician, astronomer, astrologer, and engineer, was born in Perinaldo, near Imperia, in the County of Nice, pa"}, "https://codexery.com/observatories-of-europe/e/observatories-of-europe/paris-observatory/": {"t": "Paris Observatory", "s": "World's oldest active observatory, cornerstone of French astronomy."}, "https://codexery.com/moons-with-a-prograde-orbit/e/moons-with-a-prograde-orbit/dione-moon/": {"t": "Dione (moon)", "s": "Saturn's fourth-largest moon with icy cliffs and a possible subsurface ocean."}, "https://codexery.com/moons-of-saturn/e/moons-of-saturn/tethys-moon/": {"t": "Tethys (moon)", "s": "Tethys is Saturn's fifth-largest moon, made almost entirely of water ice."}, "https://codexery.com/planets-and-dwarf-planets/e/planets-and-dwarf-planets/saturn/": {"t": "Saturn", "s": "Saturn is a gas giant with rings and the lowest density in the Solar System."}, "https://codexery.com/discoverers-of-astronomical-objects/e/discoverers-of-astronomical-objects/james-bradley/": {"t": "James Bradley", "s": "English astronomer and priest, third Astronomer Royal."}, "https://codexery.com/planets-and-dwarf-planets/e/planets-and-dwarf-planets/venus/": {"t": "Venus", "s": "Earth's twin, hottest planet, shrouded in sulfuric acid clouds."}, "/e/telescope-types/newtonian-telescope/": {"t": "Newtonian telescope", "s": "The earliest known functional reflecting telescope, invented by Isaac Newton."}, "https://codexery.com/science-measurement/e/science-and-measurement/telescope/": {"t": "Telescope", "s": "Observing the universe across the electromagnetic spectrum", "i": "https://codexery.com/science-measurement/img/science-and-measurement/telescope.webp", "c": "Pelligton · CC BY-SA 4.0"}, "https://codexery.com/climate/e/climate/atmosphere-of-earth/": {"t": "Atmosphere of Earth", "s": "The gaseous envelope surrounding Earth, essential for life and climate."}, "https://codexery.com/space-telescopes/e/space-telescopes/space-telescope/": {"t": "Space telescope", "s": "Telescopes in space avoiding atmospheric interference for astronomical observation."}, "https://codexery.com/astronomical-radio-sources/e/astronomical-radio-sources/cosmic-microwave-background/": {"t": "Cosmic microwave background", "s": "Relic radiation from the early universe."}, "https://codexery.com/radio-propagation/e/radio-propagation/antenna-radio/": {"t": "Antenna (radio)", "s": "Interface between radio waves and electric currents."}, "https://codexery.com/optics-and-color/e/optics-and-color/focus-optics/": {"t": "Focus (optics)", "s": "Point where light rays converge in optical systems.", "i": "https://codexery.com/optics-and-color/img/optics-and-color/focus-optics.webp", "c": "Ermell · CC BY-SA 4.0"}, "https://codexery.com/camera-image-sensors/e/camera-image-sensors/image-sensor/": {"t": "Image sensor", "s": "Sensor that converts light into electrical signals for imaging."}, "https://codexery.com/magazines-newspapers/e/magazines-and-newspapers/journal-des-s-avans/": {"t": "Journal des sçavans", "s": "The earliest academic journal in Europe, now a leading voice in French humanities."}, "https://codexery.com/mathematicians/e/mathematicians/james-gregory-mathematician/": {"t": "James Gregory (mathematician)", "s": "Scottish mathematician and astronomer, inventor of the Gregorian telescope and pioneer of calculus.", "i": "https://codexery.com/mathematicians/img/mathematicians/james-gregory-mathematician.webp", "c": "Gregory, James · Public domain"}, "/e/telescope-types/catadioptric-system/": {"t": "Catadioptric system", "s": "Catadioptric systems combine lenses and mirrors for compact, corrected optics."}, "https://codexery.com/optics-and-photonics/e/optics-and-photonics/spherical-aberration/": {"t": "Spherical aberration", "s": "Spherical aberration degrades image quality in spherical optical systems."}, "https://codexery.com/space-missions/e/space-missions/the-hubble-space-telescope/": {"t": "The Hubble Space Telescope", "s": "A versatile space telescope observing ultraviolet, visible, and near-infrared light."