Reading the Comics, September 28, 2019: Modeling Edition

The second half of last week’s mathematically-themed comic strips had an interesting range of topics. Two of them seemed to circle around the making of models. So that’s my name for this installment.

Ryan North’s Dinosaur Comics for the 26th has T-Rex trying to build a model. In this case, it’s to project how often we should expect to see a real-life Batman. T-Rex is building a simple model, which is fine. Simple models, first, are usually easier to calculate with. How they differ from reality can give a guide to how to make a more complex model. Or they can indicate the things that have to be learned in order to make a more complex model. The difference between a model’s representation and the observed reality (or plausibly expected reality) can point out problems in one’s assumptions, too.

Ryan North’s Dinosaur Comics for the 26th of September, 2019. Essays featuring discussion of some topic raised by Dinosaur Comics should appear at this link.

For example, T-Rex supposes that a Batman needs to have billionaire parents. This makes for a tiny number of available parents. But surely what’s important is that a Batman be wealthy enough he doesn’t have to show up to any appointments he doesn’t want to make. Having a half-billion dollars, or a “mere” hundred million, would allow that. Even a Batman who had “only” ten million dollars would be about as free to be a superhero. Similarly, consider the restriction to Olympic athletes. Astronaut Ed White, who on Gemini IV became the first American to walk in space, was not an Olympic athlete; but he certainly could have been. He missed by a split-second in the 400 meter hurdles race. Surely someone as physically fit as Ed White would be fit enough for a Batman. Not to say that “Olympic athletes or NASA astronauts” is a much bigger population than “Olympic athletes”. (And White was unusually fit even for NASA astronauts.) But it does suggest that merely counting Olympic athletes is too restrictive.

But that’s quibbling over the exact numbers. The process is a good rough model. List all the factors, suppose that all the factors are independent of one another, and multiply how likely it is each step happens by the population it could happen to. It’s hard to imagine a simpler model, but it’s a place to start.

Greg Wallace’s Nothing Is Not Something for the 26th of September, 2019. I don’t seem to have tagged this strip before! Well, this essay and any future ones based on Nothing Is Not Something should appear at this link.

Greg Wallace’s Nothing Is Not Something for the 26th is a bit of a geometry joke. It’s built on the idiom of the love triangle, expanding it into more-sided shapes. Relationships between groups of people like this can be well-represented in graph theory, with each person a vertex, and each pair of involved people an edge. There are even “directed graphs”, where each edge contains a direction. This lets one represent the difference between requited and unrequited interests.

Brian Anderson’s Dog Eat Doug for the 27th of September, 2019. The essays exploring some topic raised by Dog Eat Doug should appear at this link.

Brian Anderson’s Dog Eat Doug for the 27th has Sophie the dog encounter some squirrels trying to disprove a flat Earth. They’re not proposing a round Earth either; they’ve gone in for a rhomboid. Sophie’s right to point out that drilling is a really hard way to get through the Earth. That’s a practical matter, though.

Is it possible to tell something about the shape of a whole thing from a small spot? In the terminology, what kind of global knowledge can we get from local information? We can do some things. For example, we can draw a triangle on the surface of the Earth and measure the interior angles to see what they sum to. If this could be done perfectly, finding that the interior angles add up to more than 180 degrees would show the triangle’s on a spherical surface. But that also has practical limitations. Like, if we find that locally the planet is curved then we can rule out it being entirely flat. But it’s imaginable that we’d be on the one dome of an otherwise flat planet. At some point you have to either assume you’re in a typical spot, or work out ways to find what’s atypical. In the Conspiracy Squirrels’ case, that would be the edge between two faces of the rhomboid Earth. Then it becomes something susceptible to reason.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 27th of September, 2019. It’s not literally true that every Reading the Comics essay includes this strip. The essays with Saturday Morning Breakfast Cereal in them are at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 27th has the mathematician making another model. And this is one of the other uses of a model: to show a thing can’t happen, show that it would have results contrary to reason. But then you have to validate the model, showing that its premises do represent reality so well that its conclusion should be believed. This can be hard. There’s some nice symbol-writing on the chalkboard here, although I don’t see that they parse. Particularly, the bit on the right edge of the panel, where the writing has a rotated-by-180-degrees ‘E’ followed by an ‘x’, a rotated-by-180-degrees ‘A’, and then a ‘z’, is hard to fit inside an equation like this. The string of symbols mean “there exists some x for which, for all z, (something) is true”. This fits at the start of a proof, or before an equation starts. It doesn’t make grammatical sense in the middle of an equation. But, in the heat of writing out an idea, mathematicians will write out ungrammatical things. As with plain-text writing, it’s valuable to get an idea down, and edit it into good form later.

Tom Batiuk’s Funky Winkerbean Vintage for the 28th of September, 2019. This strip originally ran the 15th of November, 1973. Both 1970s-era vintage and such 2010s-era modern Funky Winkerbean strips which inspire discussion should be at this link.

Tom Batiuk’s Funky Winkerbean Vintage for the 28th sees the school’s Computer explaining the nature of its existence, and how it works. Here the Computer claims to just be filled with thousands of toes to count on. It’s silly, but it is the case that there’s no operation a computer does that isn’t something a human can do, manually. If you had the paper and the time you could do all the steps of a Facebook group chat, a game of SimCity, or a rocket guidance computer’s calculations. The results might just be impractically slow.

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And that’s finished the comic strips of last week! Sunday I should have a new Reading the Comics post. And then tomorrow I hope to resume the Fall 2019 A to Z series with ‘J’. Thanks for reading.

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Reading the Comics, September 24, 2019: I Make Something Of This Edition

I trust nobody’s too upset that I postponed the big Reading the Comics posts of this week a day. There’s enough comics from last week to split them into two essays. Please enjoy.

Scott Shaw! and Stan Sakai’s Popeye’s Cartoon Club for the 22nd is one of a yearlong series of Sunday strips, each by different cartoonists, celebrating the 90th year of Popeye’s existence as a character. And, I’m a Popeye fan from all the way back when Popeye was still a part of the pop culture. So that’s why I’m bringing such focus to a strip that, really, just mentions the existence of algebra teachers and that they might present a fearsome appearance to people.

Scott Shaw! and Stan Sakai’s Popeye’s Cartoon Club for the 22nd of September, 2019. This is the first (and likely last) time Popeye’s Cartoon Club has gotten a mention here. But appearances by this and by the regular Popeye comic strip (Thimble Theatre, if you prefer) should be gathered at this link.

Lincoln Pierce’s Big Nate for the 22nd has Nate seeking an omen for his mathematics test. This too seems marginal. But I can bring it back to mathematics. One of the fascinating things about having data is finding correlations between things. Sometimes we’ll find two things that seem to go together, including apparently disparate things like basketball success and test-taking scores. This can be an avenue for further research. One of these things might cause the other, or at least encourage it. Or the link may be spurious, both things caused by the same common factor. (Superstition can be one of those things: doing a thing ritually, in a competitive event, can help you perform better, even if you don’t believe in superstitions. Psychology is weird.)

Lincoln Pierce’s Big Nate for the 22nd of September, 2019. Essays inspired by something in Big Nate, either new-run or the Big Nate: First Class vintage strips, are at this link.

But there are dangers too. Nate shows off here the danger of selecting the data set to give the result one wants. Even people with honest intentions can fall prey to this. Any real data set will have some points that just do not make sense, and look like a fluke or some error in data-gathering. Often the obvious nonsense can be safely disregarded, but you do need to think carefully to see that you are disregarding it for safe reasons. The other danger is that while two things do correlate, it’s all coincidence. Have enough pieces of data and sometimes they will seem to match up.

Norm Feuti’s Gil rerun for the 22nd has Gil practicing multiplication. It’s really about the difficulties of any kind of educational reform, especially in arithmetic. Gil’s mother is horrified by the appearance of this long multiplication. She dubs it both inefficient and harder than the way she learned. She doesn’t say the way she learned, but I’m guessing it’s the way that I learned too, which would have these problems done in three rows beneath the horizontal equals sign, with a bunch of little carry notes dotting above.

Norm Feuti’s Gil rerun for the 22nd of September, 2019. Essays inspired by either the rerun or the new Sunday Gil strips should be gathered at this link.

Gil’s Mother is horrified for bad reasons. Gil is doing exactly the same work that she was doing. The components of it are just written out differently. The only part of this that’s less “efficient” is that it fills out a little more paper. To me, who has no shortage of paper, this efficiency doens’t seem worth pursuing. I also like this way of writing things out, as it separates cleanly the partial products from the summations done with them. It also means that the carries from, say, multiplying the top number by the first digit of the lower can’t get in the way of carries from multiplying by the second digits. This seems likely to make it easier to avoid arithmetic errors, or to detect errors once suspected. I’d like to think that Gil’s Mom, having this pointed out, would drop her suspicions of this different way of writing things down. But people get very attached to the way they learned things, and will give that up only reluctantly. I include myself in this; there’s things I do for little better reason than inertia.

