This year we've been keeping track of some of the surprising things that we have learned. For December, we're compiling a list of some of the things we've learned this year.
Here are the "Today I Learned", or TILs, from July 2021.
July 2, 2021:
- TIL Ted Kaczynski, the Unabomber, who went to Harvard to study mathematics when he was 16, was recruited in his sophomore year to participate in a "purposely brutalizing psychological experiment" where students would share their deepest-held beliefs, views, and goals, which were then used to belittle and verbally abuse the students. The study was a part of the CIA's MK-Ultra program studying methods of mind control. (Link)
July 8, 2021:
- TIL Nunavut is a territory of Canada that was formed in 1999 and provided to the Inuit people for independent governance. (Link)
July 9, 2021:
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TIL people 55 and older own 72% of the wealth in the US; they make up 28.5% of the population. (Source: USA FACTS, via PBS News Hour)
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TIL that throughout most of the 2010s, the population of millennials was soaring, but number of households headed by people under 35 was declining. But since 2016, household formation rates among millennials have been rising, with the pandemic having only a short term negative impact on that trend. (Source: Harvard report, "The State of the Nation's Housing")
July 10, 2021:
- TIL how modifying the number of suits and number of cards per suit in a deck of cards can affect the relative
probability of the most rare outcomes (straight, flush, and full house).
- For example, for regular deck of cards, 13 cards per suit, 4 suits, the ranking is straights lose to flushes lose to full houses.
- But if you use a modified deck with 13 cards per suit and 8 suits (clubs/spades/diamonds/hearts/tridents/roses/hatchets/doves), straights are easier, as are full houses, so the ranking becomes straights lose to full houses lose to flushes.
- Related: https://charlesreid1.com/wiki/Cards
July 11, 2021:
- TIL about apscheduler (advanced Python scheduler), which allows you to run Python code at specified dates, intervals, or schedules. (Link)
July 15, 2021:
- TIL that giant brushes make cows very happy. (Link)
July 16, 2021:
- TIL about the gamer motivation model. There is a survey by the inventors to see what kind of a gamer you are. I am a bounty hunter. (Link)
July 17, 2021:
- TIL that China was formerly referred to as the Celestial Empire. It was common in 19th century US, Canada, and Australia. The name originates from how the Chinese characters for "China" are translated (basically, celestial/heavenly dynasty)
July 18, 2021:
- TIL you can calculate the perimeter of a Möbius strip, all you have to do is integrate a complex parametric curve from 0 to 4π (also fun fact, it can't be done analytically). (Link)
July 30, 2021:
- TIL: Monrovia, the capital of Liberia, is named after US President James Monroe. (It's the second capital city named after a US president, the other being Washington DC.) It was called that because in 1816 a group of emancipated slaves arrived there under the American Colonization Society, with support from the US government. They named the city after James Monroe because of his support of the colony as a place for emancipated slaves to go, if they preferred that to life as an emancipated slave in the US.
July 31, 2021:
- TIL there's a branch of mathematics called braid theory, that is a kind of intersection of topology and linear algebra, and has some really interesting applications (and visualizations). (Link)