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Patrick Riley
Patrick Riley
Encyclopædia Britannica Editor
BIOGRAPHY

Patrick Riley is the Senior Illustrator for Encyclopædia Britannica. He has worked at Britannica since 2007.

Primary Contributions (101)
A chart displaying the enlisted rank insignias for each branch of the United States military-Army, Marine Corps, Air Force, Navy, Coast Guard, and Space Force-organized by rank and showing the corresponding symbols for each position. Enlisted rank insignias of the United States military
Diagram explaining hot mixing in Roman concrete production, showing steps from preparing quicklime, volcanic ash, and aggregates, to mixing with water, and illustrating how the resulting concrete self-repairs using lime clasts formed during hot mixing to create calcium carbonate in cracks. How Roman concrete repairs itself
An illustration shows a green armchair with a charred, smoky human silhouette burned into the upholstery, with only a pair of legs and shoes remaining, referencing spontaneous human combustion. Artist's conception of spontaneous human combustion
Illustration of the Saffir-Simpson hurricane wind scale, showing five categories ranked by increasing wind speed and damage: Category 1 (74-95 mph) with minor damage, up to Category 5 (157 mph or higher) with near-total destruction. Each category is color-coded and includes simple images of houses and trees showing escalating storm damage. Saffir-Simpson hurricane scale
Infographic illustrating various American landing craft used in World War II, especially during the Normandy invasion. Central silhouettes compare the sizes of ships and vehicles, from the large Landing Ship, Tank (LST) to the smaller amphibious truck (DUKW), with measurement bars for reference. Side panels show labeled diagrams and descriptions of each craft's purpose, capacity, and features, such as troop and tank loads, with icons representing personnel and tanks. American landing craft of World War II
Infographic titled Pirates Throughout History showing a world map with highlighted regions of major pirate activity and a timeline of significant piracy events from ancient times to the 2010s, including notable pirates and key historical moments. Pirates Throughout History
Illustration comparing the sizes of asteroid 2024 YR4, asteroid Bennu, a Boeing 767 airplane, and the Eiffel Tower. 2024 YR4 and the Boeing 767 are similar in width, while Bennu is much larger, and the Eiffel Tower stands taller than both asteroids. Comparison of asteroid 2024 YR4 with various objects
A chart showing the American Academy of Pediatrics recommended immunization schedule for children from birth to 6 years, listing vaccines and timing for each dose across a timeline, with color-coded markers for standard and high-risk recommendations. Recommended immunization schedule for babies and children from birth to 6 years old,
Illustration showing three ways dopamine signals: neurotransmission between neurons at synapses, volume transmission to nearby target cells, and endocrine signaling through the bloodstream to distant cells. Modes of dopamine signaling
Infographic titled Fluoride Facts featuring a central tooth illustration and surrounding labeled boxes explaining what fluoride is, its sources, health effects, recommended levels, and common products containing fluoride, along with statistics on global water fluoridation. Facts about fluoride
An iceberg diagram compares the World Wide Web's layers: the small visible tip labeled surface web (4%), the much larger submerged section labeled deep web (96%), and a tiny portion at the bottom labeled dark web (less than 1%), with descriptive text explaining each layer. proportions of World Wide Web content constituting the surface web, deep web, and dark web
Diagram illustrating the levels of ecological organization, from ecological community and habitat to ecosystem and biome, using labeled landscape cross-sections and showing interactions like energy flow, disturbances, and nutrient cycling. A diagram showing that different levels of ecological organization often occur in a given area.
