Reading the Comics, February 14, 2020: Simple Edition


Greg Evans’s Luann Againn for the 12th features some poor tutoring on Gunther’s part. Usually a person isn’t stuck for what the answer to a problem is; they’re stuck on how to do it correctly. Maybe on how to do it efficiently. But tutoring is itself a skill, and it’s a hard one to learn. We don’t get enough instruction in how to do it.

The problem Luann’s doing is one of simplifying an expression. I remember doing a lot of this, in middle school algebra like that. Simplifying expressions does not change their value; we don’t create new ideas by writing them. So why simplify?

Any grammatically correct expression for a concept may be as good as any other grammatically correct expression. This is as true in writing as it is in mathematics. So what is good writing? There are a thousand right answers. One trait that I think most good writing has is that it makes concepts feel newly accessible. It frames something in a way which makes ideas easier to see. So it is with simplifying algebraic expressions. Finding a version of a formula that makes clearer what you would like to do makes the formula more useful.

Gunther: 'OK, let's see what you did wrong here on number 26.' Luann notices Aaron Hill walking past, and goes out to follow him. Meanwhile Gunther works out 'Simplify: 6x + 7(3 + x + 4)'. After Luann's gone through several rooms following Aaron, Gunther calls out, 'The answer is 13x + 49!' Luann: 'What? Oh! OK, thanks!'
Greg Evans’s Luann Againn for the 12th of February, 2020. The strip originally ran the 12th of February, 1992. Essays mentioning something inspired by Luann, either the current run or the 1992-vintage Luann Againn reruns, are at this link.

Simplifying like this, putting an expression into the fewest number of terms, is common. It typically makes it easier to calculate with a formula. We calculate with formulas all the time. It often makes it easier to compare one formula to another. We compare formulas some of the time. So we practice simplifying like this a lot. Occasionally we’ll have a problem where this simplification is counter-productive and we’d do better to write out something as, to make up an example, 4(x^2 + 2x + 1)^2 + 4(x^2 + 2x + 1) + 1 instead. Someone who’s gotten good at simplifications, to the point it doesn’t take very much work, is likely to spot cases where one wants to keep part of the expression un-simplified.

Chen Weng’s Messycow Comics for the 13th starts off with some tut-tutting of lottery players. Objectively, yes, money put on a lottery ticket is wasted; even, for example, pick-three or pick-four daily games are so unlikely to pay any award as to be worth it. But I cannot make myself believe that this is necessarily a more foolish thing to do with a couple dollars than, say, buying a candy bar or downloading a song you won’t put on any playlists.

Woman, looking at people buying lottery tickets: 'I feel sorry for them.' Cow: 'Why?' Woman: 'Because, statistically, their chances are so slim that they're wasting their money.' Later, Cow: 'Let's go play!' Woman: 'Can't, need to work.' Cow: 'Why?' Woman: 'Because I want to become a successful artist and give my family a good life.' Cow: 'You know, statistically, your chance is so slim that you are wasting your time.' This word balloon stabs the woman between the eyes.
Chen Weng’s Messycow Comics for the 13th of February, 2020. The occasional essay mentioning something raised by Messycow Comics appear at this link.

And as the Cow points out, the chance of financial success in art — in any creative field — is similarly ridiculously slight. Even skilled people need a stroke of luck to make it, and even then, making it is a marginal matter. (There is a reason I haven’t quit my job to support myself by blog-writing.) People are terrible at estimating probabilities, especially in situations that are even slightly complicated.

Teacher: 'So what is 3 times 55?' Looking out over a bunch of students, many with hands up. One with her hand way up, several feet taller than anyone else's. Gracie's hand is this; she's got a fake extra-long arm on a stick and waves that. Other students near her look at her and glare.
Hector D. Cantü and Carlos Castellanos’s Baldo for the 14th of February, 2020. Essays featuring something mentioned by Baldo appear at this link.

Hector D. Cantü and Carlos Castellanos’s Baldo for the 14th just has Gracie very enthusiastic for arithmetic class. It’s a cute bit.


And now I’m all caught up. Please check in this link next week as I read the comics for their mathematics content some more.

Reading the Comics, February 11, 2020: Symbols Edition


Finally we get to last week’s comics. This past one wasn’t nearly so busy a week for mathematically-themed comic strips. But there’s still just enough that I can split them across two days. This fits my schedule well, too.

Rick Detorie’s One Big Happy for the 9th is trying to be the anthropomorphized numerals joke of the week. It’s not quite there, but it also uses some wordplay. … And I’ll admit being impressed any of the kids could do much with turning any of the numerals into funny pictures. I remember once having a similar assignment, except that we were supposed to use the shape of our state, New Jersey, as the basis for the picture. I grant I am a dreary and literal-minded person. But there’s not much that the shape of New Jersey resembles besides itself, “the shape of Middlesex County, New Jersey”, and maybe a discarded sock. I’m not still upset about this.

Parents night at the school. On the wall are assignments: 'Make a funny picture drawing using a numeral', with kids who've drawn 2 as a dog or 0 as a clown or 8 as a snowman or such. Ruthie's drawn 5 as a figure with a cap and a bindle walking away. Ruthie's Mom 'I liked your drawing, Ruthie, the 'Five' running away from home.' Ruthie: 'Oh yeah, my roamin' numeral!'
Rick Detorie’s One Big Happy for the 9th of February, 2020. Essays exploring something from One Big Happy, current (creators.com) or rerun (gocomics.com) runs, are at this link.

Samson’s Dark Side of the Horsefor the 11th is another on the counting-sheep theme. It’s built on the resemblance between the numeral ‘2’ and the choice of ‘z’ to represent sleeping.

Horace, counting sheep: '222,220' as a sheep staggers past the imagined fence. '222,221' as a sheep barely climbs over the fence. '222,222' as the sheep, and Horace, collapses flat into sleep.
Samson’s Dark Side of the Horsefor the 11th of February, 2020. This and other essays featuring Dark Side of the Horse trying to sleep are at this link.

The choice of ‘z’ to mean a snore is an arbitrary choice, no more inherent to the symbol than that ‘2’ should mean two. Christopher Miller’s American Cornball, which tracks a lot of (American) comedic conventions of the 20th century, notes a 1911 comic postcard representing snoring as “Z-Z-Z-Z-R-R-R-R-Z-Z-Z-Z-R-R-R-R”, which captures how the snore is more than a single prolonged sound.

Dave Blazek’s Loose Parts for the 11th has the traditional blackboard full of symbols. And two mathematics-types agreeing that they could make up some more symbols. Well, mathematics is full of symbols. Each was created by someone. Each had a point, which was to express some concept better. Usually the goal is to be more economical: it’s fewer strokes of the pen to write = instead of “equals”, and = is quicker even than “eq”. Or we want to talk a lot about a complicated concept, which is how we get, say, \sin^{-1} x for “a representative of the set of angles with sine equal to x”.

Two figures in front of a board full of symbols. One says: 'I think you're right, John. If we can come up with one new nonsense symbol a week, we can stretch this gig out for, like, a year.'
Dave Blazek’s Loose Parts for the 11th of February, 2020. Essays featuring some discussion of Loose Parts are at this link.

I suspect every mathematician has made up a couple symbols in their notes. In the excitement of working out a problem there’ll be something they want to refer to a lot. That gets reduced to an acronym or a repeated scribble soon enough. Sometimes it’s done by accident: for a while when I needed a dummy variable I would call on “ksee”, a Greek letter so obscure that it does not even exist. It looks like a cross between zeta and xi. The catch is, always, getting anyone else to use the symbol. Most of these private symbols stay private, because they don’t do work that can’t be better done by a string of symbols we already have (letters included). Or at least they don’t to well enough to be worth the typesetting trouble. I’d be surprised if any of the students I used “ksee” in front of reused the letter, even if they did find a need for a dummy variable. Founding a field, or writing a definitive text in a field, helps your chances.

I am curious how the modern era of digital typesetting will affect symbol creation. It’s relatively easy to put in a new symbol — or to summon one in the Unicode universe not currently used for mathematics — in a document and have it copied. Certainly it’s easy compared to what it was like in typewriter and Linotype days, when you might need to rely on a friend who knows a guy at the type foundry. On the other hand, it’s hard enough to get the raw file in LaTeX — a long-established standard mathematics typesetting computer language — from another person and have it actually work, even without adding in new symbols. I don’t see that changing just because several people have found that a bubble tea emoji quite helps their paper on sedimentation rates.

A long multipanel story called 'Girls Win', about the contest of boys versus girls. The relevant section starts with the narration, 'Even at school, I knew boys always lose to girls.' Teacher: 'OK, children, we're going to play Math Baseball' (a game played on the chalkboard by getting three problems right.) 'Girls were just smarter somehow.' Teacher: 'Let's separate into boys vs girls.' 'Even though we had math-wiz Sergio on our team, he alone couldn't save us from ourselves.' Teacher: 'Strike three! Yer out!' Teammate, berating Pedro, who's missed 11 - 9: 'Dang it, Pedro! We had this!'
Pedro Martin’s Mexikid Stories for the 11th of February, 2020. I haven’t had cause to discuss this strip before, so it’s a new tag. But this and any future essays mentioning Mexikid Stories should be at this link.

Pedro Martin’s Mexikid Stories for the 11th recounts childhood memories and anxieties of being matched, boys versus girls, in various activities. This includes mathematics quizzes. Here, the mathematics is done as a class game, which is a neat coincidence as I’d been thinking of similar public mathematics quiz-games that I’d done. I liked them, but then, I was almost always at top or second in the class rankings, and — after the initial couple rounds — never fell below third. My recent thoughts were for how much less fun this must have been for the kids in 26th place, especially if they’re ones who can do the work just fine, given time and space. We do value speed, in working, and that comes from practicing a task so often that we do it in the slightest time possible. And we value ability to perform under pressure, so we put people into anxiety-producing states until they can do a particular task anyway.


Thanks for reading. I should have another post at this link, most likely Thursday.

