TIL / betaveros

_.site / blog / _.github.io / Twitter / math_exploration
more than slightly inspired by phenomist

UPDATE: well, we had a pretty good run, but I ran out of steam in late 2016, and also Dropbox's Public folder stopped being an option for sharing HTML files, so this probably won't update any more.

At first I was like, haha, I can use Twitter for this purpose, but then I realized that there was something prohibitively formal about tweeting anything — I wonder, do my followers care about it? How do I summarize to squeeze it into the character limit? Is it phrased properly? — and I wasn’t actually jotting down the hundreds of things I learned. Having to git commit anything is probably overkill too because it involves coming up with a public commit message.

So here is a single markdown file, hosting outsourced to Dropbox (briefly on brace.io, which is getting sunsetted Jan. 2015, so never mind, I guess), processing outsourced to kramdown (can’t go wrong with GitHub’s preference), postprocessing and templating outsourced to a Python script written in ten minutes (which has then been overengineered to become a polling engine and also calculate a TIL count per day). I hope the pipe never becomes too large. Maybe I can archive it to my GitHub page every month?

(Also, half of these TILs are almost more like mini-diary-entries)

Whatever, here goes reverse chronological order:

9/24

• [Inside Out] is localized to accommodate international audiences: In the Japanese version, for example, Riley is disgusted by green bell peppers, rather than by broccoli, to reflect the fact that Japanese children do not consider broccoli gross.

• Nimmer on Copyright is a multi-volume legal treatise on United States copyright law that is widely cited in American courts, and has been influential for decades as the leading secondary source on American copyright law.

  The work … was for several decades the only significant treatise in United States copyright law.

9/23

• Google’s calculator does not use e for scientific notation qq
• It is also not trivial to make gnuplot plot an empty graph, you have to hack it by making it plot something out of range
• gnuplot uses ** for exponentiation
• The numbers in online problems change between people. I guess it’s only natural…
• Patent secrecy orders exist.

9/21

• I just took a closer look at all the MIT mailing lists I’m part of due to being on ec-discuss@ and learned that some nonzero number of MIT students definitely like making mailing lists. The list of lists I’m on due to ec-discuss includes ec-discuss-plays-2048@, fork@, how-do-mit-students-use-mailing-lists@, and im-having-a-furry-inclination@.
• Apparently there is a patent for the way Scrabble score squares are drawn so you can see them on the edges of the tiles after they are laid down.
• Oops, thawing meat by just leaving it out is bad.

9/20

• In East Asia, live animals are occasionally the prize in the claw game. In Chinese supermarkets, a live crab or lobster can be won, presumably to be eaten by the winner. In Japan, pet turtles can be won, though this practice has come under scrutiny from animal rights groups.[citation needed]

9/19

• The first “a” in “quasar” is pronounced as an /ay/ sound. As a (possibly disputed) consequence, the second “a” in “Rayquaza” is pronounced as an /ay/ sound too.

9/18

• The integral of the secant function is so complicated it has its own Wikipedia article. (And the implied form my E&M textbook gives me isn’t even one of its forms — it’s sec θ + tan θ expanded into sines and cosines, which is reasonable, I guess.)
• Wow, Bank of America has some basic automated voice comprehension stuff on its phone lines. (I don’t intend to suggest it’s unique or particularly special for doing this — I bet it’s pretty common — but it’s my one data point.)

9/17

9/16

• The Android calculator has an e key that serves double duty as either Euler’s constant or scientific notation, depending on context. Nice.
• ATM machines in the US can dispense multiples of $20. That’s good. For some reason I assumed they’d dispense multiples of $100.

9/15

9/14

9/13

• Wow, I’m learning a lot of LaTeX. \iint and \iiint are densely typeset double and triple integrals.

9/12

• mhchem is a great package for typesetting chemistry stuff in LaTeX.

9/11

9/10

9/9

• Center a single line in LaTeX with \centerline{...}.

9/8

• MIT’s print quota is not all that strict?

9/7

• The topology used in a Book Proof of the infinitude of primes, where neighborhoods are two-way arithmetic sequences and open sets are sets containing neighborhoods, can be obtained from a suitable metric on ℤ. (Napkin exercise. Fun.)

9/6

• The fastest stroke in swimming is most precisely termed the front crawl, but “freestyle” often metonymically refers to it since almost everybody uses it for its speed in freestyle competitions.

9/5

9/4

• The song 童話 is a thing at MOP.

9/3

9/2

9/1

• MIT printers used to be all separated and you had to print to a specific one. They got unified not too long ago.

8/30

• Normally, tap water is drinkable everywhere in the United States. (Note that just because it’s drinkable doesn’t mean it tastes good.)

8/29

• Hormesis is the idea that low exposure to toxins or radiation is actually good. Anecdotally, from people who really know radiation, it could actually reasonably be a thing for ionizing radiation.

8/28

• The Jacobian conjecture is notorious for the large number of attempted proofs that turned out to contain subtle errors. As of 2015, there are no plausible claims to have proved it. Even the two variable case has resisted all efforts. There are no known compelling reasons for believing it to be true, and according to van den Essen (1997) there are some suspicions that the conjecture is in fact false for large numbers of variables.

8/27

• The Hessian matrix is the square matrix (or one of the two sensible ones) of all second-order partial derivatives of a scalar function. It is the Jacobian matrix of the gradient, and the second derivatives test amounts to testing it for positive semi-definiteness. That makes more sense.

8/26

• Edgar Allan Poe’s The Gold-Bug features a specific substitution ciphertext and a detailed solution. The ciphertext is on Wikipedia. This popularized cryptograms. Also it is apparently the story that he got the most money from.

8/25

I can’t even retrofill this day because my Firefox history is literally blank.

8/24

• Once upon a time, three MIT students showed how to crack the MBTA system for infinite money and got sued. In separate news, I can’t figure out if the MBTA is actually free from the airport to MIT.

8/23

• Apple cider donuts are REALLY GOOD!

8/22

• My map-reading and spatial orientation skills are far better than I had previously assumed.
• Houston Street exists in Manhattan, New York; its name is pronounced /how-sten/, unlike the city in Texas, even though they are spelled the same way.

8/21

• “Scratchiti” is a term for, like, graffiti, but with scratching.

8/20

• Wow, all the flak United Airlines gets isn’t for nothing…

8/19

• Fish and chips are a thing in Seattle, as is feeding them to seagulls.

8/18

• tpope has a color scheme vividchalk based on… I don’t even know what this is.

8/17

• MATLAB uses the tilde ~ to indicate output arguments you want to throw away. I think. Like an underscore _ in Haskell and (in some contexts) Scala and (by convention only) Python.

8/16

• What the pseudoinverse is. It’s pretty cool.

8/15

• Dance Dance Revolution is exhausting!

8/14

• Quest for the Crown eventually gets harder if you play through repeatedly; the little man skips more spaces when you move it, and you have to align yourself with the gap to get the crown by forcing him to stop at certain bricks.

8/13

• bash has builtin substitutions that strip specified prefixes or suffixes off variables.

  • ${a#foo} strips “foo” from front of $a
  • ${b%foo} strips “foo” from back of $b
  • in both cases, foo can be a glob pattern; the above substitutions strip the shortest match, if any, but doubling the # or % makes it strip the longest.

8/10

• Shady fix for when my Android/HTC device fails to connect to my MacBook Pro’s ethernet-shared-to-wi-fi: shut it off, change the wi-fi password, and start it up again. Maybe it’s one or the other that affects it. I don’t know. Too lazy to find out.

  Shady fix for an app that fails to install on Android/HTC: settings > applications > whatever, then clear the data and cache for Google Play Store and Google Services Framework (“Google 服務架構/框架”).

  (Note: The first two slashes in the previous two paragraphs are pronounced “on” as in a chord.)

8/9

• Chinese is weird! Simplified Chinese and Traditional Chinese write the horizontal line in the top box of characters like 骨 (“bone”) or 過 (“over”, among many other meanings) in different ways: Simplified goes to the left, Traditional goes to the right.

8/8

• Hurricanes and typhoons are basically the same thing, just in different places.

8/7

• Name changes due to the Islamic State of Iraq and the Levant (via Slate Star Codex)

8/6

• Porters at airports are called skycaps?

8/5

• Names of the conjugate transpose: Hermitian transpose, Hermitian conjugate, bedaggered matrix, adjoint matrix, transjugate.

8/4

• This isn’t a TIL at all but eevee tweeted a Slate Star Codex post somewhat recently. The world is small.

8/3

Note for below:

• The subject of the metaphor is called the tenor and the comparison is called the vehicle.

8/2

• In Japanese, 人參 refers to the carrot.

8/1

• There s a red “loop and a half” problem?

7/29

• Miura fold

7/27

• Even though I’ve watched its trailer before, only after reading a blurb did I realize that the animated alien movie “Home” is probably based on a hilarious book I’ve read called The True Meaning of Smekday.

7/26

• You can hold the Enter key down to repeatedly click a focused button in many browsers. If not worked around, this can tend to break idle or incremental games that are supposed to involve the difficulty of repeated clicking.

7/25

• On Wikipedia, Birthday Wish currently redirects to List of The Fairly OddParents Episodes.

7/24

• Of the three platforms advertised on haskell.org’s downloads page, only OS X seems to have a 7.10 build, and it’s only visible if you click all the way through. The others are still at 7.8. Weird.

7/23

• GIMP has nice rounded rectangle selections under its rectangle selection tool.

7/22

• According to GNU’s list of licenses, the term “MIT license” is ambiguous and can refer to either the Expat license or X11 license. I’m pretty sure the one I use is the former.

7/21

• Wait omg my first duplicate TIL — something I wrote down as having learned in this log twice, which implies I failed to learn it the first time — occurred as early as 2/10 (February 10th) of this year: the apportionment paradox, which I had already written down in 2014/12/3. Goshdarjnite.
• tee and process substitution can let you pipe stdout from one process to multiple other commands or programs, including both echo it and further process it. From this SO answer.

7/20

• Chip firing is tricky. But it appears the classic original result is by Björner, Lovász, and Shor, 1991 (PDF) and on a finite connected undirected graph with n vertices and m edges, Theorem 2.3 has an excellent classification: chip firing

  • does not terminate with more than 2m − n chips
  • will terminate for some configurations but not for others (both types exist) for any number of chips between m and 2m − n inclusive
  • must terminate for fewer than m chips.
• There is a somewhat technical term of a wicked problem.
• As of late 2014, Microsoft owns Minecraft.

7/19

• Okay, I didn’t learn this today, but I relearned it: people sometimes upload sped-up or slowed-down versions of music onto YouTube to avoid getting flagged and having their audio removed.
• CSS line-height only applies to block elements? Or something?

7/18

• To prevent the slash and apostrophe from activating Quick Find in Firefox, you have to intercept and .preventDefault() the keydown event; it won’t work if you intercept the keypress event. Darn.
• Language Log, Two Dots Too Many (via Hacker News). Wow. Unicode matters, people.
• Person Space. Somebody has had the same thought as I think I had innumerable years ago. E is a hundred times more eloquent than I ever was, though, so I don’t feel like pointing out my old post. I just feel warm and fuzzy knowing there are people like me. Yay.

7/17

• This natural attempt at optimization that surprisingly makes things slower.

7/16

• jQuery’s width and height return content-box-style dimensions, whereas its outerWidth and outerHeight return border-box-style dimensions, regardless of the actual value of box-sizing.

7/15

• /r/learnprogramming’s wiki provides an analogy for the relation between Java and JavaScript I haven’t seen before: “the same way that a grape is related to a grapefruit.”
• Tails, the amnesic incognito live system, exists. You can boot up its operating system from a USB stick for privacy and anonymity, even possibly if your computer is compromised.
• Google Panda and Google Penguin are names of updates to Google’s search algorithm.

7/14

• Um. I only noticed today that pearlcatchers have a horn in the middle of their heads (males have an additional smaller one).

  What am I doing.

7/13

• When you ask node to log a nested list, it only logs up to around four levels deep before giving up. console.log([[[[]]]]) prints [ [ [ [] ] ] ] but console.log([[[[[]]]]]) prints [ [ [ [Object] ] ] ].

7/12

• The term “AMAgeddon” is KnowYourMeme-official.

7/11

• MATLAB functions can know how many output arguments they’re being expected to supply, and built-ins like lu can supply radically different combinations of things when called with different numbers of output arguments. Sheesh.

