For most of recorded history dreams were considered divine in origin.

The earliest record of dream interpretation dates to Ancient Sumer, an analysis of a Sumerian priest king's dream around 2700 BCE.

Dreams have long been used for religious and political power.

What do your dreams mean, according to science

Humans have been interpreting dreams as signs from deities, spirits, or the psyche for ages, and research shows that reflecting on and analyzing one's dreams can be beneficial. In alignment with dreams' elusive nature, they have no objective or clearly assigned meaning. However, variations of common dreams, such as a surprise exam in a forgotten class, are rife with shared primal fears.

The study of dreams, formally called oneirology, has evolved over the centuries, from anecdotal interpretations to advanced brain imaging.

Dream interpretation has evolved from ancient mystical explanations, to dream reports, to tracking electrical activity in the brain and more.

Famed psychologist Sigmund Freud believed dreams were symbolic expressions of desire.

The dreaming brain, as understood by scientists

Technology has advanced to where the seemingly separate fields of psychology and neuroscience are asking the same questions about dreams, such as whether they're more closely related to perception or visualization. Some field-intersecting findings include research that shows people with impaired face perception don't dream of faces, those with brain legion-related cognition difficulties deal with similar issues in dreams, and children's dreams change in parallel to their cognitive development.

Visualizing how we dream via Google search trends

When dreams perplex us, we often want to understand them—and in the age of Google, millions go to its search engine to find answers. Now, researchers have compiled a decade's worth of dream-related queries to glean dream trends across seven languages. See what dream was most commonly searched in Arabic in 2015, or what fears and hopes are specific to one culture and time alone with this unique visual essay.

Humans have speculated about alien life since ancient times

Around 50 B.C.E., Roman poet and philosopher Lucretius shared the idea that alien life was possible, which was put forth by Greek philosopher Epicurus. The writing is believed to be the first straightforward assertion in Western literature that aliens must exist.

Dreaming under the Nazi Regime

Days after Hitler seized power, a man told psychoanalyst Charlotte Beradt that he had dreamed of being forced to raise his arm in a Nazi salute ("It took me half an hour to get my arm up, inch by inch"). Beradt recorded this dream and many others so they "might one day serve as evidence." This is an English translation of her work, "The Third Reich of Dreams."

Philosophers have debated the nature of time since at least the 6th century B.C.E.

Greek philosopher Parmenides of Elea was skeptical of time and reasoned that if it were real, then the present would emerge from nothing because the future did not yet exist. Just as the color red is our perception of a specific wavelength of light, others have suggested time is a psychological projection based on how we interpret the world.

Studies of psychedelic use may help shed light on the nature of consciousness

The nature of consciousness—what it is, where it comes from, and how it manifests as moment-to-moment experience—remains under debate by scientists. Recent studies show psychedelics were found to boost low-frequency brain signals known as delta waves, a behavior also seen during dream states.

The earliest mention of time travel

Time travel has fascinated humans for centuries. It appears in myths, literature, and science fiction. One of the earliest examples comes from the 400 BCE Hindu epic Mahabharata, describing time dilation long before Einstein’s Theory of Relativity. By the 19th century, stories introduced machines enabling time travel—setting the stage for modern sci-fi.

Carl Jung proposed the controversial idea of the 'collective unconscious'—all humans share a common psychic realm.

Near-death experiences have been reported across cultures across for millennia

This collection of ten of the earliest recorded NDEs gives an idea of how pervasive the phenomenon really is. Stories range from ancient Greek philosopher Plato telling the story of a soldier named Er to a first-century Japanese monk who claimed to have visited both heaven and hell.

Wilhelm Wundt's place in the history of psychology

While ancient philosophers considered the central problems of psychology, it was Wilhelm Wundt who first called himself one. Here's a quick video overview of his contribution.

Pareidolia, the cognitive bias that leads people to find meaning in randomness, helps explain why humans look for meaning in their dreams and even in their tea leaves.

Scholars trace existential anxiety back to early Hebrew scriptures

Paul Megna, a scholar of literature and philosophy, notes that the existentialist ideas of Kierkegaard (and, to a lesser extent, Sarte and Camus) had their roots in much earlier texts, which posited that "fear of the Lord" was "the beginning of wisdom."

The ancient Greeks and Romans viewed comets and meteors as divine omens

Both considered the appearance of a comet or its fragments as a precursor to significant events, such as the birth of a notable figure or the death of a ruler. One observed in 44 BCE was believed to be a sign of the deification of Julius Caesar after his assassination.

