Robin's Blog

Today I Learned – in 2024 and 2025

A Discord server I use has a channel called #til, standing for Today I Learned. It’s a place to post interesting or surprising things you recently learned.

I took my posts to that channel from the last couple of years, tidied them up and have listed them below. Hopefully you’ll find something interesting there:

• TIL that elements with even atomic numbers are more abundant than elements with odd atomic numbers, because of the way elements are formed through fusion. [Source]

• TIL that the BCG vaccine (for TB, you may have had it as a child/teenager) is also an effective chemotherapy treatment for bladder cancer, apparently by causing a local immune reaction against the tumor. [Source]

• TIL how guns are traced by serial numbers in the US, with no computers allowed. [Source]

• TIL a lot about the extremely complex engineering behind the Manhattan Project. [Source]

• TIL that 314159 is a prime number. [Source]

• TIL more details about how various types of display screens work. [Source]

• TIL that by freezing (literally, lowering the temperature significantly) a RAM chip, you can keep the values there for a while after removing power, allowing attackers to extract chips and read them [Source]

• TIL that when replacing some ball-and-socket joints, surgeons will sometimes reverse the joint when the natural socket is badly damaged. [Source]

• TIL that the British Library was only created in 1973 as a combination of several earlier libraries, including the British Museum Library. [Source]

• TIL that a PDF of the first issue of Linux Format magazine (from 2000) is available online, featuring distributions like Mandrake and Corel Linux. [Source]

• TIL how much the UK National Lottery was played in the 1990s, with around two-thirds of adults buying tickets weekly, despite extremely poor odds. [Source]

• TIL about the Volkswagen sausage — a genuine VW product with an official part number. [Source]

• TIL that UK police operate at least one fixed-wing aircraft as well as helicopters (and when I learned this it was circling over my house). [Source]

• TIL about baby evacuation aprons. [Source]

• TIL that in 1841, the population of Ireland was 8.2 million, more than three times that of Scotland, and over half that of England. Then the potato blight came. There are still fewer people living on the island of Ireland than there were in 1841. I knew the Irish potato famine was bad, but I hadn’t realised the population had never grown back to the levels before it. [Source]

• TIL that the processor name Pentium comes from pent meaning five — effectively the successor to the 486 (i.e. 586).

• TIL that pyrophones are musical instruments that produce sound via explosions or rapid heating, described as “internal combustion instruments.” [Source]

• TIL that Plymouth has roughly double the population of Exeter – for some reason I thought Exeter was larger. [Source] [Source]

• TIL about the enormous complexity involved in building and operating semiconductor fabrication plants. [Source]

• TIL that datacentres consumed 18% of Ireland’s electricity in 2021–22, and likely more since. [Source]

• TIL that there is a place in England called New Invention, with debate over what the invention actually was. [Source]

• TIL about the surprisingly varied cow silhouettes used on European road signs. [Source]

• TIL about the idea that “the rain follows the plough,” a mistake of correlation for causation suggesting that starting to farm desert/dry lands will bring rain [Source]

• TIL that a radio station for biscuit-factory employees became Britain’s first independent radio station. [Source]

• TIL about unusual and humorous units of measurement. [Source] [Source]

• TIL that apparently I had completely the wrong idea about belly dancing. I assumed you danced on your belly, but apparently the thing I was picturing was breakdancing. [Source]

• TIL of obtundity. [Source]

• TIL the details of how the Postgres query planner works. [Source]

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This post originally appeared on Robin's Blog.

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Categorised as: Short Interesting Things