7/10

• The Googology Wiki exists for studying large numbers. I think the biggest number as of time of writing is called BIG FOOT.
• More than a couple country flags feature AK-47s.

7/9

• /r/SubredditSimulator exists.
• The U.S. Pirate Party exists.
• Apparently strip is a utility that strips out unnecessary bits from executables?

7/8

• Randomly grabbing n real numbers from a normal distribution about 0 and using them as coordinates produces a point whose direction from the origin is uniformly random. This is because the probability density function for the normal distribution at x is e^−x2 times fudge factors so the p.d.f. for a point (x,y,z…) is e^{−x2−y2−z2−…} = e^−r2 so the distribution at points that are a constant distance from the origin is constant.

7/7

• Case-sensitivity in CSS is weird.

• Yet another CSS framework: Pure, by Yahoo.

  (Previously on TIL: Materialize, by four students from Carnegie Mellon who based it on Google’s design principles, and Bootstrap by Twitter.)

• Calvin and Hobbes can also be abbreviated C&H. Darn. So I suppose we have to use Cy&H for Cyanide & Happiness.
• The nonlocal feature in Python 3.x was never backported to 2.x, so until the switch, one is stuck with read-only outer variables in inner scopes. One work around is to put a variable as a property of an outer object, though. You’re allowed to modify that.

7/6

• Here is a thing. Neil Patrick Harris wrote a CYOA autobiography.

7/5

• Mozilla seems to have pretty high salaries for a largely open-source company.
• Darn, with Yosemite’s blur effect, my prime spiral background gets blurred into a flat gray.
• Glomar response (via (via))

7/4

• smcFanControl is great — open-source and everything — even if you just want to look at your Mac’s temperature and fan speed in the top bar, not actually control the fan speed or anything. I skipped it previously because I thought otherwise.
• There’s a Real Life section on the trope Attractive Bent Species. Who would have known?

7/3

• In (at least my version of) Mac OS X, you can drag a file into a terminal window and it’ll paste the file path.

7/2

• It’s called Arson, Murder, and Jaywalking because Furries Loli-Porn And Dubs is too much of a gratuitous Take That to the anime fandom. And furries, of course. (links in original)

  — TVTropes, Lousy Alternate Titles

  Well.

  I laughed.

7/1

• TVTropes is quite possibly the reason I feel so comfortable using the not-too-common term “snark” to mean something like “be sarcastic and cynical”. They have a snark index.

6/30

• Pando

6/29

• jQuery has no built-in for setting or getting id. Just do .attr('id').

6/28

• I started reading a webcomic, Wilde Life, today. Um, it exists. Also sometimes Google Ads aren’t that bad really. I’m sad there’s not more of it.

6/27

• In titles, the components of phrasal verbs are supposed to be capitalized. So you can’t just look up each word and not-capitalize it if it’s a preposition.
• This is the asexual flag. Also, “asexual” is sometimes abbreviated “ace” and there is a different spectrum “aromantic”/”aro”.

6/26

• Wikipedia features a list of most viewed YouTube videos, which turns out to be almost entirely music videos. The exceptions include Charlie Bit My Finger and the borderline 54-minute collection of nursery rhymes, Wheels on the Bus. The first five and a half minutes include three parts of the titular “Wheels on the Bus”, each seven verses long with the first verse of each part being about wheels on the bus but the remaining six verses each being unique.
• Somehow, National Standard Time is unique enough to redirect to Time in Taiwan.

6/25

• jQuery UI makes an API to let you create draggable things, among many others.

6/24

• Contrary to phonetic resemblance, the Newark airport is in New Jersey, although it is still really close to New York.

6/23

• Despite what Google Translate will tell you, the illegal thing where you park beside the normal row of parked cars is double parking, not parallel parking.

6/22

• My dorm preferences differ drastically from those of the MIT community at large. Although that’s after FYRE and I have no idea whether my ranking will change later.

6/21

• The no-hair theorem postulates that all black hole solutions of the Einstein-Maxwell equations… can be completely characterized by only three externally observable classical parameters…

  (snip)

  There is still no rigorous mathematical proof of the no-hair theorem, and mathematicians refer to it as the no-hair conjecture.

6/20

• Control.Exception.Base.evaluate is what turns an expression into an IO thing so you can catch errors arising in it.

6/19

• There are weird names for other groups of the periodic table, e.g. group 15 is the pnictogens.
• The Rado graph is a thing.
• The Outlook Web App that MIT uses for its email doesn’t let you separate emails with commas; I think you have to use newlines or semicolons.

6/18

• So in medical test terminology, between “reactive” and “nonreactive”, there’s “equivocal”.

6/17

• News from wherever: a district judge being good at programming.

6/16

• Google Chrome has very nice mobile device emulation capabilities.

6/15

Really nothing today :(

6/14

• WordPress’s scheduling feature actually fires at some particular number of seconds after the minute you set for it. Maybe it’s the same second count of the time when you hit the schedule button? I have no idea.

6/13

• So, WordPress’s post-to-Facebook feature doesn’t include the first few words of a blog post in its Facebook post if the blog post was scheduled.

6/12

• The reaction when people want to break restrictions on their freedom is termed reactance in psychology.

6/11

• There’s a pre-extension of the “How do you put an elephant/giraffe in a refrigerator?” joke.

6/10

• There is a Frozen sequel in the works. And there’s a lot of other stuff, enough to justify a Wikipedia page on the franchise.

6/9

• There’s this children’s song that goes,

  Make new friends but keep the old,
  One is silver and the other gold

  Well, everybody sings it differently, including me. As I remembered, in the first line, “keep” is mi-fa and “the” is mi-re, and I prefer it to the versions I found, which go mi-so-fa-mi. There were other versions that barely even had a melody. This is important because I invoked it in my valedictorian speech.

6/8

• As of some point Find the Invisible Cow supports goats and other animals as unlockables.

6/7

• Google.org is the “charitable arm of Google”.
• In C99 and above, prepending a z to a format specifier lets it accept size_t, e.g. %zu.

6/6

• They killed /r/thebutton! I actually kind of wanted to press at some point…

6/5

• The MIT Online Subject Evaluation system does exist, although several people I asked about courses didn’t seem to know about it or feel like it was worth mentioning or something.

6/4

• A Softer World ended this year.

6/3

• Wait, what?

  The Study of Anglophysics (in a tweet Emily Short called this a “Counterfeit-Monkey-like short story”, and I retweeted said tweet) was a Slate Star Codex post.

  …I can’t remember when I first noticed Slate Star Codex and decided it was interesting enough to put in my RSS reader (without being distracting enough to destroy my productivity), but I feel like it was at some point after reading that link, and not directly caused by it, which is pretty surprising.

  Or maybe that is actually what happened and my memory is just faulty.

  (The most recent post is …And I Show You How Deep the Rabbit Hole Goes, which is excellent, except a large part of me is very disappointed/sad about the early death — this is a vague description to not spoil it because you’ll know it when you see it)

• Two of the departments on MIT’s list of departments and programs have multi-word names that aren’t one unified link, but link to other pages. They are Linguistics and Philosophy, and Music and Theater Arts.

6/1

• So first there was ack then there was ag (the silver searcher) and now there’s pt (the platinum searcher), which purports to be even faster than ag. It is written in Go.

5/31

• There exists a 1993 Super Mario Bros. movie.

5/30

• There are a lot of other fics in HPMoR’s worldspace. Not nearly enough in Ra’s.

5/29

• Wait, I didn’t even realize Ra concluded December 2014. I was planning to reread the whole thing once that happened. I should get to it.

  (I believe I have currently read up to the start of Chapter 86 of HPMoR.)

• Vantablack is “the blackest substance known, absorbing a maximum of 99.965% of radiation in the visible spectrum.”
• Lima Syndrome is the inverse of Stockholm Syndrome, i.e. when captors become sympathetic with their captives
• Pokémon: The Mew-sical

5/28

• The Gilligan Cut was apparently the very first TVTrope.

• Ergative verbs are verbs

  that can be either transitive or intransitive, and whose subject when intransitive corresponds to its direct object when transitive.

  “Break” is an example, as outlined later in the article: “the burglar breaks the window” but “the window breaks”.

• So apparently when I play First Person Tetris, people watching me play get dizzy very quickly, but I don’t.

  I’m not sure if this is because I’m occipitally special or because I’m controlling the piece and so can anticipate turns.

• LastPass runs on PHP ::shudder::

5/27

• Rashomon is representative enough to be a trope namer. (It appeared in passing in our Chinese textbook.)

5/26

• Apple computers have an Apple Hardware Test, activated by powering up and holding the D key before anything happens.
• Turn signal lights turn off automatically when you turn the wheel back from the direction you turned it.

5/25

• Find the Longest Path is an excellent song about algorithm time complexity and grad school.

5/24

• The uppercase delta (Δ) or triangle (△) is the alchemical symbol for sulfur, associated with fire. This may be the reason we write Δ above arrows in chemical reactions to denote that heat is added.

5/23

• That e^π√163 is almost an integer is not a complete coincidence, but related to the fact that 163 is a Heegner number.

5/22

• Weird (and mildly depressing) Wikipedia category of the day: Category:American_animation_with_person_of_color_as_protagonist

TIL is on hiatus

for grad trip

5/19

• IAP has been backronymed as “Infinitely Awesome Period”.
• The Colin de Verdière graph invariant is a powerful-looking graph invariant.

5/18

• According to Mathematicians’ anniversaries throughout the year (via Curiosa Mathematica), I share my birthday with a bunch of mathematicians, none of which I have ever heard of.

  Well, maybe Hopf rings a bell but I’m not sure.

5/17

• Mac OS X’s Preview can view .docx files and export them as PDFs, albeit pretty badly.

• Kuratowski, the guy who proved Kuratowski’s theorem characterizing the planarity of finite graphs, also proved Zorn’s lemma.

  Also:

  K. Kuratowski proved in 1922 a version of the lemma close to its modern formulation… Essentially the same formulation… was independently given by Max Zorn in 1935, who proposed it as a new axiom of set theory replacing the well-ordering theorem, exhibited some of its applications in algebra, and promised to show its equivalence with the axiom of choice in another paper, which never appeared.

  I feel a lot better for promising blog posts that never appear :)

• Acronym § Contrived Acronyms

  The US Department of Defense’s Defense Advanced Research Projects Agency (DARPA) is known for developing contrived acronyms to name projects, including RESURRECT, NIRVANA, and DUDE. In July 2010, Wired Magazine reported that DARPA announced programs to “…transform biology from a descriptive to a predictive field of science” named BATMAN and ROBIN…

• The DC of DC Comics originally stood for “Detective Comics”, so “DC Comics” can be said to suffer from RAS syndrome (redundant acronym syndrome syndrome).

5/16

• Finding Dory, the sequel to Finding Nemo (which I hope is obvious), is slated for release in 2016.

• Rust, the programming language, is named after an awesome fungus.

   <graydon> I think I named it after fungi. rusts are amazing creatures.
   <graydon> Five-lifecycle-phase heteroecious parasites. I mean, that's just _crazy_.
   <graydon> talk about over-engineered for survival
   (snip...)
   <graydon> fungi are amazingly robust
   <graydon> to start, they are distributed organisms. not single cellular, but also no single point of
             failure.
   <graydon> then depending on the fungi, they have more than just the usual 2 lifecycle phases of
             critters like us (somatic and gamete)
   (snip...)
   <graydon> it's madness. basically like someone was looking at sexual reproduction and said "nah, way
             too failure-prone, let's see how many other variations we can do in parallel"
  

5/15

• Proset is a game equivalent to finding linear dependencies in 𝔽₂⁶, so any 7 cards will always have a set.
• Software clones that imitate things like the functionality or interface of other software without stealing their code, such as ReactOS of Windows and GNU Octave of MATLAB, have been upheld by the Supreme Court case Lotus Development Corp. v. Borland International, Inc..

5/14

• Legless lizards exist. Snakes “can be distinguished from legless lizards by their lack of eyelids and external ears.”

• However, a majority of contemporary paleontologists concerned with dinosaurs reject the traditional style of classification in favor of phylogenetic nomenclature; this approach requires that, for a group to be natural, all descendants of members of the group must be included in the group as well. Birds are thus considered to be dinosaurs and dinosaurs are, therefore, not extinct.

  guys we did it shut down the internet

5/13

• The idiom ”[to] screw the pooch” exists.
• The Putnam math competition is limited to (quoth Wikipedia) “undergraduate college students enrolled at institutions of higher learning in the United States and Canada”.
• The Big5 encoding is called what it is because it was developed by 5 big companies in Taiwan.

