Why the nature of consciousness is such a difficult problem

The debate on why humans are conscious—and what that means

Understanding what consciousness is, and why and how it evolved, is perhaps the greatest mystery known to science. Watch interviews with the world's leading experts on what it is and whether we'll ever know.

Can physics explain where consciousness comes from?

Consciousness is a complex emergent phenomenon of the brain, which is primarily composed of neurons and glial cells. Since all matter is composed of atoms that follow the laws of physics, there may be quantum processes beyond classical electrochemical interactions that can explain where consciousness comes from.

Panpsychism suggests that all matter possesses consciousness

The theory describes consciousness as a fundamental, ubiquitous property, rather than separate or emerging from matter. Cosmopsychism posits that the universe is conscious, while some critics argue that consciousness itself may be an illusion.

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 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.

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.

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.

Would you opt for a life with no pain?

Philosopher Robert Nozick famously posed a question challenging the philosophy of hedonism—the idea that maximizing pleasure is the greatest good in life. His thought experiment imagined people could plug into a machine that would give total pleasure, suggesting the idea itself is not a compelling or desirable one. Learn the arguments and ideas in this short video.

Challenges for synthetic biology

Can engineering approaches tame the complexity and unpredictability of living systems? An exploration of five challenges for the field and how they might be resolved.

Meet the Dutch cardiologist who believes consciousness can exist outside the body

Dutch cardiologist Dr. Pim van Lommel conducted one of the largest studies of near-death experiences following cardiac arrest, publishing the results in the prestigous journel The Lancet. He later went on to argue (to significant criticism from peers) that his findings suggest consciousness can exist outside the body.

How does the cocktail party effect work?

In the 1950s, British cognitive scientist Colin Cherry started to explore how we could focus our hearing on one single source, even in a noisy environment. This video animation explains the phenomenon known as the cocktail effect and how selective hearing works. Discover how our brain is on the lookout for important or personally relevant information, even as we are occupied in other discussions.

Mathematicians often solve problems using wordless mental processes

It's a common technique among expert mathematicians, where thinkers rely on intuition, blurry perceptions and subconscious work—no writing, no formulas. The state is distinct from daydreaming, and often relies on sudden illuminations stemming from extended periods of subconscious reflection.

Understanding how gravity works at the quantum scale is physics's greatest challenge

While the theory of general relativity explains how gravity works and quantum mechanics explains interactions at the subatomic scale, the two frameworks contradict one another. Developing a model of gravity mediated by particles can help complete the Standard Model.

Anthropic's staff philosopher discusses the importance of teaching ethics to AI

Amanda Askell's work focuses on the behavior and values reflected in Claude, the company's AI chatbot, and how its character can better align with how the "ideal person" would act in Claude's position. She also emphasizes the importance of humans being ethical in their interactions with current models, from which future ones will be built.

What is it like to be a bee?

Scientists have long known the intimate features of bee anatomy: six limbs, five eyes, lots of hair, a long, tasteless tube -like tongue, and wings that stroke close to 12,000 times a minute. But getting inside the mind or consciousness of a...

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.

The neuroscience of heartbreak

An analysis of functional MRIs revealed a difficult fact: the active brain areas of people experiencing heartbreak were very similar to those actively in love. This is a major reason why people in the middle of rejection can't accept the reality of their loss. This article breaks down the various changes in neurotransmitters and neural pathways for those enduring that universal experience, heartbreak.

Engineer explains VR at five levels of complexity

While its possible to grab a virtual reality headset and hop into an immersive world with little effort, a significant amount of technical and biological science has gone into creating the effect of a 3D world. This video breaks down the technology in five layers of increasing complexity.

Less than 1% of people globally have schizophrenia, a syndrome strongly linked to genetics

Schizophrenia's causes remain largely unknown, though scientists suggest it's caused by multiple factors. Its symptoms include disruption of thought processes rather than the exhibiting of multiple personalities. This brief video provides an overview of the condition.

Noam Chomsky believed it might be possible to communicate with aliens

The father of modern linguistics argued that there is a genetic component to language, and that the ability to acquire and comprehend language is innate. If aliens existed, he believed they could potentially observe the same "universal grammar" rules as humans.

Take a quiz to identify whether you can spot deepfakes

Advances in artificial intelligence have made deepfakes increasingly difficult to identify, as they are intentionally designed to appear real. The technology has exacerbated some of the problems brought on by digital editing tools like Photoshop.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states

Unlike physical therapy, chiropractic lacks substantive, evidence-based support

Originating as a practice focused on removing blockages in the spine that impede the flow of mystical energy in the body, chiropractic has claimed to resolve many ailments, even those unrelated to the spine or skeletal system. However, no scientific studies have identified such blockages, and there are insufficient clinical trials supporting these treatments.

Apple CEO Tim Cook on what it takes to run the world's largest company

Apple CEO Tim Cook is a tough interview subject. He doesn't give many of them, and when he does it's often difficult to move him off of his talking points. In this interview for Dua Lipa's podcast, however, he opens up for a wide-ranging discussion about everything from artificial intelligence to the impact of technology on climate change—in addition to his own personal journey and his philanthropic endeavors.

Is conventional wisdom about amyloid plaques wrong?

Neurobiologist Karl Herrup makes the case for reevaluating current research paradigms and embracing a more comprehensive understanding of Alzheimer's disease. He highlights years of failed clinical trials of drugs reducing amyloid plaques in treating Alzheimer's, the establishment of that theory based on a single patient, and more.

The Constitution is difficult to amend

Amended just 27 times in more than 230 years, the US Constitution is deliberately hard to change. This animated video from TED-Ed explains why the amendment process is so complex and what that rigidity means in practice.

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

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

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.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

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

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

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.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

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

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

The concept of phantom limbs, the perception that amputated limbs are still present, dates back to a French military surgeon in the 16th century.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

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

Despite being favored by 87% of Americans, Congress does not have term limits.

Search a massive database of over 4 decades of clues from the TV quiz show 'Jeopardy!'

Warren Buffett's former professor Benjamin Graham is known as the 'father of value investing,' a strategy in which investors seek to buy stocks trading below their intrinsic worth.