People will get hung up on the number of “steps” involved in a mathematical process. They shouldn’t. Whether, say, “37 x 2” is done in one step, two steps, or three steps is a matter of how you’re keeping the books. Even if we agree on how much computation is one step, we’re left with value judgements. Like, is it better to do many small steps, or few big steps? My own inclination is towards reliability. I’d rather take more steps than strictly necessary, if they can all be done more surely. If you want speed, my experience is, it’s better off aiming for reliability and consistency. Speed will follow from experience.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 22nd of September, 2019. Essays which go into some aspect of Saturday Morning Breakfast Cereal turn up all the time, such as at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 22nd builds on mathematical physics. Lagrangian mechanics offers great, powerful tools for solving physics problems. It also offers a philosophically challenging interpretation of physics problems. Look at the space made up of all the possible configurations of the system. Take one point to represent the way the system starts. Take another point to represent the way the system ends. Grant that the system gets from that starting point to that ending point. How does it do that? What is the path in this configuration space that goes in-between this start and this end?

We can find the path by using the Lagrangian. Particularly, integrate the Lagrangian over every possible curve that connects the starting point and the ending point. This is every possible way to match start and end. The path that the system actually follows will be an extremum. The actual path will be one that minimizes (or maximizes) this integral, compared to all the other paths nearby that it might follow. Yes, that’s bizarre. How would the particle even know about those other paths?

This seems bad enough. But we can ignore the problem in classical mechanics. The extremum turns out to always match the path that we’d get from taking derivatives of the Lagrangian. Those derivatives look like calculating forces and stuff, like normal.

Then in quantum mechanics the problem reappears and we can’t just ignore it. In the quantum mechanics view no particle follows “a” “path”. It instead is found more likely in some configurations than in others. The most likely configurations correspond to extreme values of this integral. But we can’t just pretend that only the best-possible path “exists”.

Thus the strip’s point. We can represent mechanics quite well. We do this by pretending there are designated starting and ending conditions. And pretending that the system selects the best of every imaginable alternative. The incautious pop physics writer, eager to find exciting stuff about quantum mechanics, will describe this as a particle “exploring” or “considering” all its options before “selecting” one. This is true in the same way that we can say a weight “wants” to roll down the hill, or two magnets “try” to match north and south poles together. We should not mistake it for thinking that electrons go out planning their days, though. Newtonian mechanics gets us used to the idea that if we knew the positions and momentums and forces between everything in the universe perfectly well, we could forecast the future and retrodict the past perfectly. Lagrangian mechanics seems to invite us to imagine a world where everything “perceives” its future and all its possible options. It would be amazing if this did not capture our imaginations.

Bil Keane and Jeff Keane’s Family Circus for the 24th of September, 2019. I’m surprised there are not more appearance of this comic strip here. But Family Circus panels inspire essays at these links.

Bil Keane and Jeff Keane’s Family Circus for the 24th has young Billy amazed by the prospect of algebra, of doing mathematics with both numbers and letters. I’m assuming Billy’s awestruck by the idea of letters representing numbers. Geometry also uses quite a few letters, mostly as labels for the parts of shapes. But that seems like a less fascinating use of letters.

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The second half of last week’s comics I hope to post here on Wednesday. Stick around and we’ll see how close I come to making it. Thank you.

Reading the Comics, September 21, 2019: Filling Out The Week, Part 1 Edition

There were a couple more comic strips than made a good fit in yesterday’s recap. Here’s the two that I had much to write about.

Jason Poland’s Robbie and Bobby for the 18th is another rerun. I mentioned it back in December of 2016. Zeno’s Paradoxical Pasta plays on the most famous of Zeno’s Paradoxes, about how to get to a place one has to get halfway there, but to get halfway there requires getting halfway to halfway. This goes on in infinite regression. The paradox is not a failure to understand that we can get to a place, or finish swallowing a noodle.

Jason Poland’s Robbie and Bobby rerun for the 18th of September, 2019. This is another strip I’m gathering has lapsed into perpetual reruns, so might drop it. But essays featuring Robbie and Bobby should be at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 21st gets that strip back to my attention after, like, days out of it. It’s a logic joke, as promised, and that’s mathematics enough for me. Of course the risk of dying from a lightning strike has to be even lower than the risk of being struck by lightning.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 21st of September, 2019. I too am surprised it’s been almost a month since an essay with Saturday Morning Breakfast Cereal, as gathered at this link. But then Andertoons went missing for like four months in 2018. All sorts of things will happen and we’re not ready for any of them.

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And then there were comic strips that are just of too slight mathematical content for me to go into at length. Several of them all ran on the same day, the 15th of September. Let me give you them.

Jenny Campbell’s Flo and Friends has a couple senior citizens remembering mathematics lessons from their youth. And getting oddly smug about doing it without calculators.

Richard Thompson’s Richard’s Poor Almanac reruns a mention of infinite monkey authorship. Always fun, to my way of thinking.

Samson’s Dark Side of the Horse was the Roman Numerals joke for the week.

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And that’s enough for just now. I expect to finish off the casual mentions with a Wednesday Reading the Comics post. The A to Z series should have ‘G’ tomorrow. And I’m still open for suggestions for the letters I through N. Thank you for reading.

Reading the Comics, August 23, 2019: Basics of Logic Edition

While there were a good number of comic strips to mention mathematics this past week, there were only a few that seemed substantial to me. This works well enough. This probably is going to be the last time I keep the Reading the Comics post until after Sunday, at least until the Fall 2019 A To Z is finished.

And I’m still open to topics for the first third of the alphabet. If you’d like to see my try to understand a thing of your choice please nominate one or more concepts over at this page. You might be the one to name a topic I can’t possibly summarize!

Gordon Bess’s Redeye rerun for the 18th is a joke building on animals’ number sense. And, yeah, about dumb parents too. Horses doing arithmetic have a noteworthy history. But more in the field of understanding how animals learn, than in how they do arithmetic. In particular in how animals learn to respond to human cues, and how slight a cue has to be to be recognized and acted on. I imagine this reflects horses being unwieldy experimental animals. Birds — pigeons and ravens, particularly — make better test animals.

Gordon Bess’s Redeye rerun for the 18th of August, 2019. It originally ran the 1st of April, 1973. Essays with mention of Redeye are at this link. This seems to be the first time in over a year the strip has included an actual image and not just a casual “oh, this also mentioned mathematics” line.

Art Sansom and Chip Sansom’s The Born Loser for the 18th gives a mental arithmetic problem. It’s a trick question, yes. But Brutus gives up too soon on what the problem is supposed to be. Now there’s no calculating, in your head, exactly how many seconds are in a year; that’s just too much work. But an estimate? That’s easy.

At least it’s easy if you remember one thing: a million seconds is about eleven and a half days. I find this easy to remember because it’s one of the ideas used all the time to express how big a million, a billion, and a trillion are. A million seconds are about eleven and a half days. A billion seconds are a little under 32 years. A trillion seconds are about 32,000 years, which is about how long it’s been since the oldest known domesticated dog skulls were fossilized. I’m sure that gives everyone a clear idea of how big a trillion is. The important thing, though, is that a million seconds is about eleven and a half days.

Art Sansom and Chip Sansom’s The Born Loser for the 18th of August, 2019. Appearances by The Born Loser should be at this link.

So. Think of the year. There are — as the punch line to Hattie’s riddle puts it — twelve 2nd’s in the year. So there are something like a million seconds spent each year on days that are the 2nd of the month. There about a million seconds spent each year on days that are the 1st of the month, too. There are about a million seconds spent each year on days that are the 3rd of the month. And so on. So, there’s something like 31 million seconds in the year.

You protest. There aren’t a million seconds in twelve days; there’s a million seconds in eleven and a half days. True. Also there aren’t 31 days in every month; there’s 31 days in seven months of the year. There’s 30 days in four months, and 28 or 29 in the remainder. That’s fine. This is mental arithmetic. I’m undercounting the number of seconds by supposing that a million seconds makes twelve days. I’m overcounting the number of seconds by supposing that there are twelve months of 31 days each. I’m willing to bet this undercount and this overcount roughly balance out. How close do I get?

There are 31,536,000 seconds in a common year. That is, a non-leap-year. So “31 million” is a bit low. But it’s not bad for working without a calculator.

Ryan North’s Dinosaur Comics for the 19th of August, 2019. This and other essays with Dinosaur Comics under discussion should be at this link.

Ryan North’s Dinosaur Comics for the 19th lays on us the Eubulides Paradox. It’s traced back to the fourth century BCE. Eubulides was a Greek philosopher, student of “Not That” Euclid of Megara. We know Eubulides for a set of paradoxes, including the Sorites paradox. As T-Rex’s friends point out, we’ve all heard this paradox. We’ve all gone on with our lives, knowing that the person who said it wanted us to say they were very clever. Fine.

