Tuesday, June 20, 2017

The bottle says, “SPF 50,” but we have to take into account that France is a Metric country. SPF, of course, is a unit-less number. Metric unit-less scalar numbers are worth roughly 1.4 times their Imperial counterparts. Now you might be tempted to cube this number to get the conversion factor because sunscreen is a liquid, three-dimensional. But, in fact, the number refers to the light absorption properties of the skin. The skin's surface-area is a two-dimensional quantity (measured in square-meters or square-feet), but its exposure of light is measured per-unit of area, so the conversion factor is the inverse-square of 1.4, which is a little more than a half. So this sunscreen is about SPF 25, by American standards.

If you think that's bad, it gets much more confusing in Britain, which is mostly on the Metric system except for grumpy old people and in matters of alcohol. Grumpy old people don't buy a lot of sunscreen, but if you've had a couple pints (which are of course different from American pints), you might have to take this into consideration. In this case there may be a distinction based on the length of the foot of the reigning monarch. In the 19th Century, as Dickens writes in A Tale of Two Cities, the King of England had a square jaw, so the ratio of his foot size to the standard foot was introduced squared. This was a serious inconvenience when buying sunscreen in these days, when people really had a whole lot else to worry about. The resulting epidemic of sunburn precipitated the tragic plot of Dickens' great novel, which is remembered as a rallying cry in the movement to adopt the Metric system in Britain. Ironically, when this finally happened, sunscreen applied while drunk retained this annoying conversion. Fortunately the monarch from then through today, Elizabeth II, has more of a round jaw, so though her feet are shorter than a foot, they just round up to a foot and the conversion is moot. So Americans and Europeans alike can consider SPF numbers in Britain exactly as they're accustomed to in their own countries.

But if you're from Australia you have to turn the bottle upside-down before reading.

Monday, June 5, 2017

The Thing(s) with Bitcoin

Alright, The Guardian! Y'all were just at Paralelní Polis in Prague! I was, too! They really will sell you coffee for Bitcoins, and only for Bitcoins!

And you got a Bitcoin wallet on a card and started scanning a QR code, printed therein, on machines in order to buy stuff! In the same room as people that walk around in facemasks in response to the combination of ubiquitous surveillance and various improvements in computing bandwidth (including, but not limited to, facial-recognition), which could otherwise allow them to be tracked literally everywhere! That's a bit ironic: ubiquitous surveillance is related to one of the reasons a Bitcoin wallet-card is not such a great idea. So here's a counterpoint to the Guardian piece: why Bitcoin isn't going to directly replace the Koruna (or Euro, or any of the various Dollars)... ever.

Bitcoin's security is rather unforgiving as regards personal security. A Bitcoin wallet-card has two QR codes (in case you don't know, a QR code is essentially a 2-D barcode) on it, each of which is used to access your wallet. One gives the necessary information for anyone (with the right software and an Internet connection) to give you Bitcoins. The other gives the necessary information for anyone to take your Bitcoins. Obviously, to buy a coffee you need to show the side that lets anyone take your Bitcoins. So you'd better trust your café! On the surface this is no worse than swiping a debit card. But there's a key difference: the ability to charge people's debit (and credit) cards is gated by payment networks that can revoke the access of scammers. Not so much with Bitcoin: the software is open-source. In order to counter fraud, institutions basically similar to the credit-card payment networks would have to form within the Bitcoin ecosystem. Anyway, once the Bitcoins are taken there's probably no way to get them back... except possibly by involving the old fuddy-duddy legal system (i.e. by convincing the state to pursue a case against your adversary, backed by the physical force of the police), in which case you're not much of a crypto-anarchist, are you? Also, the state, knowing that one of the major reasons to use crypto-currency over state-backed currency is avoiding regulations and taxes, may not be so eager to help you out.

Of course, in the age of ubiquitous surveillance, anyone operating a camera that sees your QR code could instantly empty your account! This is the ironic part of the juxtaposition of wallet-cards and facemasks; people are worried about tracking via facial recognition — QR codes are much easier to recognize and read than faces! They were literally designed to be easy for computers to recognize and read! I severely doubt that the people wearing facemasks walk around with wallet-cards, at least not ones representing wallets with any real value in them.

One apparent way around this (I just thought of this off the top of my head, so either people are already doing it or it's wrong) is to keep your savings in one wallet, with no associated card, and transfer small amounts of money to a “holding” wallet to make routine transactions. All the modes of operation I can think of would require consumers to have mobile phones with good Internet connections in order to buy anything. But then... you'd better trust the people writing these apps! Generally I don't think people are very good at figuring out what or whom to trust, and with scams being very simple to do and hard to protect against, scammers will absolutely savage the less techno-literate for years.