Reading the Comics, February 8, 2020: Delta Edition


With this essay, I finally finish the comic strips from the first full week of February. You know how these things happen. I’ll get to the comics from last week soon enough, at an essay gathered under this link. For now, some pictures with words:

Art Sansom and Chip Sansom’s The Born Loser for the 7th builds on one of the probability questions people often use. That is the probability of an event, in the weather forecast. Predictions for what the weather will do are so common that it takes work to realize there’s something difficult about the concept. The weather is a very complicated fluid-dynamics problem. It’s almost certainly chaotic. A chaotic system is deterministic, but unpredictable, because to get a meaningful prediction requires precision that’s impossible to ever have in the real world. The slight difference between the number π and the number 3.1415926535897932 throws calculations off too quickly. Nevertheless, it implies that the “chance” of snow on the weekend means about the same thing as the “chance” that Valentinte’s Day was on the weekend this year. The way the system is set up implies it will be one or the other. This is a probability distribution, yes, but it’s a weird one.

Gladys: 'I wonder what the weather will be like this weekend.' Brutus; 'The TV forecaster says there's less than a 10% chance of snow! Of course, that forecaster has less than a 10% chance of being correct!'
Art Sansom and Chip Sansom’s The Born Loser for the 7th of February, 2020. When I discuss something raised by The Born Loser I put the essay at this link.

What we talk about when we say the “chance” of snow or Valentine’s on a weekend day is one of ignorance. It’s about our estimate that the true value of something is one of the properties we find interesting. Here, past knowledge can guide us. If we know that the past hundred times the weather was like this on Friday, snow came on the weekend less than ten times, we have evidence that suggests these conditions don’t often lead to snow. This is backed up, these days, by numerical simulations which are not perfect models of the weather. But they are ones that represent something very like the weather, and that stay reasonably good for several days or a week or so.

And we have the question of whether the forecast is right. Observing this fact is used as the joke here. Still, there must be some measure of confidence in a forecast. Around here, the weather forecast is for a cold but not abnormally cold week ahead. This seems likely. A forecast that it was to jump into the 80s and stay there for the rest of February would be so implausible that we’d ignore it altogether. A forecast that it would be ten degrees (Fahrenheit) below normal, or above, though? We could accept that pretty easily.

Proving a forecast is wrong takes work, though. Mostly it takes evidence. If we look at a hundred times the forecast was for a 10% chance of snow, and it actually snowed 11% of the time, is it implausible that the forecast was right? Not really, not any more than a coin coming up tails 52 times out of 100 would be suspicious. If it actually snowed 20% of the time? That might suggest that the forecast was wrong. If it snowed 80% of the time? That suggests something’s very wrong with the forecasting methods. It’s hard to say one forecast is wrong, but we can have a sense of what forecasters are more often right than others are.

Caption; 'When I hear two dogs barking ... ' And the picture shows one dog going 'Arf! Arf! Arf', interrupted by a dog barking. Then the first dog goes, 'Woof! Woof! Arf! Arf' Caption: ' ... I like to imagine that one of them is trying to count, while the other is yelling out random numbers.' First dog: '36 ... 37 ... 38' Second Dog: '72!' First Dog: 'Dude! Stop it! 1 ... 2 ... '
Doug Savage’s Savage Chickens for the 7th of February, 2020. Essays that mention something based on Savage Chickens are put at this link.

Doug Savage’s Savage Chickens for the 7th is a cute little bit about counting. Counting things out is an interesting process; for some people, hearing numbers said aloud will disrupt their progress. For others, it won’t, but seeing numbers may disrupt it instead.

Scientist types, standing in a room full of dogs, with a right triangle diagram on the wall. Scientist: 'Now we have proof, Wickingham! If you show this image to 500 golden retrievers every day for ten years, they are UNABLE to discover Pythagoras's Theorem.'
Niklas Eriksson’s Carpe Diem for the 8th of February, 2020. The occasional essay based on something mentioned in Carpe Diem is gathered at this link.

Niklas Eriksson’s Carpe Diem for the 8th is a bit of silliness about the mathematical sense of animals. Studying how animals understand number is a real science, and it turns up interesting results. It shouldn’t be surprising that animals can do a fair bit of counting and some geometric reasoning, although it’s rougher than even our untrained childhood expertise. We get a good bit of our basic mathematical ability from somewhere, because we’re evolved to notice some things. It’s silly to suppose that dogs would be able to state the Pythagorean Theorem, at least in a form that we recognize. But it is probably someone’s good research problem to work out whether we can test whether dogs understand the implications of the theorem, and whether it helps them go about dog work any.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 8th speaks of the “Cinnamon Roll Delta Function”. The point is clear enough on its own. So let me spoil a good enough bit of fluff by explaining that it’s a reference to something. There is, lurking in mathematical physics, a concept called the “Dirac delta function”, named for that innovative and imaginative fellow Paul Dirac. It has some weird properties. Its domain is … well, it has many domains. The real numbers. The set of ordered pairs of real numbers, R2. The set of ordered triples of real numbers, R3. Basically any space you like, there’s a Dirac delta function for it. The Dirac delta function is equal to zero everywhere in this domain, except at one point, the “origin”. At that one function, though? There it’s equal to …

Graph: 'The Cinnamon Roll Delta Function.' y-axis: tastiness. x-axis: quality of ingredients. For a long stretch of quality the taste is at zero: 'tastes like dry bread with sugar.' Then the vertical spike. After that, the taste is zero again: 'Why is there fennel and orange blossom? Did I strange my inner child?'
Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 8th of February, 2020. If you don’t see an essay mentioning this strip, wait five minutes. Or look at my collection of Saturday Morning Breakfast Cereal-inspired discussions, here.

Here we step back a moment. We really, really, really want to say that it’s infinitely large at that point, which is what Weinersmith’s graph shows. If we’re being careful, we don’t say that though. Because if we did say that, then we would lose the thing that we use the Dirac delta function for. The Dirac delta function, represented with δ, is a function with the property that for any set D, in the domain, that you choose to integrate over

\int_D \delta(x) dx = 1

whenever the origin is inside the interval of integration D. It’s equal to 0 if the origin is not inside the interval of integration. This, whatever the set is. If we use the ordinary definitions for what it means to integrate a function, and say that the delta function is “infinitely big” at the origin, then this won’t happen; the integral will be zero everywhere.

This is one of those cases where physicists worked out new mathematical concepts, and the mathematicians had to come up with a rationalization by which this made sense. This because the function is quite useful. It allows us, mathematically, to turn descriptions of point particles into descriptions of continuous fields. And vice-versa: we can turn continuous fields into point particles. It turns out we like to do this a lot. So if we’re being careful we don’t say just what the Dirac delta function “is” at the origin, only some properties about what it does. And if we’re being further careful we’ll speak of it as a “distribution” rather than a function.

But colloquially, we think of the Dirac delta function as one that’s zero everywhere, except for the one point where it’s somehow “a really big infinity” and we try to not look directly at it.

The sharp-eyed observer may notice that Weinersmith’s graph does not put the great delta spike at the origin, that is, where the x-axis represents zero. This is true. We can create a delta-like function with a singular spot anywhere we like by the process called “translation”. That is, if we would like the function to be zero everywhere except at the point a , then we define a function \delta_a(x) = \delta(x - a) and are done. Translation is a simple step, but it turns out to be useful all the time.

Thanks again for reading. See you soon.

Reading the Comics, February 3, 2020: Fake Venn Diagrams and Real Reruns Edition


Besides kids doing homework there were a good ten or so comic strips with enough mathematical content for me to discuss. So let me split that over a couple of days; I don’t have the time to do them all in one big essay.

Sandra Bell-Lundy’s Between Friends for the 2nd is declared to be a Venn Diagram joke. As longtime readers of these columns know, it’s actually an Euler Diagram: a Venn Diagram requires some area of overlap between all combinations of the various sets. Two circles that never touch, or as these two do touch at a point, don’t count. They do qualify as Euler Diagrams, which have looser construction requirements. But everything’s named for Euler, so that’s a less clear identifier.

Caption: 'The Venn Diagram of the Sandwich Generation.' Two tangent circles, one 'The Problem' and one 'The Solution'. Two friends sit pondering this over coffee 'It's what put the 'vent' in 'venti'.'
Sandra Bell-Lundy’s Between Friends for the 2nd of February, 2020. Essays mentioning Between Friends and its imperfectly formed Venn Diagrams are at this link.

John Kovaleski’s Daddy Daze for the 2nd talks about probability. Particularly about the probability of guessing someone’s birthday. This is going to be about one chance in 365, or 366 in leap years. Birthdays are not perfectly uniformly distributed through the year. The 13th is less likely than other days in the month for someone to be born; this surely reflects a reluctance to induce birth on an unlucky day. Births are marginally more likely in September than in other months of the year; this surely reflects something having people in a merry-making mood in December. These are tiny effects, though, and to guess any day has about one chance in 365 of being someone’s birthday will be close enough.

Toddler, pointing: 'Ba ba ba.' Dad: 'Her? ... Excuse me, my son would like to give you something.' Woman: 'Uh ... OK?' Dad: 'It's a birthday card he made.' Woman: 'But it's not my birthday. ... It's ... lovely.' Dad: 'He likes to give them out to random people. He figures the odds are 1 in 365 it'll be someone's birthday and it'll make them happy.' Woman: 'What are the odds it won't be someone's birthday and it'll still make them happy?'
John Kovaleski’s Daddy Daze for the 2nd of February, 2020. Essays which mention something from Daddy Daze should be at this link.

If the child does this long enough there’s almost sure to be a match of person and birthday. It’s not guaranteed in the first 365 cards given out, or even the first 730, or more. But, if the birthdays of passers-by are independent — one pedestrian’s birthday has nothing to do with the next’s — then, overall, about one-365th of all cards will go to someone whose birthday it is. (This also supposes that we won’t see things like the person picked saying that while it’s not their birthday, it is their friend’s, here.) This, the Law of Large Numbers, one of the cornerstones of probability, guarantees us.

Conference room. Projected on a wall is 'Diplopia', represented by two overlapping circles. Man at the table asks: 'Is everyone seeing a Venn diagram, or just me?'
Mark Anderson’s Andertoons for the 2nd of February, 2020. Some of the many essays mentioning Andertoons are at this link.

Mark Anderson’s Andertoons for the 2nd is the Mark Anderson’s Andertoons for the week. And it’s a Venn Diagram joke, at least if the two circles are “really” there. Diplopia is what most of us would call double vision, seeing multiple offset copies of a thing. So the Venn diagram might be an optical illusion on the part of the businessman and the reader.

