• Things in the Sky

    Recently I’ve changed up my FlightAware alerts. I’m receiving alerts about more planes, but I’ve cut down on the number of alerts I get for each plane. Crucially, I no longer get alerts when the planes are diverted.

    We get one 747 a day here in San Diego, the daily British Airways flight from LHR. It tends to arrive around 5pm, give or take. Thursday evening I checked my phone while I was eating dinner with some knitting friends and I saw that this plane had just filed a flight plan to San Diego roughly around the time when it was usually landing. Super-surprising? Had it been diverted?

    A quick check of FlightAware showed that it flew in a circle over the airport, went to LAX, landed, and then flew to SAN.

    I listened to the LiveATC archives, and this is what happened over the course of roughly 15 minutes.

    1. Pilot contacted SoCal approach, like normal.

    2. Pilot told SoCal approach that they had a problem and wanted to check it out before landing. Started to circle.

    3. Pilot requested a diversion to LAX due to a problem with a flap. ATC provided directions on how to get to LAX.

    4. Pilot asked for a short cut because they did not have a lot of fuel left.

    I am not an aviation expert, but I am wondering about the motivation for requesting the diversion to LAX. There are two possibilites here:

    1. When you have this sort of flap problem, it is safer to land at LAX than at SAN, even if you are using terms like “minimum fuel.”

    2. If a plane has a flap problem, as soon as it lands it will be stuck to the ground until a mechanic can take appropriate action and this action is properly blessed by the correct paperwork. Do we have the right mechanics and parts here in San Diego? Maybe not. If the plane landed here as originally scheduled, would it have been able to fly back to London later that evening?

    In unrelated plane-watching news, every Saturday I read more and more about this ridiculous paparazzi-style lens that I want to buy. Since B&H does not do transactions on Saturdays, I am less tempted to actually buy it.

  • Friday Omens

    1. Cat in cone. She had minor surgery on Wednesday afternoon. She also had her teeth cleaned while she was under anesthesia. She had been on a hunger strike since returning home after the procedures, but she appears to be eating again. I worry about the water situation because I’m not sure if she is smart enough to get her head in the water dish. When I offer her the dish inside the cone region, she just tries to rub her incision on the side of the dish.

    2. Speaking of water, the hot water is out in my building today. I have lost track of how many slab leaks in the downstairs apartments have led to plumbing emergencies throughout the whole building.

    3. I am writing code that is impossible to test. It will hit an external API many tens of thousands of times and then record the responses. We only need to run the code once in order to get the information that we need. Each call to the API costs real money. It costs enough real money that it is worth spending a decent number of hours of my time writing the code in a way that cuts down on the number of calls we need to make in order to get all the information. The steps of preparing the payload, querying the API, and then recording the response are slow enough that there are a lot of ways that this script could time out. And goodness knows how many ways the API could return an error response.

    4. We have a utility function that we run on a somewhat regular basis on our test servers in order to get things all freshened up from time to time. This had been a shell script, as nature intended. Now we are rewriting them in JavaScript.

  • I Hear There is a New Star Wars Movie

    1. I have not seen the new Stars Wars movie, and I know nothing more about it than its title. And I sometimes get the title wrong and call it “The Revenge of Skywalker.”

    2. I joke that I have movie amnesia. This has been a thing since well before any of my head injuries or weird neurological events. I see a movie, and roughly immediately afterwards, I forget most of what it was about. This is one of the things that has been keeping me from watching Season 4 of The Man in the High Castle because I am going to need to remind myself what had happened up to this point (this applies to TV shows as well as to movies).