5/12

• The D of BDSM is apparently “discipline” and not “dominance”.

• List of references to Pokémon in popular culture

  Somebody claims this in Detective Conan, although no reference is given (what?)

  Ash, Misty, and Brock make a cameo appearance as kids staying in a train station. However, the distinct facial features each possess, such as their hairstyles and Brock’s eyes, were slightly altered and switched between them

  The reference on House, M.D. is there. Excellent.

  Ok the number of other catches is amazing.

  On the virtual pet site Neopets, a Pikachu can be seen on the Gallery of Evil page.

  (What this is referring to was surprisingly hard to spot for me. If you’re reading this, I invite you to try finding it. You don’t need an account or any Neopets knowledge.)

  Also:

  During a Republican debate for the 2012 United States presidential election, candidate Herman Cain quotes a “poet” saying “Life can be a challenge, life can seem impossible, but it’s never easy when there’s so much on the line.” These are actually the beginning lines of The Power of One, the theme song for the movie of the same name. During his withdrawal speech, he reused the line but with proper attribution.

• List of references to popular culture in Pokémon

  In Pokémon Omega Ruby and Alpha Sapphire when the language is set to French, before battle Brawly says, “J’ai découvert le secret de la vraie puissance en fixant un Nautile pendant des jours et des jours…”, a reference to Twitch Plays Pokémon.

  What? French? Why?

  (compare: Oasis Tonic at TheDailyNeopets’ Battlepedia)

• There are lots of 50 Shades of Grey parody Twitter accounts.
• The illusion where people misperceive which diagonal segment continues a diagonal segment on the other side of a thick vertical bar is called the Poggendorff illusion.

5/11

• The Mozart effect is an observed effect where students temporarily test smarter after listening to Mozart.

Fun rings!

• Rings can be localized, which is when you systematically add multiplicative inverses to them, but not necessarily completely (if you add as many as possible you get the field of fractions).

  You should just usually assume the subset you localize by is closed under multiplication. If you localize ℤ by the odd numbers, you get the ring of fractions whose denominators are odd numbers. This is either a really bizarre example or a totally normal example of a local ring, I don’t know enough to tell yet.

• A dyadic rational is a rational number with denominator a power of two. Dyadic rationals form a ring, straightforwardly.

  Time signatures in Western musical notation traditionally consist of dyadic fractions, although non-dyadic time signatures have been introduced by composers in the twentieth century. (Non-dyadic time signatures are often called “irrational” by musicians, but this is a misnomer because they still consist of ratios of integers.)

5/10

• Wikimedia Commons has File:Wikiball Crystal.svg, “a free icon to represent the Pokémon franchise without using any images under Nintendo copyright”.
• It is now possible for a Pokémon to have three types during a battle, if the Pokémon was originally dual-type and is hit with Forest’s Curse or Trick-or-Treat, each of which add a type to the Pokémon. Amusingly, I learned this from the type article on the Chinese Bulbapedia; it’s not mentioned in the English one.

5/9

• Slate Star * has a tumblr too!

  Assorted fun links from the archives, after following links to the source:

  • Advanced Trolley Problems

  • salad bar

  • something Ruth Bader Ginsburg something tumblr

• Link

  This is why I’m glad I didn’t wave about my college acceptances too much.

5/8

• The “characteristic” of the common (= base-10) logarithm of something is its integral part.

5/7

• “Corequisites” are two (or more?) courses that you have to take at the same time.

5/6

• To continue lines in VimScript, add backslashes at the front of following lines. I saw this before but never internalized it.

5/5

• Mozilla is phasing out non-secure HTTP. It’s a controversial move; I’m not sure how it’ll play out yet.
• The British film 1984 was released in 1984.

5/4

• Bletchley Park [was] a British cryptography installation sometimes referred to as “BP” so that those making inquiries would assume the speaker meant British Petroleum without the speaker having to directly lie
• xyz(redacted) appears to be MIT 2019

5/3

• There’s this thing called “quadratic voting”.

5/2

• Ken Sugimori’s favorite Pokémon is Gengar and his least favorite is Venusaur [citation needed]
• It looks like MIT Effective Altruism does exist…

5/1

• The Clojure build tool Leiningen is named after the classic short “Leiningen and the Ants”.
• The Japanese programming language nadesiko exists. It even seems reasonably active and has a dedicated Japanese page. I can’t understand any Japanese though.

• Here is a list of the most active GitHub users.

  The top few are PHP and JavaScript. Still, Haskell shows up pleasingly early, with jgm (pandoc, CommonMark) and snoyberg (conduit, various preludes)

4/30

• Hero: 108 is a Cartoon Network series very loosely based on Water Margin (水滸傳).
• C-SPAN has AP US Government review sessions.
• The main author of Idris (programming language), Edwin Brady, is also one of two coauthors of the Whitespace programing language.

4/29

• Digital Ecologies Research Partnership

  Note the participating websites. The acronym is deliberate.

• The words yes and no are not easily classified into any of the eight conventional parts of speech. Although sometimes classified as interjections, they do not qualify as such, and they are not adverbs. They are sometimes classified as a part of speech in their own right, sentence words, word sentences, or pro-sentences, although that category contains more than yes and no and not all linguists include them in their lists of sentence words. Sentences consisting solely of one of these two words are classified as minor sentences.

4/28

• The exam document class exists for LaTeX. Its documentation (PDF) has funny example questions.
• The concept of a formula for awarding estimates of probabilities in a way that incentivizes you to accurately report the probability you estimate in order to maximize your expected value (a normalized choice being to award 1 − log₂p points if an event you estimate to have probability p occurs and 1 − log₂(1 − p) points points if it doesn’t) is called a scoring rule.

4/27

• Category:Wikipedia_objectionable_content

  okaaaay that’s enough internet for today

• Git has a GUI you can call up with git gui. What is this black magic!?

4/26

• If you pass -p to git stash show you can look at the full patch of a stashed change.

4/25

• “Snickers” in Chinese is 「士力架」/shi4li4jia4/. Why??
• It seems generally accepted that the “i” of “omicron” is pronounced as a short i. Darn.
• The pun is also called “paronomasia”.

• https://en.wikipedia.org/wiki/Australian_Mathematics_Competition

  Ivan Guo, Sydney Boys High School, New South Wales was the first person to win three consecutive BH Neumann certificates, which are only awarded to those who achieve a perfect score.

  This guy did some SUMS puzzlehunt stuff, right? Like 2010 A4S2 Hazardous or 2011 A3S1 A Dash of Rain?

4/24

• simmonsetal11.pdf

  …we asked 20 University of Pennsylvania undergraduates to listen to either “When I’m Sixty-Four” by The Beatles or “Kalimba.” Then, in an ostensibly unrelated task, they indicated their birth date (mm/dd/yyyy) and their father’s age. We used father’s age to control for variation in baseline age across participants.

  An ANCOVA revealed the predicted effect: According to their birth dates, people were nearly a year-and-a-half younger after listening to “When I’m Sixty-Four”… rather than to “Kalimba”… (p = .040).

4/23

• Planck lengths and other units aren’t defined to inherently be the smallest possible measurable units or something like that; they’re defined so that universal constants work out to be exactly 1. I think the whole smallest possible unit idea comes out as a convenient side effect or something.

4/22

• The common 7-note “C-G-G-A-G B-C” riff or rhythmic sequence has a name, “Shave and a Haircut”, and is very popular. However, it is offensive in Mexican culture.
• Some mathematicians think the theory of a field with one element may be useful for other fields of mathematics and even possibly “connected to … a possible proof of the Riemann hypothesis.”

4/21

• Three quarks don’t add up to a proton; there’s a lot of extra junk around it.
• Elixir is a language on the Erlang VM with Ruby-like syntax. So there are VMs other than the Java one that are getting languages built on top of them. I think concurrency is a selling point here.

4/20

• FontForge looks a lot more professional and robust than when I first attempted to get it running years ago.

4/19

• The lines of code on the Google Code Jam T-shirt are probably all from real submissions. Why did I never think about that? I thought it was odd that they’d choose to use Rust or some language that looks an awful lot like it as their final item.
• TVTropes contains a page on MySQL.

• The Python 2 and 3 Compatibility Library called six exists.

  The name, “six”, comes from the fact that 2*3 equals 6. Why not addition? Multiplication is more powerful, and, anyway, “five” has already been snatched away by the (admittedly now moribund) Zope Five project.

4/18

• Carton is called a “jackal” because it appears that, while Mr. Stryver very deftly presents each case, it is Carton’s legal acumen that helps win them, though Stryver gets all the credit—a reference to how the jackals help the lions with the kill, while the lions take all the glory.

  Wait, that’s the symbolism? It makes so much more sense!!

• “format” is a substring of “informatics”. WTF, brain?

4/17

• Darn, Haskell does not seem to have any high-level, popular, and nicely modularzed way of creating a ByteString from a mutable buffer.

  mono-traversable defines two conversion function in Data.ByteVector.

  You have to twiddle pointers to get anywhere.

4/16

• There is a list of banned works in Russia, the Federal List of Extremist Materials.
• My family all uses chopsticks differently.

4/15

• According to the terms, it’s OK to share information about Code Jam Qualification Rounds during the contest.

4/14

• Not-So-Fake Prop Weapon:

  In The Clones of Bruce Lee, the gold-smuggling director’s yes-man suggests using this to kill the Bruce Lee Clone they suspect to be a secret agent. As Spoony pointed out in his review, this is very badly Harsher in Hindsight, since Bruce’s son Brandon was killed on the set of The Crow by a weapons malfunction.

4/13

• At some point YouTube ads with opaque text floating on a transparent background came into existence.

4/12

• Traditional [Go] stones are made so that black stones are slightly larger in diameter than white; this is to compensate for the optical illusion created by contrasting colors that would make equal-sized white stones appear larger on the board than black stones. — Go (stones), Wikipedia

4/11

• GolfScript doesn’t have anything like min or max functions. Oh but they’re not that hard to golf (albeit slowly): $0= or $-1=
• Dart’s integer division operator is ~/. How do you come up with something like that!?

4/10

• Okay not a fact but that THE WORLD ACCORDING TO STUDENT BLOOPERS exists

4/9

• K’naan’s “Wavin’ Flag” started out as a normal album hit in its own right in Canada, before later getting remade for the 2010 Haiti earthquake and then for the 2010 FIFA World Cup and becoming a “truly global hit”.

• How to download emails and analyze them according to this guy

  (Note: there’s a Homebrew package offlineimap)

4/8

• “painstaking” is actually “pains” + “taking” not “pain” + “staking” as I had somehow always assumed.

  Also, the pluralization function of “-s” is the third definition on Dictionary.com; the first is the native English suffix as in “always” or “betimes” or “needs” or “unawares” and the second is the ending marking the third person singular indicative active of verbs, whatever that means.

• The inversion:

  Choose a major you love and you’ll never work a day in your life…

  because that field probably isn’t hiring

• Daniel Chester French, the sculptor of the John Harvard statue (and also more famously of the Abraham Lincoln statue), is an MIT alumnus (but only by one year of studies there.)

• This is how Wikipedia currently describes the 2015 Mystery Hunt theme:

  2015 (by One Fish Two Fish Random Fish Blue Fish): the exploration of the ocean (won by Luck, I Am Your Father)

  [Ocean] link in original. Haha.

• Externships are like internships except shorter?
• There once existed a site called Scroogle that anonymized your searches and sent them to Google.
• “copyright protection…is not available for any work of the United States Government”

4/7

• Gitter provides free chat rooms about GitHub open-source repositories. (learned from below)
• The Materialize CSS project exists.
• sumo.stanford.edu uses Hakyll *swoons*
• ‘Happy Birthday to You’ is the most recognized song in the English language, followed by ‘For He’s a Jolly Good Fellow’.
• Some feminists have alternative spellings for “woman/women” so that “man/men” is not a substring.
• You have to log in to Twitter to see who somebody is following or is followed by.

• Nine lemma and company.

  I have no idea what is happening

4/6

• Never mind, RationalWiki and LessWrong don’t like each other very much. (Caveat, of course: neither site is exactly a homogeneous entity with one consistent opinion among all its contributors)
• Wikipedia has lists of colors

4/5

• Bezier curves cannot exactly fit a circle arc. Some browsers nevertheless use beziers to approximate a circle, with a resulting 0.0273% error.

4/4

• “Rolling in the Deep” has clean / explicit versions.