Man in the Accounting department, to a person entering: 'Hey, c'mon in, Warren. We were just crunching a few numbers.' Another person is jumping up and down on a 2, a 3, and has broken several other numerals.
Brian Boychuk and Ron Boychuk’s Chuckle Brothers repeat for the 3rd of February, 2020. It originally ran the 22nd of February, 2011. Essays featuring some aspect of The Chuckle Brothers are at this link.

Brian Boychuk and Ron Boychuk’s Chuckle Brothers for the 3rd is not quite the anthropomorphic numerals joke of the week. At least, it’s built on manifesting numerals and doing things with them.

Letters 'x' and 'y' sit at a bar. The y says, 'I just knew that someday, our paths would intersect.'
Dave Blazek’s Loose Parts for the 3rd of February, 2020. Essays with some mention of topics raised by Loose Parts are at this link.

Dave Blazek’s Loose Parts for the 3rd is an anthropomorphic mathematical symbols joke. I suppose it’s algebraic symbols. We usually get to see the ‘x’ and ‘y’ axes in (high school) algebra, used to differentiate two orthogonal axes. The axes can be named anything. If ‘x’ and ‘y’ won’t do, we might move to using \hat{i} and \hat{j} . In linear algebra, when we might want to think about Euclidean spaces with possibly enormously many dimensions, we may change the names to \hat{e}_1 and \hat{e}_2 . (We could use subscripts of 0 and 1, although I do not remember ever seeing someone do that.)

Mikki: 'First our teacher says 6 and 4 make 10. Then she says 7 and 3 equals 10. Then 5 and 5 make 10. We need a teacher who can make up her mind.'
Morrie Turner’s Wee Pals repeat for the 3rd of February, 2020. Many, but not all, of the essays featuring Wee Pals are at this link.

Morrie Turner’s Wee Pals for the 3rd is a repeat, of course. Turner died several years ago and no one continued the strip. But it is also a repeat that I have discussed in these essays before, which likely makes this a good reason to drop Wee Pals from my regular reading here. There are 42 distinct ways to add (positive) whole numbers up to make ten, when you remember that you can add three or four or even six numbers together to do it. The study of how many different ways to make the same sum is a problem of partitioning. This might not seem very interesting, but if you try to guess how many ways there are to add up to 9 or 11 or 15, you’ll notice it’s a harder problem than it appears.


And for all that, there’s still some more comic strips to review. I will probably slot those in to Sunday, and start taking care of this current week’s comic strips on … probably Tuesday. Please check in at this link Sunday, and Tuesday, and we’ll see what I do.

Reading the Comics, February 8, 2020: Exams Edition


There were a bunch of comic strips mentioning some kind of mathematical theme last week. I need to clear some out. So I’ll start with some of the marginal mentions. Many of these involve having to deal with exams or quizzes.

Jonathan Mahood’s Bleeker: The Rechargeable Dog from the 3rd started a sequence about the robot dog helping Skip with his homework. This would include flash cards, which weren’t helping, in preparation for a test. Bleeker would go to slightly ridiculous ends, since, after all, you never know when something will click.

Bleeker extends his arms, cupping them together in a square shape. Skip: 'Do you think this will help me figure out the square root of these numbers?' Bleeker: 'We should try everything, Skip.'
Jonathan Mahood’s Bleeker: The Rechargeable Dog for the 8th of February, 2020. Essays that mention something brought up by Bleeker appear at this link.

There are different ways to find square roots. (I can guarantee that Skip wasn’t expected to use this one.) The term ‘root’ derives from an idea that the root of a number is the thing that generates it: 3 is a square root of 9 because multiplying 3’s together gives you 9. ‘Square’ is I have always only assumed because multiplying a number by itself will give you the area of a square with sides of length that number. This is such an obvious word origin, though, that I am reflexively suspicious. Word histories are usually subtle and capricious things.

Bill Watterson’s Calvin and Hobbes for the 3rd began the reprint of a storyling based on a story-problem quiz. Calvin fantasizes solving it in a wonderful spoof of hardboiled detective stories. There is a moment of Tracer Bullet going over exactly what information he has, which is a good first step for any mathematics problem. I assume it’s also helpful for solving real mysteries.

Calvin, narrating as Tracer Bullet, wandering through inky, rain-soaked city streets at night: 'I stepped out into the rainy streets and reviewed the facts. There weren't many. Two saps, Jack and Joe, drive toward each other at 60 and 30 mph. After 10 minutes, they pass. I'm supposed to find out how far apart they started. Questions pour down like the rain. Who ARE these mugs? What are they trying to accomplish? Why was Jack in such a hurry? And what difference does it make where they started from? I had a hunch that, before this was over, I'd be sorry I asked.'
Bill Watterson’s Calvin and Hobbes rerun for the 5th of February, 2020. It originally ran the 7th of February, 1990. Essays inspired by something in Calvin and Hobbes should be at this link. I appreciate this all the more since I got into old-time radio, and could imagine the narration in the cadence of specific shows. This is more remarkable since Watterson’s claimed he didn’t care about the hardboiled detective genre and was just spoofing stuff he had picked up elsewhere. It speaks to Watterson’s writing skills that this spoof-based-on-spoofs still feels funny. Of course, he’s helped by how if anything is off, that’s all right, since it’s in the voice of a seven-year-old.

The strip for the 8th closing the storyline has a nice example of using “billion” as a number so big as to be magical, capable of anything. Big numbers can do strange and contrary-to-intuition things. But they can be reasoned out.

Tony Cochran’s Agnes for the 4th sees the title character figuring she could sell her “personal smartness”. Her best friend Trout wonders if that’s tutoring math or something. (Incidentally, Agnes is one of the small handful of strips to capture what made Calvin and Hobbes great; I recommend giving it a try.)

Bill Amend’s FoxTrot Classics reprint for the 6th mentions that Peter has a mathematics test scheduled, and shows part of his preparation.

Charlie Brown, looking at the problems 7 + 6 = and 4 - 3 = on the board: 'Why do I always get the hardest problems? Let's see. If our team had 7, and we scored a touchdown but failed to convert, we'd have 13. And if par on a hole is four, and you get a birdie, you're one under.' He walks away, having successfully done 7 + 6 = 13 and 4 - 3 = 1.
Charles Schulz’s Peanuts Begins for the 5th of February, 2020. The strip originally ran the 6th of February, 1952. The other strip ran the 9th of February that year. And appearances by Peanuts or Peanuts Begins should be in essays at this link. (Peanuts Begins reprints comics from the 1950s. The ordinary run of Peanuts is reprinting strips, this year, from 1973.)

Charles Schulz’s Peanuts Begins for the 5th sees Charlie Brown working problems on the board. He’s stuck for what to do until he recasts the problem as scoring in football and golf. We may giggle at this, but I support his method. It’s convinced him the questions are worth solving, the most important thing to doing them at all. And it’s gotten him to the correct answers. Casting these questions as sports problems is the building of falsework: it helps one do the task, and then is taken away (or hidden) from the final product. Everyone who does mathematics builds some falsework like this. If we do a particular problem, or kind of problem, often enough we get comfortable enough with the main work that we don’t need the falsework anymore. So it is likely to be for Charlie Brown.

On the 8th is another strip of Charlie Brown doing arithmetic in class. Here he just makes a mistake from having counted in a funny way all morning. This, too, happens to us all.


I will have more Reading the Comics posts at this link, hopefully this week. Incidentally other essays mentioning Agnes are at this link, and essays mentioning FoxTrot, reruns or the new-run Sundays, are here. Thanks for reading.

How January 2020 Treated My Mathematics Blog


Let me now take a moment to review my readership figures for the last past month. I know February is already off to a sluggish start for me as a writer. I’ve had, particularly, my paying job demanding more mental focus than usual. But I got a wonderful crop of comic strips to discuss last week, so that’ll be some nice fun posts to write over the current week.

The month was, in readership, almost a repeat of December 2019. There were 1,436 page views from 951 unique visitors. December saw 1,386 page views from 909 unique visitors. These figures are both well below the twelve-month running average of 2,055.2 page views from 1,393.2 unique visitors. I am going to be filing a lot of reports like that, at least until either the great spike of October 2019 fades into history. Or I get another like it.

Bar chart of several years' worth of readership figures, by month. The great spike in October is moving into the past; January's is nearly a duplicate of December's.
I finally did it! I caught my statistics right at midnight server time! … Wait, this says 950 visitors in January, while the statistic now says 951. Did I get this before the 11:59 UTC page views were logged?

There were 34 things liked here in January, down even from December’s figure and about half the twelve-month average of 66.5. There were also seven comments in January, not quite half the twelve-month average of 15.0. But, compared to December’s 0, that’s a great rise.

The per-post figures look generally better. This is because January was a laconic month, with a mere ten posts. And two of them were statistics-review posts. But that gives me 143.6 views per posting, above the average of 114.2. And 95.1 visitors per posting, above the average of 76.6. There were 3.4 likes per posting, below the average of 4.2. And 0.7 comments per posting, a statistic I didn’t need my spreadsheet to calculate. But that’s still below the twelve-month running average of 1.0.

218 pages, including my home page, got any page views in January. There’d been 224 getting such in December. 102 pages got more than one view in January, which is exactly the count that got more than one view in December. This underscores what a duplicate month January was. 23 got at least ten views, down from 27, so that’s a difference finally.

The most popular posts in January included two perennials, that one linear programming post that got linked from somewhere, and one that seems like it must have fit some weird search engine term:

Really, though, why would a comics post from January 2019 get back to the top of the pile suddenly?