The next big thing I have against Bitcoin is that crypto-currency is, economically, a new form of precious-metal-based currency, and hardly anyone thinks that's a good idea anymore. There is a finite amount of Bitcoins, which is determined by hard math. Well, there's also a (practically) finite amount of gold (on Earth, in the short-term), which is determined by hard geology. The gold standard, as a basis for practical currency, was terrible. When gold appears set to appreciate in value, as when there isn't much new gold being mined but the economy is growing, people hoard it instead of investing or loaning it out. An economy where there's no better investment than holding cash is an economy in trouble. Well, Bitcoin has certainly appreciated (exemplified by the article's cited prices for coffee), and if it has any prospects as a real currency it will only appreciate more!

Of course, humanity has plenty of experience with currencies backed by geology, so we've been there before. And there's a response: try a different metal. The Free Silver movement wasn't successful, but other currency changes have been. The institutions you'd need to convince to switch to a different crypto-currency are more diffuse than governments and have different interests. And, of course, people have traded different metals, pressed directly into coins, before (names like “dollar”, “dime”, and “pound” originated with silver coins; “crown”, like the Czech Koruna, originated with gold coins). But then people ended up relying on governments to set standards. Of course, people didn't want to have to figure out which shops accepted gold, silver, or copper, but they were also bad at detecting counterfeit money, and governments were in the position to scare counterfeiters with threats of heavy punishment.

And this places a lot of power in the hands of governments, which can use it for bad things. Today some people claim that the Czech government is, under the influence of big business (and politicians with direct big-business interests), implementing regulations aimed at excessively burdening small businesses to benefit larger ones. I don't know enough to evaluate the claim, but if these regulations are onerous enough, they may exceed the difficulties of stepping outside mainstream payment systems. Therefore the possibility of everyday Bitcoin use, even if only by knowledgeable and motivated people, could act as a check on certain kinds of government overreach.

The other opportunity for Bitcoin, in some sense, is by analogy the Linux story. I didn't come up with this, I heard it on the radio somewhere. The “year of Linux on the Desktop” never really came, not as its advocates envisioned, but as the importance of “The Desktop” has receded, Linux has taken over servers and mobile devices. Similarly, Bitcoin is backed by some cool software that might be very important, in finance and elsewhere, in the near future, even if everyday Bitcoin use never takes off much. But, as with the rise of Linux, it may largely occur under the control of big businesses (including startups that become behemoths) and governments, not anarchist hackers. If this happens, it may bring about some changes to the cultures of these institutions, but I'd guess only minor, adaptive changes, not fundamental ones. That is, I don't think we're headed for the freewheeling world of Snow Crash.

Friday, May 19, 2017

Slytherin Software Engineering: Checked Exceptions, Java 8 Streams, and you!

There's nothing quite so Slytherin in software as functional programming. A functional program is not a heroic quest to impose order on the chaos of memory, but the evaluation of elegant mathematical and logical expressions, over data structures that can never change, with no side-effects. Is all as it ever was? Yes. Our machines are not as perfect as our ideas, but we use compilers to keep the (vaguely dirty) world of processors, instructions, and memory separate from our timeless forms. Additionally there's a bit of the esoteric: pure functional programming disallows the most basic elements of the imperative style that most people learn first, data structures like arrays and control-flow ideas like iteration. This lends itself to uniform syntax with meaning differentiated by position and hierarchy, not ugly flat structures with wide varieties of (plucky?) characters. This is serious Slytherin stuff, right here.

Alas, sometimes even a Slytherin must code in Java. Java's endemic flaw is that it never has enough features; in this it is infinitely preferable to, say, C++, which always has too many! The consequence of this flaw is that we must write lots of redundancies. A redundancy is a statement that offers no possibility for expression, but that we must write anyway. This is drudgery, mere toil, not befitting our high nature! Java has long supported some functional idioms and even anonymous classes, but using them was an exercise in managing redundant boilerplate. Java 7 helped clear some Generics-related boilerplate, but Java 8's compact lambda expressions and Streams API finally made functional expressions look good on the page.

There's just one problem: what if your lambda expression calls some function that throws a checked exception? Streams methods won't accept such a lambda! This sort of problem predates Java's lambdas and Streams, but now that functional idioms are good-looking enough to use it's a problem worth re-examining. So let's consider the possibilities.

