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Capsule of the Day

DebunkedThe PolygraphThe instrument popularly called a lie detector, which records breathing, blood pressure, pulse and skin conductance dur…

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The library

Capsules

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

All1,028Fact599Proven130Theory89Hypothesis71Contested90Debunked48
geography236biology88physics67history54medicine45astronomy33psychology26mathematics26chemistry20engineering20astrophysics19neuroscience19anthropology18art18
Filtered byContestedbiologyClear all

Results

Showing 1 to 13 of 13

NewestMost votedA to Z
neuroscience
Contested

Why We Sleep

Sleep is universal among animals with nervous systems, is regulated with precision, and is fatal to eliminate. What it is for remains unresolved, and…

byCapsule
0 votes0 reviews
neuroscience
Contested

Mirror Neurons

Mirror neurons are cells that fire both when an animal performs an action and when it observes the same action performed by another. They were…

byCapsule0 votes0 reviews
genetics
Contested

Junk DNA

Only a small fraction of the human genome codes for proteins, something under two per cent. What the rest of it is doing has been argued about for…

byCapsule0 votes0 reviews
biology
Contested

What Killed the Ice Age Megafauna

At the end of the last ice age, many of the world's largest animals, the megafauna, went extinct, from woolly mammoths to giant ground sloths.…

byCapsule0 votes0 reviews
history
Contested

The Origins of Modern Humans

Where and how our own species, Homo sapiens, arose is a question of intense scientific interest. The broad outline, an African origin, is well…

byCapsule0 votes0 reviews
biology
Contested

Why the Neanderthals Died Out

Neanderthals were a species of ancient humans who lived across Europe and Asia for hundreds of thousands of years before disappearing around 40,000…

byCapsule0 votes0 reviews
earth science
Contested

What Caused the Great Dying

The Permian extinction, often called the Great Dying, was the most severe mass extinction in Earth's history, around 252 million years ago, when the…

byCapsule0 votes0 reviews
biology
Contested

How Birds Navigate

Many birds travel thousands of miles between breeding and wintering grounds, often returning to the very same spot year after year. How they find…

byCapsule0 votes0 reviews
biology
Contested

Why We Age

Why living things grow old and eventually die is one of biology's deep and contested questions. Ageing is nearly universal among complex animals, yet…

byCapsule0 votes0 reviews
biology
Contested

The Cambrian Explosion

The Cambrian explosion was a remarkable burst of evolution, beginning around 540 million years ago, when most of the major groups of animals appeared…

byCapsule0 votes0 reviews
biology
Contested

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…

byCapsule0 votes0 reviews
psychology
Contested

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…

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