Wealthy Egyptians slept on woven beds to allow air circulation in hot climates

The history of beds is a fascinating look at economics, social science, and cultural beliefs around what takes place during sleep. This brief survey of the history of bed-making begins roughly 5,000 years ago and runs through ancient Egypt and Rome to modern Europe. Take a look here.

The prophetic Oracle of Delphi held real power in ancient Greece

It was said to have a direct line to Apollo, the Greek god of various domains, including music and prophecy. The oracle was believed to be the most important job in the city and could only be held by women. After years of training, oracles-to-be would be assessed to see if they could become the Pythia—the single oracle who would communicate Apollo's will.

The scientific name for northern lights came from two Greco-Roman gods

Although cave paintings may have depicted them millennia earlier, one of the oldest known references to auroras is a Babylonian cuneiform tablet from about 600 BCE. In 1619, Galileo Galilei named the phenomenon in the northern hemisphere "aurora borealis" after the Roman goddess of dawn—Aurora—and the Greek god of the north wind—Boreas.

How seizures (potentially) alter consciousness

Seizures occur when intense electrical activity floods the brain, prompting significant loss of self-control and a variety of sensory disruptions and hallucinations. Cultures interpret the episodes differently, with many contemporary norms viewing them as negative while others characterize them as intense spiritual occasions. Author Fyodor Dostoyevsky viewed his seizures this way, as well as cultures in Mongolia, some Shamanic indigenous religions, and others.

Ancient Greece originated roughly 4,000 years ago around the Aegean Sea

From architectural feats to the Western alphabet, ancient Greece has helped shape modern life. Over centuries, the eastern Mediterranean culture grew as far as India, Egypt, and Spain. Its cultural influence has long since spread beyond any physical boundaries.

Analysis finds dementia was rare in ancient Greece

Ancient medical texts seldom mention severe cognitive decline, suggesting that such conditions were uncommon. This scarcity is attributed to factors like shorter lifespans and active lifestyles, implying that modern environmental and lifestyle changes—along with longer life expectancy—contribute to the current prevalence of dementia.

The 'definitive' history of magic mushrooms

Where did magic mushrooms come from, and how did they get their magical reputation? This article explains the history of the psychedelic fungi from pre-history to now. The earliest concrete evidence of psychedelic mushroom use is 12,000-year-old murals in Northern Australia that portray mushroom iconography. Considering how many species seek out and consume psychoactive substances, such as Siberian reindeer, it's possible human use of these psychedelic mushrooms may predate these murals.

Miracles versus magic: How early Christians distinguished their beliefs from pagan ones

This in-depth article describes how early Christians attempted to differentiate their beliefs and rituals from those that came before. One major difference? Demons. For pagans, demons could be good or bad, occupying the middle ground between gods...

A 2,000-year history of alarm clocks

Clocks have revolutionized the way we live, structuring our days into abstract, regular units and providing quantification for those who are chronically late. The alarm clock was the next obvious step: clocks which not only tell you the time but...

Who was the world's first author?

This article details the effort to define the world's first author, as supported by current archaeological evidence. Clay disks found in an ancient Sumerian city point to Enheduanna, a high priestess and daughter of Akkadian King Sargon, as the...

Why human brains were bigger 3,000 years ago

Our modern civilisation may be the most advanced to ever exist on Earth, but around 100 generations ago, our ancestors had brains that were larger than our own.

In 1968, a Harvard Medical School committee issued the first neurological definition of death

The definition set a legal and medical precedent for how we define death, important for issues including organ donation. This 2020 video podcast discusses the history of brain death controversies and the variability in how death has been determined, including discussions in the late 1960s about when patients are considered dead in the context of organ donations.

Enlightenment ideals of reason informed the foundation of the Revolution

From the 17th to 19th centuries, an intellectual movement took place in Europe and its colonies that emphasized reason over authority. Following the Scientific Revolution, thinkers like Descartes, Kant, and Locke sought to explain the world in rational—rather than religious—terms. The movement caused a paradigm shift in how societies are organized and how people perceive themselves.

For most of human history, property rights were in the elite’s hands

Humans learned to domesticate dogs long before they formed the concept of private property. But by the era of the ancient Greeks and Romans, property law and ownership became more sophisticated.

'Those who dream by day are cognizant of many things which escape those who dream only by night.'