But if we take this seriously we find … this keeps not being simple. We can avoid the problem by declaring self-referential statements exist outside of truth or falsity. This forces us to declare the sentence “this sentence is true” can’t be true. This seems goofy. We can avoid the problem by supposing there are things that are neither true nor false. That solves our problem here at the mere cost of ruining our ability to prove stuff by contradiction. There’s a lot of stuff we prove by contradiction. It’s hard to give that all up for this (Although, so far as I’m aware, anything that can be proved by contradiction can also be proven by a direct line of reasoning. The direct line may just be tedious.) We can solve this problem by saying that our words are fuzzy imprecise things. This is true enough, as see any time my love and I debate how many things are in “a couple of things”. But declaring that we just can’t express the problem well enough to answer it seems like running away from the question. We can resolve things by accepting there are limits to what can be proved by logic. Gödel’s Incompleteness Theorem shows that any interesting enough logic system has statements that are true but unprovable. A version of this paradox helps us get to this interesting conclusion.

So this is one of those things it should be easy to laugh off, but why it should be easy is hard.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 21st of August, 2019. In case I ever mention Saturday Morning Breakfast Cereal in an essay you’ll see it at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 21st is about the other great logic problem of the 20th century. The Halting Problem here refers to Turing Machines. This is the algorithmic model for computing devices. It’s rather abstract, so the model won’t help you with your C++ homework, but nothing will. But it turns out we can represent a computer running a program as a string of cells. Each cell holds one of a couple possible values. The program is a series of steps. Each step starts at one cell. The program resets the value of that cell to something dictated by the algorithm. Then, the program moves focus to another cell, again as the algorithm dictates. Do enough of this and you get SimCity 2000. I don’t know all the steps in-between.

So. The Halting Program is this: take a program. Run it. What happens in the long run? Well, it does something or other, yes. But there’s three kinds of things it can do. It can run for a while and then finish, that is, ‘halt’. It can run for a while and then get into a repeating loop, after which it repeats things forever. It can run forever without repeating itself. (Yeah, I see the structural resemblance to terminating decimals, repeating decimals, and irrational numbers too, but I don’t know of any link there.) The Halting Problem asks, if all we know is the algorithm, can we know what happens? Can we say for sure the program will always end, regardless of what the data it works on are? Can we say for sure the program won’t end if we feed it the right data to start?

If the program is simple enough — and it has to be extremely simple — we can say. But, basically, if the program is complicated enough to be even the least bit interesting, it’s impossible to say. Even just running the program isn’t enough: how do you know the difference between a program that takes a trillion seconds to finish and one that never finishes?

For human needs, yes, a program that needs a trillion seconds might as well be one that never finishes. Which is not precisely the joke Weinersmith makes here, but is circling around similar territory.

Mark Anderson’s Andertoons for the 23rd of August, 2019. Tune in to all the times Wavehead says something to a teacher with the Andertoons-based essays at this link.

Mark Anderson’s Andertoons for the 23rd is the Mark Anderson’s Andertoons for the week. And it teases my planned post for Thursday, available soon at this link. Thanks for reading.

Reading the Comics, July 26, 2019: Children With Mathematics Edition

Three of the strips I have for this installment feature kids around mathematics talk. That’s enough for a theme name.

Gary Delainey and Gerry Rasmussen’s Betty for the 23rd is a strip about luck. It’s easy to form the superstitious view that you have a finite amount of luck, or that you have good and bad lucks which offset each other. It feels like it. If you haven’t felt like it, then consider that time you got an unexpected $200, hours before your car’s alternator died.

If events are independent, though, that’s just not so. Whether you win $600 in the lottery this week has no effect on whether you win any next week. Similarly whether you’re struck by lightning should have no effect on whether you’re struck again.

Gary Delainey and Gerry Rasmussen’s Betty for the 23rd of July, 2019. I thought this might be a new tag, but, no. Other essays mentioning Betty are at this link.

Except that this assumes independence. Even defines independence. This is obvious when you consider that, having won $600, it’s easier to buy an extra twenty dollars in lottery tickets and that does increase your (tiny) chance of winning again. If you’re struck by lightning, perhaps it’s because you tend to be someplace that’s often struck by lightning. Probability is a subtler topic than everyone acknowledges, even when they remember that it is such a subtle topic.

It sure seems like this strip wants to talk about lottery winners struck by lightning, doesn’t it?

Darrin Bell’s Candorville for the 23rd of July, 2019. Essays inspired by Candorville in some way are here.

Darrin Bell’s Candorville for the 23rd jokes about the uselessness of arithmetic in modern society. I’m a bit surprised at Lemont’s glee in not having to work out tips by hand. The character’s usually a bit of a science nerd. But liking science is different from enjoying doing arithmetic. And bad experiences learning mathematics can sour someone on the subject for life. (Which is true of every subject. Compare the number of people who come out of gym class enjoying physical fitness.)

If you need some Internet Old, read the comments at GoComics, which include people offering dire warnings about what you need in case your machine gives the wrong answer. Which is technically true, but for this application? Getting the wrong answer is not an immediately awful affair. Also a lot of cranky complaining about tipping having risen to 20% just because the United States continues its economic punishment of working peoples.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 25th of July, 2019. Haven’t seen this comic mentioned since two days ago. Essays mentioning some aspect of Saturday Morning Breakfast Cereal should be gathered at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 25th is some wordplay. Mathematicians often need to find minimums of things. Or maximums of things. Being able to do one lets you do the other, as you’d expect. If you didn’t expect, think about it a moment, and then you expect it. So min and max are often grouped together.

Paul Trap’s Thatababy for the 26th of July, 2019. Essays exploring some topic mentioned by Thatababy are here.

Paul Trap’s Thatababy for the 26th is circling around wordplay, turning some common shape names into pictures. This strip might be aimed at mathematics teachers’ doors. I’d certainly accept these as jokes that help someone learn their shapes.

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And you know what? I hope to have another Reading the Comics post around Thursday at this link. And that’s not even thinking what I might do for this coming Sunday.

Reading the Comics, July 22, 2019: Mathematics Education Edition

There were a decent number of mathematically-themed comic strips this past week. This figures, because I’ve spent this past week doing a lot of things, and look to be busier this coming week. Nothing to do but jump into it, then.

Jason Chatfield’s Ginger Meggs for the 21st is your usual strip about the student resisting the story problem. Story problems are hard to set. Ideally, they present problems like mathematicians actually do, proposing the finding of something it would be interesting to learn. But it’s hard to find different problems like this. You might be fairly interested in how long it takes a tub filling with water to overflow, but the third problem of this kind is going to look a lot like the first two. And it’s also hard to find problems that allow for no confounding alternate interpretations, like this. Have some sympathy and let us sometimes just give you an equation to solve.

Jason Chatfield’s Ginger Meggs for the 21st of July, 2019. Essays which mention Ginger Meggs are at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 21st is a pun built on two technical definitions for “induction”. The one used in mathematics, and logic, is a powerful tool for certain kinds of proof. It’s hard to teach how to set it up correctly, though. It’s a way to prove an infinitely large number of logical propositions, though. Let me call those propositions P₁, P₂, P₃, P₄, and so on. P_j for every counting number j. The first step of the proof is showing that some base proposition is true. This is usually some case that’s really easy to do. This is the fun part of a proof by induction, because it feels like you’ve done half the work and it amounts to something like, oh, showing that 1 is a triangular number.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 21st of July, 2019. It’s not quite every Reading the Comics post with some mention of this comic. Those which do explore Saturday Morning Breakfast Cereal are at this link.

The second part is hard. You have to show that whenever P_j is true, this implies that P_{j + 1} is also true. This is usually a step full of letters representing numbers rather than anything you can directly visualize with, like, dots on paper. This is usually the hard part. But put those two halves together? And you’ve proven that all your propositions are true. Making things line up like that is so much fun.

Mark Anderson’s Andertoons for the 22nd of July, 2019. It’s not quite every Reading the Comics post with some mention of this comic. Those which do explore Andertoons are at this link.

Mark Anderson’s Andertoons for the 22nd is the Mark Anderson’s Andertoons for the week. It’s again your student trying to get out of not really knowing mathematics in class. Longtime readers will know, though, that I’m fond of rough drafts in mathematics. I think most mathematicians are. If you are doing something you don’t quite understand, then you don’t know how to do it well. It’s worth, in that case, doing an approximation of what you truly want to do. This is for the same reason writers are always advised to write something and then edit later. The rough draft will help you find what you truly want. In thinking about the rough draft, you can get closer to the good draft.

Stephen Bentley’s Herb and Jamaal rerun for the 22nd of July, 2019. It originally ran sometime in 2014, based on the copyright notice. Essays mentioning Herb and Jamaal in some way are at this link. Also, what’s the cheaper but more fun snark: observing the genericness of “that new rap song” or the slightly out-of-date nature of a kid listening to the radio?

Stephen Bentley’s Herb and Jamaal for the 22nd is one lost on me. I grew up when Schoolhouse Rock was a fun and impossible-to-avoid part of watching Saturday Morning cartoons. So there’s a lot of simple mathematics that I learned by having it put to music and played often.

Still, it’s surprising Herb can’t think of why it might be easier to remember something that’s fun, that’s put to a memory-enhancing tool like music, and repeated often, than it is to remember whether 8 times 7 is 54. Arithmetic gets easier to remember when you notice patterns, and find them delightful. Even fun. It’s a lot like everything else humans put any attention to, that way.