Diagram of the branches of the U.S. government showing the Constitution at the top, connected to the legislative, executive, and judicial branches, with executive departments listed below. How the government works
Illustration of eutrophication showing nutrient runoff from farmland entering a lake, causing an algae bloom that blocks sunlight, kills aquatic plants, leads to decomposition, and creates a hypoxic dead zone. Eutrophication
Illustration showing a brick firewall with flames symbolizing protection between the internet and a laptop labeled internal network. Arrows indicate the firewall blocks harmful traffic and allows safe data through based on rules. firewall
Infographic featuring a central illustration of a pope, surrounded by labeled facts such as the total number of popes, most common papal names, oldest and youngest elected, longest and shortest reigns, number of popes made saints, official titles, and origins by country. Pope facts
Infographic depicting the Space Race between the U.S.S.R. and the U.S. from 1957 to 1969, with a central rocket illustration and milestone achievements listed on either side. Soviet milestones on the left include the first artificial satellite, first animal in space, first human in orbit, and first woman in space. U.S. milestones on the right include the first American in orbit, first American spacewalk, first docking in space, and the first humans landing on the Moon. The timeline highlights ke Space race
An illustration shows five human profiles with varying images of a horse inside each head, progressing from a vivid, realistic horse to a faint outline and finally no image, representing the spectrum from vivid mental imagery to aphantasia, the inability to create mental images. Aphantasia
Diagram showing how a mechanical ventilator delivers oxygen to a patient's lungs through an intubation tube, with labeled parts including the monitor, humidifier, flow sensors, and tubes for inspiratory and expiratory airflow. The diagram also highlights key safety features such as positive air pressure and monitoring of vital signs. Mechanical ventilation
Diagram explaining chronic venous insufficiency, with illustrations comparing healthy and varicose veins, and a series of legs showing disease progression from spider veins to varicose veins, swelling, skin discoloration, and venous ulcers. The stages of progression of chronic venous insufficiency
Infographic titled "Knights of the Order of the British Empire." It explains who can be honored, how candidates are chosen, the history of knighthood, and what recipients receive. Members are called knights or dames, with no gender-neutral title. British and Commonwealth citizens can be recognized for major contributions in science, arts, culture, industry, or society. Non-British citizens may receive honorary knighthood but cannot use “Sir” or “Dame.” Nominations can come from the public. Committees and leaders review candidates, with the final decision made by the monarch. The tradition began in the 11th century when knights were soldiers. The Order of the British Empire was introduced in 1917 by King George V to recognize civilian service. In the ceremony, knights kneel while dames stand. The monarch taps knights' shoulders with a sword. Both receive insignia: a badge for the top three ranks and a star for the top two. Understanding knighthood in the Order of the British Empire
An illustrated diagram explains ski mountaineering as a Winter Olympic sport, showing a sprint race course with labeled sections for ascent, descent, and transitions. It also depicts a ski mountaineer with equipment details, highlighting ski and pole dimensions and the use of climbing skins for uphill traction. Ski mountaineering: Sprint
Illustration of a Maine Coon cat with long, thick brown fur and a bushy tail, shown in profile standing on all four legs. A scale bar at the top right indicates size, with the label Maine Coon beside the cat. Maine Coon cat
Illustration of a sabre-toothed cat, Smilodon, showing a large, muscular feline with tan fur and dark spots, its mouth open to reveal long, curved canine teeth. A scale bar in the corner indicates size. Smilodon
This infographic compares film formats by showing side-by-side images of IMAX 70 mm, standard 70 mm, and 35 mm film strips, highlighting their relative sizes and perforation counts. Film sizes and aspect ratios
A Sphynx cat with pale, nearly hairless skin, large ears, and green eyes sits upright, highlighting its slender build and prominent wrinkles. Sphynx cat
Skulls depicting and explaining the seven deadly sins. Seven deadly sins
Infographic featuring a central illustration of a pope, surrounded by labeled facts such as the total number of popes, most common papal names, oldest and youngest elected, longest and shortest reigns, number of popes made saints, official titles, and origins by country. Pope facts
Diagram showing a mountain glacier collapse in which melting ice destabilizes rock, triggering a rockslide that changes the ice into water to flood the valley below with water, mud, and debris. The collapse of a mountain glacier can trigger a landslide that produces a cascade of water, mud, and debris.
