Capsules

Komodo Dragon

The Komodo dragon, Varanus komodoensis, is the largest living lizard, restricted to a handful of islands in eastern Indonesia. It grows to around three metres and 70 to 90…

Seahorse

Seahorses are small marine fish of the genus Hippocampus, around fifty species, distinguished by an upright posture, a prehensile tail, a tubular snout, and a reproductive…

Factmedicine

Nursing

The care of the sick, injured and dependent. Nursing is the largest health profession by a wide margin, its outcomes are measurable and substantial, and its history is inseparable…

by Capsule · Aug 5, 2026

Browse all

Showing 381 to 400 of 1,028

Newest Most voted A to Z

The Action Potential

The electrical pulse a nerve cell uses to signal. It is the unit of communication in every nervous system, its mechanism is understood in…

byCapsule

medicine

Surgery

Treatment by physical intervention in the body. Surgery was limited for millennia not by knowledge of anatomy but by three specific obstacles, and the century in which those were…

by Capsule · Aug 5, 2026

Hummingbird

Hummingbirds, the family Trochilidae, are small nectar-feeding birds of the Americas that hover in sustained flight and run the highest mass-specific metabolic rate of any…

Wolf

The grey wolf, Canis lupus, is the largest wild member of the dog family and once the most widely distributed land mammal on Earth after humans. It is also the ancestor of the…

byCapsule0 votes0 reviewsAug 7, 2026

Seahorse

Seahorses are small marine fish of the genus Hippocampus, around fifty species, distinguished by an upright posture, a prehensile tail, a tubular…

byCapsule0 votes0 reviewsAug 5, 2026

Nursing

The care of the sick, injured and dependent. Nursing is the largest health profession by a wide margin, its outcomes are measurable and substantial,…

Also new

Morden

Morden is a city in the Pembina Valley of southern Manitoba, close to the United States border and about twenty kilometres west of Winkler, with…

Horse

The horse, Equus ferus caballus, is a large grazing mammal domesticated on the Eurasian steppe and, for roughly four thousand years, the fastest way…

media studies

The Telegraph

Communication by coded electrical signal over wires. It was the first technology to separate the speed of a message from the speed of travel, and…

Axolotl

The axolotl, Ambystoma mexicanum, is a salamander that never leaves the larval form. It reaches sexual maturity while keeping its gills and its…

Monarch Butterfly

The monarch, Danaus plexippus, is a large orange and black butterfly of the Americas, and the migratory population of eastern North America performs…

Portage la Prairie

Portage la Prairie is a city in central Manitoba on the Assiniboine River, about eighty kilometres west of Winnipeg, with 13,270 residents at the…

Common Raven

The common raven, Corvus corax, is the largest songbird in the world and among the most widely distributed birds on Earth, occupying the whole…

Albatross

Albatrosses are large seabirds of the family Diomedeidae, with the longest wingspans of any living bird and a way of flying that costs them almost…

On this day

A birth or event with an anniversary today

Statue of Liberty

The Statue of Liberty is a colossal copper statue on an island in New York Harbor, one of the most famous monuments in the United States and a…

Settled science

Verified facts and proven results

The Sun

The Sun is the star at the centre of the Solar System, a vast sphere of hot plasma whose gravity holds the planets in their orbits and whose light…

Great White Shark

The great white shark, Carcharodon carcharias, is the largest predatory fish, reaching about six metres. It is warm-blooded in a limited and…

The Sahara

The Sahara is the largest hot desert on Earth, a sweep of sand, gravel, and bare rock stretching across northern Africa from the Atlantic Ocean to…

Great Wall of China

The Great Wall of China is not a single wall but a vast, discontinuous system of fortifications, walls, watchtowers, garrisons, and beacon towers,…

Octopus

Octopuses are eight-armed cephalopod molluscs, around three hundred species, found in every ocean. They have three hearts, blue blood, no skeleton,…

chemistry

Water (H₂O)

Water is a chemical compound with the formula H₂O, consisting of two hydrogen atoms covalently bonded to one oxygen atom. Its bent molecular geometry…

Black Hole

A black hole is a region of space where gravity is so intense that nothing, not even light, can escape once it passes a certain boundary. They are…

The Founding and Agricultural Development of Brandon, Manitoba

Brandon, Manitoba was established in 1881 as a planned railway town along the Canadian Pacific Railway and rapidly became the agricultural hub of the…

Lion

The lion, Panthera leo, is the only truly social cat and the second largest after the tiger. It once ranged from southern Africa through the Middle…

Mount Everest

Mount Everest is the highest mountain on Earth as measured from sea level, with a summit reaching 8,848.86 metres (29,031.7 feet) above sea level, a…

The Moon

The Moon is Earth's only natural satellite and the brightest object in our night sky. Large in proportion to its planet and close enough to study…

Great Barrier Reef

The Great Barrier Reef is the world's largest coral reef system, stretching more than 2,300 kilometres along the north-east coast of Australia. So…

Open questions

Hypotheses under investigation and ideas still debated

Are Animals Conscious?