63 countries sent me any page views at all in January, down from 60 in December and 94 in November. There were 15 single-view countries, down fro 18 the previous month and 24 the month before that. Here’s the roster:

Mercator-style map of the world with the United States in darkest pink. Western Europe, South Asia, Australia, and much of South America are in a more uniform pink.
Oh, hi, Tunisia. Nice to see you! I hope everything’s okay. Uganda’s the landlocked African country to show up here and that’s honestly going to help me remember where Uganda is now.
Country Readers
United States 847
United Kingdom 65
Philippines 60
Canada 58
India 47
Germany 41
Australia 37
Argentina 35
Brazil 22
Singapore 21
Spain 19
Finland 12
Japan 12
Thailand 9
Sweden 8
France 7
Netherlands 7
Romania 7
South Africa 7
Norway 6
Greece 5
Italy 5
Malaysia 5
Mexico 5
Nigeria 5
Uganda 5
Austria 4
Denmark 4
Guyana 4
New Zealand 4
Russia 4
Costa Rica 3
Croatia 3
Hungary 3
Israel 3
Lithuania 3
Poland 3
Serbia 3
Switzerland 3
U.S. Virgin Islands 3
Vietnam 3
Bahrain 2
Brunei 2
Hong Kong SAR China 2
Ireland 2
Pakistan 2
Taiwan 2
Turkey 2
American Samoa 1 (*)
Bangladesh 1
Belgium 1
Cambodia 1
Chile 1
Ecuador 1
Indonesia 1
Panama 1
Portugal 1
Saudi Arabia 1 (*)
Slovakia 1 (*)
Slovenia 1
South Korea 1
Tunisia 1
United Arab Emirates 1

American Samoa, Saudi Arabia, and Slovakia were single-view countries in December. None of these were also single-view countries in November.

In January I published 6,158 words, says WordPress. I don’t know how that counts things like subject lines and image captions. It’s a shame there’s literally no way to find out, ever. But with that spread over ten posts, I have an average of 616 words per posting for the month, and so far for the year. My average post for 2019 was 861 words. This was driven up by things like the A-to-Z sequence.

As of the start of February I’d posted 1,413 things on this blog. They attracted 99,013 views from a recorded 53,928 unique visitors. I’m trying to not watch obsessively as I approach 100,000.

If you’d like to take a chance at being reader number 100,000, please visit this page, or click on the “Follow Nebusresearch” button at the upper right corner of this page. If you don’t care about being reader 100,000, I don’t mind. You can use your RSS reader to watch the https://nebusresearch.wordpress.com/feed/ at your leisure. And my automated-but-lost-to-me Twitter account @Nebusj posts announcements of things as they are published.

Thank you for reading, whatever way you choose to do it.

Reading the Comics, February 1, 2020: I Never Talk About Marvin Edition


There’s some comic strips that get mentioned here all the time. Then there’s comic strips that I have been reading basically my whole life, and that never give me a thread to talk about. Although I’ve been reading comic strips for their mathematics content for a long while now, somehow, I am still surprised when these kinds of comic strip are not the same thing. So here’s the end of last week’s comics, almost in time for next week to start:

Kevin Fagan’s Drabble for the 28th has Penny doing “math” on colors. Traditionally I use an opening like this to mention group theory. In that we study things that can be added together, in ways like addition works on the integers. Colors won’t quite work like this, unfortunately. A group needs an element that’s an additive identity. This works like zero: it can be added to anything without changing its value. There isn’t a color that you can mix with other colors that leaves the other color unchanged, though. Even white or clear will dilute the original color.

Mom: 'How was school today, Penny?' Penny: 'Great, Mommy! I learned how to do math! Want me to show you? Blue plus red equals purple!'
Kevin Fagan’s Drabble for the 28th of January, 2020. It doesn’t come up often, but when it does, Drabble appears in essays at this link.

If you’ve thought of the clever workaround, that each color can be the additive identity to itself, you get credit for ingenuity. Unfortunately, to be a group there has to be a lone additive identity. Having more than one makes a structure that’s so unlike the integers that mathematicians won’t stand for it. I also don’t know of any interesting structures that have more than one additive identity. This suggests that nobody has found a problem that they represent well. But the strip suggests maybe it could tell us something useful for colors. I don’t know.

Marvin: 'After all the talk about 'fake news' I'm starting to question EVERYTHING big people tell me.' He's looking at a teacher holding up the flashcard 1 + 1 = 2.
Tom Armstrong’s Marvin for the 28th of January, 2020. I don’t think it has ever come up before, but what the heck. Any essays which mention Marvin should be at this link.

Tom Armstrong’s Marvin for the 28th is a strip which follows from the discovery that “fake news” is a thing that people say. Here the strip uses a bit of arithmetic as the sort of incontrovertibly true thing that Marvin is dumb to question. Well, that 1 + 1 equals 2 is uncontrovertibly true, unless we are looking at some funny definitions of ‘1’ or ‘plus’ or something. I remember, as a kid, being quite angry with a book that mentioned “one cup of popcorn plus one cup of water does not give us two cups of soggy popcorn”, although I didn’t know how to argue the point.

Title: 'The Math Homework.' Dad, in the kitchen, to kid: 'What's surface area? Ask your mother.' The mother is in the kitchen, working, and has every bit of surface area that isn't being used for homework with cooking tools. Footer joke: Mom asks, 'Can you please move? I need this space.'
Hilary Price and Rina Piccolo’s Rhymes with Orange for the 30th of January, 2020. Essays with some mention of Rhymes With Orange should be at this link.

Hilary Price and Rina Piccolo’s Rhymes with Orange for the 30th is … well, I’m in this picture and I don’t like it. I come from a long line of people who cover every surface with stuff. But as for what surface area is? … Well, there’s a couple of possible definitions. One that I feel is compelling is to think of covering sets. Take a shape that’s set, by definition, to have an area of 1 unit of area. What is the smallest number of those unit shapes which will cover the original shape? Cover is a technical term here. But also, here, the ordinary English word describes what we need it for. How many copies of the unit shape do you need to exactly cover up the whole original shape? That’s your area. And this fits to the mother’s use of surfaces in the comic strip neatly enough.

Mutt: 'What's the matter, you stuck?' Jeff, looking at his car: 'Yes and no! I tried the cary products they advertise on TV. They claimed this car would use 50% less gas. Then I bought a carburettor which saves 30%, special spark plugs which save 20% and a new brand of gas which saved 10%! Now when I drive the gas tank overflows!' Jeff shows gas pouring out of the tank.
Bud Fisher’s Mutt and Jeff for the 31st of January, 2020. And the essays which have mentioned Mutt and Jeff comics appear at this link.

Bud Fisher’s Mutt and Jeff for the 31st is a rerun of vintage unknown to me. I’m not sure whether it’s among the digitally relettered strips. The lettering’s suspiciously neat, but, for example, there’s at least three different G’s in there. Anyway, it’s an old joke about adding together enough gas-saving contraptions that it uses less than zero gas. So far as it’s tenable at all, it comes from treating percentage savings from different schemes as additive, instead of multiplying together. Also, I suppose, that the savings are independent, that (in this case) Jeff’s new gas saving ten percent still applies even with the special spark plugs or the new carburettor [sic]. The premise is also probably good for a word problem, testing out understanding of percentages and multiplication, which is just a side observation here.


This wraps up last week’s mathematically-themed comic strips. This week I can tell you already was a bonanza week. When I start getting to its comics I should have an essay at this link. Thanks for reading.

Reading the Comics, January 27, 2020: Alley Oop Followup Edition


I apologize for missing Sunday. I wasn’t able to make the time to write about last week’s mathematically-themed comic strips. But I’m back in the swing of things. Here are some of the comic strips that got my attention.

Jonathan Lemon and Joey Alison Sayers’s Little Oop for the 26th has something neat in the background. Oop and Garg walk past a vendor showing off New Numbers. This is, among other things, a cute callback to one of the first of Lemon and Sayers’s Little Oop strips.. (And has nothing to do with the daily storyline featuring the adult Alley Oop.) And it is a funny idea to think of “new numbers”. I imagine most of us trust that numbers are just … existing, somewhere, as concepts independent of our knowing them. We may not be too sure about the Platonic Forms. But, like, “eight” seems like something that could plausibly exist independently of our understanding of it.

Science Expo. Little Alley Oop leads Garg past the New Numbers stand to the Multistick. Garg: 'A stick? That sounds boring.' Vendor, holding up a stick: 'Quite the opposite, young man! The multi-stick can do everything! You can use it as a weapon, you can light it on fire and use it as a torch, you can use it as a fishing pole. It has literally dozens of uses!' Garg: 'Can I use it as a toy for my pet dinosaur?' Vendor: 'Well, I wouldn't recommend it. We haven't tested it out for that.' Garg: 'Eh, no thanks.'
Jonathan Lemon and Joey Alison Sayers’s Little Oop for the 26th of January, 2020. The handful of times I’ve head to talk about Alley Oop or Little Oop are gathered at this link.

Still, we do keep discovering things we didn’t know were numbers before. The earliest number notations, in the western tradition, for example, used letters to represent numbers. This did well for counting numbers, up to a large enough total. But it required idiosyncratic treatment if you wanted to handle large numbers. Hindu-Arabic numerals make it easy to represent whole numbers as large as you like. But that’s at the cost of adding ten (well, I guess eight) symbols that have nothing to do with the concept represented. Not that, like, ‘J’ looks like the letter J either. (There is a folk etymology that the Arabic numerals correspond to the number of angles made if you write them out in a particular way. Or less implausibly, the number of strokes needed for the symbol. This is ingenious and maybe possibly has helped one person somewhere, ever, learn the symbols. But it requires writing, like, ‘7’ in a way nobody has ever done, and it’s ahistorical nonsense. See section 96, on page 64 of the book and 84 of the web presentation, in Florian Cajori’s History of Mathematical Notations.)

Still, in time we discovered, for example, that there were irrational numbers and those were useful to have. Negative numbers, and those are useful to have. That there are complex-valued numbers, and those are useful to have. That there are quaternions, and … I guess we can use them. And that we can set up systems that resemble arithmetic, and work a bit like numbers. Those are often quite useful. I expect Lemon and Sayers were having fun with the idea of new numbers. They are a thing that, effectively, happens.

Francis, answering the phone: 'Hi, Nate Yeah, I did the homework. No, I'm not giving you the answers. ... I'm sure you did try hard ... I know it's due tomorrow ... You're not going to learn anything if I just ... of course I don't want to get in trouble but ... all right! This once! For #1, I got 4.5. For #2, I got 13.3. For #3, I got ... hello?' Cut to Nate, hanging up the phone: 'Wrong number.' Nate's Dad: 'I'll say.'
Lincoln Peirce’s Big Nate: First Class for the 26th of January, 2020. It originally ran the 15th of January, 1995. Essays mentioning either Big Nate or the rerun Big Nate: First Class should be gathered at this link.

Lincoln Peirce’s Big Nate: First Class for the 26th has Nate badgering Francis for mathematics homework answers. Could be any subject, but arithmetic will let Peirce fit in a couple answers in one panel.