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This was a busy week for comic strips. I hope to have another Reading the Comics post around Tuesday, and at this link. There might even be another one this week. Please check back in.

Reading the Comics, July 2, 2019: Back On Schedule Edition

I hoped I’d get a Reading the Comics post in for Tuesday, and even managed it. With this I’m all caught up to the syndicated comic strips which, last week, brought up some mathematics topic. I’m open for nominations about what to publish here Thursday. Write in quick.

Hilary Price’s Rhymes With Orange for the 30th is a struggling-student joke. And set in summer school, so the comic can be run the last day of June without standing out to its United States audience. It expresses a common anxiety, about that point when mathematics starts using letters. It superficially seems strange that this change worries students. Students surely had encountered problems where some term in an equation was replaced with a blank space and they were expected to find the missing term. This is the same work as using a letter. Still, there are important differences. First is that a blank line (box, circle, whatever) has connotations of “a thing to be filled in”. A letter seems to carry meaning in to the problem, even if it’s just “x marks the spot”. And a letter, as we use it in English, always stands for the same thing (or at least the same set of things). That ‘x’ may be 7 in one problem and 12 in another seems weird. I mean weird even by the standards of English orthography.

Hilary Price’s Rhymes With Orange for the 30th of June, 2019. Essays with some mention of Rhymes With Orange should be at this link.

A letter might represent a number whose value we wish to know; it might represent a number whose value we don’t care about. These are different ideas. We usually fall into a convention where numbers we wish to know are more likely x, y, and z, while those we don’t care about are more likely a, b, and c. But even that’s no reliable rule. And there may be several letters in a single equation. It’s one thing to have a single unknown number to deal with. To have two? Three? I don’t blame people fearing they can’t handle that.

Mark Leiknes’s Cow and Boy for the 30th has Billy and Cow pondering the Prisoner’s Dilemma. This is one of the first examples someone encounters in game theory. Game theory sounds like the most fun part of mathematics. It’s the study of situations in which there’s multiple parties following formal rules which allow for gains or losses. This is an abstract description. It means many things fit a mathematician’s idea of a game.

Mark Leiknes’s Cow and Boy rerun for the 30th of June, 2019. The comic strip is long since ended, but hasn’t quite rerun enough times for me to get tired of it. So essays featuring Cow and Boy appear this link. The gnome is a lawn gnome who came to life and … you know, this was a pretty weird comic and I understand why it didn’t make it in the newspapers. Just roll with it.

The Prisoner’s Dilemma is described well enough by Billy. It’s built on two parties, each — separately and without the ability to coordinate — having to make a choice. Both would be better off, under interrogation, to keep quiet and trust that the cops can’t get anything significant on them. But both have the temptation that if they rat out the other, they’ll get off free while their former partner gets screwed. And knowing that their partner has the same temptation. So what would be best for the two of them requires them both doing the thing that maximizes their individual risk. The implication is unsettling: everyone acting in their own best interest is supposed to produce the best possible result for society. And here, for the society of these two accused, it breaks down entirely.

Jason Poland’s Robbie and Bobby for the 1st is a rerun. I discussed it last time it appeared, in November 2016, which was before I would routinely include the strips under discussion. The strip’s built on wordplay, using the word ‘power’ in its connotations for might and for exponents.

Jason Poland’s Robbie and Bobby rerun for the 1st of July, 2019. I think but am not sure that this comic strip has lapsed into eternal reruns. In any case the essays that mention some topic raised by Robbie and Bobby are at this link.

Exponents have been written as numbers in superscript following a base for a long while now. The notation developed over the 17th century. I don’t know why mathematicians settled on superscripts, as opposed to the many other ways a base and an exponent might fit together. It’s a good mnemonic to remember, say, “z raised to the 10th” is z with a raised 10. But I don’t know the etymology of “raised” in a mathematical context well enough. It’s plausible that we say “raised” because that’s what the notation suggests.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 2nd argues for the beauty of mathematics as a use for it. It’s presented in a brutal manner, but saying brutal things to kids is a comic motif with history to it. Well, in an existentialist manner, but that gets pretty brutal quickly.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 2nd of July, 2019. This one doesn’t appear in every Reading the Comics essay, so you can find my discussions inspired by Saturday Morning Breakfast Cereal at this link.

The proof of the Pythagorean Theorem is one of the very many known to humanity. This one is among the family of proofs that are wordless. At least nearly wordless. You can get from here to with very little prompting. If you do need prompting, it’s this: there are two expressions for how much area of the square with sides a-plus-b. One of these expressions uses only terms of a and b. The other expression uses terms of a, b, and c. If this doesn’t get a bit of a grin out of you, don’t worry. There’s, like, 2,037 other proofs we already know about. We might ask whether we need quite so many proofs of the Pythagorean theorem. It doesn’t seem to be under serious question most of the time.

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And then a couple comic strips last week just mentioned mathematics. Morrie Turner’s Wee Pals for the 1st of July has the kids trying to understand their mathematics homework. Could have been anything. Mike Thompson’s Grand Avenue for the 5th started a sequence with the kids at Math Camp. The comic is trying quite hard to get me riled up. So far it’s been the kids agreeing that mathematics is the worst, and has left things at that. Hrmph.

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Whether or not I have something for Thursday, by Sunday I should have anotherReading the Comics post. It, as well as my back catalogue of these essays, should be at this link. Thanks for worrying about me.

Reading the Comics, June 27, 2019: Closing A Slow Month Edition

Some months stretch my pop-mathematics writing skills, tasking me with finding new insights into the things I thought I understood and new ways to present them. Some months I’ve written about comic strips a lot. This was one of the latter. Here, let me nearly finish writing about the comic strips of June 2019 that had some mathematical content.

Jonathan Lemon’s Rabbits Against Magic for the 23rd is the Venn Diagram meta-joke for the week. Properly speaking, yes, Eight-Ball hasn’t drawn a Venn Diagram here. Representing two sets in a Venn Diagram, by the proper rules, requires two circles with one overlap. Indicating that both sets have the same elements means noting that there are no elements outside the intersection of these circles. One point of a Venn Diagram is showing all the possible logical relations between sets and maybe then marking off the ones that happen to be relevant to the problem. What Eight-Ball is drawing is an Euler Diagram, which has looser requirements. There’s no sense fighting this terminology battle, though. It makes cleaner pictures to draw a Venn Diagram modified to only show the relations that actually exist. If the goal is to communicate information, clarity counts. A joke counts as information.

Jonathan Lemon’s Rabbits Against Magic for the 23rd of June, 2019. Oh, this strip again. You’ve seen Rabbits Against Magic in essays at this link.

Eight-Ball’s propositions are … well, a bit muddled. His first set is “people who like to think they are good at math”. His second set is “which of those people like Venn Diagrams”. This implies the second set can’t be anything but a subset of the first. So this we’d represent as one circle inside another, at least if we allow that there exists at least one person who likes to think they’re good at math, but still doesn’t like Venn Diagrams. It’s fine for the purposes of comic hyperbole to claim there is no such thing, of course, and I don’t quarrel with that.

Why not have the second group be “people who like Venn Diagrams”, without the restriction that they already think they’re good at math? Here I think there is a serious logical constraint. My suspicion is that Venn Diagrams are liked by people who don’t think they’re good at math. Also by people who aren’t good at math. Venn Diagrams are a wonderful tool because they present the relationships of sets in a way that uses our spatial intuitions. They wouldn’t make a good Internet joke format if they were liked only by people who think they’re good at math. Which is why Jonathan Lemon had to write the joke that way. It’s plausible comic hyperbole to say everyone who thinks they’re good at math likes Venn Diagrams. But there are too many people who react to explicit mathematics content with a shudder, but who like Venn Diagram jokes, to make “everyone who likes Venn Diagrams thinks they’re good at math” plausible.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 23rd of June, 2019. Oh, this strip again. You’ve seen Saturday Morning Breakfast Cereal in essays at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 23rd is a lying-with-statistics joke. The median is an average of a data set. It’s “an” average because, in English, we mean several different things by “average”. Translated into mathematics these different things are, really, completely unrelated. The “median” is the midpoint of the ordered list of the data set. So, as the Man In Black says, half the data in the set is below that value, and half is above. This can be a better measure of “average” than the arithmetic mean is. It tells us a slight something about the distribution, about how the data is arranged. Not much, but then, it’s just one number. What do you want? It has an advantage over the arithmetic mean, which is the thing normal people intend when they say “average”. That advantage is that it’s relatively insensitive to outliers. One or two really large, or tiny, data points can throw the mean way off. The classic example we use these days is to look at the average wealth of twenty people in the room. If Bill Gates enters the room, the mean jumps way up. The median? Doesn’t alter much. (Bill Gates is the figure I see used these days, but it could be anyone impossibly wealthy. I imagine there are versions where it’s Jeff Bezos entering the room. I imagine a century ago, the proposition would be to imagine J P Morgan entering the room, except that a century ago he had been dead six years.)

