Capsule
DonateLog inCreate account
Menu

Navigation

  • Main page
  • Capsules
  • Learning
  • Mapping
  • Rankings
  • Organizations
  • Create
  • Forums
  • Research

Interaction

  • Messages
  • Verify
  • Help
  • About Capsule

Display

Appearance

Environment

EnvironmentsDefault
Capsule
Log in

Navigation

  • Main page
  • Capsules
  • Learning
  • Mapping
  • Rankings
  • Organizations
  • Create
  • Forums
  • Research

Interaction

  • Messages
  • Verify
  • Feedback
  • Help
  • About Capsule

Truth Classification

  • Fact
  • Theory
  • Hypothesis
  • Proven
  • Contested
  • Debunked
How classification works

Capsule of the Day

FactSurgeryTreatment by physical intervention in the body. Surgery was limited for millennia not by knowledge of anatomy but by th…

New in the Library

  • FactTardigrade
  • FactMonarch Butterfly
  • FactSpider

Capsule

© 2026 Solis Holdings Group Inc. All rights reserved.

Built by Solis Dev, a technology studio operating under Solis Holdings Group Inc.

  • Policy
  • Terms of Use
  • Methodology
  • Corrections
  • Non-partisanship
  • Transparency
  • Developers
  • About
  • Discord
  • Sitemap

Capsule, the capsule-pill mark, and the clock logo are trademarks of Solis Holdings Group Inc. All content, source code, and design assets are the exclusive property of Solis Holdings Group Inc., unless otherwise noted. Unauthorized reproduction is prohibited.

The library

Capsules

1,028 capsules, each one classified by the strength of its evidence.

All1,028Fact599Proven130Theory89Hypothesis71Contested90Debunked48
geography236biology88physics67history54medicine45astronomy33psychology26mathematics26chemistry20engineering20astrophysics19neuroscience19anthropology18art18

Trending now

Most recent activity

Factbiology

Sea Turtle

Sea turtles are marine reptiles of the superfamily Chelonioidea, seven living species that have been in the oceans for more than a hundred million years. They breathe air,…

by Capsule · Aug 7, 2026
Facteducation

Libraries

Organised collections of recorded knowledge, held for use. Libraries are older than most of the writing systems that survive, their defining problem has always been finding rather…

by Capsule · Aug 5, 2026
Factbiology

Tardigrade

Tardigrades, also called water bears, are microscopic eight-legged animals forming their own phylum, Tardigrada, with around 1,500 described species. They are famous for surviving…

by Capsule · Aug 7, 2026
Fact

Browse all

Showing 681 to 700 of 1,028

NewestMost votedA to Z
geography
Fact· Empirical

Uzbekistan

Uzbekistan is a country in the heart of Central Asia, a doubly landlocked nation, meaning it and all its neighbours are without a coast. It lies…

byCapsule
geography

Flin Flon

Flin Flon is a mining city on the Manitoba and Saskatchewan boundary, about 630 kilometres northwest of Winnipeg, built directly on the rock of the Canadian Shield. It is one of…

by Capsule · Aug 7, 2026
Factbiology

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…

by Capsule · Aug 7, 2026
Factagriculture

Livestock

Domesticated animals kept for food, fibre, labour and other products. Livestock made agriculture viable on land that grows no crops, and they are now among the largest single…

by Capsule · Aug 5, 2026
Fact

Libraries

Organised collections of recorded knowledge, held for use. Libraries are older than most of the writing systems that survive, their defining problem…

byCapsule0 votes0 reviewsAug 5, 2026
Fact· Empirical

Tardigrade

Tardigrades, also called water bears, are microscopic eight-legged animals forming their own phylum, Tardigrada, with around 1,500 described species.…

byCapsule0 votes0 reviewsAug 7, 2026

Also new

More from the last few days

geography
Fact· Empirical

Dauphin

Dauphin is a city in the Parkland region of western Manitoba, between Riding Mountain National Park and Lake Dauphin, with 8,368 residents at the…