Other Man: 'Do you ever play the lottery?' Brutus: 'I believe your chances of winning the lottery are the same as your chances of being struck by lightning!' Other: 'Have I told you the time I bought an instant lottery ticket on a whim? I won one thousand dollars!' Brutus: 'No kidding? That changes everything I said about the odds! That must've been the luckiest day of your life!' Other: 'Not really; as I left the store, I was struck by lightning!'
Art Sansom and Chip Sansom’s The Born Loser for the 26th of January, 2020. There are times that I discuss The Born Loser, and those essays are at this link.

Art Sansom and Chip Sansom’s The Born Loser for the 26th is another strip on the theme of people winning the lottery and being hit by lightning. And, as I’ve mentioned, there is at least one person known to have won a lottery and survived a lightning strike.

Woman: 'How's the project coming?' Boy: 'Fine.' Quiet panel. Then, a big explosion. Woman: 'I thought you guys were doing math!' Girl: 'Engineering!' Boy: 'It's *like* math, but louder.'
David Malki’s Wondermark for the 27th of January, 2020. I am surprised to learn that I already have a tag for this comic, but it turns out I’ve mentioned it as long ago as late December. So, essays mentioning Wondermark: they’re at this link.

David Malki’s Wondermark for the 27th describes engineering as “like math, but louder”, which is a pretty good line. And it uses backgrounds of long calculations to make the point of deep thought going on. I don’t recognize just what calculations are being done there, but they do look naggingly familiar. And, you know, that’s still a pretty lucky day.

Wavehead at the chalkboard, multiplying 2.95 by 3.2 and getting, ultimately, to '.9.4.4.0.' He says: 'I forgot where to put the decimal, so I figured I'd cover all the bases.'
Mark Anderson’s Andertoons for the 27th of January, 2020. And I have a lot of essays mentioning something from Andertoons gathered at this link.

Mark Anderson’s Andertoons for the 27th is the Mark Anderson’s Andertoons for the week. It depicts Wavehead having trouble figuring where to put the decimal point in the multiplication of two decimal numbers. Relatable issue. There are rules you can follow for where to put the decimal in this sort of operation. But the convention of dropping terminal zeroes after the decimal point can make that hazardous. It’s something that needs practice, or better: though. In this case, what catches my eye is that 2.95 times 3.2 has to be some number close to 3 times 3. So 9.440 is the plausible answer.

Baseball dugout. One player: 'Jim makes $2.1 million per year. Fred makes $9.3 million over a three-year period. How much more does Fred make than Jim each year?' Second player: '60% of Roger's income last year came from promotional work. If his annual earnings are $17.2 million, how much of his income came just from baseball?' Third player: 'Tom was traded for two relief pitchers. If together they'll earn 1.3 times Tom's former annual yearly salary of $2.5 million, how much will each earn?'
Mike Twohy’s That’s Life for the 27th of January, 2020. So I have some essays mentioning this comic strip, but from before I started tagging them. I’ll try to add tags to those old essays when I have the chance. In the meanwhile, this essay and maybe future ones mentioning That’s Life should be at this link.

Mike Twohy’s That’s Life for the 27th presents a couple of plausible enough word problems, framed as Sports Math. It’s funny because of the idea that the workers who create events worth billions of dollars a year should be paid correspondingly.


This isn’t all for the week from me. I hope to have another Reading the Comics installment at this link, soon. Thanks for reading.

Some News on the Travelling Salesman Problem


I need to get back to just talking about mathematics problems some. Happily there was some news come across my desk. It’s about the Travelling Salesman Problem. This is one of those classic problems, simple to state and obviously interesting, and that are terribly hard to solve. How do you draw a path connecting a large number of points with the shortest total path? You can recast what you’re doing: make the path that takes the shortest time, or that has the lowest cost, the least energy, the greatest profit, whatever. Optimization problems are very alike, and useful.

There’s not many good answers to the problem, though. Basically, test out every possible combination and pick the best one from all that. For large enough problems this is hopeless. For small enough problems, though? You can work something out. So there’s this report of researchers, lead by Professor Takayuki Kawahara at the Tokyo University of Science. They’ve developed an integrated circuit with really good performance for, they believe, up to 22 ‘cities’. That 22 is a breakthrough tells you something of how hard the problems are.

I’m unclear, from the press release, just how the system works. (I’m also unsure, from reading the press releases, that they have actually used this for 22 cities or whether they have good reason to think it will work as hoped for. I may be over-parsing.) There’s a description of using “spin cells” and it happens I know about something named spin cells. And that they are used in optimization problems. What I do not know is that my spin cells are the spin cells being used here. If I find out, I’ll share.

Reading the Comics, January 25, 2020: Comic Strip Master Command Is Making This Hard For Me Edition


Or they’re making it easy for me. But for another week all the comic strips mentioning mathematics have done so in casual ways. Ones that I don’t feel I can write a substantial paragraph about. And so, ones that I don’t feel I can fairly use the images of here. Here’s strips that at least said “math” somewhere in them:

Mark Pett’s Mr Lowe rerun for the 18th had the hapless teacher giving out a quiz about fractions.

Greg Cravens’s The Buckets for the 19th plays on the conflation of “zero” and “nothing”. The concepts are related, and we wouldn’t have a zero if we weren’t trying to worth with the concept of nothing. But there is a difference that’s quite hard to talk about without confusing matters.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 19th has a student accused of cheating on a pre-algebra test.

Liniers’s Macanudo for the 21st has a kid struggling with mathematics while the imaginary friend goes off and plays.

Lincoln Peirce’s Big Nate: First Class for the 21st has Nate struggling with mathematics. The strip is a reprint of the Big Nate from the 23rd of January, 1995.

Greg Curfman’s Meg for the 21st has Meg doing arithmetic homework.

Scott Hilburn’s The Argyle Sweater for the 23rd is a wordplay joke, with a flash card that has an addition problem on it.

One of Gary Larson’s The Far Side reprints for the 24th has a man demanding the answer to one question: the square root of an arbitrary number. It’s a little over 70, and that’s as far as anyone could reasonably expect to answer off the top of their head.

James Beutel’s Banana Triangle for the 24th quotes The Wizard Of Oz’s famous garbled version of the Pythagorean Theorem.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 25th presents a sinister reading of the fad of “prove you’re human” puzzles that demanded arithmetic expressions be done. All computer programs, including, like, Facebook group messages are arithmetic operations ultimately. The steps could be translated into simple expressions like this and be done by humans. It just takes work which, I suppose, could also be translated into other expressions.


And with that large pile of mentions I finish off the mathematical comic strips for the day. Also for the month: next Sunday gets us already into February. Sometime then I should post at this link a fresh Reading the Comics essay. Thank you for reading this one.

How All Of 2019 Treated My Mathematics Blog


I’d promised during my review of the past month that I’d also look at my readership for the whole of 2019. It took a bit longer than I figured, but I’ve gotten there. 2019 was the eighth full year that I’ve been mathematics-blogging. I started in September of 2011 and needed a while to figure out what the heck I was doing. I think I knew what I was doing for roughly half of last year’s A-to-Z sequence. I’ve since forgotten it.

2019 was my most-read year to date: 24,662 page views from 16,718 unique visitors. It’s a heck of growth from even my 2018 figures, of 16,597 page views and 9,769 unique visitors. This 49 percent growth in year-to-year page views is the second greatest I’ve had. 2014-to-2015 saw a 60 percent growth. 2015 is also the first year I did an A-to-Z and I’m certain that made a difference. The 71 percent growth in unique visitors was the greatest growth in that statistic.

Bar chart showing annual readership, which rose significantly in 2012, 2015, 2018 and 2019, and held steady or drifted downward in the other years.
WordPress only started tracking, or at least reporting, unique visitors partway through 2012 which is why the darker unique-visitors bar in these makes it look like I had two visitors who read three thousand posts each that year.

A good part of that is a fluke event, though. One post in my A-to-Z sequence got linked from somewhere and that brought a flood of readers in. Easily something like five thousand people came in, read one or two posts, and left again. I’d still have a record year without that influx. But I don’t see anything else getting a reference like that, so I have to suppose that 2020 is going to be a more challenging year.

Bar chart showing the number of likes over the years; 2014, 2017, 2018, and 2019 were at roughly a thousand likes, with 2015 and 2016 four times and two times that figure.
Again, those 2012 and 2013 figures look suspiciously low, but I can’t think of any changes in how WordPress reported statistics which would make that make sense.

I always talk about how I’m getting fewer likes and even fewer comments than I used to. The yearly statistics show just how big the drop off is. There were 798 things liked in 2019, the lowest number since 2013. I’m not sure that the statistics for 2011 through 2013 are quite right. The jump between 2013’s 262 and 2014’s 1,045 seems suspicious. I’ve had a steady decline since 2015, though.

Bar chart showing the number of comments over the years. 2015 had the unquestioned peak, with 2016 and 2018 next-best, but the progression is a decline from that 2015 high point.
I certainly am not looking at this chart and the Likes chart and thinking that my chance to be a successful blogger came and went in 2015, nope!

And there were 181 comments in all of 2019. That’s half of 2018’s comment count. It’s my lowest number since 2013. I suspect part of the trouble is Reading the Comics posts. They’re good content, yes, but as initial posts they’re fairly closed things. Even the A-to-Z posts, apart from the appeals for subject matter, are pretty closed topics. I’ve clearly forgotten how to write open essays.

Besides my home page there were 797 pages that got at least one page view over 2019. There were 635 that got at least two page views, 304 getting at least ten views, 16 getting at least a hundred, and two that got over a thousand page views. Also, 109 of the pages viewed were Reading the Comics posts. The most popular of these were:

The first and third of these were posted in 2019. The top five essays posted in 2019 would be the linear programming and the Hamiltonian essays, plus:

Apart from the linear programming essay, I understand why these A-to-Z topics should be so popular. They’re big topics, ones that support wide swaths of mathematics.