    3. OK, so there have been some Star Wars movies in the past.
      • In original Star Wars, they had to put together a team to destroy the Death Star. In some ways it was like The A-Team, but without the plagiarism.
      • Due to my generational alligiences, I am required to insist that Empire Strikes Back is the best Star Wars movie of all time, even though I don’t remember anything about it other than Luke wore black.
      • Then there was Return of the Jedi which I don’t remember either, but maybe that was the one with the Ewoks?
      • Many years elapsed, and I was probably in graduate school when they released more Star Wars movies. There must have been three of them? One of them had Jar-Jar. Was that the same one that had Natalie Portman?
      • That clump of movies that I can not remember is making me nervous about seeing the new one because the name “Skywalker” is in the title. Wasn’t there some sort of weird quasi-supernatural thing going on with Skywalkers in those movies? Like Mrs. Skywalker was magical? Do I need to know anything about Mrs. Skywalker’s arcane backstory to understand the new one?
      • There have also been a whole bunch of Star Wars movies recently. Even worse for me, I can’t keep track of which ones were from the main series and which ones were just there to bring in more money. There is the one where Han shot first, which I think was a side story. And I think that there was one with a girl who is different from the girl in the other movies?
    4. Jim is out of town right now, so I will not be able to watch Star Wars with him until he gets back.

    5. I am not particularly worried about hearing spoilers between now and when he gets back because I think that almost every character whose name I know is dead. The only two living characters that I am aware of are the girl who doesn’t dress warmly enough for the ice planet, and Adam from Girls. And since they are frenemies, they are probably going to have to battle it out. Plus, I’m just going to forget anyway.

    6. I mean, it’s been many, many hours of good vs. evil with light saber battles and space ship battles and other ancillary battles, so they are probably going to stick to that because it has made them good money so far. Cute critters have also worked well for them (as long as they are small and don’t speak).

    7. Perhaps we will learn that Alderaan shot first.

  • Finding the Entry with the Largest Value of Another Column in MySQL

    This is totally and 100% cheating. If someone catches you doing this, the SQL police will come after you and cite you for not using a self-join. Just so you know.

    Let’s say you have a table that keeps track of users, colors, and timestamps, and you want to know the most recent color for each user. It might look something like:

    Table: user_colors

    user color timestamp
    Sophie green 2019-08-12 12:34:56
    Sophie blue 2019-03-28 10:42:23
    Gwen red 2018-12-12 03:23:12
    Sophie purple 2013-09-12 04:52:23
    Gwen fuchsia 2017-07-02 11:12:13

    There are two standard solutions.

    SELECT `user`, `color`
    FROM (
    	SELECT `user`, MAX(`timestamp`) AS `timestamp`
    	FROM `user_colors`
    	GROUP BY `user`
    ) `alias1`
    INNER JOIN `user_colors`
    USING (`user`, `timestamp`)

    Or you could do a left join and handle this with the criterion for joining.

    SELECT `user`, `color`
    FROM `user_colors` AS `uc1`
    LEFT JOIN `user_colors` AS `uc2`
    ON (`uc1`.`user` = `uc2`.`user` AND `uc1`.`timestamp` < `uc2`.`timestamp`)
    WHERE `uc2`.`user` IS NULL

    I can never remember how to do the second one, and full disclosure, it might be wrong. I don’t have anything easy around to test it on. I frequently get the direction wrong on the inequality. Sometimes I forget the WHERE clause until I look at my results and notice that they are totally not what I wanted.

    Don’t read any further if you are worried about the SQL police.

    For whatever reason, there is something about my tables and their size and their structure that makes these self-joins really slow. I have come up with a work-around.


    	ORDER BY `timestamp` DESC
    	SEPARATOR "," ), ",", 1 )
    FROM `user_colors`
    GROUP BY `user`

    The GROUP_CONCAT makes a comma-separted list of all the colors for the user, in descending order by timestamp. The SUBSTRING_INDEX takes the part of the string before the first comma. To be honest, I have no idea what sort of witchcraft the query planner is doing to make this work, but on my tables it is faster than the self-join.

    Note that a GROUP_CONCAT will fail silently and horrifically if you have more than a thousand characters in a group. There are ways around this, but the finer points tend to depend on the system that you’re using.