byCapsule0 votes0 reviews
biology
Fact· Empirical

Bat

Bats, the order Chiroptera, are the only mammals capable of powered flight. There are more than 1,400 species, roughly a fifth of all mammal species,…

byCapsule0 votes0 reviews
biology
Fact· Empirical

Ant

Ants are eusocial insects of the family Formicidae, with over 14,000 described species and an estimated global population around twenty quadrillion…

byCapsule0 votes0 reviews
biology
Fact· Empirical

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…

byCapsule0 votes0 reviews
media studies
Fact

Radio

Communication using electromagnetic waves without a conductor between sender and receiver. It was the first medium to reach a mass audience…

byCapsule0 votes0 reviews
biology
Fact· Empirical

Platypus

The platypus, Ornithorhynchus anatinus, is a semiaquatic egg-laying mammal of eastern Australia. It lays eggs, produces milk without nipples, detects…

byCapsule0 votes0 reviews
media studies
Fact

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…

byCapsule0 votes0 reviews
economics
Fact

Insurance

The transfer of risk from an individual to a pool in exchange for a payment. It works because large numbers behave predictably even when individuals…

byCapsule0 votes0 reviews

On this day

A birth or event with an anniversary today

history
Fact· Empirical

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…

byCapsule0 votes0 reviews

Settled science

Verified facts and proven results

See all
astronomy
Fact· Empirical

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…

byCapsule0 votes0 reviews
geology
Fact· Empirical

Volcano

A volcano is an opening in a planet's crust through which molten rock, gas, and ash erupt from the hot interior to the surface. On Earth they are…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Grand Canyon

The Grand Canyon is one of the most spectacular landscapes on Earth: an immense gorge carved by the Colorado River through the high plateau of…

byCapsule0 votes0 reviews
biology
Fact· Empirical

Honey Bee

Honey bees are eusocial insects of the genus Apis, of which the western honey bee, Apis mellifera, is the one kept worldwide. They communicate the…

byCapsule0 votes0 reviews
geography
Fact· Empirical

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…

byCapsule0 votes0 reviews
engineering
Proven

Arc Flash Hazard Mitigation in Industrial Electrical Systems

An arc flash is a high-energy electrical fault that produces an explosive release of heat, light, and pressure when a phase-to-phase or…

byCapsule0 votes0 reviews
biology
Fact

DNA (Deoxyribonucleic Acid)

Deoxyribonucleic acid (DNA) is the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of…

byCapsule0 votes0 reviews
chemistry
Fact

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…

byCapsule0 votes0 reviews
history
Fact· Empirical

The Colosseum

The Colosseum is a giant amphitheatre in the centre of Rome, the largest ever built and one of the most recognisable monuments of the ancient world.…

byCapsule0 votes0 reviews
astronomy
Fact· Empirical

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…

byCapsule0 votes0 reviews
physics
Fact

Gravity

Gravity is the universal attractive interaction between masses, described at low energy by Newton's law of universal gravitation and at all energies…

byCapsule0 votes0 reviews
biology
Fact· Empirical

Octopus

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

byCapsule0 votes0 reviews

Open questions

Hypotheses under investigation and ideas still debated

See all
astronomy
Hypothesis

The Dyson Sphere

A Dyson sphere is a hypothetical megastructure that an extremely advanced civilization might build around a star to capture a large share of its…

byCapsule0 votes0 reviews
biology
Contested

Are Viruses Alive?