}, "https://codexery.com/british-inventors/e/british-inventors/horace-dall/": {"t": "Horace Dall", "s": "English amateur astronomer and optical inventor."}, "https://codexery.com/media-and-publishing/e/media-and-publishing/scientific-american/": {"t": "Scientific American", "s": "Oldest continuously published U.S. magazine."}, "https://codexery.com/electromagnetism-and-waves/e/electromagnetism-and-waves/refraction/": {"t": "Refraction", "s": "Refraction redirects waves when they change speed between media."}, "https://codexery.com/electromagnetism-and-waves/e/electromagnetism-and-waves/reflection-physics/": {"t": "Reflection (physics)", "s": "Wavefront returns into the original medium upon striking an interface."}, "https://codexery.com/egyptian-inventions/e/egyptian-inventions/lighthouse/": {"t": "Lighthouse", "s": "Tower emitting light for maritime navigation."}, "https://codexery.com/science-measurement/e/science-and-measurement/microscope/": {"t": "Microscope", "s": "Instrument for viewing objects invisible to the naked eye.", "i": "https://codexery.com/science-measurement/img/science-and-measurement/microscope.webp", "c": "Chad Anderson, staff photographer for SFO Museum · CC BY-SA 2.0"}, "https://codexery.com/crime-and-deviance/e/crime-and-deviance/surveillance/": {"t": "Surveillance", "s": "Systematic observation for information gathering, influence, or control."}, "https://codexery.com/historical-figures/e/notable/augustin-jean-fresnel/": {"t": "Augustin-Jean Fresnel", "s": "French civil engineer and physicist who pioneered the wave theory of light and invented the Fresnel lens."}, "https://codexery.com/scientists-and-mathematicians/e/scientists-and-mathematicians/l-on-foucault/": {"t": "Léon Foucault", "s": "The physicist who proved Earth rotates with a pendulum"}, "https://codexery.com/astrophotography/e/astrophotography/astrograph/": {"t": "Astrograph", "s": "A telescope designed exclusively for astrophotography and sky surveys."}, "/e/telescope-types/cassegrain-reflector/": {"t": "Cassegrain reflector", "s": "Folded optical path with concave primary and convex secondary mirrors."}, "/e/telescope-types/maksutov-telescope/": {"t": "Maksutov telescope", "s": "Catadioptric design using a meniscus corrector to correct aberrations."}, "/e/telescope-types/lurie-houghton-telescope/": {"t": "Lurie–Houghton telescope", "s": "Catadioptric telescope with spherical surfaces and Newtonian-style diagonal."}, "https://codexery.com/scottish-inventions/e/scottish-inventions/gregorian-telescope/": {"t": "Gregorian telescope", "s": "Reflecting telescope designed by James Gregory in 1663."}, "https://codexery.com/astrophotography/e/astrophotography/altazimuth-mount/": {"t": "Altazimuth mount", "s": "A simple two-axis mount for rotating instruments about vertical and horizontal axes."}, "https://codexery.com/amateur-astronomy/e/amateur-astronomy/john-dobson-amateur-astronomer/": {"t": "John Dobson (amateur astronomer)", "s": "Amateur astronomer who created the portable Dobsonian telescope.", "i": "https://codexery.com/amateur-astronomy/img/amateur-astronomy/john-dobson-amateur-astronomer.webp", "c": "Graham Robson · CC BY-SA 2.0"}, "https://codexery.com/amateur-astronomy/e/amateur-astronomy/amateur-astronomy/": {"t": "Amateur astronomy", "s": "Amateur astronomers observe celestial objects for passion, education, and citizen science."}, "https://codexery.com/galaxies/e/galaxies/deep-sky-object/": {"t": "Deep-sky object", "s": "Faint celestial objects beyond stars and Solar System bodies."}, "https://codexery.com/optics-and-photonics/e/optics-and-photonics/magnification/": {"t": "Magnification", "s": "Magnification enlarges apparent size without changing physical size or perspective."}, "https://codexery.com/astrophotography/e/astrophotography/equatorial-mount/": {"t": "Equatorial mount", "s": "A mount that tracks celestial objects by aligning with Earth's rotation."}, "https://codexery.com/amateur-astronomy/e/amateur-astronomy/amateur-telescope-making/": {"t": "Amateur Telescope Making", "s": "Three books that launched the amateur telescope making movement."