You could handle the exception. Yeah, right. In your nice, pithy lambda? What are you, a Hufflepuff? You didn't throw that exception, it's not your responsibility. Let someone else handle it.

You could catch it, wrap it in RuntimeException, and throw that. You'd do that with a higher-order function, obviously. The downside to this is that by wrapping the checked exception you obscure its true nature to callers. That's a red flag right there (we obviously prefer green ones). Another core Slytherin value this violates is reciprocity. You had to deal with the annoyance of a checked exception and it's your right to propagate this annoyance up the call stack. But to force the caller to check arbitrary levels of getCause() and try to guess the intentions of the various wrapping layers? I'm not going to lecture you about fairness or the social contract, but think of the possible consequences: your caller could denounce your method for being imprecise. You don't want that reputation. It's just this fear that makes us civilized; do heed it.

You could wrap the exception to get it through the Streams expression, then catch it outside and unwrap it for the caller. For this you need a more specific type than RuntimeException, one that is only used for this purpose — if you wouldn't make your caller guess at the meaning of a caught RuntimeException you certainly shouldn't have to do it. This is the Golden Rule of Entitlement shared by all Slytherins, in case you were already developing a habit of skipping class by Kindergarten. So you declare such a type along with your function-wrapper and take care to use it consistently. But now your aesthetic is starting to slip. I once had such code reviewed by a Ravenclaw that commented, “That's an awful lot of control-flow just to avoid a for loop.” I could only sulk, “And an awful lot of type-names just to avoid a builder,” and take my laptop and cognac into the stairwell to rewrite the whole module, newly enlightened to the futility of striving for beauty, for unity of expression and purpose. Never have your code reviewed by a Ravenclaw.

It turns out that the best way, for a Slytherin, was invented in 2009. Do the sneakyThrow. Like it just by the sound of the name? I thought you might. You still have to wrap your lambda expression, but you don't need an extra try-catch block around the Streams expression, and the exception that comes out is exactly the type that was thrown. All you did was abuse Generics so you could make an unchecked cast and deliberately make that cast incorrectly to an unchecked type1 to fool the complier's static exception-type checks — the ends justify the means. Now you can put a (correct) throws declaration on your method, tie it up in a nice little bow, and laugh as the compiler warns you about it: how naïve it is, how little it knows of the dark arts.

You could also leave the throws declaration off and lift the burden of checked-exception handling from your caller. This could have real consequences: there are exception-handling schemes out there that rely on the methods they invoke to honor their declarations. Some Slytherins would say that the weakness of those that trust in the honor of others is their own fault, that we should not be blamed for doing what we must. I mean, it's just code, so do whatever, but don't be a douchebag about stuff that really matters, OK?


1 Two different meanings of “unchecked” in one sentence... oh, dear...

Saturday, May 6, 2017

Should a word have two meanings? What the fuck for?

When first I sat at the table I took all the cards at face value. It was bad enough when they gave me directions according to where the old post office used to be. Worse when I arrived there with a package to mail. “And where should I take this, the hospital?”
“Only if it's for a patient, dear.” She took a drag, stamped out her cigarette on the curb, and walked back into the bookstore.

In the town square stood a statue of a man in a military coat and cap, striding forward with anger in his face. “A civic or national hero?”
“Why, no. He led a revolution for a country that no longer exists in a land that, though it's a lot like ours, still seems a world away.”
“Then, what, he was an exponent of our ideals?”
“Well, I can't speak for everyone, but not mine. His professed ideology ridiculed political and personal freedoms from the first. When he held power he indeed suppressed these and others besides, and used racist oppression as a tool to consolidate political support. This came to be a hallmark of his country and its successors, though of course this is hardly unique in the world.”
“Then why should we keep his statue here?” The plaque below mentioned something about its artistic significance. It had been pulled from a scrap heap after the war.

A bar off the square had its own statue outside. A person holding a glass, with a motorized arm lifting the glass to drink and lowering it back down, over and over again, forever. A sticker on the door read, “Register to vote here.” Inside a drinker slapped his arm around me. He was, it turned out, in this strange city, from my home town, and that's one of our local pastimes: getting black-out drunk and hugging eachother. That's one of the reasons I left. He raised his glass and toasted a candidate for local office whose speeches were false fiction (fiction is no different from fact or prophecy, it can be false but it isn't always). I wasn't going to change his mind.