Illustration of the Saffir-Simpson hurricane wind scale, showing five categories ranked by increasing wind speed and damage: Category 1 (74-95 mph) with minor damage, up to Category 5 (157 mph or higher) with near-total destruction. Each category is color-coded and includes simple images of houses and trees showing escalating storm damage. Saffir-Simpson Hurricane Wind Scale
Infographic titled Jaws Bites featuring a large illustrated shark at the center, surrounded by colorful fact blocks about the 1975 movie Jaws, including release date, cast, box office totals, shark statistics, death count, and trivia such as the famous improvised line and Oscar wins. Jaws bites
Infographic showing the size comparison of the largest snakes recorded: the prehistoric Titanoboa and two reticulated pythons, Medusa and Ibu Baron, alongside an average adult U.S. male human silhouette, highlighting their lengths and weights. Size comparison: Titanoboa and two of the longest reticulated pythons recorded
Circular diagram of the Jewish religious year showing Hebrew months around the outer ring and Gregorian months inside, with major holidays and fasts such as Rosh Hashanah, Yom Kippur, Sukkot, Hanukkah, Passover, and Purim labeled with their dates. The cycle of the Jewish religious year
Illustration of a golden dharma wheel (dharmachakra) on a red background, with each of its eight spokes labeled to represent the steps of the Buddhist Eightfold Path, including right view, intention, speech, action, livelihood, effort, mindfulness, and concentration. Eightfold Path
Side-view skull diagram highlighting the red superficial and deep masseter muscles between the cheekbone and mandible. Masseter muscle anatomy of the jaw
A graphic features a central name tag reading Hello, my pronouns are they/them, surrounded by colorful circles displaying various pronouns, including she/her, he/him, they/he, she/them, they/them/theirs, she/her/hers, he/him/his, and ze/zir. Each circle uses different pride flag colors to represent gender diversity. Personal pronouns come in multiple forms
Infographic about serial killer Ed Gein, titled The Butcher of Plainfield. It includes a portrait of Gein, a Wisconsin map marking Plainfield, La Crosse, and Milwaukee, and illustrations of key locations linked to his life and crimes: Gein family home, Central State Hospital, Mary Hogan's Tavern, Worden's Hardware Store, Spiritland Cemetery, and Plainfield Cemetery. Text highlights his abusive childhood, the mysterious death of his brother, his mother's dominance, and his later murders of Mary Hogan and Bernice Worden. Notes his grave robbing, use of human remains to make household items, and trial verdict of insanity. References his influence on horror films like Psycho (1960), The Texas Chain Saw Massacre (1974), and The Silence of the Lambs (1991). Ed Gein
Circular zodiac wheel showing the twelve astrological signs with symbols, illustrations, and date ranges. The chart includes elemental groups—fire, earth, air, and water—and gender symbols for masculine and feminine signs on a dark purple background. Signs of the zodiac
Infographic titled Pirates Throughout History showing a world map with highlighted regions of major pirate activity and a timeline of significant piracy events from ancient times to the 2010s, including notable pirates and key historical moments. piracy
Diagram of a human brain in side view with labeled parts of the limbic system, including the basal ganglia, cingulate gyrus, thalamus, hypothalamus, amygdala, and hippocampus. primary components of the limbic system
Create your own exquisite corpse with Britannica's Exquisite Corpse Experience! Create your own exquisite corpse with Britannica's Exquisite Corpse Experience!
Infographic about the Eastland disaster on July 24, 1915, in Chicago, showing a timeline of events, a diagram of the SS Eastland ship, a map of the disaster location on the Chicago River, estimated death tolls compared to other disasters, and causes such as inadequate ballast and top-heavy design. Quick facts about the Eastland disaster
The infographic titled “From Sport to Spectacle: The Evolution of the Super Bowl” shows how the Super Bowl has grown since its first game in January 1967 into a major cultural event. At the center, text explains that pregame ceremonies, halftime shows, and commercials now rival the game itself for attention. Charts show ticket prices rising steadily, reaching about $8,000 in 2025 when adjusted for inflation, and advertising costs growing from $40,000 for a 30-second ad in 1967 to about $8 million in 2025. A viewership bar chart shows audiences increasing over time, surpassing 130 million viewers by 2025. Sections describe the evolution of pregame flyovers and military tributes, the coin toss tradition, and halftime entertainment shifting from marching bands to major pop concerts, with notable moments like Michael Jackson's 1993 show and Kendrick Lamar's record-setting 2025 performance. A food section highlights Super Bowl consumption, including beer, chicken wings, and rising avocado use for guacamole. Evolution of off-the-field Super Bowl traditions
Aerial view of the Sagrada Familia basilica in Barcelona with text inviting users to start an interactive tour and describing Antoni Gaudi's architectural vision. Interactive tour of the Sagrada Família
Who signed the Declaration of Independence? Who signed the Declaration of Independence?