Steve Skelton’s 2 Cows and a Chicken for the 26th of June, 2019. Oh, this strip ag — wait, no. Is this a new tag?. No, but the strip was on hiatus a while. 2 Cows And A Chicken has appeared before, in essays at this link. You know it wasn’t until transcribing this comic for the alt text that I realized the ‘dings’ were Chicken pecking at the pot and not a noise that he was making directly. I don’t know why I would have thought he’d have just been making ‘ding’ noises. Also it was the end of my transcribing when I realized what Chicken was doing.

Steve Skelton’s 2 Cows and a Chicken for the 26th shows off a counting chicken as a wonder. Animals do have some sense of mathematics. We know in some detail how well crows and ravens can count, and do simple arithmetic. This is partly because we know good ways to test crow and raven arithmetic skills. And we’ve come to appreciate their intelligence as deep and surprising. Chickens, to my knowledge, have gotten less study. But I would expect they’ve got skills. If nothing else, I would expect chickens to have a good understanding of the transitive property. This is the rule that if ‘a’ is greater than ‘b’, and ‘b’ is greater than ‘c’, then it follows that ‘a’ is greater than ‘c’. Chickens have a pecking order, and animals with that kind of hierarchy tend to know transitivity. I don’t know that the reasons for that link have been proven, but, c’mon. And animals doing arithmetic, like the cook says, have been good sideshow attractions or performances for a long while. They’ve also been good starts for scientific study, as people try to work out questions like how intelligence formed, and what other ways it might have formed.

Greg Cravens’s The Buckets for the 27th of June, 2019. All right, this one appears kind of middlingly often. The Buckets turns up in essays at this link.

Greg Cravens’s The Buckets for the 27th is a joke about the representation of numbers. Cravens has a good observation here about learning the differences between representations, and of not being able to express just what representation you want. I love Eddie’s horrified face as his mother (Sarah) tries to spell out the word. There’s probably a good exercise to be done in thinking of as many ways to represent fifteen as possible.

Etymologically, “fifteen” has exactly the origin you would say if you were dragged out of a sound sleep by someone demanding the history of the word RIGHT NOW, THERE’S NO TIME TO EXPLAIN. In Old English it was “fiftyne”, with “fif” meaning “five” and “tyne” meaning “ten more than”. This construction, pretty much five-and-ten, has fallen out of favor in English. Once we get past nineteen we more commonly write out, like, “twenty-one” and “thirty-five” and such. The alternate construction, which would be, like, one-and-twenty, or nine-and-sixty, or such, seems to have fallen out of use except as a more poetic way to express the idea. I don’t know why, say, five-and-twenty would have shifted to twenty-five while the equivalent five-and-ten didn’t shift to … teenfive(?). I would make an uninformed guess that words used more commonly tend to be more stable, and we tend to need smaller numbers more than bigger ones.

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I’ll have some more comic strips for you later in the week. Before then should be a statistics review, as I figure out whether anyone is reading this blog after a month when I wrote basically nothing. The next Reading the Comics post should be at this link probably on Thursday. Thank you for reading any of this.

Reading the Comics, June 21, 2019: I Have An Anecdote Edition

A couple years back we needed to patch a bunch of weak spots in the roof. We found all the spots that needed shoring up and measured how long they were, and went to buy some wood and get it cut to fit. I turned over the list of sizes and the guy told us we’d have to buy more than one of the standard-size sheets of plywood to do it. I thought, wait, no, that can’t be, and sketched out possible ways to cut the wood and fit pieces together. Finally I concluded that, oh, yes, the guy whose job it was to figure out how much wood was needed for particular tasks knew what he was talking about. His secret? I don’t know. What finally convinced me was adding up the total area of the wood we’d need, and finding that it was more than what one sheet would be.

Dave Blazek’s Loose Parts for the 19th uses a whiteboard full of mathematics as visual shorthand for “some really complicated subject”. It’s a good set of mathematics symbols on the whiteboard. They don’t mean anything in the combination shown, though. It’s just meant to bewilder.

Dave Blazek’s Loose Parts for the 19th of June, 2019. When I have something to write about Loose Parts the result should be at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 21st is bewildering, unless you know what the mathematics principle the joke intends to present. This is what I’m here for.

The key is the Mover’s claim that he can look at any amount of stuff and tell you whether it fits in the moving bins. Working out something like this is a version of the knapsack problem. The knapsack problem is … well, the problem you imagine it might be, if someone told you “some mathematicians study a thing called the knapsack problem”? That’s about right. Formally, it’s about selecting from a set of things of different value. How hard is it to pick a subset of things with exactly that value? Or find that there is no such subset?

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 21st of June, 2019. I don’t always write about this strip, but when I do write about Saturday Morning Breakfast Cereal, the essay should appear here.

Well, in a sense, not hard at all. You can just keep trying combinations. Eventually you’ll either find a set that works, or you’ll try every possibility and find none of them work. This is known as “exhaustion”, and correctly. If there are ten things, there are 3,628,800 possibilities. Then it gets really bad. If there are twenty things, there are 2,432,902,008,176,640,000 possibilities. Finding the one that works? That could take a while.

So being able to tell whether a collection of things can fit within a particular space? That’s a form of the knapsack problem. Being able to always solve that any faster than just “try out every combination until you find one that works”? That would be incredible. The problem is hard. That’s a technical term. It means what you imagine it means, but more precisely.

So why the mathematician’s response? It’s because the problem of hacking the common Internet security algorithms is also hard. (I am discussing here how difficult hacking would be if the algorithm were implemented perfectly. There are many hacking techniques available because of bugs. Programs are not written perfectly. Compilers do not translate them to computer code perfectly. Computers are not built perfectly. These and more flaws make hacking more possible than it should be.) It’s the same kind of hard as this knapsack problem. I mean “the same” more technically than you might imagine. If you had a method to quickly solve this knapsack problem, then, you could use this to break computer encryption quickly. And, it turns out, vice-versa, so at least there’s some fairness to things. So if the the Mover can, truly, always instantly tell whether a set of things fit in the moving bins, then hacking e-mails should be possible to. The Mover would have to team up with a mathematician who studies computational problems like this. I don’t know how to do it, myself. I think about the how to do this and feel lost, myself.

So is the Mover full of it? Let’s put this more nicely. Is he at least unduly optimistic about his claims?

Nah. What makes the knapsack problem hard is that you have to find a solution that quickly finds answers for every possible set of things. But the Mover doesn’t have to deal with that. Most of the stuff is in boxes. It’s in mostly simple polygonal shapes. There’s not, like, 400 million items, each the size of a Cheerio. The Mover may plausibly have never encountered a set of things to move where he couldn’t tell whether it fits.

And, yes, there’s selection bias. Suppose he declared that no, this load had to fit into two vans. But that actually a sufficiently clever arrangement would have let it fit in one. Who would ever know he was wrong? He’d only ever know his intuition was wrong if he declared something would fit in one van and, in fact, it couldn’t.

Percy Crosby’s Skippy for the 21st of June, 2019. It originally ran, looks like, the 9th of February, 1932. Essays featuring Skippy should be at this link.

Percy Crosby’s Skippy for the 21st is a student-at-the-board problem. It’s using the punch line that “I don’t know” might be a true answer to any problem. There are many real mathematics problems for which nobody really knows an answer.

But Miss Larkin has good advice here. Maybe you don’t know the final answer. But do you know anything? Write it down. It’s good for partial credit, at least. Working out a part of the problem might also be useful, too. Often you can work out how to do a hard problem by looking at a similar but simpler problem. If Skippy is lost at 8 + 4 + 7 + 5, could he do at least 8 + 4 + 7? Could he do 8 + 4? Maybe this wouldn’t help him get to the ultimate answer. Often a difficult problem turns out to be solved by solving a circle of simple problems, that starve out the hard.

Samson’s Dark Side of the Horse for the 21st of June, 2019. And I don’t always write about this comic either, but when I do write about Dark Side of the Horse I make an essay that should appear at this link.

Samson’s Dark Side of the Horse for the 21st is the Roman Numerals joke for this time around. I’m not sure this whether this is a repeat. The strip does a lot of Roman Numerals jokes, and counting-sheep jokes.

Our roof patches held up for their need, which was just to last a couple months while we contracted for a replacement roof. And, happily, the roof replacement got done speedily and during a week that did not rain. (Back in grad school the apartment I was in had its roof replaced on a day that, it turns out, would get a spontaneous downpour halfway through. My apartment was on the top floor. This made for an exciting afternoon.)

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This wraps up the past week’s comics. There weren’t any that mentioned mathematics more fleetingly than Dark Side of the Horse did. A new Reading the Comics post should be at this link on Sunday. Thank you for reading along.

Reading the Comics, June 20, 2019: Old Friends Edition

We continue to be in the summer vacation doldrums for mathematically-themed comic strips. But there’ve been a couple coming out. I could break this week’s crop into two essays, for example. All of today’s strips are comics that turn up in my essays a lot. It’s like hanging out with a couple of old friends.