}, "https://codexery.com/polymers-and-macromolecules/e/polymers-and-macromolecules/polytetrafluoroethylene/": {"t": "Polytetrafluoroethylene", "s": "Accidentally discovered fluoropolymer used widely for non-stick and chemical resistance."}, "https://codexery.com/planets-stellar-astronomy/e/planets-and-stellar-astronomy/star-cluster/": {"t": "Star cluster", "s": "Groups of stars sharing origin, held by gravity."}, "https://codexery.com/ngc-objects/e/ngc-objects/new-general-catalogue/": {"t": "New General Catalogue", "s": "A foundational catalogue of 7,840 deep-sky objects."}, "https://codexery.com/galaxy-clusters-and-groups/e/galaxy-clusters-and-groups/abell-catalogue/": {"t": "Abell catalogue", "s": "All-sky catalog of 4,073 rich galaxy clusters."}, "https://codexery.com/astrophotography/e/astrophotography/astrophotography/": {"t": "Astrophotography", "s": "Astrophotography records celestial objects using long exposures and specialized equipment."}, "https://codexery.com/stars-and-stellar-objects/e/stars-and-stellar-objects/comet/": {"t": "Comet", "s": "Icy wanderers that bloom when near the Sun."}, "/e/telescope-types/heliometer/": {"t": "Heliometer", "s": "A telescope that splits its lens to measure angular distances."}, "https://codexery.com/astrophotography/e/astrophotography/comet-seeker/": {"t": "Comet seeker", "s": "A short-focal-length telescope for comet hunting."}, "https://codexery.com/irish-inventors/e/irish-inventors/thomas-grubb/": {"t": "Thomas Grubb", "s": "Irish optician and telescope maker of the Victorian era."}, "https://codexery.com/astronomy/e/astronomy/halley-s-comet/": {"t": "Halley's Comet", "s": "First comet recognized as periodic, observed for over two millennia.", "i": "https://codexery.com/astronomy/img/astronomy/halley-s-comet.webp", "c": "via Wikipedia: Halley's Comet · see source"}, "/e/telescope-types/aerial-telescope/": {"t": "Aerial telescope", "s": "A tubeless refracting telescope using a string to align objective and eyepiece."}, "https://codexery.com/astronomers-and-cosmologists/e/astronomers-and-cosmologists/johann-gottfried-galle/": {"t": "Johann Gottfried Galle", "s": "German astronomer who first identified Neptune"}, "https://codexery.com/optical-telescopes/e/optical-telescopes/newall-telescope/": {"t": "Newall Telescope", "s": "Once the world's largest refractor, now used for education."}, "https://codexery.com/moons-of-jupiter/e/moons-of-jupiter/amalthea-moon/": {"t": "Amalthea (moon)", "s": "Jupiter's fifth moon, last discovered by direct visual observation."}, "/e/telescope-types/great-refractor/": {"t": "Great refractor", "s": "Large achromatic refractors defined 19th and early 20th century astronomy."}, "https://codexery.com/languages-and-dialects/e/languages-and-dialects/greek-language/": {"t": "Greek language", "s": "Greek is the world's oldest recorded living language."}, "https://codexery.com/named-stars/e/named-stars/sun/": {"t": "Sun", "s": "The Sun is the central star of the Solar System."}, "https://codexery.com/astronomical-concepts-and-techniques/e/astronomical-concepts-and-techniques/stellar-parallax/": {"t": "Stellar parallax", "s": "Trigonometric method for measuring distances to nearby stars."}, "https://codexery.com/astronomers-and-cosmologists/e/astronomers-and-cosmologists/friedrich-wilhelm-bessel/": {"t": "Friedrich Wilhelm Bessel", "s": "German astronomer who first measured the distance to a star.", "i": "https://codexery.com/astronomers-and-cosmologists/img/astronomers-and-cosmologists/friedrich-wilhelm-bessel.webp", "c": "Christian Albrecht Jensen · via Wikipedia: Friedrich Wilhelm Bessel · Public domain"}, "https://codexery.com/variable-stars/e/variable-stars/61-cygni/": {"t": "61 Cygni", "s": "Binary star system with the highest proper motion visible to the naked eye."}, "https://codexery.com/astrophotography/e/astrophotography/astronomical-seeing/": {"t": "Astronomical seeing", "s": "Atmospheric turbulence blurs astronomical images, limiting telescope resolution."