4/3

Today turned out to be a TVTropes day.

• Mystic chord wha
• Mega Rayquaza and (both forms of) Mega Mewtwo are the two Pokémon with the highest base stat total, 780.
• Magikarp Power: Magikarp and Gyarados came from a Japanese legend that a fish who climbed the falls to a place called Dragon Gate would become a dragon.
• Convection Schmonvection (warning: TVTropes link) is the general disregard of the lethality of the heat in the air above molten lava.
• And the inversion: Space is Cold… no, for most regions of space considered in fiction, it isn’t, and spaceships have trouble getting rid of the heat they produce.

4/2

• https://en.wikipedia.org/wiki/Hungarian_language#Two_words_for_.22red.22
• Fan fiction of real people is not that rare…
• Some soap dispensers dispense when you pull the tab. Whyyy would you do that ._.

• I discovered Eric Harshberger’s website today and a lot of cool stuff on it, including:

  • Go First dice, four dice such that you can roll any subset to generate a fair permutation
  • his puzzle parties including a fascinating scoring system for keeping teams balanced
  • a wonderfully concise cheat sheet (PDF) as well as puzzlehunt pencils for common puzzlehunt codes

4/1

• Due to physical constraints, memory access in any modern computer is really not O(1). So one can argue that updating functional (immutable/persistent/substructure-sharing) data structures is not asymptotically worse than updating them imperatively. That doesn’t mean that performance isn’t a concern, of course.

3/31

• Dolphins have been studied giving names to each other.
• “Away from puzzles, Thomas [Snyder] is a scientist developing new medical diagnostics for the immune system.” (Did I know this at some point??)

3/30

• The numbers 2²ⁿ form an irrationality sequence… Despite the rapid growth of this sequence, it is the slowest-growing irrationality sequence known. — Wikipedia
• The Big Hero 6 movie is based on an eponymous Marvel Comics superhero team. The Walt Disney Company acquired Marvel Entertainment in 2009.
• In some religions it is custom to write “G-d” instead of “God” in media that may be defaced, including, of course, websites.
• Facebook has this “memories” feature that reminds you of stuff from years ago.

3/29

• The tablets/candies for sore throats are called throat lozenges among other names.
• GitHub is defending against a DDoS.

• Dinosaurs are neither warm- nor cold-blooded?

  (via Worldbuilding Stack Exchange on dragons. Fun.)

3/28

• My version of (Mac)Vim is outdated.
• mathgrant’s alternate name for Ripple Effect is just Ripple Play.
• academia.edu is a social networking site for academics that was grandfathered into the .edu subdomain.

3/27

• There are Pandoc vim plugins with a somewhat ridiculous number of features. It turns spellcheck on, conceals markup, and does a plethora of other stuff.

3/26

• In exceptional conditions, OEIS is okay with a sequence with only one known term.

• Wait, Pandoc is pretty amazing. AND it’s written in Haskell.

  Fiddling with kramdown to make it support LaTeX is completely the wrong thing to do.

• Vitamins are defined in a subjective way that particularly depends on the organism consuming or requiring them.

• In the days of Usenet, the regulars of rec.puzzles coined the word “nugry” to mean a newbie who posted a puzzle which was already in the FAQ — especially the “gry” puzzle — to rec.puzzles.

3/25

• Math with Bad Drawings boasts four extremely popular posts that are, I’m assuming, proportionally close in the number of views. I only had impressions of the check-splitting one and the tic-tac-toe one being popular.

3/24

• http://static.stanford.edu/ ???

3/23

• OK I finally figured out how to use the ERB file thing for kramdown; you just write <%= @body %> in your template file.

• Homebrew cleaning tasks to get some disk space back: brew cleanup and brew cleanup --cache

  (GrandPerspective is a thoroughly awesome piece of software. I like the Monaco palette.)

3/22

• FIRST is not just the robotics competition.

3/21

• On can use “747” can rhyme with “heaven”.

  I thought Ed Sheeran actually did this (“Autumn Leaves”) but apparently the second word was actually “forever”.

• Circadian → ultradian, infradian

3/20

• Following TrueCrypt’s abandon, the most well-established Lifehacker-endorsed file encryption software, which is based on TrueCrypt’s code, is VeraCrypt.

3/19

• You get emailed if people just look at your LinkedIn profile
• Going up and going down

3/18

• “Wikipeetia the misspelled encyclopedia”
• Hlawka’s inequality

3/17

• The nat is the natural unit of information based on e.
• “My Immortal” is an internet-famous, bizarrely badly-written Harry Potter fanfic, as discussed on vulture.com.

3/16

• Back-to-back life sentences
• Weird Al’s “Word Crimes” was thoroughly discussed and generally disliked in the linguistic/grammar community for selling prescriptivism.

3/15

• “Why are there so many songs about rainbows?” is a lyric from a real song.
• In the 2000s– Chronicles of Narnia movies, Aslan is voiced by Liam Neeson.
• Hermite’s identity

3/14

• For some perverse reason Facebook’s Graph API doesn’t let you get at the polls/questions in the feed of a group.
• Rule of succession

3/13

• Harvard’s exact RD release date as well as the date of their prefrosh event thing have actually been neatly mentioned in a gazette article.

• Slate Star Codex hosts a rather amazing Rationalist Community Map.

  That mysterious group blog “More Right” is on it.

  Even Quixey is on it. Why??? I mean, big thanks to them for sponsoring NIMO and apparently SPARC too, but is that all?

  OK I ddged it. “Quixey is a startup founded by LW readers” and apparently they host rationalist meetings there from time to time.

• Judging by their Facebook group, I know 7~10 of 2014 SPARC attendees, while their website suggests they “will admit about 30 students” (for 2015, but without further information it seems an excellent guess for how large their 2014 class was; the FB group contains 52 members but I know a significant proportion are staff).

  I’m not sure what the rationalist response to this is.

  I notice that I am confused. Well, not really.

  Explanations:

  • High levels of competitive mathematics/computer science are a lot more strongly correlated with rationality than I expected.
  • There’s a strong networking effect among attendees that makes the selection of these people strongly correlated events.

• Google Code is shutting down…

3/12

• Hola is the Lifehacker-recommended VPN.
• “It was confirmed on June 24, 2014 that Pentatonix will play the role of a rival group to the Barden Bellas.” aaaaahhhhh
• “The most common mascot symbol for the [Democratic party] has been the jackass, or donkey. Andrew Jackson’s enemies twisted his name to “jackass” as a term of ridicule regarding a stupid and stubborn animal. However the Democrats liked the common-man implications and picked it up too, so the image persisted and evolved.”

3/11

• Facebook has quite a sticker collection. But even though it looks like it’s set up to charge some small money to make some stickers available and I’d expect them to do so, I can only see free ones.

• -B

  Sound the bell at the start of each (major) garbage collection.

  Oddly enough, people really do use this option! Our pal in Durham (England), Paul Callaghan, writes: “Some people here use it for a variety of purposes—honestly!—e.g., confirmation that the code/machine is doing something, infinite loop detection, gauging cost of recently added code. Certain people can even tell what stage [the program] is in by the beep pattern. But the major use is for annoying others in the same office…”

3/10

• Wikipedia has an alarmingly detailed list of about 100 paraphilias.
• Ok there is some really hardcore math going on in Singularity circles.

3/9

• IO is parallel to BC iff AO is parallel to HD (D is where incircle touches BC)

  lol I suck

3/8

• User stories are a thing
• Hey, Norwegian Recycling has more mashups.
• Atbash was originally a substitution cipher for Hebrew.

3/7

• Today is phiRe’s first visit to AoPS after the redesign.
• Embarrassingly parallel
• Adrenarche

3/6

• The [Goo Goo Dolls] trio picked their name from a True Detective ad for a toy called a Goo Goo Doll. “We were young and we were a garage band not trying to get a deal. We had a gig that night and needed a name. It’s the best we came up with, and for some reason it stuck. If I had had five more minutes, I definitely would have picked a better name,” John stated.

3/5

• Fear of robots (a la Five Nights at Freddy) is automatonophobia and has a wikipage

3/4

• Hank Green’s real first name isn’t Hank.
• Pixar Animation Studios has won 7 of the 14 Academy Awards for Best Animated Features so far.

3/3

(Written 2015/5/28: Wow I can’t believe I can still retroactively patch TILs at dates nearly three months earlier. This applies to 3/1–3/3.)

• Yesod, the large Haskell web framework, has a bunch of different templating systems dubbed Shakespearean Templates — Hamlet for HTML, Lucius and Cassius for CSS, and Julius for Javascript.

3/2

• CakePHP is the rapid development PHP framework. People use it.

3/1

• I knew that Scala’s operator precedence rules are based on the first character of the operator for determining precedence and the last character for determining associativity. However, assignment operators (which are operators ending in an equals sign that do not happen to also start with an equals sign and are not <=, >=, or !=) are an exception to the precedence rules.

  (By the way, although it’s controversial, I rather like Scala’s approach to determining precedence. It pragmatically preserves the precedences of the basic arithmetic operators, it allows :: to work like the cons function one would expect from other functional languages, it permits the symmetric and memorable +: and :+ operators for prepending and appending (the mnemonic is the COLon is on the COLlection side), and it generalizes to all operators neatly. Well, maybe not that last part, given assignment. Still, the ability to parse operator precedences mechanically or mentally, without having to consider the action-at-a-distance resulting from letting operators have user-defined precedences and associativities as in Haskell, is pretty neat.)

• The semipredicate problem refers to “when a subroutine intended to return a useful value can fail, but the signalling of failure uses an otherwise valid return value.”

2/28

• Benedict Cumberbatch voiced and motion-capture-acted Smaug. Smaug got interviewed on the Colbert Report. What? Go find the episode and watch it, it’s crazy.

2/27

• “idr” = I don’t remember (also Indonesian rupiah, also Idris file extension)
• Elm the programming language arose from a thesis written at Harvard.

2/26

• Timsort, as implemented in Python and Java, is buggy.

2/25

• It is really hard to scan a picture of a QR code on creased paper — they survive isometries, similarities, and affine transformations OK, but a little uneven squeeze in the middle and none of 5 QR scanners we found can handle it.

2/24

• HabitRPG got hugged by imgur. Ouch. Also I did not know people on imgur did stuff like spreading pics of sites.
• Under really weird conditions, it is useful to multiply an expression by e^x/e^x and then apply L’Hôpital’s rule.
• GHC 7.10 will use Plan FTP!!!!

2/23

• Simon Peyton-Jones works for Microsoft Research. Amusingly, he announced this soon after an April Fools press release about Microsoft licensing Haskell in Microsoft products that “quotes” him; the announcement was unknown and a surprise to the author.

2/22

• Sydney Carton’s number at his execution is 23, which would not be remarkable if I hadn’t learned about 23’s conspiracy/illuminatus significance around a week ago.
• I hope my incredibly Haskell-and-Vim-ecosystem-centric TIL’s aren’t boring anybody. The original author of hdevtools has disappeared, but in an excellent open source moment, a successor maintains a fork at schell/hdevtools.

2/21

• http://cabal.gamepedia.com/CabalWiki:Sandbox oh man such a painful spurious search hit
• scrooloose (author of syntastic and nerdtree, among other Vim plugins) has an, um, jarringly offensive blog.

2/20

• It is officially officially confusing which animal the coming Chinese zodiac year is concerned with, as the Language Log notes. They settle on “year of the ovicaprid”.
• Tale of Two Cities vocab:
  • blunderbuss: a type of muzzled firearm
  • hardihood: boldness, daring
  • sonorous: capable of giving out a deep, resonant sound; full of sound
  • supplicatory: begging
  • wittles?
  • spile: a post, a plug, a spout; to support with a spile; to plug or tap with a spile
  • postilion: a rider mounted on the near horse to guide them, whatever that means
  • vinous: of the color of red wine; related to wine
  • rustic: pastoral, rural; a person from a rural area
  • supercilious (I suspect I knew this at one point): arrogantly superior
• Some soft-drink machines officially sanction mixing drinks together for weird flavors.

2/19

• It is officially confusing to English speakers which animal the coming Chinese zodiac year is concerned with, as BBC reports.

2/18

• Some speakers have a feature that you can enable to filter out human voices to make any song a karaoke track.
• It’s not officially announced but apparently Heroku does support Haskell.
• “It’s very rarely addressed that [somebody with water-based powers] could just sap the water directly from a person’s body, killing or weakening them instantly, but this could be an issue of dramatic license, since that would result in some very short and uninteresting fight scenes.” – TVTropes, Making a Splash

2/17

• Twitter’s Scala HTTP library is called finagle. The word means to cheat or deceive.
• HabitRPG deprecated its habitrpg-shared repo.

