Physics, Pixelated

A black hole shadow ringed by a bright photon ring, with its glowing accretion disk lensed around it

What Is the Photon Sphere, and What Did the Eve...

Near a black hole there is a radius where gravity bends light into a circle: the photon sphere, at r = 3GM/c² for a non-spinning hole. It is unstable, so...

What Is the Photon Sphere, and What Did the Eve...

Near a black hole there is a radius where gravity bends light into a circle: the photon sphere, at r = 3GM/c² for a non-spinning hole. It is unstable, so...

One glowing orb per step on a staircase beside many identical orbs piling into one bright pool

Fermions vs Bosons: What Is the Difference?

Every particle in nature is either a fermion or a boson. Fermions, like electrons and quarks, have half-integer spin and obey the Pauli exclusion principle. Bosons, like photons, have integer...

Fermions vs Bosons: What Is the Difference?

Every particle in nature is either a fermion or a boson. Fermions, like electrons and quarks, have half-integer spin and obey the Pauli exclusion principle. Bosons, like photons, have integer...

Pixel-art two-chamber box holding a single glowing particle, with heat rising as the bit is erased

Does Erasing Information Cost Energy? Landauer’...

Deleting a file feels free, but physics says erasing information has a minimum cost. Landauer’s principle puts it at kT ln 2 per bit, about 2.9 × 10⁻²¹ joules at...

Does Erasing Information Cost Energy? Landauer’...

Deleting a file feels free, but physics says erasing information has a minimum cost. Landauer’s principle puts it at kT ln 2 per bit, about 2.9 × 10⁻²¹ joules at...

Jupiter's moon Io slipping into Jupiter's shadow with light travelling to distant Earth

How Did Rømer Measure the Speed of Light with Io?

In 1676, at the Paris Observatory, Ole Rømer noticed that eclipses of Jupiter’s moon Io came late when Earth was moving away from Jupiter and early when it was approaching....

How Did Rømer Measure the Speed of Light with Io?

In 1676, at the Paris Observatory, Ole Rømer noticed that eclipses of Jupiter’s moon Io came late when Earth was moving away from Jupiter and early when it was approaching....

Pixel-art screen where single glowing dots build up into bright interference bands

What Is the Born Rule, and Why Is Probability |...

Quantum mechanics describes a particle with a wavefunction ψ, but experiments record definite clicks. The Born rule is the bridge: the probability of finding the particle is the squared magnitude...

What Is the Born Rule, and Why Is Probability |...

Quantum mechanics describes a particle with a wavefunction ψ, but experiments record definite clicks. The Born rule is the bridge: the probability of finding the particle is the squared magnitude...

Four coloured streams of force spiralling inward and converging on one brilliant knot of light

Is There a Theory of Everything, and What Would...

Physics has a tested theory for three forces and a separate one for gravity, but no accepted theory joining them. The graviton, gravity’s hypothetical carrier particle, has never been seen....

Is There a Theory of Everything, and What Would...

Physics has a tested theory for three forces and a separate one for gravity, but no accepted theory joining them. The graviton, gravity’s hypothetical carrier particle, has never been seen....