Samson’s Dark Side of the Horse for the 17th uses the motif of arithmetic expressions as “difficult” things. The expressions Samson quotes seem difficult for being syntactically weird: What does the colon under the radical sign mean in ? Or they’re difficult for being indirect, using a phrase like “50%” for “half”. But with some charity we can read this as Horace talking about 3:33 am to about 6:30 am. I agree that those are difficult hours.

Samson’s Dark Side of the Horse for the 17th of June, 2019. Some of the many essays inspired by Dark Side of the Horse are at this link.

It also puts me in mind of a gift from a few years back. An aunt sent me an Irrational Watch, with a dial that didn’t have the usual counting numbers on it. Instead there were various irrational numbers, like the Golden Ratio or the square root of 50 or the like. Also the Euler-Mascheroni Constant, a number that may or may not be irrational. Nobody knows. It’s likely that it is irrational, but it’s not proven. It’s a good bit of fun, although it does make it a bit harder to use the watch for problems like “how long is it until 4:15?” This isn’t quite what’s going on here — the square root of nine is a noticeably rational number — but it seems in that same spirit.

Mark Anderson’s Andertoons for the 18th sees Wavehead react to the terminology of the “improper fraction”. “Proper” and “improper” as words carry a suggestion of … well, decency. Like there’s something faintly immoral about having an improper fraction. “Proper” and “improper”, as words, attach to many mathematical concepts. Several years ago I wrote that “proper” amounted to “it isn’t boring”. This is a fair way to characterize, like, proper subsets or proper factors or the like. It’s less obvious that is a boring fraction.

Mark Anderson’s Andertoons for the 18th of June, 2019. Essays with some mention of a topic from Andertoons are at this link.

I may need to rewrite that old essay. An “improper” form satisfies all the required conditions for the term. But it misses some of the connotation of the term. It’s true that, say, the new process takes “a fraction of the time” of the old, if the old process took one hour and the new process takes fourteen years. But if you tried telling someone that they would assume you misunderstood something. The ordinary English usage of “fraction” carries the connotation of “a fraction between zero and one”, and that’s what makes a “proper fraction”.

In practical terms, improper fractions are fine. I don’t know of any mathematicians who seriously object to them, or avoid using them. The hedging word “seriously” is in there because of a special need. That need is: how big is, say, ? Is it bigger than five? Is it smaller than six? An improper fraction depends on you knowing, in this case, your fourteen-times tables to tell. Switching that to a mixed fraction, , helps figure out what the number means. That’s as far as we have to worry about the propriety of fractions.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 20th uses the form of a Fermi problem for its joke. Fermi problems have a place in mathematical modeling. The idea is to find an estimate for some quantity. We often want to do this. The trick is to build a simple model, and to calculate using a tiny bit of data. The Fermi problem that has someone reached public consciousness is called the Fermi paradox. The question that paradox addresses is, how many technologically advanced species are there in the galaxy? There’s no way to guess. But we can make models and those give us topics to investigate to better understand the problem. (The paradox is that reasonable guesses about the model suggest there should be so many aliens that they’d be a menace to air traffic. Or that the universe should be empty except for us. Both alternatives seem unrealistic.) Such estimates can be quite wrong, of course. I remember a Robert Heinlein essay in which he explained the Soviets were lying about the size of Moscow, his evidence being he didn’t see the ship traffic he expected when he toured the city. I do not remember that he analyzed what he might have reasoned wrong when he republished this in a collection of essays he didn’t seem to realize were funny.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 20th of June, 2019. Anyone who’s been reading these for a couple weeks knows, but, Saturday Morning Breakfast Cereal features in essays at this link. Hey, every essay is somebody’s first.

So the interview question presented is such a Fermi problem. The job applicant, presumably, has not committed to memory the number of employees at the company. But there would be clues. Does the company own the whole building it’s in, or just a floor? Just an office? How large is the building? How large is the parking lot? Are there people walking the hallways? How many desks are in the offices? The question could be answerable. The applicant has a pretty good chain of reasoning too.

Bill Amend’s FoxTrot Classics for the 20th has several mathematical jokes in it. One is the use of excessively many decimal points to indicate intelligence. Grant that someone cares about the hyperbolic cosines of 15.2. There is no need to cite its wrong value to nine digits past the decimal. Decimal points are hypnotic, though, and listing many of them has connotations of relentless, robotic intelligence. That is what Amend went for in the characters here. That and showing how terrible nerds are when they find some petty issue to rage over.

Bill Amend’s FoxTrot Classics for the 20th of June, 2019. It originally ran the 3rd of July, 1997. Essays based on FoxTrot, either the current-run Sundays, newspaper-rerun 2000s strips, or 90s-run Classics, are at this link.

Eugene is correct about the hyperbolic cosine being wrong, there, though. He’s not wrong to check that. It’s good form to have some idea what a plausible answer should be. It lets one spot errors, for one. No mathematician is too good to avoid making dumb little mistakes. And computing tools will make mistakes too. Fortunately they don’t often, but this strip originally ran a couple years after the discovery of the Pentium FDIV bug. This was a glitch in the way certain Pentium chips handled floating-point division. It was discovered by Dr Thomas Nicely, at Lynchberg College, who found inconsistencies in some calculations when he added Pentium systems to the computers he was using. This Pentium bug may have been on Amend’s mind.

Eugene would have spotted right away that the hyperbolic cosine was wrong, though, and didn’t need nine digits for it. The hyperbolic cosine is a function. Its domain is the real numbers. It range is entirely numbers greater than or equal to one, or less than or equal to minus one. A 0.9 something just can’t happen, not as the hyperbolic cosine for a real number.

And what is the hyperbolic cosine? It’s one of the hyperbolic trigonometric functions. The other trig functions — sine, tangent, arc-sine, and all that — have their shadows too. You’ll see the hyperbolic sine and hyperbolic tangent some. You will never see the hyperbolic arc-cosecant and anyone trying to tell you that you need it is putting you on. They turn up in introductory calculus classes because you can differentiate them, and integrate them, the way you can ordinary trig functions. They look just different enough from regular trig functions to seem interesting for half a class. By the time you’re doing this, your instructor needs that.

The ordinary trig functions come from the unit circle. You can relate the Cartesian coordinates of a point on the circle described by to the angle made between that point and the center of the circle and the positive x-axis. Hyperbolic trig functions we can relate the Cartesian coordinates of a point on the hyperbola described by to angles instead. The functions … don’t have a lot of use at the intro-to-calculus level. Again, other than that they let you do some quite testable differentiation and integration problems that don’t look exactly like regular trig functions do. They turn up again if you get far enough into mathematical physics. The hyperbolic cosine does well in describing catenaries, that is, the shape of flexible wires under gravity. And the family of functions turn up in statistical mechanics, often, in the mathematics of heat and of magnetism. But overall, these functions aren’t needed a lot. A good scientific calculator will offer them, certainly. But it’ll be harder to get them.

There is another oddity at work here. The cosine of 15.2 degrees is about 0.965, yes. But mathematicians will usually think of trigonometric functions — regular or hyperbolic — in terms of radians. This is just a different measure of angles. A right angle, 90 degrees, is measured as radians. The use of radians makes a good bit of other work easier. Mathematicians get to accustomed to using radians that to use degrees seems slightly alien. The cosine of 15.2 radians, then, would be about -0.874. Eugene has apparently left his calculator in degree mode, rather than radian mode. If he weren’t so worked up about the hyperbolic cosine being wrong he might have noticed. Perhaps that will be another exciting error to discover down the line.

This strip was part of a several-months-long story Bill Amend did, in which Jason has adventures at Math Camp. I don’t remember the whole story. But I do expect the strip to have several more appearances here this summer.

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And that’s about half of last week’s comics. A fresh Reading the Comics post should be at this link later this week. Thank you for reading along.

Reading the Comics, May 30, 2019: Catching Out Tiger Mode

So this has been a week full of plans and machinations. But along the way, I made a discovery about Tiger. Curious? Of course you are. Who would not be? Read on and learn what my discovery is.

Hector D. Cantú and Carlos Castellanos’s Baldo for the 26th has Gracie counting by mathematical expressions. This kind of thing can be fun, at least for someone who enjoys doing arithmetic. Several years ago someone gave me a calendar in which every day was designated by an expression. As a mental exercise it wasn’t much, to my tastes. If you know that this is the second of the month, it’s no great work to figure out what should be. But there is the fun in coming up with different ways to express a number. And here let me mention an old piece about how Paul Dirac worked out an expression for every counting number, using exactly four 2’s.

Hector D. Cantú and Carlos Castellanos’s Baldo for the 26th of May, 2019. It’s been a while since I’ve had reason to discuss this strip, but Baldo-inspired essays should be at this link.

John Graziano’s Ripley’s Believe It or Not for the 26th mentions several fairly believable things. The relevant part is about naming the kind of surface that a Pringles chip represents. That is, the surface a Pringles chip would be if it weren’t all choppy and irregular, and if it continued indefinitely.

The shape is, as Graziano’s Ripley’s claims, a hypberbolic paraboloid. It’s a shape you get to know real well if you’re a mathematics major. They turn up in multivariable calculus and, if you do mathematical physics, in dynamical systems. It’s also a shape mathematics majors get to calling a “saddle shape”, because it looks enough like a saddle if you’re not really into horses.

