mobeets - What I Learned

2022-12-07. Unless you've seen a truffle shaved in front of you into your food, anything you've eaten that has "truffle" in the name likely does not contain the real deal. Instead, it's synthetic truffle flavor extracted from petroleum (!); any truffle bits you see are likely "decorative" truffles---cheaper, flavorless species of truffles. [source]

2022-10-29. Moravec's paradox: Things that are hard for humans to learn are easy for machines to learn (e.g., chess, video games), while those that are easy for humans to learn are nearly impossible for machines (e.g., walking, social skills, etc.). [source]

2022-10-22. White button, brown button, cremini, portobello: All of these are the exact same species of mushroom at different stages in its maturity.

2022-10-21. Pando, in Utah, is one of the world's largest and oldest living organisms. It appears to be a grove of aspen trees (taking up over 100 acres), but is in fact a single tree with many mini genetically identical "trees" growing out of a single root system. [source]

2022-10-14. Many people have hallucinations (called "hypnagogic hallucinations") as they're falling asleep, and as they're waking up ("hypnopompic").

2022-10-01. Four U.S. states were once independent nations: Texas, Hawaii, California, and Vermont.

2022-09-22. Weekends around the world are not all the same, or even the same length! This is in part because different religions have different holy days (e.g., Friday for Islam, Saturday for Judaism, Sunday for Christianity).

2022-09-21. Daisugi is a Japanese method for growing Japanese cedar trees so that you can harvest long straight logs without having to cut down the whole tree. [source]

2022-09-15. The cheetah is the fastest land animal, but there are at least ten animals that are faster overall (most of them birds), including the common pigeon. [source]

2022-09-08. For roughly 1,400 years, a key ingredient in most ink was oak galls (a gall is a plant outgrowth caused by wasp larvae). [source]

2022-09-04. Dirichlet was co-advised by Poisson, Fourier, and Gauss.

2022-08-17. 90% of your body's serotonin is in your intestines! Only 1-2% is in your brain. [source]

2022-08-08. Think of a friend. On average, that friend has more friends than you do. (This is known as the "Friendship Paradox".) [source]

2022-08-07. When we eat salt, it's the sodium ions that actually taste salty. (But that doesn't mean elemental sodium tastes salty! If you ate elemental sodium, when it touched your tongue you'd get immediate chemical burns, so you may not taste anything---except pain.)

2022-08-04. If you divide 1 by 998,001 you get all three-digit numbers from 000 to 999 in order, except for 998. [source]

2022-06-30. The man who performed Einstein's autopsy decided to cut open Einstein's skull, remove his brain, and then simply keep it for himself. [source]

2022-06-24. The term "genocide" was not coined until 1944. During the Nuremberg Trials, for example, the Holocaust was referred to as "mass murder," or "crimes against humanity." [source]

2022-06-19. Solresol is a constructed language where each word is made up of 1-4 syllables, and each syllable is one of the notes in a C major scale sung as do-re-mi... [source]

2022-06-08. Salvador Dalí's last painting was based on a topic in mathematics called catastrophe theory, which identifies seven ways that dynamical systems can become unstable. [source]

2022-06-02. The characters +!()][ are all that's needed to write any Javascript program [source]

2022-05-24. 8-bit music ("chiptunes") sounds like it does not because of the 8 bit limitation, but purely because of the synth sounds (e.g., square and triangle waves). If you take a normal song and compress it to use an 8 bit resolution it will sound basically identical to the original. [source]

2022-05-20. Some early cars were actually steam engines, like trains. Steam was more familiar to people than gas. But steam cars required more maintenance and took about 30 minutes to start up. [source]

2022-05-18. The Earth's land surface itself has tides, called "Earth tide." [source]

2022-05-06. Some birds take non-stop flights that last anywhere from days to months. During these non-stop flights, they sleep---while flying! [source]

2022-05-05. Naked molerats cannot feel pain, can live in environments with extremely low oxygen levels, and have an insect-like social structure. [source]

2022-05-03. In the last major extinction event (aka the end of the dinosaurs), all creatures over 10kg died.

2022-05-02. In humans and other vertebrates, genetic mutations are so rare that our replication machinery could copy a nearly 2,000 page book without a single mistake. [source]

2022-04-20. Suppose you have galaxies of the same size but at different distances. Then surprisingly, "beyond a certain distance, the farther away the galaxy is, the BIGGER it appears in the sky." [source]

2022-04-18. Every function of N variables can be written as a linear combination of 1D functions. This was originally a theorem from Kolmogorov, and later used to show that a neural network is a universal approximator. [source]

2022-03-31. Making crosswords is incredibly complicated. Making the theme, rules for symmetries, writing good clues...it involves a lot more than you might think! [source]

2022-03-17. "Black holes do not actually have 'stronger gravity' than other objects of comparable mass...If you are 10 AU from (the centre of) a star, and that star collapses to a black hole (without changing mass) then the gravitational effect of the mass at your position will be the same." [source]

2022-02-23. Hyperbolic discounting is a theory for why we find some good decisions easy to defer to the future, and hard to do in the short term (e.g., dieting, budgeting, chores, etc.).

2022-02-22. Virgin olive oil is just extra virgin oil with some type of imperfection. [source]

2022-02-13. Resonance describes the fact that force applied to an object at different frequencies will have different effects on the oscillations of that object. For example, on a playground, a swing has a frequency where pushing the swing at that frequency will make it swing higher. Whereas pushing too frequently wastes energy. [source]

2022-02-05. In the English-speaking world, the dates September 3rd-13th, 1752 never happened. [source]

2022-02-02. The most recent date that used 8 unique digits was 06/25/1987, and there won't be another such date until 06/16/2345. (Until now, there had never been a gap of more than 37 years between dates with 8 unique digits, ever since the first such date on 06/27/1345.)

2022-01-29. Logistic regression, the standard statistical approach for modeling binary outcomes, didn't even really exist until 1972 or so. By contrast, linear regression was first used in the early 1800s. [source]

2022-01-28. In cinema, a complete transition from digital to film happened within the span of a year or two (around 2011), thanks to a single camera: the Arri Alexa. With this camera, the dynamic range of digital was finally better than film. To this day, Arri cameras dominate the film industry. [source]

2022-01-17. Whenever you see a planet taking an elliptical orbit around the Sun, the Sun shouldn't be at the center of the ellipse, but at its 'focus'. Also, technically the planets don't orbit the Sun. The planets and Sun all orbit a point called the solar barycenter (aka their center of mass), which gradually moves over time. [source]

2022-01-15. The fattest internal organ in the body is the brain. As adults, the brain makes up about 2% of our body weight but uses 20+% of its energy. (In newborns, the brain uses like 75% of the body's energy, and this number decreases with age.) [source]

2022-01-08. Pluto's circumference is the same distance as a round-trip drive between Boston and El Paso. [source]

2022-01-06. The Earth has been around about as third as long as the universe: Earth is 4.5 billion years old, while the universe is 14 billion years old. [source]