2/16

• Data.Real.Constructible exists.
  • I knew the name of the guy who wrote this was familiar — he hosts http://moppers.kaseorg.com/.
• Lifehacker recommends μTorrent.
• The partition function (which counts the number of unordered partitions of its argument) grows as e^{τ⋅√(n/6)}/4n√3.

2/15

• ”… the reason Meowth is trying to catch Pikachu is because he’s a mouse.” ???

2/14

• Wizard rock is a genre of music.
• There are video games for all eight Harry Potter book-halves.

2/13

• But shell scripts can’t set or export variables that propagate to the outside shell, unless you source them.
• Deleting a variable in bash is unset.

2/12

• classy-prelude has whenM and unlessM. It’s actually that detail that I’ve been looking for forever.
• Haskell’s wreq package seems to be the most high-level HTTP client around, with sessions and stuff. But holy hell does it has a lot of dependencies. Its sandbox is 150 MB. (I wonder how big idris’s sandbox is going to be…)
• cabal exec lets you run things inside a cabal sandbox.

2/11

• WeChall has a SPOJ link.
• BasicPrelude already exists. It even has equating, the long-lost cousin of comparing.
• “genericLength has absolutely abysmal performance” – https://ghc.haskell.org/trac/ghc/wiki/Prelude710/FTP

2/10

• “United as one, divided by zero.” – Anonymous (nice, very witty, no sarcasm)
• As I expected, people giving their computers names from Lord of the Rings is totally common once you look closely.
• The apportionment paradox
• phenomist fills gapped days in his TIL by going through his browser history. This is a really good idea that I am going to imitate. Unfortunately my browser history doesn’t go as far back as early November, so some gaps there will have to stay, and some of the other filled facts are kind of forced, but it’s better than nothing.
• There is a Haskell package Math.OEIS that provides an interface to the OEIS. It pretends to be referentially transparent while it looks stuff up via the Internet.

2/9

• Okay, so the stray file in my .vim/colors was causing this weird error:

  Error detected while processing /Applications/MacVim.app/Contents/Resources/vim/runtime/menu.vim:
  line  399:
  E327: Part of menu-item path is not sub-menu
  line 1207:
  E334: Menu not found: Edit.Font.Show\ Fonts
  

  (I backed up jellybeans.vim to mess with it and try to figure out why it was bolding all my normal text. For some really weird reason, ctermfg=White made everything bold white, so instead I just gave it the override:

  let g:jellybeans_overrides = { 'Normal': { 'ctermfg': '7' } }
  

  It works now. That was probably TIL-worthy; I don’t know why I didn’t write it down.)

2/8

• Also a “trivialization” is an actual term in some sort of geometry.
• “Math is the science of trivialization.”
• OEIS has a pretty stringently overseen sign-up system.

2/7

• Flash Proxies

2/6

• A donkey vote is when somebody votes in a preference voting system by ranking candidates in the order they appear on the ballot paper. It can be genuine, but most likely arises when the voter doesn’t care.
• The range voting analog for proportional representation (the scenario when you want to elect multiple representatives to reflect the proportion of people supporting them) is reweighted range voting and is not that compelling.

2/5

• Archaeology awareness playing cards get their own Wikipedia page?
• “clockblock” (v.) um, something related to timed math contests that people on AoPS are suddenly using a lot

• (late, but I forgot when I learned this)

  The idiom for (size_t i = n; i-- > 0; ) { ... } works for iterating with an unsigned index down to 0, and it’s the direct “dual” of the traditional for loop in that it’s also exclusive of the upper bound but inclusive of the lower. You can reformat to use the “long arrow” --> in the process if you feel trollish.

2/4

• Numbers in Chinese are not trivial.

  Note: twenty is 二十，two hundred is 兩百，two thousand is 兩千，twenty thousand (two myriad) is 兩萬，and yet two hundred and twenty thousand (twenty-two myriad) is 二十二萬 and two million and twenty thousand is 兩百零二萬.

• Industrial Light & Magic (name hammered into my head by art appreciation classes) uses Python.

2/3

• You have to tell iTerm2 to emulate 256 colors (Preferences > Profiles > Terminal > Report Terminal Type: xterm-256) and set t_Co=256 in .vimrc if you want nice terminal colors. There is support for it but somehow it’s not default. (whyyy. I feel so stupid with my GUI-window-dragging now)

2/2

• I do not think I have heard any vulgar puns about cockroaches before in my life. Weird.
• DeviantArt has an online image drawing thingy called muro. I have no idea if it’s easy or practical to use, but it looks like it has a lot of features.

2/1

• Your Fave is Problematic exists. Eh, decide for yourself.
• A night-watchman state refers to a state(/government) with minimal (but existent) legitimate powers: protecting its people from “assault, theft, breach of contract, and fraud”. The corresponding belief is “minarchism”.

1/31

• npm-expansions
• There is a programming language called Go! (with an exclamation mark).

1/30

• What I thought were only colloquially described as “snowball sentences” have a dedicated descriptor word: “rhopalic”. Well, it’s a bit more general than that but it works.
• Wikipedia has a help page dedicated entirely to editors with autism and Asperger’s.

1/29

• Lua’s object-oriented facilities are prototype-based. Also, Lua is popular for scripting video games.

1/28

• “I disapprove of what you say, but I will defend to the death your right to say it.”

  — not Voltaire, but Evelyn Beatrice Hall paraphrasing his attitude, I think. The search results are very misleading!

• gvim --remote to open a file in a Vim instance that’s already running. Way easier than I was worrying.

1/27

• Aw, it looks like WordPress slugs must be globally distinct even though the URL it generates includes the year and month and day. I need to rethink my slug-choosing strategy.

1/26

• http://en.wikipedia.org/wiki/List_of_people_diagnosed_with_ulcerative_colitis
• NAND is the Sheffer stroke and NOR is Peirce’s arrow.

1/25

• Instapundit, a (conservative? libertarian?) link-heavy blog, is popular enough that there’s a word for a traffic spike it causes by linking to another site (a la Slashdot effect, reddit hug of death, etc.), an “Instalanche” (portmanteau with “avalanche”).
• Executables can try to detect if they’re being gdbed by ptraceing themselves, because an executable can only ptrace once. Or something like that.
• Bad Writing Contest (actual sentences from actual scholars)

1/24

• Although the functions like Data.ByteString.map and Data.ByteString.filter are specialized to take Word8 -> Word8s, Data.ByteString.zipWith is not; it takes Word8 -> Word8 -> a and returns [a].

  However, all is not lost for ByteString speed, because there’s a rewrite pragma when a ~ Word8.

1/23

• Eliezer Yudkowsky is on Tumblr!

1/22

(in which I finally try to learn some nontrivial binary exploitation by walking through picoCTF 2013)

• “Said the actress to the bishop” is British for “that’s what she said” and is the Wikipedia article on the combined linguistic phenomenon.
• Nonstandard format specifiers of the form %17$x do stuff directly with the 17th argument.
• Tip: instead of brute-forcing every combination of bytes or letters or printable ASCII or whatever, try a dictionary file.

1/21

• Nine Point Eight (of Deemo) has really, really depressing lyrics. (The official lyric video seems too flashy for me.) But it kind of ruins it for me that the words’ accented syllables are so completely disregarded…
• International Men’s Day is on my birthday…

1/20

• You can use the same basic trick for proving the infinitude of primes to prove that given any field F, there are infinitely many irreducible monic polynomials in F[x].

• Java Swing is “in the process of being replaced by” JavaFX.

  I guess this is good justification why scala.swing doesn’t have a maintainer. Maybe I should port to ScalaFX.

1/18

• On Google Docs, floor(-0.1) = 0. (This interfered with one team’s attempt at solving Pipe, alas.)
• Online judges are nice because they expand the recursion limit for you. This is something you have to learn to do yourself.

1/17

• Windows Command Line uses the caret as its escape character.

1/16

• 3³ = 33 in base 8 aka 2³. This is ASCII Escape.

• Sometimes, photography companies will photoshop the pictures they took for you without being asked.

  Some of those times, they will seriously suck at photoshopping.

  Ugh.

1/15

• I can drag the statusbar up and down in MacVim. Is this built-in or part of vim-airline or something?
• Ayn Rand was Russian-American. I guess I never bothered to figure out other than guess (badly) from the name.

1/14

• There’s a Wikimedia Commons category for the WTFPL.

  Some of the things there are pretty WTF. Like, what?

1/13

• “Lucifer” means something like “shining” or “morning star” or “light-bringing”.
• RationalWiki has an article simply titled Goat.
• If you hold three fingers sideways it kind of looks like the figure 3…

1/12

• Tragedy of the anticommons is a thing. So is comedy of the commons. The fourth entry completing the square with “tragedy of the commons” is “successful capitalism”.
• There is a group blog called More Right, which is, as far as I can tell, quite weakly aligned with Less Wrong, although I haven’t spent too much time investigating.

1/11

• IBM opposed dropping trigraphs from C++. IBM still uses EBCDIC in places. *shudder*

1/10

• Unfriendly AI in the paperclip-maximizer sense cannot be the (earliest) Great Filter because a superintelligence-driven expanding sphere of paperclips would be super visible in the universe. Wow. I had never thought of that.

1/9

• Python has defaultdict objects that act like dicts with default values for missing keys. Wow, for my tied-for-second favorite language, I understand its standard library quite poorly.
• Long and short scale names for large numbers (where “billion” means either 10¹² or 10⁹ respectively) are both adapted from a French system.

1/8

• The Segal-Cover score tries to quantify the qualifications and ideological leanings of SCOTUS justices.

1/7

• The usage of the word “analogy” to refer to “A is to B as C is to what?” questions is quite scantily documented in Wikipedia.

1/6

• The process of deliberately misspelling words for effect is called sensational spelling.
• YellowGreen and GreenYellow are noticeably different web color names.
• Also, DarkGray is actually lighter than Gray. WTF?

1/5

We reached 200 today!

• Unlike most of the rest of the play, Macbeth 4.1 is trochaic (tetrameter, to be precise). I am amazed I read through this part and just thought “wow, nice meter” without realizing the stresses were totally different. I wonder what other instances of trochaic poetry I just filtered out mentally?
• LLVM has a totally rad dragon mascot. (For those of you keeping track at home, Idris is also named after a dragon from a 70’s kids’ TV show.)

1/4

• You can follow people on oneword™. Because I just got a follower. (For no particular reason: I was linked to oneword from Holden Lee’s website.)
• Data.List.delete exists.

1/3

• Django redesigned its site.
• GHC converts typeclass constraints into dictionary arguments, which is a confusing thing the point of which is that unfortunately that there is no way right now to specialize Foldable.elem to Set.member.

1/2

• The tryte is an actual term for 6 trits (ternary digits).

1/1

Happy new year!

• #SELFIE contains the line “Let’s go take some shots”, which makes it good for remixing.
• BY THE WAY (I didn’t learn this today, I forgot when I learned it, but it was within the last week or so, so I’m just going to put it here) Sam Tsui covered #SELFIE. This is amazing.

12/31

• The noted Honda Rube Goldberg machine advertisement is called “Cog”, and won awards. There are awards for good advertisements.
• Colloquy saves transcripts with the totally radical file extension .colloquyTranscript. (Beneath the hood it’s just XML.)

12/30

• According to TVTropes, Elsa was supposed to be a pure villain until Idina Menzel’s empathizable rendition of “Let It Go” inspired the writers to make her an anti-hero instead.

  (why am I going on TVTropes? why am I going on TVTropes!??!?!!?)

• Oh wait, Macbeth is the Trope Namer for “No Man of Woman Born”. I still don’t remember enough from the article to be particularly spoiled, thankfully.
• Our school allegedly has a Chromebook cart that I have never seen.
• Also, Na’vi grammar has its own Wikipedia article. I didn’t expect it to meet notability guidelines. (Maybe it doesn’t.)
• All of Avatar (the movie)’s creatures are named, both normally and scientifically binomially.
• No, really, don’t try to interleave submission of the Common App to two institutions at the same time. The submission part breaks hard enough that somebody will email you about it.

12/29

• Don't try to interleave submission of the Common App to two institutions at the same time. Nothing really bad happened, I mean, but the submission part fails.
• De-emphasized text is .text-muted in Bootstrap.
• Mormons are a subtype of Christians.
• WordPress disallows duplicate post slugs within some time frame wider than a single day (I’m not sure what it is). Darn.

