Hear Carl Sagan reflect on the smallness of humanity

A scale of the universe, from atoms to cosmos

Can you really appreciate just how small protons are, or how massive the universe is? To attempt to grasp it, watch this short video which zooms out from a young woman in California to the very limits of the cosmos using established scales. Then, dive deep into the atoms of her white blood cells for a fully-rounded effect.

Explore our favorite visualization of the immense scale of space, from an astronaut to the size of the observable universe

Stephen Hawking on the need to explore space

Should we be content with being cosmic couch potatoes? In this interview, the late Professor Stephen Hawking lays out the case for continued and increased human space exploration, despite its cost and challenges.

'On the return trip home, gazing through 240,000 miles of space toward the stars and the planet from which I had come, I suddenly experienced the universe as intelligent, loving, harmonious..'

-Apollo 14 astronaut Edgar Mitchell, in "The Way of the Explorer"

Carl Sagan, the host of 'Cosmos,' gave Bill Nye advice on his future show

Originally wanting to lean into his engineering background to explain the workings of objects such as bicycles and bridges, Nye ran his idea past his former professor at a college reunion. Sagan told him that children resonated with pure science, not technology, altering the show's future topics.

'The more clearly we can focus our attention on the wonders and realities of the universe about us, the less taste we shall have for destruction.'

- Marine biologist and environmentalist Rachel Carson (1907-1964)

Imagining a fourth dimension

Famous astronomer Carl Sagan attempts to describe what it's like to think about the fourth dimension using the famous Flatland example from author Edwin Abbott in this classic video.

The world, one year after humanity goes extinct

The Earth is so shaped by human action, it's hard to imagine what it would look like without us. This brief, digestible explainer for kids highlights what a humanless world would look like one year after the extinction event.

How the ancients calculated Earth's size correctly

Watch this seven-minute video to hear Carl Sagan explain how ancient Greek polymath Eratosthenes correctly calculated the size of the Earth in the third century BCE. At some point, Eratosthenes noticed a discrepancy in the length of shadows cast in different cities during the summer solstice. This observation grew into a simple experiment that enabled Eratosthenes, the head librarian at the Library of Alexandria, to calculate the Earth's size precisely.

Building the solar system to scale in the Nevada desert

On a dry lakebed in Nevada, a group of friends build the first scale model of the solar system with complete planetary orbits: a true illustration of our planet's humble position in space.

Will AI kill us all? A debate

As AI becomes a bigger part of our lives, what does that mean for the future of humanity? The podcast Entanglements hosts a pessimistic former OpenAI employee and an optimistic Princeton professor to discuss whether AI brings dystopia or a brighter future.

Depending on environment, aliens' bodies would have wide-ranging possibilities

Humans tend to imagine aliens as humanlike, but that's probably unlikely. From small space spiders to metallic carnivores, life on other planets—and how we could interact with it—is difficult to imagine.

John Steinbeck's philosophical ideas, which he often explored in his novels, wrestled with the role of the individual and the power of community.

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.

The science of dogs, from wolf origins to color-blindness

This under 10-minute podcast episode dives into the rich, fascinating science behind dogs: From their world-class sense of smell to their domestication from wolves.

What the stars once meant to ordinary people

The stars were a crucial aid for ordinary human beings in premodern societies, acting as regular timekeeping phenomena and celestial navigators. Today, light pollution and modern technology have rendered the stars a mere aesthetic delight for most of us, but their significance in history remains. Watch this brief video to learn how premodern humans used the stars for navigation, mathematics, and more.

David Attenborough discusses creationism and his position as an agnostic

Attenborough argues that accounts of humanity's origins from different cultures cannot all be correct because they often differ, whereas geological records are consistent worldwide, meaning science provides the best understanding of the natural world. However, he acknowledges that, just as insects lack awareness of human goings-on, humans may be unaware of the existence of a deity.

Watch the full broadcast of humanity's first walk on the moon

On the night of July 20, 1969, Neil Armstrong stepped down the lunar module's ladder onto the moon's surface. The broadcast was watched by an estimated 650 million people—about a fifth of the then global population.

'Few will have the greatness to bend history itself, but each of us can work to change a small portion of events, and in the total of all those acts will be written the history of this generation.'

- Senator Robert F. Kennedy (1925–1968)

Language is evolution's great mystery

What we call language is something more specific than communication. Language is about sharing what’s in our minds: stories, opinions, questions, the past or future, imagined times or places, ideas. So what does language mean for humanity, and how did we come to have it? Watch this brief video to discover more.

Existentialist writer Jean-Paul Sartre coined the famous phrase 'Hell is—other people' in his play 'No Exit'

What is galactic archaeology?

In the same way that archaeologists excavate and analyze artifacts of human civilization, galactic archaeologists observe the light in the universe to glean lessons on its age, evolution, and more. Learn about this niche area of study with this 10-minute podcast.

'And I knew that it was better to live out one's absurdity than to die for that of others.'

-Ralph Ellison, from "Invisible Man" (1913-1994)

Supermassive black holes create pressure waves, detectable as extremely low sounds

Space is largely silent because it lacks a medium for sound waves. Some Mars rovers capture sounds of wind, though the sounds are too low to hear. Through sonification, astronomical data can be translated into hearable sounds for broader engagement.

'We are all in the gutter, but some of us are looking at the stars.'

- Playwright Oscar Wilde (1854-1900)

'Our Towns' offers a portrait of civic life in smaller cities in America

Based on the book of the same name by journalists James and Deborah Fallows, the 2021 documentary follows the pair as they travel across small and mid-sized American cities to show how communities handle economic setbacks and reinvent themselves locally.

A student researcher working on the Human Genome Project shares their perspective

In a conversation with Ewan Birney, Director of the European Bio-informatics Institute, he discusses what it was like to be a PhD student working on the Human Genome Project in the months before the draft announcement and its impact on him and the field of genetics.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Apeirophobia is an overwhelming fear of living forever, perhaps stemming from the brain's inability to conceptualize an infinite life.

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

Famed poet TS Eliot rejected the manuscript for George Orwell's political fable 'Animal Farm,' writing that its criticism of authoritarianism was not 'the right point of view.'

Hear about the 250-year history of the United States Postal Service, complete with some of its strangest deliveries, important innovations, and the figures that made it an American institution.

This site reaches millions of visitors who are tired of AI chatbots and seeking human connection. Pretend to be an AI chatbot and ask questions, provide answers, and draw for people in real time.

SpaceX's S-1 or 'prospectus' revealed many previously unknown details about the company, including its unprofitability despite doing $18.7B in revenue in 2025, exactly how many voting shares Elon Musk will have in the company (roughly 85%), and more.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

Watch a 1934 short film starring jazz legend Cab Calloway, a major figure in the Harlem Renaissance's music scene

Exploring the Larry Bird punch that almost changed March Madness

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

The tragic Pulitzer Prize-winning image 'The Vulture and the Little Girl' (1993) generated controversy, raised concerns about ethics in photography, and eventually led to the photographer's death.

The animatronic shark from Steven Spielberg's 'Jaws,' the first modern blockbuster, was a complex underwater apparatus called 'Bruce.'

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people