Mood
Time spent here is not time wasted.
502 sites · page 11 of 11
Live safari drives broadcast twice a day from South African reserves, with guides answering viewer questions over the radio as they go.
Answers computed rather than retrieved: integrals, unit conversions, orbital mechanics and the nutritional content of a Mars bar.
Thousands of interactive maths and science notebooks contributed over two decades, each one a single slider-driven idea.
Six goes at one five-letter word, the same word for everybody, once a day. The puzzle that spawned an entire genre in three months.
A dictionary showing real usage, related words and examples pulled from the wild rather than agreed by committee.
Readings from thousands of air monitoring stations worldwide on one map, colour-coded from a calm green to a genuinely alarming maroon.
Free indicators for every country going back decades, with charts, maps and bulk downloads on each series.
Plain map and flag quizzes covering every continent, aimed at classrooms and quietly excellent for adults as well.
The free, open-source answer to GeoGuessr, with unlimited rounds, a daily challenge and multiplayer that costs nothing.
Guess the country from its silhouette alone, with each miss handing you the distance and compass bearing to the real answer.
Live counters for population, emissions, water use and books published, ticking faster than is entirely comfortable.
A browser planetarium stitched from real survey data, letting you pan the whole sky in visible light, infrared or radio.
Modern MUD platform with a proper browser client: play the hosted worlds, or build one yourself without touching a server.
Drag a hundred colour chips into one perfect gradient. The score tells you how good your colour vision actually is.
Real-time fractal zoomer ported to the browser, smooth enough that the boundary keeps unfolding as fast as you dive.
Recordings of very nearly every bird call on earth, uploaded by amateurs and searchable by species, country and even call type.
Stick figures on romance, sarcasm, maths and language, with a second joke in the alt text of every single strip.
Nonprofit solutions journalism on climate, housing and democracy — more sober than cheerful, but pointed the same way.
The moral foundations questionnaires run by the psychologists who published them, plotting you against the wider research sample.
The same deep management sim rebuilt for American football, baseball and hockey, all free and all running in the browser.
Two minutes of mental arithmetic at whatever difficulty you set, boiled down to a single number. Trading desks drill on this one.
Real research that needs human eyes: classify galaxies, transcribe ships' logs or count penguins, and end up in a published paper.
One button, one detour. Press it as often as you like.