- Edgar Allan Poe (1809-1849) in "Elenora"

Environmental determinism links human traits and societal progress to geography

Also known as climatic determinism, the theory states that the latitudes where people are located influence their emotional and intellectual capabilities. Originating in Ancient Greece, these ideas were used throughout history to justify racial hierarchies.

Horror evolved from Gothic literature

Although creepy tales can be found in nearly every folk tradition, the roots of modern horror can be traced back to Gothic literature, which focused on the battle between humans and unnatural, evil forces.

The history of blood, as told by a hematologist

Since ancient times, blood has been seen as a semi-magical substance. Alchemists theorized it was a mixture of the four elements. Others proposed it was one of four bodily fluids whose balance dictated health. This 2019 essay by a hematologist reviews blood's reputation across cultures and centuries.

Who was Salvador Dalí?

Salvador Dalí reshaped modern art with surrealism, symbolism, and eccentricity. This snapshot covers his rise from Spanish prodigy to global icon, his Surrealist break, and his fascination with dreams and celebrity.

Humans have used geothermal resources for thousands of years

In North America, Indigenous peoples viewed hot springs as sacred places and used them for medicinal purposes, cooking, and surviving cold weather. The ancient Greeks and Romans also viewed them as sacred, partaking in hot mineral baths to relieve ailments and using them for space heating.

Synesthesia: when sensation in one sense triggers an unrelated sense in the brain

The first reported clinical case of synesthesia dates back to the early 1800s, though the perceptual phenomenon may be much older than surviving records imply. This article by researcher Richard Cytowic details the scientific history of synesthesia, a neurological trait that causes some senses to overlap, giving color to numbers and flavors to names.

Some founders of quantum mechanics thought consciousness could influence phenomena

Since quantum systems exist as a superposition of states before producing a definitive outcome, some quantum pioneers wondered if the act of conscious observation was what collapsed the wave function of possibilities into one state.

Food allergies were first documented more than 4,000 years ago

Although food allergies are on the rise in modern times, they have been documented in written records for thousands of years. More than 3,000 years ago, Chinese emperors advised patients to avoid certain foods, and Hippocrates noted in his work that food could cause serious harm to certain individuals, and even lead to death.

Meet Hipparchus, the Greek astronomer who created the world's first star map

Astronomer Hipparchus created accurate maps of the night sky way ahead of his time, with coordinates sometimes within a single degree of modern values. Hipparchus founded a new theory of star motion, modeling the sky as a celestial sphere with coordinates similar to latitude and longitude—concepts only recently created in Hipparchus' time.

When did humans start kissing romantically?

This article explores the ancient roots of romantic kissing. Current archaeological evidence dates sexual and romantic lip kissing to about 2,500 BCE. A Mesopotamian clay tablet from the time shares a tale of two deities locking lips. There's also...

A brief history of drones

While accounts of military strategists using uncrewed hot air balloons for attacks and surveillance exist from the 19th century, the first use of drones as a modern concept began in World War I with a radio-controlled propeller craft. This online...

The word ‘fantasy’ wasn't used to describe the genre until the 20th century

The word—at least as a word used to describe fiction—didn’t appear in the Oxford English Dictionary until 1949. Scholars believe that’s due to the arrival of the Magazine of Fantasy and Science Fiction, an influential publication, and the rise in fantasy’s popularity following World War II.

Critic Harold Bloom believed Shakespeare invented the modern human

Yale critic Harold Bloom believed the Bard transformed the way humanity understood itself, a thesis laid out in his book "Shakespeare: The Invention of the Human."

The Ouija board originated in 19th-century America

The bizarre board game that helps people communicate with the dead at sleepovers first emerged in the 19th century as a business-minded response to the growing fascination with spiritualism. The Ouija Board has since generated an abundance of sales, as well as scientific research.

A Belgian Catholic priest was the first to come up with the idea for the Big Bang

In 1931, Georges Lemaître presented his radical idea that the universe came from a “primeval atom,” challenging the long-held belief that the universe had always existed. Einstein initially dismissed Lemaître’s work as having “abominable” physical insight, only to accept it later.

An 1893 speech in Chicago set the stage for yoga in the US

Swami Vivekananda, a Hindu monk, spoke to the World’s Parliament of Religions, addressing those in attendance as his “sisters and brothers of America.” The speech—and Vivekananda’s subsequent lecture tours—introduced many in the West to Hinduism, setting the stage for the interest in yoga that would follow in the next century.