Physics

The Mpemba Effect: Can Hot Water Freeze Faster?

Under some conditions, hot water seems to freeze faster than cold. Explore the Mpemba effect and a genuine, unresolved puzzle in physics.

The Physics of the Rainbow

A rainbow is sunlight, rain, and geometry combined. Explore the physics of the rainbow and why it always appears as an arc.

The Science of Rust: The Slow Burning of Metal

Rust is a slow chemical reaction that consumes iron. Explore the science of rust, why it forms, and why it is so destructive.

Why the Moon Causes the Tides

The Moon's gravity raises the ocean tides—but the explanation is subtler than it seems. Explore the real science of why the tides rise and fall.

The Doppler Effect: Why a Passing Siren Changes Pitch

A passing siren drops in pitch as it goes by, though its sound never changes. Explore the Doppler effect and its reach from sirens to the stars.

Why Mirrors Seem to Reverse Left and Right

A mirror seems to swap your left and right, but not your top and bottom. Why? Explore the genuinely tricky physics of mirror reflection.

Surface Tension: Why Some Insects Can Walk on Water

Water behaves as though it has an invisible skin. Explore surface tension and how it lets small insects walk across a pond.

Why Metal Feels Colder Than Wood

A metal spoon and a wooden one in the same room feel different temperatures— but they are not. Explore thermal conductivity and the science of feeling cold.

The Science of Static Electricity

The shock from a doorknob and the cling of laundry share one cause. Explore the science of static electricity and the movement of charge.

Why Ice Floats: The Strange Density of Water

Almost every substance is denser as a solid than as a liquid—but not water. Explore why ice floats and why this oddity matters for life.

Sound Localization: Why We Have Two Ears

With two ears, the brain can pinpoint where a sound comes from. Explore sound localization and the tiny time differences the brain decodes.

The Science of Color Vision: How the Eye Builds Color

Color is not a property of the world but a creation of the mind. Explore the science of color vision and how the eye builds color from just three signals.