Live & interactive
Waterfall.
Spectrogram · micA full FFT waterfall, frequency across, time falling down, loudness in the palette. Point it at a stack and watch the sub-bass bloom.
Spectrum analyzer.
Signal · micLive microphone FFT on a log axis, room modes, tuning, and the mains hum you pretend not to hear.
The tuner.
A = 440Chromatic, play a note, the needle does the judging. Audio never leaves the browser.
Kármán vortex street.
CFDA live D2Q9 lattice-Boltzmann fluid shedding vortices past a cylinder, the Strouhal number, caught in the act.
Reaction–diffusion.
TuringGray–Scott: two reactants diffuse and react until spots, stripes, and coral emerge from noise.
Harmonograph.
LissajousTwo frequency ratios, four damped pendulum swings. Signal processing that thinks it's jazz.
Pharmacokinetics.
Half-lifeSteady-state accumulation for repeated dosing, where the drug piles up, and when it stops.
Buffer pH.
Henderson–HasselbalchpH from pKa and the conjugate base/acid ratio, or solve the ratio for a target pH.
Dilution & molarity.
Bench mathC1V1 = C2V2, or grams to molarity. Leave one field blank (or 0); I solve for it.
Dimensionless numbers.
TransportThe ratios that run the universe, pick one.
Engineer's converter.
UnitsPressure, temperature, flow, viscosity, the ones that actually come up.
Sound & space.
AcousticsFrequency ↔ note ↔ wavelength, and your room's first standing waves.
Below the waterline.
OpticsPressure, light, color, gas, and time, the physics of a dive.
Chasing light.
SolarSunrise, sunset, and golden hour for any spot on Earth.
Depth of field.
OpticsHyperfocal distance and the sliver of the world that lands sharp.
Espresso dial-in.
CFD dept.Enter a shot; get ratio, flow, and what to change next.
The cooling curve.
ThermoNewton's law of cooling, when is it actually drinkable?