12/28

• Wikipedia has an article category “Living people”, with 689,243 entries. There is also “Category:Living people on EN wiki who are dead on other wikis”.
• explainxkcd has names for all the xkcd characters. Also, there’s a binary connect-the-dots puzzle in 1000.

12/27

• The Stanford Puzzle Hunt (website, to give it the benefit of the doubt) is… underwhelming…

12/26

• Some people once tried to give their child a name including a backslash. Okay…

12/25

• The “BFG Repo-Cleaner” cleans Git repos. It’s in Scala, and it’s fast. Also, it says its jar file doesn’t depend on Scala because everything is packed.

  Hmm, I guess this is a good sign for doing more stuff in Scala.

• “Tree” is also a term in descriptive set theory.

12/24

• Firefox has a smartphone called the Fx0 now. It’s transparent and pretty cool.
• Mozilla’s Shumway project attempts to emulate Flash in JavaScript. Actually, TypeScript, to be precise, which is a superset of JavaScript with static typing and class-based OO facilities. TypeScript is by Microsoft and open-source under Apache 2.0. Interesting, I didn’t know Microsoft did significant open-source stuff until now.

12/23

• The C (not C++) standard library has bsearch.

12/22

• The Clock of the Long Now is an actually prototyped clock and everything. (I only knew it as an MIT Mystery Hunt answer before this.)

12/21

• The Haskell package arithmoi exists and it is totally number-theoretically awesome.

12/20

• The when switch-case syntax that CoffeeScript uses is from Ruby. Yeah, I should have known.

12/19

• It appears that Caltech has more a cappella groups per undergraduate student than MIT.
• Goodhart’s law, in school context, is that all tests become inaccurate if used as standards. I’ve seen this before but haven’t solidly committed it to my memory bank of eponymous laws yet.

12/18

• OS X has automatic transformations like turning quotes into smart quotes and double or triple hyphens into hashes in native apps. The first “native app” I’ve used in more than two years that I’ve noticed this in is the IRC client Colloquy.

12/17

• The Burrows-Wheeler transform is pretty cool.

12/16

• Codeforces has multiples-of-250 points now.
• Rust 0.12 has switched to requiring uints for indexing everything? Aww, I thought this was one of the things C++ did wrong. (Too easy to depend on an index becoming negative to terminate a loop.)
• Apparently Rust programmers have adopted the demonym “Rustaceans”.

12/15

• Monads are also the name for indivisible units in Pythagorean philosophy.
• git mergetool is scary. Something happened and hogged all my memory.
• Fully qualified URLs have a dot at the end.

12/14

• Bruce Schneier Facts. lol.

• The periods of the Fibonacci numbers under moduli are called Pisano periods, written π(n), no doubt because they were investigated by a guy named Pisano.

  Actually, Pisano is just another of Fibonacci’s names.

  What???

• Avi Kaplan (of Pentatonix) covered “All About That Bass” with two other people I’ve never heard of before. Notable not so much for the singing (though of course it’s good) as for the delicious (literally!) humor.
• Qiaochu Y. was an MIT blogger. Hmm.
• Tibetan describes numbers with 1/2 fractional part as “half less than X”. There exist “half digits” in Unicode that there is only very weak evidence for them meaning half less than the digit. The “half zero” is therefore, wonderfully, −1/2.
• SVG <path d="...">. Who invented this codegolfy syntax?

12/13

• DST mnemonic: clocks “spring forward and fall back”.

  I still don’t remember when it happens.

• You can “Complete My Album” in iTunes if you’ve bought some of the tracks — the album’s total price becomes discounted by the price of whatever tracks you’ve bought already — so you don’t lose anything by buying one track first. That’s weird. This isn’t the first individual track off an album I bought (I do this very sparingly) but I guess I didn’t notice the first time. Yay for non-strategic buying.
• Canada and Kenya use all three date component orders, YMD, DMY, and MDY.

12/12

• Perl’s -M is “script start time minus file modification time, in days”. So -M $a > -M $b if file $a was modified earlier than file $b. I guess you should think of it as file $a is older than file $b. Still, meh.

12/11

• Xcode why do you want to open markdown files
• The Leyden jar wasn’t named after a guy called Leyden (although there are several such), but after the city that the Dutch scientist Pieter van Musschenbroek discovered it in.

12/10

• “Aloha”’s essential meaning is “love”, which is why it’s suitable for both a greeting and a farewell.
• Wow, this article on autoantoynms is quite the wiki-rabbit-hole. I knew “cleave” was weird, but that was about all.
  • “Cleave”’s autoantonymic meanings have separate etymologies and come from different Old English words.
  • “nouns being verbed”. Is that Wikipedia having a sense of humor?
    • The linguistic terms are “conversion” and “zero derivation” (creating a word from an existing one without changing form). The rhetorical device of using words novelly is “anthimeria” and does most frequently involved using nouns as verbs, i.e. verbing them.
  • “Inflam[m]able” only means “flammable” in Spanish/French. So even if you try to be unambiguous by using “flammable” in English, you’ll still cause confusion if you try to be multilingual at the same time.
  • “Let” frequently has the archaic meaning of “forbid” in the Bible.
• 「創」is sort of an autoantonym in Chinese since it can mean to create or to seriously hurt something.
• Neoplasm (cancer) and pleonasm (redundant words) are natural perfect Spoonerisms. What the zarking fish, English.
• Right now, if I have smart quotes in Google Docs with the font Ubuntu, I see superscript 8s and 9s instead. It doesn’t seem to be a problem with the same font elsewhere or with other fonts or with anybody else online, so I don’t know if this is a problem on my end with my computer or my cache or what. Even weirder, a single smart double quote looks normally smart before you type the closing quote, which changes both of them to look like superscript characters — but the codepoint underlying that opening double quote is the same, which can be seen by copying into a text editor. Fonts are wonky.
• You need a lot of free disk space to generate or export movies. Eep.

12/9

• Ronald Reagan’s Chief of Staff was called Don(ald) Regan.
• There was an official process in the Directors Guild of America for directors who wanted to disown a movie they directed by replace their names with the “Alan Smithee” pseudonym. The 1997 film about a director disowning a movie was disowned by its director and led to the DGA disowning, so to speak, the pseudonym “Alan Smithee”. This film also set a record for the number of Golden Raspberry awards (four) won by a single person (its writer).
• Edgar Allan Poe’s The Raven is in trochaic meter. I’ve been feeling like poems in non-iambic meter were generally incredibly underrepresented for a while; it’s nice to have a famous counterexample. (I could have just found it by looking up “trochee” on Wikipedia, actually. I’m being silly.)

12/8

• Annotations on YouTube can only have links of one of a couple whitelisted types.
• Google Chrome has a “poof” animation and sound effect when you delete a bookmark from the bar.
• Ceva’s theorem was proven much earlier, around the eleventh century, by the Arab mathematician Yusuf ibn Ahmad al-Mu’taman ibn Hūd. Quite a mouthful. Also, the “C” is proounced /ch/.
• Auxiliary parallel line for proving Menelaus. Got it.

12/7

• kramdown thinks my vertical bars are tables. Be careful around vertical bars.

• You can get Mac OS X to write to NTFS drives if you try hard enough.

  I was following these three roughly equivalent guides, about how you do

    sudo echo 'LABEL=DRIVE_NAME_HERE none ntfs rw,auto,nobrowse' >> /etc/fstab
  

  and then the drive will be writable, even though it doesn’t appear in Finder. They didn’t work; the drive wouldn’t show up in /Volumes at all.

  Then I followed this guide and got the error mentioned somewhere in the comments:

  The OSXFUSE library version this program is using is incompatible with the loaded OSXFUSE kernel extension.

  Oh well. I restored the backup /sbin/mount_ntfs and decided to try the /etc/fstab solution again. This time, somehow, it worked.

  I don’t get computers.

• !! in Bash runs the previous command again. I knew this at some time.

  You can also e.g. sudo !!.

  Or !-3 for the third-last command, or !a to run the last command starting with a.

  Writing this down because I’m deleting files.

12/6

• Wolfram|Alpha thinks that EST is Australian Eastern Standard Time but that ET is (the more common North American) Eastern Standard Time. What?
• The name of the O(n) palindromic-substrings-computing algorithm is Manacher’s algorithm. One of them, anyway.
• Use %1 etc. in a Windows batch file for arguments. Basically, replace $ by % and there’s a chance of things working.

12/5

Rescued from dipping under 3 TILs per day!

• The most widely cited, but inaccurate, formula for maximum heart rate is due to Haskell and Fox. I just didn’t expect seeing that last name around.

• “Hung” is the default past tense for “hang”; “hanged” is generally used only for the meanings involving death by suspension from a rope or something similar.

  Wow, morbid TILs today.

• Cryonics is already well under way in the transhumanist community; in particular there are a lot of famous people at the Alcor Life Extension Foundation.

  No, dammit, self.

  …

  It feels weird seeing lesswrong.com between kongregate.com and news.ycombinator.com on my primary LeechBlock list, but I think this is the way it was meant to be.

• Metapedia is the name of a neo-Nazi electronic encyclopedia.
• Dogs sense very similar scents from identical twins?

12/4

• Ubuntu-the-font’s alpha (α) is really not distinctively alpha-like. Darn, do I have to find a new favorite font?
• Gangnam Style has over 2³¹ − 1 views and YouTube has had to upgrade to a 64-bit integer.

12/3

• The Apportionment paradox
• Soylent, the food product that tries to supply all the nutrients you need cheaply and quickly so you can eat/drink only it and nothing else, has a sub-website DIY Soylent where people share recipes for making their own similar one-stop-shop-for-everything foods.

12/2

• Microsoft Internet Explorer 11 has no trace of Internet Explorer or MSIE in its userAgent or appName. Absolutely nothing.

  Apparently, the goal is to get user-agent sniffers to treat it like standards-compliant browsers.

  Unfortunately, I just ran into an IE-specific bug today that persists in IE 11 (not that I have access to any other version of IE or that I’m going to put much effort into trying to get that access). Fortunately, there was a pretty clear workaround that worked and was probably better memory-performance-wise anyway.

12/1

• Blood Sport (Kickstarter project, currently suspended): when you lose blood in a game, you lose blood in real life. (It gets donated.)

11/30

• As of the most recent (2010) census, Ferguson, Missouri had 8,192 (= 2¹³) households.
• Greasemonkey has this really weird and fun intervention when you first try to paste something into its script editor — the toolbar tells you to be careful about pasting code and then makes you type “allow pasting” in the same area where you write code.
• There is a file called ++++++ in my script folder. Why is there a file called ++++++ in my script folder?
• Chinese Uncyclopedia = 偽基百科, which is actually a pretty nice name for it.

11/29

• obj.addEventListener("mouseover", function() { ... }, false);

  Not "onmouseover".

  What am I doing!?

  This is not so much a TIL as it is a venting about the idiocy of my debugging — I was stuck on this bug for something like two days.

• Hitler was addicted to amphetamines.

11/28

• “Before the mid 18th century, double dots were not used. Until then, in some circumstances, single dots could mean double dots.” — Wikipedia on the dotted note, with a citation I didn’t know traditional musical notation could be this imprecise (for lack of a better word).

11/27

• Obamacare, actually the Affordable Care Act, actually the Patient Protection and Affordable Care Act, has the long title “An act entitled The Patient Protection and Affordable Care Act”. According to Wikipedia…
• Even SparkNotes cannot spell the names in Things Fall Apart properly.
• Mosquitos distance ε outside a mosquito net can be equally annoying as mosquitos inside them >_<

11/26

• There are equality tests for some function types that are guaranteed to terminate if the functions provided to it always terminate. [Bool] -> Bool (or, perhaps more faithfully, (Integer -> Bool) -> Bool ((Nat -> Bool) -> Bool might be even better)) is one such. Ooh. (PDF talk)

11/25

• Eliezer Yudkowsky has performed three more AI-Box experiments after the two on his website. They’re documented not-very-conspicuously on this article Shut Up and Do the Impossible:

  There were three more AI-Box experiments besides the ones described on the linked page… I played another three AI-Box experiments. I won the first, and then lost the next two. And then I called a halt to it.

  Also the Singularity Institute isn’t called that any more.

  Also, please remind me never to go near information about the technological singularity and superoptimizers on days when I have homework.