Over the whole of 2019, people from 148 countries or country-like entities read something here. I feel pretty good about the spread of people, really. The only anomaly is that it’s been yet another year with no Greenland readers. I know there’s 14 people in Greenland but it does seem like someone would have read a page of mine by accident. Madagascar is a similar curious anomaly. 31 countries had only a single page view, which is really not that different to how many single-view countries I’ll have in any one month. Here’s the full roster of reading countries:

Mercator-style map of the world. The United States is in the darkest red, but most of the world has at least some pink in it. The exceptions are some of Saharan Africa, Greenland, Cuba, Madagascar, Mozambique, Afghanistan, Turkmenistan, and Tajikistan.
I normally don’t mind Mercator but it does create this enormous visual over-estimation of how many people in Greenland refuse to read me.
Country Readers
United States 13,872
India 1,161
United Kingdom 1,153
Canada 997
Philippines 907
Germany 562
Australia 466
France 347
Sweden 294
Singapore 250
Italy 245
Brazil 244
Netherlands 232
South Africa 180
Finland 176
Denmark 175
Spain 166
Russia 148
Poland 146
Switzerland 129
Ireland 121
Hong Kong SAR China 120
Norway 111
Japan 110
Belgium 106
Mexico 106
Pakistan 89
Slovenia 86
Turkey 85
Malaysia 77
New Zealand 74
Austria 66
Thailand 65
Indonesia 63
Portugal 62
Israel 59
Czech Republic 58
China 54
Greece 54
South Korea 54
Romania 52
Taiwan 52
United Arab Emirates 52
Colombia 51
European Union 47
Argentina 42
Ukraine 40
Hungary 39
Vietnam 39
Nepal 36
American Samoa 35
Latvia 32
Macedonia 31
Serbia 31
Slovakia 31
Bangladesh 30
Croatia 28
Chile 25
Kenya 24
Saudi Arabia 24
Nigeria 23
Egypt 18
Lithuania 18
Peru 18
Puerto Rico 18
Sri Lanka 17
Ecuador 16
Bulgaria 15
Jordan 15
Jamaica 14
Morocco 12
Lebanon 11
Belarus 10
Algeria 9
Belize 9
Uruguay 9
Bosnia & Herzegovina 8
Guatemala 8
Iceland 8
Malta 8
Myanmar (Burma) 8
Panama 8
Uganda 8
Costa Rica 7
Estonia 7
Tanzania 7
Cyprus 6
Ghana 6
Guam 6
Iraq 6
Trinidad & Tobago 6
Tunisia 6
Bolivia 5
Cape Verde 5
Georgia 5
Luxembourg 5
Venezuela 5
Zimbabwe 5
Armenia 4
Bahrain 4
Ethiopia 3
Kuwait 3
Mongolia 3
Albania 2
Azerbaijan 2
Botswana 2
Cambodia 2
Dominican Republic 2
El Salvador 2
Fiji 2
Martinique 2
Mauritius 2
Namibia 2
Papua New Guinea 2
Paraguay 2
Rwanda 2
Uzbekistan 2
Angola 1
Bermuda 1
Brunei 1
Burundi 1
Cameroon 1
Congo – Kinshasa 1
Côte d’Ivoire 1
Curaçao 1
Djibouti 1
Faroe Islands 1
Guyana 1
Honduras 1
Iran 1
Kazakhstan 1
Laos 1
Maldives 1
Marshall Islands 1
Moldova 1
Montenegro 1
Nicaragua 1
Oman 1
Palestinian Territories 1
Qatar 1
Réunion 1
Senegal 1
Sint Maarten 1
Somalia 1
Sudan 1
Turks & Caicos Islands 1
U.S. Virgin Islands 1
Zambia 1

I’m delighted there were three countries that had at least a thousand page views. I’ll try not to think how there could have been a fourth thousand-view country if only I’d hit refresh a couple times more when I was in Canada back in June.

So for the whole of 2019 I posted 173,087 words, according to WordPress’s figures. This was the third-greatest number of words I’ve written in a year, after 2016’s 199,465 words and 2018’s 186,639 words. These were spread over 201 posts. That’s my second-greatest number of posts in a year, after 2016’s 213 posts. This implies my average posting was 861 words. This I’m glad to see. It’s the first time in four years that I’ve averaged under 900 words per posting.

For the year, I averaged 1.5 comments per posting. That’s the lowest figure I’ve had for any completed year. It’s under half the average for each year from 2013 through 2018. The average likes per post is a less dire dropoff. For 2019 I had an average 3.8 likes per posting; that’s the first time since 2013 that it’s been fewer than five likes per posting.

Twice over 2019 I set a new record for daily views. My record now was set the 16th of October, when 5,003 page views came in. 720 came in the next day. It was a bit much. That 16th of October, I believe, upset the previous record that was set the 2nd of October. Before that, my greatest number of page views had been some weird day back in … I want to say March 2014. Sometime around then, anyway.

And that’s last year, in reading around here. I remain quite happy to have you as reader here this year. You can do that by using the “Follow Nebusresearch” button that’s currently on the upper-right corner of the page. (I am doing my annual thinking about changing the theme around here, if I can find a new theme that I like at all. If I do change, that might relocate the button.) Or you can use an RSS reader with the feed https://nebusresearch.wordpress.com/feed to view posts as they come in without my being able to track anything. And again, a free account in Dreamdwidth or Livejournal, which both still exist, lets you use their Friends page as RSS reader.

Reading the Comics, January 18, 2020: Decimals In Fractions Edition


Let me first share the other comic strips from last week which mentioned mathematics, but in a casual way.

Jerry Scott and Jim Borgman’s Zits for the 14th used the phrase “do the math”, and snarked on the younger generation doing mathematics. This was as part of the longrunning comic’s attempt to retcon the parents from being Baby Boomers to being Generation X. Scott and Borgman can do as they like but, I mean, their kids are named Chad and Jeremy. That’s only tenable if they’re Boomers. (I’m not sure Chad has returned from college in the past ten years.) And even then it was marginal.

John Kovaleski’s Bo Nanas rerun for the 14th is a joke about the probability of birthdays.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 14th features “the Bertrand Russell Drinking Game”, playing on the famous paradox about self-referential statements of logic.

Stephan Pastis’s Pearls Before Swine for the 17th has Rat use a bunch of mathematical jargon to give his declarations authority.

Cy Olson’s Office Hours for the 18th, rerunning a strip from the 9th of November, 1971, is in the line of jokes about parents not understanding their children’s arithmetic. It doesn’t seem to depend on mocking the New Math, which is a slight surprise for a 1971 comic.


Classroom. The blackboard problem is 0.25 / 0.05 = ? Wavehead, to teacher: 'Decimals *in* fractions?! Have you no shame?!'
Mark Anderson’s Andertoons for the 12th of January, 2020. This and other essays with some topic raised by Andertoons should appear at this link.

So Mark Anderson’s Andertoons for the 12th is the only comic strip of some substance that I noticed last week. You see what a slender month it’s been. It does showcase the unsettling nature of seeing notations for similar things mixed. It’s not that there’s anything which doesn’t parse about having decimals in the numerator or denominator. It just looks weird. And that can be enough to throw someone out of a problem. They might mistake the problem for one that doesn’t have a coherent meaning. Or they might mistake it for one too complicated to do. Learning to not be afraid of a problem that looks complicated is worth doing. As is learning how to tell whether a problem parses at all, even if it looks weird.


And that’s an end to last week in comics. I plan to have a fresh Reading the Comics post on Sunday. Thank you for reading in the meanwhile.

Reading the Comics, January 13, 2020: The State Pinball Championships Were Yesterday Edition


I am not my state’s pinball champion, although for the first time I did make it through the first round of play. What is important about this is that between that and a work trip I needed time for things which were not mathematics this past week. So my first piece this week will be a partial listing of comic strips that, last week, mentioned mathematics but not in a way I could build an essay around. … It’s not going to be a week with long essays, either, though. Here’s a start, though.

Henry Scarpelli’s Archie rerun for the 12th of January was about Moose’s sudden understanding of algebra, and wish for it to be handy. Well, every mathematician knows the moment when suddenly something makes sense, maybe even feels inevitably true. And then we do go looking for excuses to show it off.

Art Sansom and Chip Sansom’s The Born Loser for the 12th has the Loser helping his kid with mathematics homework. And the kid asking about when they’ll use it outside school.

Jason Chatfield’s Ginger Meggs for the 13th has Meggs fail a probability quiz, an outcome his teacher claims is almost impossible. If the test were multiple-choice (including true-or-false) it is possible to calculate the probability of a person making wild guesses getting every answer wrong (or right) and it usually is quite the feat, at least if the test is of appreciable length. For more open answers it’s harder to say what the chance of someone getting the question right, or wrong, is. And then there’s the strange middle world of partial credit.

My love does give multiple-choice quizzes occasionally and it is always a source of wonder when a student does worse than blind chance would. Everyone who teaches has seen that, though.

Jan Eliot’s Stone Soup Classics for the 13th just mentions the existence of mathematics homework, as part of the morning rush of events.

Ed Allison’s Unstrange Phenomenon for the 13th plays with optical illusions, which include several based on geometric tricks. Humans have some abilities at estimating relative areas and distances and lengths. But they’re not, like, smart abilities. They can be fooled, basically because their settings are circumstances where there’s no evolutionary penalty for being fooled this way. So we can go on letting the presence of arrow pointers mislead us about the precise lengths of lines, and that’s all right. There are, like, eight billion cognitive tricks going on all around us and most of them are much more disturbing.


That’s a fair start for the week. I hope to have a second part to this Tuesday. Thanks for reading.

Reading the Comics, January 11, 2020: Saturday was Quiet Too Edition


So I did get, as I hoped, to Saturday’s comics and they didn’t have much of deep mathematical content. There was an exception, though.

Morrie Turner’s Wee Pals for the 8th has Rocky failing a mathematics test.

Lorie Ransom’s The Daily Drawing for the 10th is the anthropomorphic geometric-figures joke for the week.

Mark Pett’s Mr Lowe rerun for the 11th has Quentin sitting through a dull mathematics class. And then, ah, the exceptional case …

Ryan North’s Dinosaur Comics for the 10th sees T-Rex pondering the point of solitaire. As he notes, there’s the weird aspect of solitaires that many of them can’t be won, even if you play perfectly. This comes close, without mentioning, an important event in numerical mathematics. So let me mention it.

