The Hidden Geometry of a Rainbow
Every raindrop bends and bounces sunlight into a cone exactly 42 degrees wide. That single angle explains the arc, the order of the colors, and why you can never reach the end.
- Waves & Light
The garden
Documents
Living documents we keep tending, revising, and growing.
16 documents
Why the Sky Is Blue (and Sunsets Aren't)
Air scatters blue light far more than red, so the daytime sky glows blue and the setting sun, seen through more air, turns red. The same physics, two times of day.
- Waves & Light
A Field Guide to the Light You Can't See
Every colour you can see is a thin slice of one vast family of waves — and most of the family is invisible, passing through the room right now. A field guide to the light you can't see.
- Waves & Light
Where a Soap Bubble Gets Its Colors
Soap is colourless and so is water, yet a bubble swirls with every colour there is — none of it painted on. The colours come from something stranger than a prism.
- Waves & Light
Why You Can See Through Glass
Glass is a dense solid, yet light crosses it untouched. Not because light finds the gaps — because visible light has no allowed energy rung to spend itself on, and so is never absorbed at all.
- Waves & Light
- Quantum Physics
Measuring the Speed of Light With a Microwave and Chocolate
A genuinely doable kitchen experiment: melt chocolate in a microwave with the turntable off, measure the gaps between hot spots, and recover the speed of light to within a few percent. Full method, data, and error budget.
- Waves & Light
How a Laser Gets Its Light to March in Step
A laser isn't just a brighter, tidier flashlight. It's light doing something ordinary light never does — moving in perfect lockstep — and Einstein predicted the trick forty years before anyone built one.
- Waves & Light
- Quantum Physics
Resonance
Push a swing at the right moment and it climbs on a whisper. The same trick tunes a radio, photographs your knee, and shatters a wine glass with a note — and it is not what wrecked the Tacoma Narrows Bridge.
- Waves & Light
A Field Guide to Brain Waves
Delta, theta, alpha, beta, gamma — the brain hums at different frequencies depending on what it's doing. A guide to the rhythms an EEG picks up, and what each one means.
- Neuroscience
- Waves & Light
Reading a Star's Temperature in Its Color
Blue stars are scorching, red stars are cool — the opposite of the kitchen tap. The color of a star is a thermometer you can read with your naked eye, and it's the same physics as a glowing coal.
- Astronomy
- Waves & Light
What the Sun Is Really Made Of
For decades astronomers assumed the Sun was built of much the same elements as the Earth. A twenty-five-year-old's 1925 thesis proved it is almost entirely hydrogen — and she was pressured to call her own result wrong.
- Astronomy
- Waves & Light
The Most Famous Failed Experiment
In 1887 two Americans built the most precise instrument on Earth to catch the wind of the aether — and found nothing at all. The nothing broke physics, and a century later the same design heard two black holes collide.
- Relativity & Gravity
- Waves & Light
The Double-Slit Experiment, One Particle at a Time
Fire electrons one by one at two slits and an interference pattern still appears — as if each electron passes through both. The experiment Feynman called the heart of quantum mechanics.
- Quantum Physics
- Waves & Light
Wave or Particle? Yes.
Light behaves like a wave until you ask it to behave like a particle, and matter returns the favor. Duality isn't a paradox so much as a warning that our two words are too small.
- Quantum Physics
- Waves & Light
The Discovery That Won Einstein His Nobel
Not relativity — a humble experiment about light knocking electrons out of metal. It forced physics to accept that light comes in particles, and it explains the solar panel on your roof.
- Quantum Physics
- Waves & Light
Why a Passing Siren Drops in Pitch
The falling pitch of a passing siren is the same trick we use to weigh unseen planets and clock fleeing galaxies. Why the change lives in the space between you and the source, never in the source itself.
- Waves & Light
- Astronomy