Monopoly was patented in 1904 as a warning about landlords

I have finally admitted that the plant on my desk is plastic, after watering it faithfully since March.

The scientist behind the memory number seven suspected a coincidence

George Miller opened his best-known paper, in 1956, with a complaint: "My problem is that I have been persecuted by an integer." The integer was seven. People seemed able to hold about seven items in immediate memory, give or take two, and the number kept intruding on his data.

By the final paragraph he had talked himself out of it. He wrote that he suspected it was "only a pernicious, Pythagorean coincidence." I have lost count of the lecture slides I have seen quoting seven plus or minus two, and I cannot remember one that quoted that sentence.

In 2001 Nelson Cowan published a major review in Behavioral and Brain Sciences arguing that the real limit is closer to four chunks, somewhere between three and five. The higher figure, he argued, comes from people grouping and rehearsing items, which lets them hold more than raw storage allows. He also read Miller closely, and concluded that the seven was "meant more as a rough estimate and a rhetorical device than as a real capacity limit."

Miller spent the rest of that final paragraph declining to make up his mind, which I still find more honest than most of what has been written about the number since.

Monopoly was patented in 1904 as a warning about landlords

In 1904 a Washington stenographer named Lizzie Magie received a patent for a board game with railroads, a jail corner and a square called Mother Earth that paid wages of $100. She called it The Landlord's Game. Inspired by the economist Henry George, she described it as "a practical demonstration of the present system of land-grabbing with all its usual outcomes and consequences."

It came with two sets of rules. Under the monopolist rules, the winner crushed everyone else. Under the Prosperity rules, wealth created by any one player benefited all of them.

Three decades later a modified version reached Charles Darrow through friends, and he sold it to Parker Brothers in 1935. The company paid Magie $500 for her patent, with no royalties, and promoted Darrow as the inventor. The story only came apart in the 1970s, when an economics professor named Ralph Anspach was sued over a game he had called Anti-Monopoly.

An Arctic town has buried no coffins since 1950

Longyearbyen, the main settlement on the Norwegian archipelago of Svalbard, has not permitted coffin burials since 1950. Residents may have an urn buried in town, and anyone who wants a coffin is buried on the mainland. The internet has turned this into a claim that dying is illegal there, which it is not.

The permafrost is the reason usually given. Seven men who died of Spanish flu in 1918 lie in the old cemetery, and the worry was that frozen ground might keep the virus intact. In August 1998 a team led by the Canadian geographer Kirsty Duncan opened their grave hoping for exactly that. The bodies were only about 30 centimetres down, in the layer that thaws each summer, and they had decayed. The team recovered fragments of viral RNA and no viable virus.

The old cemetery closed in 2017, because of landslide danger made worse by a warming climate.

Civilian GPS was promised after a Soviet jet downed an airliner

Korean Air Lines Flight 007 left Anchorage with its autopilot not following the waypoints programmed into its navigation system. The Boeing 747 drifted more than 180 kilometres off course into Soviet airspace, and on 1 September 1983 a Soviet pilot shot it down, killing all 269 people on board.

Part of the Reagan administration's response was to emphasise that the Global Positioning System, then being built for the military, would be freely available to civilian users around the world.

The promise came with a catch. For years the civilian signal was deliberately degraded by a feature called Selective Availability, which held accuracy to about 100 metres. A few minutes past midnight at the end of 1 May 2000, on President Clinton's order, it was switched off across the whole constellation, and ordinary receivers improved to 10 to 20 metres or better. In 2007 the government announced that its next generation of satellites would be built without the feature at all.

Typing squiggly security words helped transcribe old books and newspapers

More than 100 million times a day, by one 2008 estimate, someone typed a distorted word into a box to prove they were human. Luis von Ahn, a Carnegie Mellon computer scientist who had helped develop the CAPTCHA, reckoned that added up to hundreds of thousands of hours thrown away every day.

So he put the hours to work. His reCAPTCHA showed two words: one the computer already knew, and one scanned from an old book or from the New York Times archive that text-recognition software had failed to read. Get the known word right and the system trusted your guess at the other. When enough strangers agreed, the word counted as read.

On a test of 24,000 words from old Times articles, the crowd scored 99.1 percent accuracy against 83.5 percent for standard software. In its first year, people proving they were not robots deciphered more than 440 million words, the equivalent of 17,600 books.

If you repeat one of these tonight, make it the Monopoly patent.