}, "https://codexery.com/optics-and-photonics/e/optics-and-photonics/nonlinear-optics/": {"t": "Nonlinear optics", "s": "Branch of optics studying intensity-dependent optical properties of matter."}, "https://codexery.com/major-wars/e/major-wars/second-world-war/": {"t": "Second World War", "s": "Global conflict between Allies and Axis, deadliest in history."}, "https://codexery.com/electromagnetism/e/electromagnetism/electromagnetic-spectrum/": {"t": "Electromagnetic spectrum", "s": "The full range of electromagnetic radiation, from radio to gamma rays."}, "https://codexery.com/electromagnetism/e/electromagnetism/electromagnetic-radiation/": {"t": "Electromagnetic radiation", "s": "Self-propagating wave of the electromagnetic field carrying energy."}, "https://codexery.com/electromagnetism-and-waves/e/electromagnetism-and-waves/gamma-ray/": {"t": "Gamma ray", "s": "Penetrating electromagnetic radiation from nuclear decay and cosmic events."}, "https://codexery.com/meteorology/e/meteorology/water-vapor/": {"t": "Water vapor", "s": "The gaseous phase of water, a key greenhouse gas and component of Earth's hydrosphere."}, "https://codexery.com/airliners/e/airliners/boeing-747/": {"t": "Boeing 747", "s": "The original Jumbo Jet that revolutionized air travel.", "i": "https://codexery.com/airliners/img/airliners/boeing-747.webp", "c": "Luis Miguel Bugallo Sánchez (Lmbuga) · CC BY-SA 4.0"}, "https://codexery.com/asteroid-surveys/e/asteroid-surveys/iras/": {"t": "IRAS", "s": "First space telescope to survey the entire infrared sky."}, "https://codexery.com/exoplanets/e/exoplanets/the-james-webb-space-telescope/": {"t": "The James Webb Space Telescope", "s": "The largest space telescope, observing the infrared universe from beyond Earth's orbit."}, "https://codexery.com/astrophotography/e/astrophotography/far-infrared-astronomy/": {"t": "Far-infrared astronomy", "s": "Studies cold matter via far-infrared radiation from space."}, "https://codexery.com/astrophotography/e/astrophotography/submillimetre-astronomy/": {"t": "Submillimetre astronomy", "s": "Submillimetre astronomy traces cold gas and dust across the universe.", "i": "https://codexery.com/astrophotography/img/astrophotography/submillimetre-astronomy.webp", "c": "ESO/ P. Horálek · CC BY 4.0"}, "/e/telescope-types/liquid-mirror-telescope/": {"t": "Liquid-mirror telescope", "s": "A rotating liquid mirror forms a parabolic reflector for low-cost telescopes."}, "https://codexery.com/spacex-human-spaceflights/e/spacex-human-spaceflights/axiom-mission-1/": {"t": "Axiom Mission 1", "s": "First wholly commercial crewed mission to the ISS."}, "https://codexery.com/electromagnetism-and-radiation/e/electromagnetism-and-radiation/ultraviolet/": {"t": "Ultraviolet", "s": "Electromagnetic radiation beyond violet, with both harmful and beneficial effects."}, "https://codexery.com/thermodynamics-and-statistical-mechanics/e/thermodynamics-and-statistical-mechanics/temperature/": {"t": "Temperature", "s": "Temperature measures average particle kinetic energy and thermal energy distribution."}, "https://codexery.com/chemistry/e/chemistry/gallium/": {"t": "Gallium", "s": "A silvery metal that melts in your hand."}, "https://codexery.com/historical-figures/e/notable/isaac-newton/": {"t": "Isaac Newton", "s": "English polymath who formulated laws of motion and universal gravitation."}, "/e/telescope-types/liquid-mirror-space-telescope/": {"t": "Liquid-mirror space telescope", "s": "A space telescope using a rotating liquid mirror and artificial gravity."}, "https://codexery.com/lines-hemispheres/e/lines-and-hemispheres/north-pole/": {"t": "North Pole", "s": "Northernmost point on Earth, located in the Arctic Ocean."}, "https://codexery.com/lines-hemispheres/e/lines-and-hemispheres/south-pole/": {"t": "South Pole", "s": "Southernmost point on Earth, marked by shifting ice and historic expeditions."}, "https://codexery.com/radio-telescopes/e/radio-telescopes/south-pole-telescope/": {"t": "South Pole Telescope", "s": "A 10 m telescope studying the cosmic microwave background from Antarctica."