Whether viruses count as living organisms is a question biologists have debated for over a century, and there is still no settled answer. Viruses sit…

byCapsule0 votes0 reviews
astronomy
Contested

The Origin of the Moon

How the Moon came to be is a question that has fascinated and divided scientists for generations. While one explanation is now favoured, important…

byCapsule0 votes0 reviews
earth science
Contested

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…

byCapsule0 votes0 reviews
biology
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…

byCapsule0 votes0 reviews
neuroscience
Contested

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…

byCapsule0 votes0 reviews
biology
Hypothesis

Panspermia

Panspermia is the hypothesis that life exists throughout the universe and is spread between worlds by space dust, meteoroids, asteroids, and comets.…

byCapsule0 votes0 reviews
astronomy
Hypothesis

Planet Nine

Planet Nine is a hypothetical large planet proposed to exist in the far outer reaches of our Solar System, well beyond Neptune and Pluto. It has…

byCapsule0 votes0 reviews
astrophysics
Contested

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…

byCapsule0 votes0 reviews
physics
Contested

The Anthropic Principle

The anthropic principle concerns the striking observation that the universe appears remarkably fine tuned for the existence of life. Many of the…

byCapsule0 votes0 reviews
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…

byCapsule0 votes0 reviews
earth science
Hypothesis

The Gaia Hypothesis

The Gaia hypothesis proposes that life and its physical environment on Earth form a single, self regulating system that keeps the planet suitable for…

byCapsule0 votes0 reviews

Debunked

Claims the evidence overturned

See all
biology
Debunked

Lamarckism

Lamarckism is the discredited idea that organisms can pass on to their offspring the characteristics they acquire during their lifetime. Its classic…

byCapsule0 votes0 reviews
geography
Debunked

The Bermuda Triangle

The Bermuda Triangle is a region of the Atlantic Ocean, roughly between Florida, Bermuda, and Puerto Rico, said to be the site of mysterious…

byCapsule0 votes0 reviews
astronomy
Debunked

Flat Earth

The idea that the Earth is flat is a debunked belief that the planet is a disc or a plane rather than a sphere. It has been contradicted by…

byCapsule0 votes0 reviews
neuroscience
Debunked

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…

byCapsule0 votes0 reviews
biology
Debunked

Spontaneous Generation

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

byCapsule0 votes0 reviews
medicine
Debunked

Humorism: The Four Humors

Humorism, or humoral theory, was the belief that human health depends on the balance of four bodily fluids, called humors: blood, phlegm, yellow…

byCapsule0 votes0 reviews
science
Debunked

Cold Fusion at Room Temperature

The 1989 Fleischmann-Pons announcement claimed that palladium electrodes immersed in heavy water produced excess heat consistent with…

byCapsule0 votes0 reviews
nutrition
Debunked

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…

byCapsule0 votes0 reviews
medicine
Debunked

Bloodletting

Bloodletting was the practice of deliberately draining blood from a patient to cure or prevent illness. For more than two thousand years it was one…

byCapsule0 votes0 reviews
architecture
Debunked

The Golden Ratio in Art and Architecture

The golden ratio is a real and interesting number. The claim that it governs the Parthenon, the Great Pyramid, the Mona Lisa and the proportions of…

byCapsule0 votes0 reviews
literature
Debunked

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…

byCapsule0 votes0 reviews
history
Debunked

Alchemy

Alchemy was an ancient and medieval practice that sought to transform base metals such as lead into gold, to discover a universal cure for disease,…

byCapsule0 votes0 reviews

Theories explained

Well substantiated explanations of how things work

See all
mathematics
Theory

Set Theory

Set theory is the branch of mathematics that studies collections of objects, called sets. Though it begins with an idea as simple as grouping things…

byCapsule0 votes0 reviews
mathematics
Theory

Graph Theory

Graph theory is the branch of mathematics that studies networks of connected objects. A graph is simply a collection of points, called vertices,…

byCapsule0 votes0 reviews
physics
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…

byCapsule0 votes0 reviews
biology
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…

byCapsule0 votes0 reviews
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…

byCapsule0 votes0 reviews
physics
Theory

Thermodynamics

Thermodynamics is the branch of physics concerned with heat, energy, and work, and how they transform from one form to another. Its laws are among…

