Browse

Why one day on Mercury lasts two Mercury years Mercury circles the Sun in 88 Earth days and spins once every 58.6 days. That odd pairing, three spins for every two orbits, means one sunrise to the next… Earth & Space3 min read4 Oct Why a 660-tonne steel ball swings to keep Taipei 101 still Skyscrapers sway in the wind, and gusts that match the tower's own rhythm can make it sway more and more. Taipei 101's answer is a 660-tonne steel pendulum… Engineering4 min read3 Oct Egg yolk sets at a lower temperature than the white. So why is it runny? An egg yolk sets at about 70 °C. Most of the white needs about 80 °C. So why does a soft-boiled egg come out with a firm white and a runny yolk? Because… Food Science4 min read2 Oct How honeybees give directions by dancing in the dark A honeybee that finds good flowers can tell her sisters where they are, inside a pitch-black hive, by dancing. She runs in a straight line while shaking her… Biology5 min read2 Oct Earth is closest to the Sun in January. So why is that winter? Summer can't be caused by being closer to the Sun: Earth makes its closest pass around 3 January and is farthest around 4 July. The distance changes by only… Earth & Space4 min read29 Sep Why Spanish sounds faster than Vietnamese yet says just as much Listen to Spanish or Japanese and it seems to rush past; Vietnamese or Thai can sound almost unhurried. Yet when researchers timed 170 people reading the same… Language5 min read29 Sep Why some notes sound sweet together and others seem to fight Play C and E together and they sound sweet. Play C and C sharp and they buzz. The notes aren't the problem: the clash only happens when they meet. Every… Music & Sound5 min read28 Sep Why astronauts float: the space station never stops falling Astronauts on the International Space Station look weightless, but at 400 km up, Earth's gravity is still about 90% as strong as on the ground. The trick is… Earth & Space4 min read28 Sep Why the sky is blue and sunsets are red: it's the same light The blue sky and the red sunset are the same effect, seen from two angles. Air molecules scatter short, blue wavelengths far more than long, red ones: about… Physics4 min read27 Sep Why Mars sometimes walks backwards across the sky Every 26 months or so, Mars slows down, stops, and drifts backwards against the stars for a couple of months before carrying on. Ancient astronomers built… Earth & Space4 min read27 Sep Why the most common words are the shortest: Zipf's two laws of language Count the words in almost any long text and a strange pattern appears: the most common word turns up about twice as often as the second, three times as often… Language5 min read26 Sep Why English spelling doesn't match how words sound Around 1400, English spelling roughly matched speech. Bite sounded close to "beet", meet roughly like "mate", and house like "hoose". Then, over about three… Language5 min read26 Sep