Philosophy Science Psychology Society Culture

DonateNewsletterSIGN IN

Quantum theory

Essays and videos exploring physics, evolution, cosmology and other frontiers in science

Astronomy Biology Biotechnology Chemistry Complexity Computing and artificial intelligence Cosmology Deep time Earth science and climate Ecology and environmental sciences Engineering Evolution Genetics History of science Human evolution Human reproduction Illness and disease Mathematics Medicine Oceans and water Palaeontology Physics Quantum theory Space exploration

Explore more Science

Abstract colourful illustration showing various sections of a face and a black cat with lines and geometric shapes, from the perspective of someone peeing into a box.

essayPhysics

The cat that wouldn’t die

The weird paradox of Schrödinger’s cat has found a lasting popularity. What does it mean for the future of quantum physics?

Jim Baggott

Abstract photo of tree branches with a dreamy overlay of yellow and blue light creating a soft, ethereal effect.

essayMetaphysics

Many worlds, many selves

If it’s true that we live in a vast multiverse, then our understanding of identity, morality and even God must be reexamined

Emily Qureshi-Hurst

Abstract digital art of glowing, multicoloured clusters against a dark background, resembling molecules in space.

videoPhysics

Groundbreaking visualisations show how the world of the nucleus gives rise to our own

10 minutes

A digital painting of abstract shapes and lines featuring colourful spheres with light trails against a wavy background.

essayPhysics

Chasing ghost particles

Without the neutrino, the Universe might be an empty void. But this inscrutable particle isn’t giving up its secrets easily

Corey S Powell

Abstract artwork featuring geometric shapes, primarily red and black triangles, against a white background. Russian text is interspersed, with a red triangle pointing rightward and a large white circle on the right. Various smaller shapes and text elements are scattered around.

essayQuantum theory

Quantum dialectics

When quantum mechanics posed a threat to the Marxist doctrine of materialism, communist physicists sought to reconcile the two

Jim Baggott

A woman with brown hair wearing a dark blazer and light-coloured top is speaking, gesturing with her hand. The background is out-of-focus greenery.

videoCosmology

Tiny, entangled universes that form or fizzle out – a theory of the quantum multiverse

11 minutes

Simulation of particle cloud with a dense yellow centre and three green regions on a black background. Bright blue dot at the very centre.

essayQuantum theory

We are not empty

The concept of the atomic void is one of the most repeated mistakes in popular science. Molecules are packed with stuff

Mario Barbatti

Abstract depiction of two galaxies, one on the left with spiral arms and bright centre, and one on the right with swirling patterns and luminous core.

videoPhysics

There’s a striking link between quantum and astronomic scales. What could it mean?

5 minutes

Zigzag white line painted on tarmac road surface, with an adjacent grassy cobblestone strip on the left.

essayQuantum theory

Untangling entanglement

Why does the quantum world behave in that strange, spooky way? Here’s our simple, four-step explanation (no magic needed)

Huw Price & Ken Wharton

Illustration of a man crawling through two orange-framed mirrors, making it appear as if he is going in one and coming out the other.

essayQuantum theory

All possible worlds

Long a matter of philosophical speculation, the idea of multiple realities has been given new artistic licence by physics

Timothy Andersen

A moody seascape painting featuring a dark cliff on the right, a calm sea, and a starry night sky, all rendered in dark, cool blue tones.

essayQuantum theory

All is One

The ancient philosophy of monism and the physics of quantum entanglement agree: all that exists is one unified whole

Heinrich Päs

Two animated identical characters pointing at each other, one standing next to a table with sets of keys.

videoQuantum theory

Why aren’t our everyday lives as ‘spooky’ as the quantum world?

7 minutes

Abstract depiction of a wormhole with colourful galaxies and stars, connecting two black holes through a grid-like tunnel in deep space.

videoPhysics

The tangled tale of how physicists built a groundbreaking wormhole in a lab

17 minutes

A glowing black hole with a bright accretion disc in space, surrounded by stars and a distant planet against a dark, starry background.

essayCosmology

Cogitating black holes

The Universe cannot always be understood through observation. Instead, physicists explore by devising thought experiments

Michael Dine

Abstract artwork featuring two interconnected blue shapes, one with concentric circles and the other with a droplet-like form, against a beige background.

essayMathematics

Imaginary numbers are real

These odd values were long dismissed as bookkeeping. Now physicists are proving that they describe the hidden shape of nature

Karmela Padavic-Callaghan

A black and white photograph of a shattered mirror, reflecting a blurry building and trees under a cloudy sky.

essayQuantum theory

Quantum Wittgenstein

Metaphysical debates in quantum physics don’t get at ‘truth’ – they’re nothing but a form of ritual, activity and culture

Timothy Andersen

Illustration of a quantum computer’s cryogenic refrigerator, featuring multiple gold and black layers with cables extending downwards.

videoComputing and artificial intelligence

From ‘chandeliers’ to entangled qubits, here’s what happens inside a quantum computer

9 minutes

Man with blonde hair wearing a black jumper, gesturing with his hands, and speaking indoors with a painting in the background.

videoQuantum theory

Mind-bending new quantum experiments are blurring past, present and future

10 minutes

Two people walking past The Bank of New York sign, which reads “Founded 1784,” engraved on a stone wall.

essayEconomics

A softer economics

Financial markets are entangled and uncertain. When will economists let go of physics envy to embrace the quantum revolution?

David Orrell

Black-and-white photo of a man looking at a projector screen displaying scientific diagrams and symbols.

essayHistory of science

Calculate but don’t shut up

The cliché has it that the Copenhagen interpretation demands adherence without deep enquiry. That does physics a disservice

Jim Baggott

A stylised image of a starry sky with galaxies and stars on a bright pink and blue background.

videoPhysics

The Standard Model might be the most successful theory in science. But what is it?

16 minutes

A large, spherical room with golden reflective panels on walls, ceiling and floor, featuring a boat with people near the centre.

essayPhysics

The unified Universe

Physics displays an uncanny alignment at its very deepest levels. Is a grand theory of everything finally within reach?

James Wells

A man with glasses and a beard speaking, wearing a dark jacket and grey collar, with a blurred globe in the background.

videoPhysics

Time is fundamental, space is emergent – why physicists are rethinking reality

9 minutes

Black-and-white photo of a jazz band performing, with motion blur creating streaks of light from the saxophone player and other musicians.

essayQuantum theory

Quantum music

Physics has long looked to harmony to explain the beauty of the Universe. But what if dissonance yields better insights?

Katie McCormick