byCapsule0 votes0 reviews
medicine
Theory· Scientific

Germ Theory of Disease

The germ theory of disease is the scientific theory that many illnesses are caused by microorganisms, living agents too small to see, that invade the…

byCapsule0 votes0 reviews
geology
Theory

Uniformitarianism

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

byCapsule0 votes0 reviews
physics
Theory

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,…

byCapsule0 votes0 reviews
mathematics
Theory· Mathematical

Chaos Theory

Chaos theory is the branch of mathematics that studies systems whose behaviour is exquisitely sensitive to their starting conditions. Such systems…

byCapsule0 votes0 reviews
computer science
Theory· Mathematical

Information Theory

Information theory is the mathematical study of how information is measured, stored, and communicated. It defines what information actually is in…

byCapsule0 votes0 reviews
earth science
Theory

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…

byCapsule0 votes0 reviews
0 votes0 reviews
geography
Fact· Empirical

Kazakhstan

Kazakhstan is a vast country in Central Asia, the largest landlocked nation in the world and the ninth largest by area overall, stretching across the…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Jordan

Jordan is a country in the Middle East, set on the east bank of the Jordan River between the deserts of Arabia and the Mediterranean world. A largely…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Israel

Israel is a small country in the Middle East, on the eastern shore of the Mediterranean Sea, in a region of profound significance to several of the…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Syria

Syria is a country in the Middle East, on the eastern shore of the Mediterranean Sea, with a history reaching back to the dawn of civilisation. Its…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Afghanistan

Afghanistan is a landlocked, mountainous country at the crossroads of Central and South Asia, where the great ranges of the Hindu Kush meet the high…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Iraq

Iraq is a country in the Middle East, built around the valleys of the Tigris and Euphrates rivers, the land that ancient writers called Mesopotamia,…

byCapsule0 votes0 reviews
geography
Fact· Empirical

New Zealand

New Zealand is an island country in the southwestern Pacific Ocean, made up of two main islands and many smaller ones, lying far from any continent.…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Norway

Norway is a country in northern Europe occupying the western and northern reaches of the Scandinavian Peninsula, a land of deep fjords, soaring…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Chile

Chile is a long, narrow country running down the western edge of South America, squeezed between the Andes Mountains and the Pacific Ocean. Reaching…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Ghana

Ghana is a country in West Africa, set on the Gulf of Guinea where the continent meets the Atlantic. A land of tropical forests, savanna, and golden…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Morocco

Morocco is a country in the northwest corner of Africa, the only African nation with coastlines on both the Atlantic Ocean and the Mediterranean Sea,…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Poland

Poland is a country in Central Europe, a broad land of plains, forests, and lakes stretching from the Baltic Sea to the Carpathian Mountains. With a…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Ukraine

Ukraine is a large country in Eastern Europe, the biggest nation lying entirely within Europe, stretching from the forests of the north to the Black…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Philippines

The Philippines is an archipelagic country in Southeast Asia, made up of more than seven thousand islands scattered across the western Pacific. A…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Bangladesh

Bangladesh is a country in South Asia, set on the vast delta where the Ganges and Brahmaputra rivers empty into the Bay of Bengal. Lush, low-lying,…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Pakistan

Pakistan is a country in South Asia, the fifth most populous nation in the world, set between the Arabian Sea, the towering mountains of the north,…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Colombia

Colombia is a country in the northwest of South America, the only one on the continent with coastlines on both the Caribbean Sea and the Pacific…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Thailand

Thailand is a country in the heart of mainland Southeast Asia, a land of tropical beaches, lush river plains, and gilded Buddhist temples. Famed for…

byCapsule0 votes0 reviews
geography
Fact· Empirical

Sweden

Sweden is a country in northern Europe, the largest of the Nordic nations, stretching down the eastern side of the Scandinavian Peninsula. A land of…

byCapsule0 votes0 reviews
Previous1…3334353637…52Next