A blowout preventer failed to stop the Deepwater Horizon well
A blowout preventer is a seabed stack of valves built to seal a runaway well. On Deepwater Horizon in 2010 it failed. A capping stack later stopped the flow.
kind archive
Explainer.
Every explainer in the edition.
How a breeder reactor makes more fuel than it burns
A breeder reactor turns leftover uranium into plutonium fuel. The US Department of Energy says recycling it could need 100 times less uranium.
A 1606 English law turned a foiled plot into Bonfire Night
A 1605 plot to blow up parliament led to a 1606 law making 5 November an annual celebration, which stayed on the books until 1859.
How a 1992 law turned Britain's polytechnics into universities
The Further and Higher Education Act 1992 gave 34 British polytechnics degree-awarding powers, ending a divide that had run since 1965.
Australia's School of the Air: outback lessons by phone
Mount Isa's School of the Air teaches outback children scattered across 800,000 square kilometres by radio, then satellite phone, in daily lessons.
Houthi attacks pushed global shipping around Africa
Houthi attacks in the Red Sea led the biggest container lines onto the longer route around Africa. It adds 10 to 12 days and about $1m in fuel per ship.
Arm position matters more than which arm for blood pressure
Which arm barely changes a blood pressure reading. How you hold it can shift the systolic number by more than 6 points, a Johns Hopkins trial found.
A 30-point credit score rise can cut a US mortgage rate
US mortgage lenders price conventional loans in 20-point credit score tiers. A 30-point rise can cut the rate by 0.25 percentage points or more.
Half the mining power lets one party rewrite a blockchain
A miner with more than half a blockchain's computing power can build a longer chain, undo its own payments, and spend the same coins twice.
A major book prize does not always lift sales
Winning a major literary prize can send a novel back to press within a day, but publishers say the sales lift is unpredictable and sometimes negligible.
Play style decides how long a game takes to beat
Play times for the same game vary widely. IGN, Kotaku and Eurogamer timings show why: side content, difficulty, and in-game deadlines.
Cheap Broadway tickets: rush, lottery and standing room
Rush seats cost $40 to $53 at the shows checked. Lotteries open the day before, and standing room goes on sale only for sold-out shows.
Neolithic builders aligned monuments to the solstice sun
Two wooden posts near Stonehenge may be the earliest solar sightline there. Later Neolithic tombs and stones caught the solstice sun too.
Parish birth books gave way to civil records from 1837 to 1878
Civil registration replaced parish records at different times: 1837 in England and Wales, 1855 in Scotland, 1864 in Ireland, 1878 in Jamaica.
Delays sent the first nuclear reactor to a Chicago squash court
Arthur Compton moved the reactor under Stagg Field in 1942 after the planned site stalled. Enrico Fermi's team then ran the first chain reaction.
Fei-Fei Li built ImageNet while her field doubted data
Colleagues told Fei-Fei Li her plan to label 14 million images went too far. Three years after its release, it helped set off the deep learning boom.
The 1982 Falklands war left who owns the islands unsettled
The 1982 war restored British rule over the Falklands, but it left Argentina's claim to the islands exactly where the fighting found it.
The obituary said to inspire the Nobel Peace Prize is unproven
Alfred Nobel's will funded a prize for peace. The obituary usually credited for it traces to a French newspaper nobody has verified.
A dual-flush toilet saves water with one valve, not two
A dual-flush toilet releases four litres or six through a single drop valve rather than two tanks, and that valve is also where leaks begin.
Congress counts the votes that name the next US president
Every four years Congress opens the sealed electoral votes, counts them in one joint session, and reads out who won. Here is how that day works.
Chile's flat school voucher sorted pupils by family income
Under Pinochet, Chile paid every school one flat voucher per pupil. Researchers found it rewarded schools for enrolling wealthier families.
A.S. Neill let his pupils choose whether to go to lessons at all
At Summerhill School in Leiston, lessons have been optional since 1921. Ofsted called the approach a failure, but inspectors in 1949 praised it.
Forty-eight teams, one trophy: how the World Cup runs
The men's World Cup takes 48 teams through 12 groups. The top two in each, plus the eight best third-placed sides, enter single-elimination knockout rounds.
Macadamias are Australian, but the world grows Hawaiian ones
Macadamia is native to Queensland, but Hawaii turned it into a crop. Genetic studies trace most orchard trees to one small wild population near Gympie.