The shape is one of the “quadratic surfaces”. These are shapes which can be described as the sets of Cartesian coordinates that make a quadratic equation true. Equations in Cartesian coordinates will have independent variables x, y, and z, unless there’s a really good reason. A quadratic equation will be the sum of some constant times x, and some constant times x², and some constant times y, and some constant times y², and some constant times z, and some constant times z². Also some constant times xy, and some constant times yz, and some constant times xz. No xyz, though. And it might have some constant added to the mix at the end of all this.

John Graziano’s Ripley’s Believe It or Not for the 26th of May, 2019. The collection of mathematics trivia I’ve noticed in Ripley’s Believe It Or Not should be at this link.

There are seventeen different kinds of quadratic surfaces. Some of them are familiar, like ellipsoids or cones. Some hardly seem like they could be called “quadratic”, like intersecting planes. Or parallel planes. Some look like mid-century modern office lobby decor, like elliptic cylinders. And some have nice, faintly science-fictional shapes, like hyperboloids or, as in here, hyperbolic paraboloids. I’m not a judge of which ones would be good snack shapes.

Samson’s Dark Side of the Horse for the 26th of May, 2019. And I’m glad Horace has finally returned to these pages. Dark Side of the Horse gets discussed in essays at this link.

Samson’s Dark Side of the Horse for the 26th is a funny-answer-to-a-story-problem joke. I had thought these had all switched over to apples, rather than candy bars. But that would make the punch line less believable.

Bud Blake’s Tiger for the 31st is a rerun, of course. Blake died in 2005 and no one else drew his comic strip. It’s a funny-answer-to-a-story-problem joke. And, more, it’s a repeat of a Tiger strip I’ve already run here. I admit a weird pride when I notice a comic strip doing a repeat. It gives me some hope that I might still be able to remember things. But this is also a special Tiger repeat. It’s the strip which made me notice Bud Blake redrawing comics he had already used. This one is not a third iteration of the strip which reran in April 2015 and June 2016. It’s a straight repeat of the June 2016 strip.

Bud Blake’s Tiger for the 31st of May, 2019. Appearances made by Tiger in these essays are at this link. Yes, I have to think about whether I mean to retire this link. But don’t worry: I’ll forget to act on that need.

The mystery to me now is why King Features apparently has less than three years’ worth of reruns in the bank for Tiger. The comic ran from 1965 to 2003, and it’s not as though the strip made pop culture references or jokes ripped from the headlines. Even if the strip changed its dimensions over the decades, to accommodate shrinking newspapers, there should be a decade at least of usable strips to rerun.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 31st of May, 2019. And as the Andertoons of multi-panel strips, Saturday Morning Breakfast Cereal features in the many essays at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 31st uses a chart to tease mathematicians, both in the comic and in the readership. The joke is in the format of the graph. The graph is supposed to argue that the Mathematician’s pedantry is increasing with time, and it does do that. But it is customary in this sort of graph for the independent variable to be the horizontal axis and the dependent variable the vertical. So, if the claim is that the pedantry level rises as time goes on, yes, this is a … well, I want to say wrong way to arrange the axes. This is because the chart, as drawn, breaks a convention. But convention is a tool to help people’s comprehension. We are right to ignore convention if doing so makes the chart better serve its purpose. Which, the punch line is, this does.

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There’s just enough comics for me to do another essay this coming week. That next Reading the Comics post should be at this link around Thursday. That would be Tuesday except I need to fit my monthly readership report in sometime, don’t I? I think I need to, anyway.

Reading the Comics, May 25, 2019: Slighter Comics Edition.

It turned out to be Thursday. These things happen. The comics for the second half of last week were more marginal

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 20th is a joke about holographic cosmology, proving that there are such things as jokes about holographic cosmology. Cosmology is about the big picture stuff, like, why there is a universe and why it looks like that. It’s a rather mathematical field, owing to the difficulty of doing controlled experiments. Holograms are that same technology used back in the 80s to put shoddy three-dimensional-ish pictures of eagles on credit cards. (In the United States. I imagine they were other animals in other countries.) Holograms, at least when they’re well-made, encode the information needed to make a three-dimensional image in a two-dimensional surface. (Please pretend that anything made of matter is two-dimensional like that.)

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 20th of May, 2019. Always glad to discuss Saturday Morning Breakfast Cereal, as you can see from these essays.

Holographic cosmology is a mathematical model for the universe. It represents the things in a space with a description of information on the boundary of this space. This seems bizarre and it won’t surprise you that key inspiration was in the strange physics of black holes. Properties of everything which falls into a black hole manifest in the event horizon, the boundary between normal space and whatever’s going on inside the black hole. The black hole is this three-dimensional volume, but in some way everything there is to say about it is the two-dimensional edge.

Dr Leonard Susskind did much to give this precise mathematical form. You didn’t think the character name was just a bit of whimsy, did you? Susskind’s work showed how the information of a particle falling into a black hole — information here meaning stuff like its position and momentum — turn into oscillations in the event horizon. The holographic principle argues this can be extended to ordinary space, the whole of the regular universe. Is this so? It’s hard to say. It’s a corner of string theory. It’s difficult to run experiments that prove very much. And we are stuck with an epistemological problem. If all the things in the universe and their interactions are equally well described as a three-dimensional volume or as a two-dimensional surface, which is “real”? It may seem intuitively obvious that we experience a three-dimensional space. But that intuition is a way we organize our understanding of our experiences. That’s not the same thing as truth.

Gene Weingarten, Dan Weingarten, and David Clark’s Barney and Clyde for the 22nd of May, 2019. Essays which mention some aspect of Barney and Clyde should appear at this link.

Gene Weingarten, Dan Weingarten, and David Clark’s Barney and Clyde for the 22nd is a joke about power, and how it can coerce someone out of truth. Arithmetic serves as an example of indisputable truth. It could be any deductive logic statement, or for that matter a definition. Arithmetic is great for the comic purpose needed here, though. Anyone can understand, at least the simpler statements, and work out their truth or falsity. And need very little word balloon space for it.

Bill Griffith’s Zippy the Pinhead for the 25th of May, 2019. My attempts to form a quite rational and faintly linear discussion out of Zippy the Pinhead should be gathered here.

Bill Griffith’s Zippy the Pinhead for the 25th also features a quick mention of algebra as the height of rationality. Also as something difficult to understand. Most fields are hard to understand, when you truly try. But algebra works well for this writing purpose. Anyone who’d read Zippy the Pinhead has an idea of what understanding algebra would be like, the way they might not have an idea of holographic cosmology.

Teresa Logan’s Laughing Redhead Comics for the 25th of May, 2019. This one is a new tag. So there’s just the one Laughing Redhead Comics essay at this link. But that might change any day now!

Teresa Logan’s Laughing Redhead Comics for the 25th is the Venn diagram joke for the week, this one with a celebrity theme. Your choice whether the logic of the joke makes sense. Ryan Reynolds and John Krasinski are among those celebrities that I keep thinking I don’t know, but that it turns out I do know. Ryan Gosling I’m still not sure about.

And then there are a couple strips too slight even to appear in this collection. Dean Young and John Marshall’s Blondie on the 22nd did a lottery joke, with discussion of probability along the way. (And I hadn’t had a tag for ‘Blondie’ before, so that’s an addition which someday will baffle me.) Bob Shannon’s Tough Town for the 23rd mentions mathematics teaching. It’s in service of a pun.

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And now I’ve had the past week covered. The next Reading the Comics post should be at this link come Sunday.

Reading the Comics, April 26, 2019: Absurd Equation Edition

And now I’ll cover the handful of comic strips which ran last week and which didn’t fit in my Sunday report. And link to a couple of comics that ultimately weren’t worth discussion in their own right, mostly because they were repeats of ones I’ve already discussed. I have been trimming rerun comics out of my daily reading. But there are ones I like too much to give up, at least not right now.

Bud Blake’s Tiger for the 25th has Tiger quizzing Punkinhead on counting. The younger kid hasn’t reached the point where he can work out numbers without a specific physical representation. It would come, if he were in one of those comics where people age.

Bud Blake’s Tiger for the 25th of April, 2019. Essays that bring up something in Tiger appear at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 24th is an optimization problem, and an expectation value problem. The wisdom-seeker searches for the most satisfying life. The mathematician-guru offers an answer based in probability and expectation values. List all the possible outcomes, and how probable each are, and how much of the relevant quantity you get (or lose) with each outcome. This is a quite utilitarian view of life-planning. Finding the best possible outcome, given certain constraints, is another big field of mathematics.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 24th of April, 2019. There’s plenty of discussion of Saturday Morning Breakfast Cereal at this link.

John Atkinson’s Wrong Hands for the 26th is a nonsense-equation panel. It’s built on a cute idea. If you do wan to know how many bears you can fit in the kitchen you would need something like this. Not this, though. You can tell by the dimensions. ‘x’, as the area of the kitchen, has units of, well, area. Square feet, or square meters, or square centimeters, or whatever is convenient to measure its area. The average volume of a bear, meanwhile, has units of … volume. Cubic feet, or cubic meters, or cubic centimeters, or the like. The one divided by the other has units of one-over-distance.