Whether animals have conscious experiences, an inner life of feelings and awareness, is a deep and genuinely contested question. That many animals…

The Multiverse

The multiverse is the hypothesis that our universe is only one of many, perhaps even infinitely many, other universes. It is taken seriously by many…

earth science

What Causes the Ice Ages

Throughout its history, the Earth has repeatedly cooled into ice ages, when vast sheets of ice spread across the continents, and warmed again between…

psychology

The Origin of Language

How human language first arose is one of the hardest questions in science. That we alone among animals possess full language is clear; when, how, and…

engineering

Renewable Energy and Electrical Grid Stability

Wind and solar generation are non-dispatchable and produce zero rotational inertia, raising legitimate concerns about frequency regulation and…

The Bronze Age Collapse

The Bronze Age collapse was a sudden, widespread breakdown of civilizations around the eastern Mediterranean roughly 3,200 years ago. Within a few…

psychology

Nature versus Nurture

The nature versus nurture debate asks how much of who we are, our intelligence, personality, talents, and behavior, comes from our genes, and how…

neuroscience

The Hard Problem of Consciousness

The hard problem of consciousness is the question of why and how physical processes in the brain give rise to subjective experience, the felt quality…

Hypothesis

Abiogenesis: The Origin of Life

Abiogenesis is the natural process by which life is thought to have arisen from non living matter, such as simple chemical compounds. How life first…

astrophysics

Dark Energy

Dark energy is the name given to an unknown influence that appears to be driving the expansion of the universe to speed up over time. It is thought…

psychology

Hypothesis

Social Media Use and Adolescent Depression: Causal Relationship Under Investigation

The proposition that social media use directly causes depression in adolescents remains under active scientific investigation. While correlational…

science

Hypothesis

Quantum Entanglement as a Substrate for Consciousness

The hypothesis proposes that quantum entanglement between microtubule subunits inside neurons could provide a physical substrate for unified…

Debunked

Claims the evidence overturned

literature

The Shakespeare Authorship Question

The claim that the works attributed to William Shakespeare were written by someone else. It has attracted eminent supporters for a hundred and…

education

Learning Styles

The idea that each person learns best through a particular sensory channel, and that teaching matched to that channel improves learning. It is…

neuroscience

Phrenology

Phrenology was a popular nineteenth century practice that claimed a person's character and mental abilities could be read from the shape and bumps of…

neuroscience

The Left-Brain, Right-Brain Myth

The idea that people are left-brained and therefore logical, or right-brained and therefore creative, is one of the most widely believed claims about…

music

The Mozart Effect

The claim that listening to Mozart makes people, and especially babies, more intelligent. It came from one small study whose actual finding was far…

geology

The Expanding Earth

The expanding Earth was a hypothesis, taken seriously by some scientists into the twentieth century, which claimed that the planet is steadily…

Vitalism

Vitalism was the long held belief that living things contain a special, non physical "vital force" or "life energy" that animates them and that…

astrophysics

The Steady State Theory

The steady state theory was a model of the universe, popular in the mid twentieth century, which held that the universe has always looked roughly the…

Spontaneous Generation

Spontaneous generation was the long held belief that living organisms could arise directly from non living matter. People thought maggots formed from…

nutrition

Breakfast as the Most Important Meal

The claim that eating breakfast is necessary for health and weight control, and that skipping it causes weight gain. The phrase was popularised by…

The Martian Canals

The Martian canals were a network of fine, straight lines that some astronomers in the late nineteenth and early twentieth centuries believed they…

The Geocentric Model

The geocentric model was the ancient belief that the Earth sits motionless at the center of the universe, with the Sun, Moon, planets, and stars all…

Theories explained

Well substantiated explanations of how things work

Theory· Scientific

Evolution by Natural Selection

Evolution by natural selection is the scientific theory that explains how the diversity of life arose and continues to change. It holds that…