John Trumbull's painting "Declaration of Independence" shows the Founding Fathers gathered to sign the document, with interactive icons and text asking who signed it. Who Signed the Declaration of Independence?
Illustration of the Abominable Snowman, or Yeti, depicted as a tall, muscular creature covered in shaggy white fur with a dark face, hands, and feet, standing upright with arms slightly outstretched. Abominable Snowman
Infographic showing a timeline of LGBTQ+ pride flags from 1978 to 2019, with each flag's design, year of introduction, and creator's name branching from a central rainbow ribbon on a black background. LGBTQ+ Pride Flag Timeline
The Evolution of the Super Bowl The Evolution of the Super Bowl
bee diversity infographic bee diversity infographic
Infographic about the USS Indianapolis highlights its World War II mission delivering atomic bomb components, its sinking by a submarine, and the resulting casualties and survivors. It features a ship diagram, Pacific map with the ship's route, a shark illustration, a bar chart of crew loss and survival, and a timeline of key events. Learn about the sinking of the USS Indianapolis
Illustration showing the process of Santa Ana winds in California, with a map indicating high-pressure air from the Great Basin moving southwest toward the coast, funneled through mountains and valleys, warming and drying the air, which increases wildfire risk. Numbered labels explain each step and a wildfire is depicted at the end of the wind path. Santa Ana winds
Illustration comparing the sizes of four spider species-the giant huntsman, goliath birdeater, joro spider, and ground wolf spider-shown as silhouettes next to an average adult male hand for scale, with a vertical ruler on the side for precise measurement. Size comparison of four spider species
Illustration of a golden dharma wheel (dharmachakra) on a red background, with each of its eight spokes labeled to represent the steps of the Buddhist Eightfold Path, including right view, intention, speech, action, livelihood, effort, mindfulness, and concentration. The Eightfold Path illustrated with a dharmachakra
Infographic about the RMS Titanic featuring an illustration of the ship, a timeline of key events from construction to its sinking and discovery, fatality percentages for passengers and crew, and a map showing the ship's route and wreck site in the Atlantic Ocean. Titanic
Infographic listing lilies highly toxic to cats-such as daylily, tiger lily, and Easter lily-causing vomiting, lethargy, appetite loss, and dehydration, plus less toxic lilies and their effects. Not all lilies are equally toxic to cats
This infographic presents a timeline of the five major mass extinction events in Earth's history-Devonian, Ordovician-Silurian, Permian, End-Triassic, and Cretaceous-Tertiary (K-T or K-Pg)-with descriptions of each event's timing, causes, and impact on marine animal families, illustrated by a graph showing the diversity and decline of marine animal families over geologic time. Diagram showing the details of Earth's five past mass extinction events along with the current extinction episode.
Infographic timeline of the Manhattan Project set against a background of an atomic bomb explosion, detailing major scientific discoveries, project milestones, bomb test and deployment dates, and key locations such as Los Alamos, Oak Ridge, and Hanford, from the 1930s through the end of World War II. Timeline of the Manhattan Project
An illustration shows a single raised hand emerging from swirling quicksand, emphasizing the peril and struggle associated with being trapped in quicksand. How deadly is quicksand?