  • December Omens (Money Edition)

    1. Gave in to the car’s whining and brought it in for service. Service Advisor 1 confided that I am 2000 miles ahead of each service, so the car started pleading for the 120,000 mile service as I was nearing 118,000 miles. Not only is the 120,000 mile service expensive, but it also involves taking apart a lot of the car and discovering that various expensive parts of the car are leaking essential fluids. Service Advisor 2 offered me a 10% discount on the work for absolutely no reason whatsoever that I could discern. This car needs to last another four years, give or take, because we just bought a new car a few weeks ago, and I would like to stagger the number of years between car purchases.

    2. My year-end bonus will be included in the next pay period. It is roughly double what I paid in car repairs.

    3. One of my yarn-friends is starting at the company full-time on Monday! Assuming that I filled out the refer-a-friend form correctly, I should also be getting a small bonus for that. I’m going to split the after-tax value of that with her. With this money we’d each be able to knit roughly four sweaters in Cascade 220.

    4. You know how they say that you are supposed to save a certain fraction of your income for retirement yadda yadda? I get emails from my financial institution pleading with me to schedule automatic monthly transfers so that I can save money without even thinking about it. I’m not particularly good with money, so instead I tend to wait to roughly this time of year and then move some money into long-term storage. OK, it is not really long-term storage because it’s not an official retirement account. However, I haven’t yet figured out how to get the money back OUT of this account to where I could spend it.

    5. Based on my luck, now would be a great time to short the entire stock market.

    6. I know, I know, retirement account, tax advantages, blah blah blah. But if I want to buy something, like, I dunno, a house in San Diego, I could probably call someone up who would tell me how to take this money out of long-term storage and send it to the house-buying-paperwork-reconciling people.

    7. The apartment downstairs from me is for rent. You can hear me being loud early in the morning for just $2200/month.

    8. I had always thought that the building across the courtyard from mine was roughly the mirror image of my building and that all of the apartments in their building were roughly the same size as the apartments in my building. However, Apartment 1 in the next-door-building has come up for sale, and it is allegedly a 3br 1100 sqft apartment, while all of the units in my building are 2br 800 sqft. I am kind of wondering where the extra space comes from. This apartment also has two nice patios and a garage. If there were an open house scheduled, I’d be tempted to take a look. Listed for $509,000.

  • How I Know that the Democrats Have No Interest in Winning the 2020 Election

    On a somewhat regular basis you hear people talk about electability. How when you ask a bunch of people would you rather vote for Candidate X or the president who would win in a head-to-head match. This is silly. People who voted for the current president back in 2016 are typically not the sorts of people who will admit that they would vote for anyone else. People who chant about wall-building are not going to be won over by a comprehensive plan to overhaul the corporate income tax structure.

    You know what’s more likely to work? Gaming voter turnout. Especially in key locations. Get the people who side with the president to stay home, and get everyone else to go and vote. And that is how I know that the Democrats have no interest in winning because they have laid none of the groundwork for this.

    First things first – and they should have started on this over a year ago – there should be an internship program for students at HBCUs where they spend the summer driving around rural areas in the south helping poor people get valid ID. Helping people get copies of their birth certificates and marriage certificates and divorce decrees and whatever else from the courthouse. Driving them to the DMV to get the ID. Getting them signed up with some sort of microgrant program (that, to the best of my knowledge, does not currently exist) to pay for all the copies of the various documents that they need. Replicate as necessary in other communities. Run this as a non-partisan non-profit, so that it can partner with organizations (such as churches) that are supposed to stay out of politics.

    Likewise, a non-partisan non-profit should be working with community organizations to develop plans to arrange rides to polling places.

    These plans should be focused on locations where there have been closures of ID-granting government offices and consolidation of polling places and limited or non-existant public transportation options. Since we are told that the closures of various offices and polling places was most definitely for-sure not imposed in a biased way, any work to make it easier to get ID in those locations can’t possibly be political either.