T-Rex: 'Let's say you're alone in the universe with a deck of cards, and you're like, 'Welp, guess I'll make it possible to lose at sorting this deck of cards!' You put them in piles and moves them around by rules someone else invented. Eventually you think about cheating. But you're playing by yourself; who are you cheating? Yourself? THe game? Would it help if I told you almost 20% of solitaire games are provably unwinnable?' Utahraptor: 'No way!' T-Rex: 'Science confirms it! You'll lose a non-trivial amount of the time, and not in some novel way. The only novel way to lose is by dying in real life, but you do that once, and if you do, your last words are 'Oh look, a four of hearts! I can put that on the tree of hearts.' As last words go: a solid eight on ten?
Ryan North’s Dinosaur Comics for the 10th of January, 2020. Essays which discuss some aspect of Dinosaur Comics appear at this link.

There have always been things we could compute by random experiments. The digits of π, for example, if we’re willing to work at it. The catch is that this takes a lot of work. So we did not do much of this before we had computers, which are able to do a lot of work for the cost of electricity. There is a deep irony in this, since computers are — despite appearances — deterministic. They cannot do anything unpredictable. We have to provide random numbers, somehow. Or numbers that look enough like random numbers that we won’t make a grave error by using them.

Many of these techniques are known as Monte Carlo methods. These were developed in the 1940s. Stanislaw Ulam described convalescing from an illness, and playing a lot of solitaire. He pondered particularly the chance of winning a Canfield solitaire, a kind of game I have never heard of outside this anecdote. There seemed no way to work out this problem by reason alone. But he could imagine doing it in simulation, and with John von Neumann began calculating. Nicholas Metropolis gave it the gambling name, although something like that would be hard to resist. This is far from the only game that’s inspired useful mathematics. It is a good one, though.


That’s the mathematical comics for the week. Sunday, at this link, should see my next posting, with whatever comics up this week. Thanks for reading me reading the comics.

Reading the Comics, January 7, 2020: I Could Have Slept In Edition


It’s been another of those weeks where the comic strips mentioned mathematics but not in any substantive way. I haven’t read Saturday’s comics yet, as I write this, so perhaps the last day of the week will revolutionize things. In the meanwhile, here’s the strips you can look at and agree say ‘mathematics’ in them somewhere.

Dave Whamond’s Reality Check for the 5th of January, 2020, uses a blackboard full of arithmetic as signifier of teaching. The strip is an extended riff on Extruded Inspirational Teacher Movie product. I like the strip, but I don’t fault you if you think it’s a lot of words deployed against a really ignorable target.

Henry Scarpelli’s Archie rerun for the 7th has Archie not doing his algebra homework.

Bill Bettwy’s Take It From The Tinkersons on the 6th started a short series about Tillman Tinkerson and his mathematics homework. The storyline went on Tuesday, and Wednesday, and finished on Thursday.

Nate Fakes’s Break of Day for the 7th uses arithmetic as signifier of a child’s intelligence.

Mark Pett’s Mr Lowe rerun for the 7th has Lowe trying to teach arithmetic. Also, the strip is rerunning again, which is nice to see.


And that’s enough for now. I’ll read Saturday’s comics next and maybe have another essay at this link, soon. Thanks for reading.

How December 2019 Treated My Mathematics Blog


I have not been putting off the regular monthly review of my readership statistics because I didn’t like how they looked. I’ve had things occupying my day and haven’t had time to tend the blog is all. That’s come to a stop now, though, and I can look seriously at how things went around here last month. Later, I hope to do a review of the last year.

So, I don’t like how the readership around here looked. I knew there’d be some falling off, as last year’s A to Z project wrapped up. Fewer posts correspond very well with fewer page views, and fewer unique visitors. I wasn’t expecting the fall-off to be this severe, though. Here’s how it looked.

Bar chart of views per month for the last several years. The bars grow quite large in fall of 2019, with a spike about three times anything else's size for October 2019. They've dropped considerably two months in a row.
Still, the views per visitor of about 1.5 is holding around my average. That’s mediocre enough, isn’t it?

There were only 1,386 page views around here in December. That’s the lowest page views count since July. It’s well below the twelve-month running average of 2,057.1 visitors per month, too. The consoling thing: there were “only” eighteen posts in December. This is 77.0 views per posting, which is well below the average of 114.7 views per posting of the past year. But it’s basically identical to November’s record of 77.8 views per posting, and to September’s 81.5 views per posting. October 2019 is and will long remain an anomaly, unless someone else discovers me in some forum.

There were 909 unique visitors in December, again the smallest number since July. And well below the running average of 1,390.3 unique visitors. Per post, it’s 50.5 visitors, which is again way below the running average of 76.7 visitors per post. But it’s right in line with November’s 52.3 and September’s 46.2 visitors per post.

Still there’s things to be discontent about. There were 44 things liked in December, a mere 2.4 likes given per posting. That’s below the running averages of 69.7 likes per month, and of 4.4 likes per post. And then the most shocking statistics of all: zero comments in the whole month. I can’t find that that’s ever happened before, even in the earliest days of the blog when I would hit refresh to make the place seem busier than it is. The running averages are 16.4 comments per month, and 1.1 per post, and it’s hard to believe how far short of that I fell.

Well, there’s not much for me to do but lick my wounds. And to think about what I want in the blog: do I want a chatty comments section? If so, why? I like writing. But I do seem to not be good at blog conversations. I can either work to be better at that, or I can focus on what I am already enjoying. There are good things to say about both approaches.

There were popular posts in December, no matter how much I wasn’t particularly liked. The five posts most often read in December 2019 were:

All told there were 224 pages, including the home page, that got at least a single view in December. That’s down from November’s 300 and October’s 311. 102 of them got more than a single view, down from 160 and 187 the previous few months. 27 got at least ten views, down from 42 and 52 in recent months. Mm.

There were only 60 countries that sent me any page views in December. That’s down from 94 in November and 116 in October, although it’s getting close to September’s 69. There were 18 single-view countries, down from November’s and October’s 24. Here’s the readership figures for them all:

Mercator-style map of the world, with the United States in darkest red. Canada, Mexico, Brazil, most of Europe, South Asia, and Australia and New Zealand are in a fairly uniform pink too. There are a smattering of African and South American countries also offering readers.
I like to think I did Australia any bit of good by letting a couple dozen of its residents read about comic strips or other such nonsense given everything they’ve been going through, but I’m not positive this doesn’t reflect some people having left ‘curl’ processes running while they were out dealing with the fire crises.
Country Readers
United States 875
India 62
Philippines 58
Australia 55
Canada 47
United Kingdom 35
Germany 28
Brazil 23
Finland 13
Italy 13
Singapore 13
France 10
Denmark 9
Sweden 9
Israel 8
Belgium 7
Mexico 7
Bangladesh 6
Indonesia 6
Netherlands 6
Pakistan 6
Romania 6
Turkey 6
Russia 5
Spain 5
Switzerland 5
Thailand 5
Poland 4
South Africa 4
South Korea 4
Belize 3
Japan 3
New Zealand 3
Portugal 3
Chile 2
Colombia 2
Egypt 2
Nigeria 2
Serbia 2
Taiwan 2
Ukraine 2
Vietnam 2
American Samoa 1
Belarus 1
Bolivia 1
Bulgaria 1
Czech Republic 1
Georgia 1
Greece 1
Ireland 1
Jordan 1 (*)
Kenya 1
Kuwait 1
Latvia 1
Myanmar (Burma) 1
Norway 1
Oman 1
Saudi Arabia 1
Slovakia 1
Sri Lanka 1 (*)

Jordan and Sri Lanka were the only single-view countries in November, and neither of them was a single-view country in October too.

In December I had 18 posts. These had a total of 8,842 words, for an average of 491.2 words per posting. I’m surprised there’s so few of them too. This is obviously quite below the year’s average of 861 words per posting. December did a fair bit at bringing my words-per-post count down, too. December ended with my having written 201 posts over the whole year, my second-greatest number ever. And 173,087 words in total, my third-most-verbose year. I’ll get into the statistics for the full year in the look back at all 2019 that I mean to write soon. But 861 words per posting is the median of my words-per-posting average, so far.

From the dawn of time to the start of 2020 I’d had 1,403 posts around here. They drew a total of 97,577 views, from 52,978 logged unique visitors.

If you’d like to read these posts regularly, please do. You’ve already gotten much of the way there. If you have a WordPress account you can use the “Follow Nebusresearch” button on the upper right corner of this page to have it appear in your Reader regularly. If you have an RSS reader — and a free account at Dreamwidth or Livejournal will give you one, by the way — you can add the feed at https://nebusresearch.wordpress.com/feed/ to it. And, as I’ve warned, my Twitter account @Nebusj posts announcements of things as they’re published. But I haven’t had the spoons to figure out how to actually get at it myself, so it’s not a way to chat with me. I’m not sure what is a way to chat with me. Ask my parents what it’s like.

Nevertheless, thank you for reading, however it is you do it, and however often you do it.

Reading the Comics, January 4, 2020: The Little Things Edition


Today’s essay is just to mention the comic strips which, last week, said mathematics but in some incidental way. Or some way that I can’t write a reasonable blog entry for.

Gary Larson’s The Far Side reruns for the 30th of December, 2019, included this classic about curiosity killing cats. This 1985 strip rates a mention because a blackboard of mathematical symbols gets used to represent their intellectual inquiries.

Bill Amend’s FoxTrot for the 29th, a Sunday and thus new strip, is some wordplay based on the Disney+ line of entertainment product.

Jim Meddick’s Monty for the 29th has the time-travelling Professor Xemit (get it?) show a Times Square Ball Drop of the future. The ball gets replaced with a “demihypercube”, the idea being that the future will have some more complicated geometry than a mere “ball”. There is no such thing as “a” demihypercube, in the same way there is not “a” pentagon. There is a family of shapes, all called demihypercubes. There’s a variety of ways to represent them. A reasonable one, though, is a roughly spherical shape made of pointy triangles all over. It wouldn’t look absurd. There are probably time ball drops that use something like a demihypercube already.

Ruben Bolling’s Super-Fun-Pak Comix rerun for the 1st of January, 2020 features a Comics For The Elderly speaking of the advantages an abacus has over a spreadsheet.

Neal Rubin and Rod Whigham’s Gil Thorp for the 2nd has one of the student athletes working on calculus. And coach Mimi Thorp is doing the mathematics of studying athlete performance. If this strip makes you curious, too, my other blog should this Sunday recap what’s going on in Gil Thorp.