He had a landscaping practice. His best customer was always traveling for business but kept a house in a post-bohemian neighborhood up the hill from the square. He was taking classes for an Associate's Degree but was struggling with math requirements. I met an accountant once that said she never liked math, and was never good at it. Then she wondered aloud why she'd gone into accountancy! Anyway, eventually he asked me what I did for work and I didn't have a quick deflecting lie ready and it was like he knew. I have lots of quick lies ready for when my colleagues ask me about my personal life, but not for that, because they all know what I do for work! He said he'd never been so close to someone he wanted to punch in the face.

He lived a couple dozen miles south of town. Past the shipping port and the huge railyard that spreads out from a massive freight beltway, hidden to highway maps but imposing on the ground, in a glacial valley among factories and warehouses. He'd parked blocks away on a side street to avoid the specter of crime on the main drag. He was frighteningly drunk. Before my work came up and before punching-in-the-face came up he'd been laughing at my expense, or at the expense of the act I put on. Many of my lies and embellishments are self-deprecating, and I was dressed ridiculously; punch up or punch in, that's comedy. Now his sarcastic disgust was getting angrier. “I bet you take public transportation!” he sputtered. I didn't mention my bike locked up outside. I guessed at the sort of route he might take out to the freeway and made a mental note of streets to avoid on my way home.

Saturday, April 29, 2017

Current mood: 2001

It is 2001 again (or maybe 2003):

  • Mass protests have returned to mainstream consciousness
  • I am extremely “single”
  • I've messed up my body by running too fast
  • Irony's dead now, for real this time

Because it is 2001 again, I am learning to play every song on (Radiohead's classic electronic album) Kid A as an acoustic-guitar strum-along. Back then I worked out several of them on piano, and some of them really are a lot easier on piano, but I'm being stubborn and sticking to guitar. Also I didn't really know how to play piano back then and I really don't know how to play piano now.

Sunday, April 23, 2017

Why am I writing about Juicero?

There are just so many angles to this perfect exemplar of human silliness ca. 2017 (this is where I'd find a way to insert the phrase “late capitalism” if I was1 a Marxist but I'm not a Marxist; adjust per your politics).
  • Juicero is an Internet-connected “juicer” that squeezes bags of pre-chopped ingredients (sold separately) until juice comes out. You might ask what you need the Internet connectivity for, and the answer is, “Nothing.” Yet Juicero needs Internet connectivity. Not the juicer itself but the concept of such a juicer. Juicing is a dumb, overblown fad. The health benefits are dubious, and juice you buy in bottles or frozen cans is perfectly adequate — good enough to tide you over between monthly trips to that swanky juice bar in your town, if you're into that sort of thing. Only by the power of rapid, global, peer-to-peer human connection, only by the Internet, can a bunch of sparsely-distributed juice fanatics congeal into a “community”, with fresh-pressed juice becoming such a large part of their identity that they can be convinced they need this.

    Juicero the venture-capital pitch also needs Internet connectivity for a couple reasons, which only matter to a user in that they allow Juicero to exist:

    • DRM2: ensuring that only authorized Juicero juice may be juiced by a Juicero juicer3. In order to get/stay rich Juicero's founders need to be able to profit on initial sales of the machine and on continued sales of bags of chopped fruit.
      • The DRM angle includes a thin pretense of user benefit: that the machine could warn users of expired or recalled packets. I don't know, maybe you could have an online profile where you collected badges for your impressive juicing accomplishments. Whether or not you'd actually use any of that, none of it is a feature for the user — it's all there to make the company's life better, not yours.
    • Internet connectivity makes it a “tech” product, suitable to be pitched to “tech” investors. “Tech”, economically, means that you're using technological novelty to stay ahead of competition, thereby keeping profit margins high4. So there's more silly money in “tech” than in the food and beverage sector, and it's silly-arrogant money that believes it can understand all the other sectors better than the established money already in them.

  • As much as Juicero is riffing on a dumb, overblown fad to try to become a dumb, overblown fad in its own right, hating on Juicero is also a dumb, overblown fad. There's actually a product here. It's similar to the whole Keurig coffee maker thing, which has certainly taken off. Coffee from a Keurig tastes better than instant coffee from powder or crystals; the prep and clean-up is much easier than other home-brewing methods where you have to deal with grounds. On a per-serving basis it's more expensive than other home-brewing methods but cheaper than going to a cafe. On the Juicero side there's something about some frazzled dad, you get the point.