Silhouettes of three humans running in sequence after an antelope illustrate persistence hunting, with text noting the hunt can last 2 to 6 or more hours and occurs at temperatures around 100 to 105 degrees Fahrenheit. Persistence hunting
A series of illustrated clock faces show the changing setting of the Doomsday Clock from 1947 to 2026, with each clock's hands approaching midnight to symbolize global existential threats. Below each clock, text explains the number of minutes or seconds to midnight for that year and the world events influencing each setting, such as nuclear arms races, treaties, climate change, and geopolitical tensions. Doomsday Clock
Ancient clay tablet map labeled Babylonian Map of the World, showing a circular world with Babylon at the center, surrounded by labeled regions, cities, rivers, mountains, and areas marked as broken or unknown. English labels identify features such as Bitter River, Great Wall, mountain, swamp, Susa, Urartu, and several regions in between. Babylonian Map of the World
An iceberg diagram compares the World Wide Web's layers: the small visible tip labeled surface web (4%), the much larger submerged section labeled deep web (96%), and a tiny portion at the bottom labeled dark web (less than 1%), with descriptive text explaining each layer. The surface web, deep web, and dark web in contrast
The Nativity in 25 Artworks The Nativity in 25 Artworks
Infographic diagram showing the hierarchical structure of the 'Ndrangheta criminal organization, from the global meeting and governing bodies to local clans, branches, and detailed roles within major and minor societies. organizational structure of the 'Ndrangheta
A black and white American Shorthair cat with short fur sits facing forward, displaying its alert expression and long tail. The label American Shorthair appears near its head. American Shorthair cat
A Bengal cat with short, golden-brown fur covered in dark rosettes and stripes stands alert, showing its athletic build and green eyes. Bengal cat
A Tonkinese cat with a sleek, short coat and blue eyes stands in profile, showing its slender body and pointed ears. Tonkinese cat
Illustration of a Maine Coon cat with long, thick brown fur and a bushy tail, shown in profile standing on all four legs. A scale bar at the top right indicates size, with the label Maine Coon beside the cat. Maine Coon cat
Infographic depicting the Space Race between the U.S.S.R. and the U.S. from 1957 to 1969, with a central rocket illustration and milestone achievements listed on either side. Soviet milestones on the left include the first artificial satellite, first animal in space, first human in orbit, and first woman in space. U.S. milestones on the right include the first American in orbit, first American spacewalk, first docking in space, and the first humans landing on the Moon. The timeline highlights ke Space exploration
Into the Deep Into the Deep
Infographic showing the new space race among China, India, and Japan, with colored arrows from each country marking missions to the Moon, Mars, and asteroids. The background features Earth, the Moon, and Mars, with launch sites labeled in each country. A timeline at the bottom lists key missions, their years, and achievements, such as lunar and Mars landings, asteroid sample returns, and planned future missions. Space race between China, India, and Japan
Spiderweb infographic Spiderweb infographic
A Guide to the Characters of Jane Austen A Guide to the Characters of Jane Austen
Three 3-D diagrams illustrate rogue wave formation among shorter and medium waves, showing how currents, wind, and intersecting swells create exceptionally large waves through energy focusing and constructive interference, with explanatory text about wave behavior and record heights. rogue wave formation
A colorful family tree diagram visually mapping cousin relationships across generations, with second cousins highlighted in the same row as first and third cousins, showing their shared great-grandparents. Cousin family tree
Illustration of a sabre-toothed cat, Smilodon, showing a large, muscular feline with tan fur and dark spots, its mouth open to reveal long, curved canine teeth. A scale bar in the corner indicates size. sabre-toothed cat
Illustrated fake movie poster styled after Stranger Things, featuring two figures in green parkas labeled Brian B. and Joan B. with glowing, faceless heads and question marks. They stand in front of a building labeled Britannica, under northern lights and a night sky, with a row of encyclopedias and an open book in the foreground. Signs point to various global locations, and a bear and airplane appear in the snowy background. The headline reads Who Are the Britannicas? Joan and Brian Britannica
Interactive diagram of the White House floor plan with labeled sections: West Wing, Executive Residence, and East Wing. Text invites users to select a section to learn more. Interactive White House floor plan with clickable West Wing, Executive Residence, and East Wing sections