    But I have seen absolutely nothing about this. No one has asked me for any money to fund such an effort or to to fund a microgrant program for helping people get IDs. And people love asking me for money! I am regularly invited to invest in shady investments that I am not legally allowed to invest in, like funding a Bay Area-based start-up that hopes to disrupt laundry (I am not joking).

    There is the other side of the coin as well. There is not a successful propaganda machine combatting the president. And I know this because I have various Facebook friends who seem weakly aligned with him, and if there is any propaganda out there, it is not compelling enough for them to be sharing it on Facebook.

    The Russians have spent years developing minor influencers on social media who have been sharing the sort of banal but uplifting content that gets a lot of shares. The celebrity who went undercover building houses for Habitat for Humanity. That sort of thing. The picture of the ugly dog with the caption “I’m so ugly that I bet I won’t even get one share.” This is a key piece of the mechanism to depress turn-out. A small fraction of the shared stories need to be subtle digs at the president.

    Here are some examples:

    1. A federal corrections officer (ex-military) who is still suffering after the government shut-down. The prisioners that he guards get to sit around and watch TV all day or whatever, and he had to work without pay, and his truck got repossesed. The government should be looking out for hard-working Americans and not criminals.

    2. The ladies who run one of those Christian adoption agencies that won’t adopt kids to gay couples are sad about the conditions where the immigrant children are being detained. They would be able to take such great care to the surrendered children of drug addicts for $750/day and find them good Christian homes! The government should stop being so wasteful and should help American children first.

    3. Military family with young kids living in substandard military housing. Military dad says that he understands how important it is to protect our country. His pregnant wife has to breathe in black mold in their tiny and terrible home on base because the money that was set aside to fix it was diverted to pay for The Wall. Wasn’t Mexico supposed to pay for the wall? The government needs to support our troops at home so that they can defend us effectively.

    4. Someone in the manufacturing sector whose job went overseas. “We work hard and produce the highest quality widgets in the world.” (Subtext: “those people” produce inferior widgets.) The government sided with The Man and let the jobs go overseas.

    5. Hardworking soybean farmer is watching his crops die in the fields. He is a victim of the trade war with China. He doesn’t want the government handout to “bail out” the farmers. He is not afraid to work hard, and he grows the best soybeans in the world, and he just wants to compete in a fair marketplace.

    6. In October 2020 when lots of people are going through open enrollment for their health insurance plans: Some hard-working person who is faced with terrible yet expensive health insurance plans laments that the government was supposed to fix health insurance. They’ve had four years, and they haven’t done anything. Washington as usual.

    There should have been a steady drip of these over the past few years. Every time something happens to hurt hard-working “real Americans,” there should be a hard-working “real American” complaining about “the government” and “Washington as usual.” The goal is not to get them won over to the charms of the Democratic party. The goal is to get them sufficiently disillusioned that nothing is going to change that they stay home on election day. Especially if it is raining.

  • Secret Messages


    2. Sophie the Cat conflates loneliness with hunger. We tend to feed her in the morning and when we get home from work. I have been working on training her, and I think that she understands the words “hungry” and “petting.” If I ask, “Sophie, do you want petting?” she will jump on the couch and wait for me to pet her (if that’s what she wants). On the other hand, if I ask, “Sophie, do you want food?” she will run to the food dish (if that’s what she wants). I also think that she rubs the top of her head on my feet when she wants to be petted.

    3. The other day at work we had a “hackathon,” and my group worked on the first steps towards having the computer read aloud the content on the page. This is much harder for mathematical notation than it is for English words. It’s also harder when your product uses weird math notation with a home-grown parser so you can’t rely on MathML’s accessibility functions. We have taught the computer to say things like “hippopotamoose over the quantity two plus the variable x end quantity plus the fourth root of the variable x plus pink lightning end root.”

    "hippopotamoose over the quantity two plus the variable x end quantity plus the fourth root of the variable x plus pink lightning end root"

    We have not yet received a feature request for “demanding parent mode” in which the website would say things like “how could you not know that?” or “you are such a disappointment” or “why can’t you be more like your brother?”

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