• There is a Heart of Darkness collaborative storytelling MUSH. The criticism we’re reading in class by Chinua Achebe is hosted there.
• Massachusetts has used non-proprietary document formats since 2007. That’s the only state that Wikipedia has down as clearly doing so, although the subarticle has an “This article is outdated” block on top, so I don’t know what the status of this is.

11/24

• Wikipedia’s article name for the 2010 BP oil spill is the “Deepwater Horizon oil spill” (I didn’t even recognize it at first.)
• Standalone SVG files can invoke Javascript files.

11/23

• trOllolol (and the account has thanked several posts recently which is how I noticed)
• Locusts are a type of grasshopper. (I didn’t know what I thought they were before this… their own clade, I guess?)

11/22

• 棋盤、稿紙、綠豆糕的梗真的無所不在。
• Detective Conan has more than one character named after their voice actors. (I wonder how common this practice is elsewhere?)
• printfing with %f and %lf are different and using the second one will lead to lots of Wrong Answers.
• Trello’s (pretty darn cute) husky mascot is named Taco. There also exists a to-do-list manager slash collator called Taco that syncs with Trello, among many other sites; they don’t seem to be directly affiliated beyond that.

11/21

• Ellie Goulding’s Burn is nowhere as short as the osu! track makes it out to be.
• Asymptote stuff.
  • rgb takes components that are fractions between 0 and 1. Not 0 or 255 or anything.
  • sequence(n) is the typical half-open range including 0 and excluding n. And yet sequence(n, m) is doubly inclusive. wat.

  • alias(a, b) checks two arrays for identity equality (do they point to the same part of memory? like Java’s == or Python’s is). At first I didn’t understand they were referring to identity equality and thought the name of the function was wat-worthy. Then I understood: okay, so they want == to be the friendly value-equality as it is in Python?

    > new int[] {3, 5, 4} == new int[] {3, 5, 4};
    0:      true
    1:      true
    2:      true
    > new int[] {3, 5, 4} == new int[] {3, 4, 5}
    0:      true
    1:      false
    2:      false
    

    == is vectorized. I don’t even…

    I don’t know how to test if two Asymptote arrays are value-equal. I’m not going to find out either, because I don’t need it.

11/20

• 教官’s words are super influential.

11/19

• I have the same birthday as 2014 TWN1.

11/18

• For whatever reason, DuckDuckGo’s gray-box results for the query “u.s. presidents” are entirely drawn from U.S. Presidents in the Doctor Who universe. (This does not occur for the unpluralized query, “u.s. president”.)

• ephemeron (n.) something short-lived or ephemeral. Notable because (1) it sounds cool and (2) I learned this word from the Lua reference manual § 2.5.2:

  A table with weak keys and strong values is also called an ephemeron table.

  I don’t even know what that means in Lua terms yet.

• FantasySCOTUS exists.

11/17

• The vendor-prefixed versions of linear-gradient interpret angles as polar angles, so e.g. 0deg is to the right and 90deg is up. However, the official spec and the rest of CSS all use navigation angles, so e.g. 0deg is up and 90deg is to the right.

11/16

• Vim’s default digraphs dedicate many digraphs-in-the-linguistic-sense, such as “zh”, “sh”, “ch”, “an”, or “en”, to bopomofo characters.
  • Also, there are three bopomofo characters used for “non-standard dialects … and other Chinese languages”: “ㄪ” (≈ v), “ㄫ” (≈ ng), “ㄬ” (≈ gn). I’m guessing they could also be used to transliterate foreign names and languages into bopomofo, the way “w” is used in Spanish (e.g. this mysteriously titled Wikimedia file, which, on closer inspection, is titled with a bopomofo transliteration of “Preview” — except again “ㄌ” is used for the “r”, which I still don’t understand).

• “Anaphora” is simultaneously a name for:

  • the linguistic use of an expression (the anaphor) to refer to another expression (the antecedent) that occurred previously in the context (most familiarly, using a pronoun to refer to a noun, but the general term is “pro-form”, including pro-adjectives e.g. “more so than hoped” and pro-adverbs e.g. “do it this way”), and
  • the rhetorical device of repeating a word or words at the beginning of each of a series of clauses.

  The opposite of the lingustic “anaphora”, using an expression to refer to another expression that will occur later in the context, is (happily) “cataphora” (with matching terms cataphor, postcedent). Sometimes “anaphora” is used as an umbrella term for both types of referral, although the technical hypernym “endophora” exists.

  Alas, the opposite of the rhetorical “anaphora”, repeating a word or words at the end of each of a series of clauses, is “epistrophe”. And if you use both anaphora and epistrophe, you get “symploce”.

  Also unhelpfully named:

  • “epanalepsis”, repeating a word or words at both the beginning and the end of a clause or sentence — “The king is dead; long live the king.”
  • “anadiplosis”, repeating a word or words at the end of a clause and then at the beginning of the next clause — “Fear leads to anger. Anger leads to hate. Hate leads to suffering.”
  • “antimetabole”, the two above combined — “I meant what I said, and I said what I meant.”
    • A broader term for this is “chiasmus”, which includes more things in “A B B A” form and is also applied to meaning (“He who dotes, yet doubts; suspects, yet strongly loves”) or part of speech (“By day the frolic, and the dance by night”).
• YouTube autocorrects pinyin to Chinese.

• “Winter Wonderland” has a second verse.

  In the meadow we can build a snowman / And pretend that he’s a circus clown…

11/15

• Those quote boxes on AoPS are actually two independently styled <div>s, the top lacking a bottom border and the bottom lacking a top border.
• Firefox displays a “Mozilla Firefox seems slow… to…. start.” message if it starts slowly.
• There’s a bulletin board upstairs our school, around seventh grade or so, dedicated to Ayn Rand and Anthem. o_O
• iTunes thinks it’s an alert-worthy event if you uncheck all your songs.

11/14

• “Topological analysis” is something that you can apply to poetry. See Connectedness in Poetry: Toward a Topological Analysis of E. E. Cummings. It is not a coincidentally mathematical term — the paper gives a mathematical definition of a collection of subsets of a space being a topology over that space before applying it to the poems. I’m still wondering if my leg is being pulled.
• “Trochee” is autological. “Iamb” is not (I’ve been pronouncing it wrong), but “iambic trimeter” is, sort of, so that’s all right. Although I guess “-meter” is arguably a pyrrhic.

11/13

• “See you later, alligator!” has the response “After [a] while, crocodile!”
• The double amphibrach exists, a relative of the double dactyl (slightly more restrictive about the single diamphibrachic word).

11/12

• Wikipedia has names for all four disyllablic, eight trisyllabic, and sixteen tetrasyllablic poetic feet.
• The convergence problem shares with the divergence problem (learned of two days ago) equally vague naming, equally specific subject matter, and a complete lack of any relation whatsoever despite the perfectly antonymous names. (And I stumbled upon both of them independently within three days of each other!)

11/11

• The approximation 355/113 for π has a name, Milü. Which is actually just a pinyin transliteration of 密率.

11/10

• E. E. Cummings didn’t stylize his name in lowercase all the time. There’s some controversy over which form he preferred. It’s complicated.

• There’s this gigantic block of weird animals in Unicode starting at U+1F400. The Chinese zodiac animals are a subsequence in order — that can’t be a coincidence, can it? — but extremely irregularly. I have a lot of difficulty imagining the Unicode guys discussing which animals to include.

  A sampling of some of the weird animals in that section:

  • U+1F400 RAT, U+1F401 MOUSE
  • U+1F402 OX, U+1F403 WATER BUFFALO, U+1F404 COW
  • U+1F40F RAM (ok, but is it a male sheep or a male goat?), U+1F410 GOAT, U+1F411 SHEEP
  • U+1F41F FISH, U+1F420 TROPICAL FISH, U+1F421 BLOWFISH — ok, why those fish in particular and not, say, a swordfish or something?
  • To make things more bewildering, there’s a block of “animal faces” later, which includes U+1F438 FROG FACE, U+1F439 HAMSTER FACE, U+1F43A WOLF FACE, U+1F43B BEAR FACE, and U+1F43C PANDA FACE… despite the fact that there are no characters for FROG, HAMSTER, WOLF, BEAR, and PANDA.
  • Some conspicuous animals that neither have characters devoted to them nor to their faces include the fox, the deer, the bat, and the zebra.
• So, like, despite being “the missing package manager for OS X”, Homebrew got so popular that they forked it back to Linux?
• “Human beings are the most social animal on our planet. Only three other animals (termites, eusocial insects, and naked mole rats) construct social networks as complex as ours…” From this article on money and happiness via Hacker News, the rest of which is already quite fascinating.
• The divergence problem has a wonderfully generic name but is extremely specific. Guess what field of study it comes from before clicking.

11/9

None :(

11/8

• Some television shows have disclaimers to the effect of “If anybody does anything bad in this show, they will get the punishment they deserve, so don’t try this at home!”
• Python and Ruby have character-for-character identically named errors (ZeroDivisionError) for division by zero.

11/7

• Sites using CloudFlare somewhere along the line may use script tags with an extremely poorly documented type='text/rocketscript' attribute. As far as I can tell, it’s just JavaScript that’s loaded in a special way.
• Anne Sullivan (Helen Keller’s teacher) was nearly blind for most of her life.

11/6

• RedCloth’s Textile markup language deals with dashes by converting two hyphens into an em dash. At least two fonts (Fabrizio Schiavi’s Abitare Sans™ and Sys™, and I’m betting there are more) do the same thing with font ligatures.

  (Textile turns single hyphens surrounded by spaces into en dashes. The alternative method I prefer, which is used by Kramdown and (La)TeX, is turnng two hyphens into an en dash and three hyphens into an em dash. I think this is better since there are times when one needs en dashes and, as I learned about a week ago, times when those en dashes must not be surrounded by spaces for the intended typographical effect.)

• Reasonably recent versions of Google Docs save every revision after every keystroke. And somebody wrote a tool to play it back.

• It is super hard to remember which way the charge and ions go in a nerve impulse. Okay, brain? Come on, this is the stuff that’s going inside you, it should be your specialty. As a public service, here is a long arbitrary set of mnemonics:

  • Normally, the interior of the neuron is negatively charged and full of potassium (K⁺) ions. The neuron is sad. It is too sad to say anything other than a single-letter affirmative chat abbreviation, like the black guy in the meme.

    When the neuron becomes excited its interior becomes positive and full of sodium (Na⁺) ions because it is happy and loudly vocalizing one of the songs depicted below.

    

    That’s xkcd 851, if it wasn’t obvious.

    Now you know!

    Reality is a whole lot more complicated than this because the differential is maintained with ion channels actively transporting ions by various mechanisms, so please only use this to remember which ions and which charges go which ways.

• (Retconned!) Titanic the movie has, as a frame story, a quest to seek out an invaluable gem, the Heart of the Ocean, that went down with the ship. After the film, they commissioned an authentic Heart of the Ocean necklace valued at about $20 million.

11/5

• In Google Docs, if you start a line with * or - or + or ., followed by a single space, you get the beginning of a bulleted list.
• Professional tech companies try to quarantine themselves from memory sticks and stuff, under penalty of fine. As best as I can tell, they are (mostly understandably) concerned about viruses.
• The U.S. once had a plan, Project A119, to nuke the Moon.

11/4

None today :(

11/3

• “Everyone Ruvs Chin-Kee” is a riff on “Everybody Hates Chris”, isn’t it? Oh, “Everybody Hates Chris” was titled after “Everybody Loves Raymond”. But the first two share the high-school/teenager story background better.
• College acceptances can come as early as October 30.

11/2

• Add to below: WHATWG is a group of browser-vendors who split their HTML spec from the W3C spec because they thought the latter group was developing slowly and mis-applying its efforts to XML. So the WHATWG worked on HTML5, and W3C rejoined them in 2007 to make it a standard. This is really confusing.

• There is a <ruby> HTML tag (HTML spec @ WHATWG / XHTML spec @ W3C. It has been W3C-certified since 2001. It has nothing to do with Ruby the programming language — “ruby” are annotations for East Asian languages. Browser support for it is abysmal, though, so I guess it’s not surprising that I haven’t heard of it.

  Let’s play Will It Render?