Also this coming Sunday I should look at more mathematically-themed comic strips. That should appear at this link, unless something urgent commands my attention first. Thank you.

Reading the Comics, January 4, 2020: Representations Edition


The start of the year brings me comic strips I can discuss in some detail. There are also some that just mention a mathematical topic, and don’t need more than a mention that the strip exists. I’ll get to those later.

Jonathan Lemon’s Rabbits Against Magic for the 2nd is another comic strip built on a very simple model of animal reproduction. We saw one late last year with a rat or mouse making similar calculations. Any calculation like this builds on some outright untrue premises, particularly in supposing that every rabbit that’s born survives, and that the animals breed as much as could do. It also builds on some reasonable simplifications. Things like an average litter size, or an average gestation period, or time it takes infants to start breeding. These sorts of exponential-growth calculations depend a lot on exactly what assumptions you make. I tried reproducing Lemon’s calculation. I didn’t hit 95 billion offspring. But I got near enough to say that Lemon’s right to footnote this as ‘true’. I wouldn’t call them “baby bunnies”, though; after all, some of these offspring are going to be nearly seven years old by the end of this span.

Eight-Ball; 'I'm starting an online movement against the stereotype that rabbits breed like ... rabbits.' Weenus: 'In a 7-year breeding life span, a singe mother can, mathematically, be responsible for 95 billion baby bunnies.' Eight-Ball: 'Hashtag guilty as charged.'
Jonathan Lemon’s Rabbits Against Magic for the 2nd of January, 2020. This and other essays featuring Rabbits Against Magic should be at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 3rd justifies why “mathematicians are no longer allowed to [sic] sporting events” with mathematicians being difficult. Each of the signs is mean to convey the message “We’re #1”. The notations are just needlessly inaccessible, in that way nerds will do things.

0.\bar{9} first. The bar over over a decimal like this means to repeat what is underneath the bar without limit. So this is the number represented by 0.99999… and this is another way to write the number 1. This sometimes makes people uncomfortable; the proof is to think what the difference is between 1 and the number represented by 0.999999 … . The difference is smaller than any positive number. It’s certainly not negative. So the difference is zero. So the two numbers have to be the same number.

0^0 is the controversial one here. The trouble is that there are two standard rules that clash here. One is the rule that any real number raised to the zeroth power is 1. The other is the rule that zero raised to any positive real number is 0. We don’t ask about zero raised to a negative number. These seem to clash. That we only know zero raised to positive real numbers is 0 seems to break the tie, and justify concluding the number-to-the-zero-power rule should win out. This is probably what Weinersmith, or Weinersmith’s mathematician, was thinking. If you forced me to say what I think 0^0 should be, and didn’t let me refuse to commit to a value, I’d probably pick “1” too. But.

Three people holding up signs: 'We're #0.9' (bar above the 9). 'We're #0^0$'. 'We're #e^{pi/2} i^i$. Caption: 'Mathematicians are no longer allowed to sporting events.'
Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 3rd of January, 2020. I am always finding reasons to write about this strip. The essays including Saturday Morning Breakfast Cereal discussions should be at this link.

The expression x^x exists for real-valued numbers x, and that’s fine. We can look at \lim_{x \rightarrow 0 } x^x and that number’s 1. But what if x is a complex-valued number? If that’s the case, then this limit isn’t defined. And mathematicians need to work with complex-valued numbers a lot. It would be daft to say “real-valued 0^0 is 1, but complex-valued 0^0 isn’t anything”. So we avoid the obvious daftness and normally defer to saying 0^0 is undefined.

The last expression is e^{\frac{\pi}{2}} \imath^{\imath} . This \imath is that famous base of imaginary numbers, one of those numbers for which \imath^2 = -1 . Complex-valued numbers can be multiplied and divided and raised to powers just like real-valued numbers can. And, remarkably — it surprised me — the number \imath^{\imath} is equal to e^{-\frac{\pi}{2}} . That’s the reciprocal of e^{\frac{\pi}{2}} .

There are a couple of ways to show this. A straightforward method uses the famous Euler formula, that e^{\imath x} = \cos(x) + \imath\sin(x) . This implies that e^{\imath \frac{\pi}{2}} = \imath . So \imath^{\imath} has to equal (e^{\imath \frac{\pi}{2}})^{\imath} . That’s equal to e^{\imath^2 \frac{\pi}{2}}) , or e^{- \frac{\pi}{2}}) . If you find it weird that an imaginary number raised to an imaginary number gives you a real number — it’s a touch less than 0.208 — then, well, you see how weird even the simple things can be.

Locomotive engineer, speaking to Abraham Lincoln, who's making notes: 'Well, Mr President, let's see. Carry the one, take away three, carry the two ... that would be four score and seven years ago.'
Gary Larson’s The Far Side for the 4th of January, 2020. While there are only a few so far, I’m sure the number of essays based on something from The Far Side at this link will grow. This strip originally ran in 1980, if the copyright date is correct.

Gary Larson’s The Far Side for the 4th references Abraham Lincoln’s famous use of “four score and seven” to represent 87. There have been many ways to give names to numbers. As we’ve gotten comfortable with decimalization, though, most of them have faded away. I think only dozens and half-dozens remain in common use; if it weren’t for Lincoln’s style surely nobody today would remember “score” as a way to represent twenty. It probably avoids ambiguities that would otherwise plague words like “hundred”, but it does limit one’s prose style. The talk about carrying the one and taking away three is flavor. There’s nothing in turning eighty-seven into four-score-and-seven that needs this sort of arithmetic.


I hope later this week to list the comic strips which just mentioned some mathematical topic. That essay, and next week’s review of whatever this week is mathematical, should appear at this link. Thanks for reading.

Reading the Comics, December 28, 2019: Running Out The 2010s Edition


And here’s the last four comic strips from the final full week of 2019. I have already picked a couple strips for the end of December to say at least something about. Those I intend to wait for Sunday to review, though. And, as with the strips from this past Sunday, these are too slight for me to write much about. That’s all right. I don’t need the extra workload of thinking this week.

Doug Savage’s Savage Chickens for the 26th uses a blackboard of mathematics (as part of “understanding of particle physics”) as symbolic of intelligence. I’m not versed enough in particle physics to say whether the expressions make sense. I’m inclined toward it, since the first line has an integral of the reciprocal of the distance between a point x and a point x’. That looks to me like a calculation of some potential energy-related stuff.

Dana Simpson’s Phoebe and her Unicorn for the 27th uses “memorizing multiplication tables” as the sort of challenging and tedious task that a friend would not put another one through. The strip surprised me; I would have thought Phoebe the sort of kid who’d find multiplication tables, with their symmetry and teasing hints of structure (compare any number on the upper-left-to-lower-right diagonal to the numbers just up-and-right or down-and-left to it, for example), fascinating enough to memorize on their own.

Leigh Rubin’s Rubes for the 27th has a rat-or-mouse showing off one of those exciting calculations about how many rats-or-mice could breed in a year if absolutely nothing limited their growth. These sorts of calculations are fun for getting to big numbers in pretty little time. They’re only the first, loosest pieces of a model for anything’s population, though.

Pab Sungenis’s New Adventures of Queen Victoria for the 28th gets into the question about whether the new decade starts in 2020 or 2021. I wasn’t aware people were asking the question until a few weeks ago, when my father asked me for an authoritative answer. He respects my credentials as a mathematician and a calendar freak. The only answer I can defend, though, is to say of course a new decade starts in 2020. A new decade also starts in 2021. There’s also a decade starting in 2022. There’s a new decade starting five minutes from the moment you read this sentence. If you hurry you just might make it.

If you want to make any claims about “the” new decade, you have to say what you pick “the” to signify. Complete decades from the (proleptically defined) 1st of January, 1, is a compelling choice. “Years starting the 1st of January, 2020” is also a compelling choice. Decide your preference and you’ll decide your answer.

Thank you for reading, this essay and this whole year. 2020 is, of course, a leap year, or “bissextile year” if you want to establish your reputation as a calendar freak. Good luck.

Reading the Comics, December 25, 2019: Running Out The Year Edition


The last full week of the year had, again, comic strips that mostly mention mathematics without getting into detail. That’s all right. I have a bit of a cold so I’m happy not to have to compose thoughts about too many of them.

John Zakour and Scott Roberts’s Maria’s Day for the 22nd has Maria finishing, and losing, her mathematics homework. I suppose the implication’s that she couldn’t hope to reconstruct it before class. It’s not like she could re-write a short essay for history, though.

Percy Crosby’s Skippy for the 23rd has Skippy and Sookie doing the sort of story problem arithmetic of working out a total bill. The strip originally ran the 11th of August, 1932.

Cy Olson’s Office Hours for the 24th, which originally ran the 14th of October, 1971, comes the nearest to having enough to talk about here. The secretary describes having found five different answers in calculating the profits and so used the highest one. The joke is on incompetent secretaries, yes. But it is respectable, if trying to understand something very complicated, to use several different models for what one wants to know. These will likely have different values, although how different they are, and how changes in one model tracks changes in another, can be valuable. We’re accustomed to this, at least in the United States, by weather forecasts: any local weather report will describe expected storms by different models. These use different ideas about how much moisture moves into the air, how fast raindrops will form (a very difficult problem), how winds will shift, that sort of thing. It’s defensible to make similar different models for reporting the health of a business, particularly if company owns things with a price that can’t be precisely stated.

Marguerite Dabaie and Tom Hart’s Ali’s House for the 24th continues a story from the week before in which a character imagines something tossing us out of three-dimensional space. A seven-dimensional space is interesting mathematically. We can define a cross product between vectors in three-dimensional space and in seven-dimensional space. Most other spaces don’t allow something like a cross product to be coherently defined. Seven-dimensional space also allows for something called the “exotic sphere”, which I hadn’t heard of before either. It’s a structure that’s topologically a sphere, but that has a different kind of structure. This isn’t unique to seven-dimensional space. It’s not known whether four-dimensional space has exotic spheres, although many spaces higher than seven dimensions have them.

Gordon Bess’s Redeye for the 25th of December has Pokey asking his horse Loco to do arithmetic. There’s a long history of animals doing, or seeming to do, arithmetic. The strip originally ran the 23rd of August, 1973.

I’ll have some more comic strips to close out the year, I expect, which should appear at this link, most like on Tuesday. Thanks for reading.