Optics

Optics is the branch of physics that studies light: how it travels, how it interacts with matter, and how it can be controlled with lenses and…

Aerodynamics: How Flight Works

Aerodynamics is the study of how air flows around objects and the forces this creates. It is the science that explains how aircraft fly, how cars and…

Theory· Scientific

Special Relativity

Special relativity is the theory of space and time that Albert Einstein published in 1905. It revolutionized physics by showing that measurements of…

mathematics

Theory· Mathematical

Game Theory

Game theory is the mathematical study of strategic decision making, where the outcome for each participant depends not only on their own choice but…

mathematics

The Theory of Computation

The theory of computation is the branch of mathematics and computer science that asks what problems can be solved by computation, and how…

Dark Matter: The Leading Theoretical Framework for Missing Mass in the Universe

Dark matter is the leading theoretical framework proposed to explain gravitational effects observed in galaxies and galaxy clusters that cannot be…

earth science

The Greenhouse Effect

The greenhouse effect is the process by which certain gases in a planet's atmosphere trap heat, keeping the surface warmer than it would otherwise…

Theory· Scientific

General Relativity

General relativity is Albert Einstein's theory of gravity, published in 1915. It reimagines gravity not as a force pulling objects together but as…

geology

Uniformitarianism

Uniformitarianism is the foundational principle of geology: that the same natural processes we observe today, such as erosion, sedimentation, and…

The Kinetic Theory of Gases

The kinetic theory of gases explains the behaviour of gases as the result of countless tiny particles, atoms and molecules, in constant, rapid,…

Acoustics: The Science of Sound

Acoustics is the branch of physics that studies sound: how it is produced, how it travels as waves, and how it is heard. It bridges science and art,…

0 votes0 reviews

Aug 3, 2026

The Second Law of Thermodynamics

Heat does not flow from cold to hot by itself, and no engine converts heat entirely into work. The second law is the most secure statement in…

Neutrino Oscillation

Neutrinos change identity as they travel, converting between three types. The discovery resolved a thirty-year discrepancy in measurements of the Sun…

X-ray Crystallography

A technique for determining the arrangement of atoms in a solid by firing X-rays at a crystal and reading the pattern they scatter into. It has…

The Michelson-Morley Experiment

In 1887 two men in a basement in Cleveland tried to measure the Earth's motion through the medium light was assumed to travel in. They found nothing.…

Urban Renewal

The mid-twentieth-century programme of clearing dense older neighbourhoods and rebuilding them to a plan. It reshaped cities across North America and…

Induced Demand

Adding road capacity generates additional traffic that fills it, so congestion returns to roughly its previous level. The effect is well measured, it…

Auteur Theory

The position that a film's director is its author, and that the best directors impress a consistent personal vision across their work even within…

The Kuleshov Effect

Two shots placed next to each other produce a meaning that neither contains. Lev Kuleshov demonstrated it around 1918, and it is the reason film…

Ocean Acidification

The ocean absorbs roughly a quarter of the carbon dioxide released by human activity, and dissolved carbon dioxide makes seawater more acidic. The…

Thermohaline Circulation

A global system of deep ocean currents driven by differences in water density, which itself depends on temperature and salinity. It moves heat around…

Salt and Blood Pressure

That reducing salt lowers blood pressure is established. Whether population-wide salt reduction reduces deaths, and how low is low enough, is one of…

Breakfast as the Most Important Meal

The claim that eating breakfast is necessary for health and weight control, and that skipping it causes weight gain. The phrase was popularised by…

Dietary Fat and Heart Disease

The proposition that saturated fat raises cholesterol and thereby causes heart disease shaped dietary guidelines across the developed world for fifty…

The Flynn Effect

Average scores on intelligence tests rose steadily throughout the twentieth century, by roughly three points per decade in the countries with long…

Growth Mindset

The theory that believing ability can be developed, rather than being fixed, improves achievement. It became one of the most widely adopted ideas in…

Learning Styles

The idea that each person learns best through a particular sensory channel, and that teaching matched to that channel improves learning. It is…

The Medium Is the Message

Marshall McLuhan's claim that a communication technology's effects come from the technology itself rather than from what is transmitted through it.…

The Filter Bubble

The claim that personalisation algorithms enclose people in information environments matching their existing views, isolating them from disagreement…

Criminal Profiling

Offender profiling infers a perpetrator's characteristics from crime scene evidence. The specific claim that it reliably narrows a suspect pool, and…