}, "https://codexery.com/earth/e/earth/gravity-of-earth/": {"t": "Gravity of Earth", "s": "Earth's gravity varies by location due to rotation and shape."}, "https://codexery.com/classical-mechanics/e/classical-mechanics/buoyancy/": {"t": "Buoyancy", "s": "Buoyancy is the upward force exerted by a fluid on an immersed object."}, "https://codexery.com/classical-and-fluid-mechanics/e/classical-and-fluid-mechanics/net-force/": {"t": "Net force", "s": "Net force is the vector sum of all forces on an object."}, "https://codexery.com/classical-mechanics/e/classical-mechanics/centripetal-force/": {"t": "Centripetal force", "s": "Force that makes a body follow a curved path.", "i": "https://codexery.com/classical-mechanics/img/classical-mechanics/centripetal-force.webp", "c": "User:Tomia · CC BY 2.5"}, "https://codexery.com/meteorology/e/meteorology/foot-unit/": {"t": "Foot (unit)", "s": "A forgotten unit born from rods and rain, not left feet."}, "https://codexery.com/planets-and-dwarf-planets/e/planets-and-dwarf-planets/earth/": {"t": "Earth", "s": "The only known planet with liquid surface water and life."}, "https://codexery.com/optics-and-photonics/e/optics-and-photonics/optical-aberration/": {"t": "Optical aberration", "s": "Deviation from ideal image formation in optical systems."}, "https://codexery.com/fifa-world-cup/e/honours/soviet-union/": {"t": "Soviet Union", "s": "The world's flagship communist state and a superpower spanning Eurasia."}, "https://codexery.com/amateur-astronomy/e/amateur-astronomy/john-f-gregory/": {"t": "John F. Gregory", "s": "Optical engineer who designed the Gregory-Maksutov telescope."}, "https://codexery.com/manufacturing-and-materials/e/manufacturing-and-materials/mass-production/": {"t": "Mass production", "s": "Mass production is a method of making standardized products in constant flow."}, "https://codexery.com/violence-conflict/e/violence-and-conflict/military/": {"t": "Military", "s": "A heavily armed, highly organized force for warfare.", "i": "https://codexery.com/violence-conflict/img/violence-and-conflict/military.webp", "c": "Solomon203 · CC BY-SA 3.0"}, "https://codexery.com/kerbal-space-program/e/lore/g-force/": {"t": "G-force", "s": "Acceleration measured in multiples of gravity."}, "https://codexery.com/geometry-and-shapes/e/geometry-and-shapes/sphere/": {"t": "Sphere", "s": "A sphere is a set of points equidistant from a center in 3D space."}, "https://codexery.com/astrophotography/e/astrophotography/automated-planet-finder/": {"t": "Automated Planet Finder", "s": "Fully robotic 2.4-meter telescope searching for exoplanets via radial velocity."}, "https://codexery.com/science-measurement/e/science-and-measurement/prism-optics/": {"t": "Prism (optics)", "s": "Transparent element that refracts, reflects, or polarizes light.", "i": "https://codexery.com/science-measurement/img/science-and-measurement/prism-optics.webp", "c": "Polarbear24 · CC BY-SA 3.0"}, "https://codexery.com/chemical-elements/e/chemical-elements/tin/": {"t": "Tin", "s": "A soft, silvery-white post-transition metal with the largest number of stable isotopes.", "i": "https://codexery.com/chemical-elements/img/chemical-elements/tin.webp", "c": "Farmers' Trading Company · CC BY 4.0"}, "https://codexery.com/periodic-table-elements/e/periodic-table-and-elements/copper/": {"t": "Copper", "s": "A highly conductive metal essential to civilization and life."}, "https://codexery.com/moons-with-a-prograde-orbit/e/moons-with-a-prograde-orbit/galilean-moons/": {"t": "Galilean moons", "s": "Jupiter's four largest moons, discovered by Galileo in 1610."}, "https://codexery.com/planets-and-dwarf-planets/e/planets-and-dwarf-planets/jupiter/": {"t": "Jupiter", "s": "Largest planet in the Solar System, a gas giant with a Great Red Spot."}, "https://codexery.com/physical-geography-elevation/e/physical-geography-and-elevation/elevation/": {"t": "Elevation", "s": "Height of Earth's surface above a reference geoid."}}