  • Multiple annotations, WHATWG-HTML style (i.e. without <rb>):

    三ㄙㄢ 人ㄖㄣˊ 行ㄒㄧㄥˊ ， 必ㄅㄧˋ 有ㄧㄡˇ 我ㄨㄛˇ 。

  • Multiple annotations, W3C-XHTML style (i.e. with <rb>):

    三ㄙㄢ 人ㄖㄣˊ 行ㄒㄧㄥˊ ， 必ㄅㄧˋ 有ㄧㄡˇ 我ㄨㄛˇ 。

  • Interleaved <rt>s (HTML only):

    三ㄙㄢ 人ㄖㄣˊ 行ㄒㄧㄥˊ ， 必ㄅㄧˋ 有ㄧㄡˇ 我ㄨㄛˇ 。

  • Complex XHTML (nobody supports this):

    三人行，必有我。 ㄙㄢㄖㄣˊㄒㄧㄥˊㄅㄧˋㄧㄡˇㄨㄛˇ

  (The text chosen is an in-joke that you are not expected to get.)

• It’s really hard to choose a pretty shade of dark yellow.

11/1

• You can somehow embed a 3D figure that can be rotated with the mouse in a PDF through Asymptote. What???

10/31

• AoPS has [latex] code-highlight tags.

10/30

• Very little, if any, of “The Ultimate Showdown (of Ultimate Destiny)” is a rap, i.e. most of the lyrics have musical notes, sort of. I probably knew this at some point in my childhood but forgot somewhere along the line.
• There is a Yolo County in California, as well as various other landmarks named “Yolo” nearby.
• November 1st is “the EU’s birthday, the anniversary of the race where Seabiscuit defeated War Admiral, and the day the MPAA introduced their film rating system.” Thanks, UChicago.
• There’s a species of agnostid trilobite named Han solo. Possibly fittingly, it is the only member of its genus Han. The official explanation is that it was discovered in China and named after the Han people and then the only surviving member of its family. The namer said elsewhere that he was dared to name a species after a Star Wars character.

10/29

• The H2G2 phrase “a whelk’s chance in a supernova” is severely underdocumented and underappreciated on the Internet.

  “What’s a whelk got to do with a supernova?” said Arthur.

  “It doesn’t,” said Ford levelly, “stand a chance in one.”

• If you want to hyphenate a compound in which one of the phrases contains a space or is already hyphenated, you can use an en dash instead. cite (copied from Wikipedia)

  anti–Cold War

  Or you can just hyphenate the entire phrase, like the other boring non-typographical-snobs.

  Still, the en dash is probably an unbeatable option when you try to join two phrases, each of which is already hyphenated on its own. Wikipedia’s source gives the example “public-school–private-school rivalries”.

  Vimmers: ^K-N.

• Nobody has any idea how big Wikipedia is if you include the images. More interestingly, Wikipedia’s growth was modeled by the Gompertz function y(t) = ae^−be−ct. This sigmoid function, which has horizontal asymptotes 0 to the left and a to the right, is also used to model tumor growth, among other things.
• There’s a Python package called oursql. There is also a community podcast called OurSQL, which appears less popular than the Python package. (Sure beats adding .js to random words.)

• Sigh, Haskell, does your lexer have to involve such namespace-cluttering data constructors?

  λ> :t Char
  Char :: Char -> Lexeme
  

• If you enter a non-ASCII character into an MIT essay text area and save, it breaks in an utterly fascinating way. As best as I can figure out:

  • characters under U+07FF (those that take up two bytes encoded under UTF-8) get replaced with two copies of the Unicode replacement character (�, U+FFFD);
  • characters between U+0800 and U+FFFF (those that take up three bytes encoded under UTF-8) get replaced with three copies of the Unicode replacement character;
  • but characters above U+10000 (those that take up four bytes encoded unter UTF-8) just get replaced with two question marks. Yes, ASCII question marks, ? or U+3F.

  I did not figure out how to transmit a five-byte UTF-8-encoded Unicode character. (I’m certain it’s possible in principle if you could just craft a web request with the right byte sequence.)

  The fascinating bit is of course that the Unicode replacement character itself takes up three bytes… so upon each save, each Unicode replacement character gets replaced by three more Unicode replacement characters. Therefore, saving my MIT application is not only not an idempotent action, but an exponential order of growth away from being idempotent. More graphically, if you start with a single non-ASCII character taking up two bytes under UTF-8, such as §, and save 21 times, you would end up with about enough bytes for the entire text of the English Wikipedia. Ignoring network latency, that would probably take under two minutes. Unfortunately for this absurd hypothetical, we can’t actually ignore network latency while transmitting gigabytes of Unicode replacement characters. Or maybe we can, given the ridiculously low Kolmogorov complexity of a string of nothing but Unicode replacement characters, if there’s some sort of standard mechanism for compressing web requests. I’m not sure. But then you’d have to compress and decompress them at the endpoints anyway, and that would still take exponentially more time each save. Also, I’m not sure how large a role my browser plays in this interaction — maybe part of the replacement characters are caused by it replacing invalid bytes. But I really need to stop procrastinating now, sorry.

• Wait, Syntastic errors generate tooltips on mouseover?

  (Mac|g)Vim has tooltips!?

• Wingsuit flying is a thing. This despite the fact that the first prototypical wingsuit flyer, Franz Reichelt, jumped from the Eiffel tower and crashed head-first into the ground. But that didn’t kill him — a heart attack during his drop did. There are videos of him jumping on YouTube. I don’t even. (I remain slightly skeptical though, since this is cited only as a footnote on Wikipedia.)
• The Konami Code was first used in a 1986 game.
  • It does not officially end in START; this is a “common misconception”. Also, I don’t actually know why I know what the Konami code is. Is it through Achievement Unlocked?
• Oops, college 4 has an essay hidden under its Activities tab. Yeah. This is kind of troll.
• COUNT in spreadsheets (incl. Google Spreadsheets and OpenOffice) counts numeric values, not non-empty values.

10/28

• Whichever code highlighter AoPS uses actually links classes it recognizes in Java source code to Google “I’m Feeling Lucky” queries, instead of directly into Java’s official documentation. I guess Java documentation URLs are really fickle?

10/27

• (SUMS) There exists a nice list of devious (DVS) words. The page says they are officially “Grammagrams”, but that’s boring.

  Serendipitiously, I saw this theme before while digging through A.Word.A.Day archives and the last word that week was “devious” too.

• Every single other MIT applicant from my grade is some sort of club president.
• The not-too-rare text postprocessing feature of replacing an x flanked by digits with a multiplication sign has an unfortunate false positive: hexadecimal literals starting with 0x followed by a digit. <code> your hexadecimal literals, people!
• The Harkness Discussion class method was developed at Phillips Exeter Academy. That sounds familiar…
• “Holistic” contains “whole” as its first syllable. In fact “wholism/wholistic” are actual synonyms. Whoa.

10/26

• If you want to join a bunch of lines in Vim with a custom delimiter via :'<,'>s/\n/custom/, you have to select all but the last line. Kind of obvious if you think about it, actually; what gets replaced is the \n at the end of each selected line.
• Want to make sure user-written programs don’t take up too many resources? Just set hard caps on how deep the stack can get and how many iterations a loop will run in your programming language. Some people really solve this problem this way.
• Observations about Oedipus literally being a mother(4)er, despite probably not being tautological (as in one did not evolve into the other), are pretty common and not particularly witty.
• phenomist does not actually know all the other TIL lists out there. (Well, I only know one more than he did.)
• Parkinson’s law for computer storage: the amount of stuff stored on a computer expands to fill the space available.
• The Winkel Tripel projection. It exists, it’s mathy, it’s National-Geographic-Society official, it’s not a typo.
• hackage/Data.Thrist

10/25

• The (La)TeX highlighter for (Mac)Vim 7.4 now bolds stuff in \textbf{} blocks. But why doesn’t it extend into parentheses?
• Hmm http://www.taiwaneseamerican.org/
• Sometimes there’s actually an advantage to the way names in different languages are written in different order. It’s too wordy to express this in full generality, so the specific permutation I learned from is this: you can write “given-English-name family-name transliterated-given-Chinese-name” to specify the full names in both languages of a primarily Chinese-named person with non-redundant easily-understandable English, which is especially useful when the English name of the person may not be well known.
  • Yeah, that was already really wordy.
• ∃ CAPTCHA that asks of a picture, “What is this animal?” Also ∃ website requesting you to verify that you are less than a certain educational level. And ∃ confirmation emails that (1) reveal the length of your password plus the last character and (2) emphasize a word with underscores despite having already used way too detailed HTML links. Yeah, it’s all the same website. I won’t reveal it to make it more fun.
• DuckDuckGo thinks “facade” is a hex color. Which it is, of course, but that’s the sort of puzzle punchline thing that search engines shouldn’t serve up as their first result, isn’t it?
• The facade design pattern is useful for organizing people real life.
• Oh look brace.io will give you one free subdomain for your static Dropbox website. (Unfortunately you still have to hit a “publish” button now and then, because changes only automatically go to a double subdomain saying “draft”, but my GitHub Page is for that sort of stuff. There are other options e.g. KISSr but 1000 requests per month seems slightly prohibitive. I don’t know. “brace.io” is a wonderfully short domain anyway.)
• People dress up to campaign on Halloween. (For the same person. One of them was Superman. Another was in a full-body cartoonish wolf suit.)
• It’s possible to listen to a song and a six-year-old mashup dozens of times each before realizing that the song is in the mashup. The feeling when you realize this is fascinating.
• I like the power from making things font-weight: 500 way way way too much.
• Important programs are buggy too. (These both just happened to be on Hacker News.)
  • Deep Blue http://fivethirtyeight.com/features/the-man-vs-the-machine-fivethirtyeight-films-signals/. A program written with this caliber still makes a “random” legal move when it gets stuck?
    • Also, as an Internet content consumer I am still completely irrationally vulnerable to clickbait titles because I have definitely scrolled through FiveThirtyEight before and ignored this video. The article from The Verge linked on HN that then linked here was titled “How a computer error helped Deep Blue beat humanity’s best chess player”.
  • Mathematica http://www.ams.org/notices/201410/rnoti-p1249.pdf
• What? PokéDraw
• Keeping this TIL list feels about as exhausting as keeping a faithful dream journal. Maybe I should do that instead.

10/24

• Interactive fiction has spoiled me; x as short for examine as equivalent to look at is by no means universal.
• There’s this “debater’s stance” where you put one foot in front of and perpendicular to another, which is apparently supposed to help you fidget less and support yourself better.
• Deciding how you want to intone a poem is almost as hard as singing it. Possibly harder because it’s harder to describe intonation objectively and precisely.
• “gubernatorial”
• There exist people who type all uppercase letters by typing CapsLock once before and once after. Corollary: the <kbd> tag is actually useful in real life.
• It’s really hard to watch a file. (pyinotify doesn’t install on OS X 10.9 and watchdog explicitly says Vim’s way of writing files by swapping them in won’t trigger the event unless you set stuff up. I ended up just polling os.stat(mdfilename).st_mtime now and then. (Actually it’s set up with polling intervals ln 3, ln 4, etc. seconds, reset when the file change is detected. Overkill much?))
• Git “auto pack”ed my repo and told me to git prune loose objects. Cool. In other words, that is something that actually happens to people. (Obviously it was because I kept 80%~90% rewriting bootstrap.min.css)
• Default Bootstrap assigns font-weight: 500 to its headings.
• You can test if your page is on GitHub from a Jekyll template with site.github.

• Ruby or kramdown doesn’t handle Unicode all that well.

  ruby --external-encoding UTF-8 -S kramdown til.markdown
  

• Unlike pretty much every other college out there, Harvard “strongly encourage[s] you to explore all of your options including Ivy League institutions, colleges that comprise the Consortium for Financing Higher Education group, and other outstanding public and private colleges” in its unsolicited emails. (Links in original.) Making this all the more hilarious, the Consortium for Financing Higher Education page is hosted under web.mit.edu. Impressive. But I guess Harvard can afford to do that.

10/23

• I can write poetry!
• Tze-Yo-Tzuh, the top deity (think Arceus) of American Born Chinese, appears to be a Western insertion into the mythology based on the Chinese translation of the way God referes to himself from Exodus 3:14, roughly the part “I am that I am”. Hey look, a pi verse.
  • Also, translating Bible book names is hard.
• This exists. http://www.brainpop.com/games/winthewhitehouse/ Not that much strategic depth once you figure out what’s happening, and can have patently absurd outcomes (I ran as a Democrat and carried Texas 100%), but weirdly fun.
• My complex analysis textbook uses a concrete-baked invocation of the Jacobi triple product to prove a product expression for the theta function. You could have just said so, or at least mention the fact that everything is just a function of e^πiτ and e^2πiz.