    • So about Keurig, I guess they're having trouble dealing with competitors making “cups” compatible with their machines, undercutting them on price, and killing their profit margins. Hence Juicero's need for DRM from the outset, hence their Internet-connected concept.
    • The “easy” clean-up associated with Keurig machines has an associated environmental cost. A discarded, used Keurig cup contains plastic, aluminum, and organic matter all in a tight package, making it hard to recycle or compost, even though the materials in isolation are pretty well suited to recycling or compost. A Juicero bag must be quite similar. There's the outer material of the bag, strong enough to hold under the pressure of the machine. There's some kind of filter at the bottom of the bag, where the juice comes out — if that was built into the machine it would require regular cleaning, so it must be built into the bag. And there's the organic matter, the fibrous remains of the squeezed-out fruit.
      • When I make coffee at home I use a French press, and I can attest that coffee grounds are annoying, like any other damp organic kitchen waste. When I was renting the first floor of a house with a yard I could just walk out in my PJs and sandals and dump the grounds under some plants that the Internet said would appreciate having coffee grounds dumped on them. Now I toss them in a moldy compost bin for a couple days until the stink becomes unbearable, then take that bin down three flights of stairs to the bigger, moldier compost bin on the parking level of my building. Then I have to take a shower to wash the fruit flies out of my hair.
        • Point is, the inability to compost the coffee grounds and juice waste is, perversely, a feature.
        • “Why don't you just shave your head, Al?” I did that, once, because all my cross-country teammates did it for the state meet my senior year. My head is not shaped right. It looked ridiculous, even more ridiculous than shaved heads usually look.
    • So you can squeeze a Juicero bag with your hands. So, what? I'm sure you can strategically poke holes in a K-cup and pour hot water over it just the right way and end up with coffee. Who would actually do that? Not the “frazzled dad” on his way out to dad it up at some dad thing. Not the customers in the waiting room at the vet's office5. Not the waiter, hurrying-up-and-waiting like 10 tables, and this guy is going to regret that 3:00 PM coffee order at 3:00 AM, but the customer is always right...
      • The workout you get from squeezing the Juicero bag with your hands probably has more health benefits than the juice. The problem is that as you develop strength you can only do more reps by drinking more and more juice, confusing the question of what's really responsible for your newly buff forearms...

1 This is where I'd use the subjunctive voice if I was the sort of person that used the subjunctive voice in English...

2 DRM stands for Digital Rights Management. Like many software dorks of my age, when I was younger I ranted a lot about DRM in software because it represented extra complexity toward the end of making products less useful for users. Like many software dorks of my age I've mellowed on this subject. Anyway, computing models have shifted and more important work is done server-side (“in the cloud”), where big companies naturally have control of the data and the rights. Instead of seeing further erosion in users' rights to use data they possess, we've seen the erosion of users' possession of that data, often even what they'd call “their own” data. However the legal arrangements have or haven't changed, “Possession is nine-tenths of the law,” and it's also nine-tenths of practical power, power that the big companies in charge of the cloud wield mostly for their own benefit. Oh, right, the point that I should be getting to. Now there's DRM in a juicer that I'd never own, and I'm distinctly un-mellowed about it. I guess the mellowing wasn't about age, but just about what I was accustomed to. Humans are pretty good at adjusting themselves to their conditions.

3 It's really hard for me to keep typing, “Juice,” instead of, “Guice.” Just thought you should know.

4 Remember when I said I wasn't a Marxist? Well I have a very thin understanding of competition and profit margins that mostly comes from my observations of the tech industry and what I remember from the chapters of Das Kapital I managed to get through.

5 My vet's office does have a Keurig machine in the waiting area.

Saturday, April 22, 2017

Humility / Audacity

I thought about making a poster for the Seattle March for Science today, then didn't, because I figured there would be lots of posters, and I'm not that good at slogans or visual art, better at long-winded explanations of stuff, so probably other posters would be more worthy of people's attention. Indeed, there were lots of clever posters there and I didn't take any pictures of them because I'm not good at remembering to take pictures. So instead I'm writing a blog post about the poster I maybe should have made. It would have had just two words: “HUMILITY” across the top and “AUDACITY” across the bottom.

I'm probably missing a lot of the words for this, having not studied history nor philosophy of science in any depth, being just some guy that does software and reads stuff... so this is going to be a pretty square and incomplete account of things... so maybe you think about science as an institution, or as a practice. It's an institution made of people, a practice performed by people. We often fail to live up to our best ideals, but they're still our ideals (cf. the USA). Humility in particular would be good to highlight at this sort of event, both to and from the crowd.

I didn't see either of my words anywhere. That's fine. I did see a “Make America Care Again” sign, which was the first MAGA riff I've ever liked.