John Atkinson’s Wrong Hands for the 26th of April, 2019. Other essays featuring by Wrong Hands are at this link.

And I don’t know what the units of desire to have bears in your kitchen are, but I’m guessing it’s not “bear-feet”, although that would be worth a giggle. The equation would parse more closely if y were the number of bears that can fit in a square foot, or something similar. I say all this just to spoil Atkinson’s fine enough bit of nonsense.

Percy Crosby’s Skippy rerun for the 26th of April, 2019. It first ran the 3rd of December, 1931. This and other mentions of Crosby’s brilliant Skippy should appear at this link.

Percy Crosby’s Skippy for the 26th is a joke built on inappropriate extrapolation. 3520 seconds is a touch under an hour. Skippy’s pace, if he could keep it up, would be running a mile every five minutes, 52 seconds. That pace isn’t impossible — I find it listed on charts for marathon runners. But that would be for people who’ve trained to be marathon or other long-distance runners. They probably have different fifty-yard run times.

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And now for some of the recent comics that didn’t seem worth their own discussion, and why they didn’t.

Niklas Eriksson’s Carpe Diem for the 20th features reciting the digits of π as a pointless macho stunt. There are people who make a deal of memorizing digits of π. Everyone needs hobbies, and memorizing meaningless stuff is a traditional fanboy’s way of burying oneself in the thing appreciated. Me, I can give you π to … I want to say sixteen digits. I might have gone farther in my youth, but I was heartbroken when I learned one of the digits I had memorized I got wrong, and so after correcting that mess I gave up going farther.

Rick Detorie’s One Big Happy rerun for the 22nd has Ruthie seeking mathematics help from the homework hotline. The mathematics is just a pretext. And Richard Thompson’s Richard’s Poor Almanac for the 22nd is the color version of that comic with the Platonic Fir tree, discussed several times. Bud Fisher’s Mutt and Jeff for the 25th reprints the pre-relettering version of >the eating-the-roast-beef joke This is the strip that I’d found changed to “eating ham” in 2018, part of the strip’s mysterious and unexplained relettering.

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And now I am, briefly, caught up on the comic strips. I’ll be behind again by Sunday, though. I’ll do something about that, in an essay you should be able to find at this link.

Reading the Comics, April 18, 2019: Slow But Not Stopped Week Edition

The first, important, thing is that I have not disappeared or done something worse. I just had one of those weeks where enough was happening that something had to give. I could either write up stuff for my mathematics blog, or I could feel guilty about not writing stuff up for my mathematics blog. Since I didn’t have time to do both, I went with feeling guilty about not writing, instead. I’m hoping this week will give me more writing time, but I am fooling only myself.

Second is that Comics Kingdom has, for all my complaining, gotten less bad in the redesign. Mostly in that the whole comics page loads at once, now, instead of needing me to click to “load more comics” every six strips. Good. The strips still appear in weird random orders, especially strips like Prince Valiant that only run on Sundays, but still. I can take seeing a vintage Boner’s Ark Sunday strip six unnecessary times. The strips are still smaller than they used to be, and they’re not using the decent, three-row format that they used to. And the archives don’t let you look at a week’s worth in one page. But it’s less bad, and isn’t that all we can ever hope for out of the Internet anymore?

And finally, Comic Strip Master Command wanted to make this an easy week for me by not having a lot to write about. It got so light I’ve maybe overcompensated. I’m not sure I have enough to write about here, but, I don’t want to completely vanish either.

Dave Whamond’s Reality Check for the 15th of April, 2019. Appearances in these pages of Reality Check should be gathered at this link.

Dave Whamond’s Reality Check for the 15th is … hm. Well, it’s not an anthropomorphic-numerals joke. It is some kind of wordplay, making concrete a common phrase about, and attitude toward, numbers. I could make the fussy difference between numbers and numerals here but I’m not sure anyone has the patience for that.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 17th of April, 2019. I am surprised that this is the first time this strip has drawn a mention this month. Well, this and other Saturday Morning Breakfast Cereal posts are at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 17th touches around mathematics without, I admit, necessarily saying anything specific. The angel(?) welcoming the man to heaven mentions creating new systems of mathematics as some fit job for the heavenly host. The discussion of creating self-consistent physics systems seems mathematical in nature too. I’m not sure whether saying one could “attempt” to create self-consistent physics is meant to imply that our universe’s physics are not self-consistent. To create a “maximally complex reality using the simplest possible constructions” seems like a mathematical challenge as well. There are important fields of mathematics built on optimizing, trying to create the most extreme of one thing subject to some constraints or other.

I think the strip’s premise is the old, partially a joke, concept that God is a mathematician. This would explain why the angel(?) seems to rate doing mathematics or mathematics-related projects as so important. But even then … well, consider. There’s nothing about designing new systems of mathematics that ordinary mortals can’t do. Creating new physics or new realities is beyond us, certainly, but designing the rules for such seems possible. I think I understood this comic better then I had thought about it less. Maybe including it in this column has only made trouble for me.

Doug Savage’s Savage Chickens for the 17th of April, 2019. Essays inspired by something from Savage Chickens should be at this link.

Doug Savage’s Savage Chickens for the 17th amuses me by making a strip out of a logic paradox. It’s not quite your “this statement is a lie” paradox, but it feels close to that, to me. To have the first chicken call it “Birthday Paradox” also teases a familiar probability problem. It’s not a true paradox. It merely surprises people who haven’t encountered the problem before. This would be the question of how many people you need to have in a group before there’s a 50 percent (75 percent, 99 percent, whatever you like) chance of at least one pair sharing a birthday.

And I notice on Wikipedia a neat variation of this birthday problem. This generalization considers splitting people into two distinct groups, and how many people you need in each group to have a set chance of a pair, one person from each group, sharing a birthday. Apparently both a 32-person group of 16 women and 16 men, or a 49-person group of 43 women and six men, have a 50% chance of some woman-man pair sharing a birthday. Neat.

Mark Parisi’s Off The Mark for the 18th of April, 2019. And essays inspired by Off The Mark should appear at this link.

Mark Parisi’s Off The Mark for the 18th sports a bit of wordplay. It’s built on how multiplication and division also have meanings in biology. … If I’m not mis-reading my dictionary, “multiply” meant any increase in number first, and the arithmetic operation we now call multiplication afterwards. Division, similarly, meant to separate into parts before it meant the mathematical operation as well. So it might be fairer to say that multiplication and division are words that picked up mathematical meaning.

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And if you thought this week’s pickings had slender mathematical content? Jef Mallett’s Frazz, for the 19th, just mentioned mathematics homework. Well, there were a couple of quite slight jokes the previous week too, that I never mentioned. Jenny Campbell’s Flo and Friends for the 8th did a Roman numerals joke. The rerun of Richard Thompson’s Richard’s Poor Almanac for the 11th had the Platonic Fir Christmas tree, rendered as a geometric figure. I’ve discussed the connotations of that before.

And there we are. I hope to have some further writing this coming week. But if all else fails my next Reading the Comics essay, like all of them, should be at this link.

Reading the Comics, March 2, 2019: Process Edition

There were a handful of comic strips from last week which I didn’t already discuss. Two of them inspire me to write about how we know how to do things. That makes a good theme.

Marcus Hamilton and Scott Ketcham’s Dennis the Menace for the 27th gets into deep territory. How does we could count to a million? Maybe some determined soul has actually done it. But it would take the better part of a month. Things improve some if we allow that anything a computing machine can do, a person could do. This seems reasonable enough. It’s heady to imagine that all the computing done to support, say, a game of Roller Coaster Tycoon could be done by one person working alone with a sheet of paper. Anyway, a computer could show counting up to a million, a billion, a trillion, although then we start asking whether anyone’s checked that it hasn’t skipped some numbers. (Don’t laugh. The New York Times print edition includes an issue number, today at 58,258, at the top of the front page. It’s meant to list the number of published daily editions since the paper started. They mis-counted once, in 1898, and nobody noticed until 1999.)

Marcus Hamilton and Scott Ketcham’s Dennis the Menace for the 27th of February, 2019. I’m not quite confident that I have the credits right here, but if I am parsing Wikipedia’s entry correctly Hamilton and Ketcham work on the daily comics and Ron Ferdinand and Ketcham work on the Sunday strips. And I would have thought this was a new tag but it turns out I have several Dennis the Menace-based essays at this link.

Anyway, allow that. Nobody doubts that, if we put enough time and effort into it, we could count up to any positive whole number, or as they say in the trade, “counting number”. But … there is some largest number that we could possibly count to, even if we put every possible resource and all the time left in the universe to that counting. So how do we know we “could” count to a number bigger than that? What does it mean to say we “could” if the circumstances of the universe are such that we literally could not?

Counting up to a number seems uncontroversial enough. If I wanted to prove it I’d say something like “if we can count to the whole number with value N, then we can count to the whole number with value N + 1 by … going one higher.” And “We can count to the whole number 1”, proving that by enunciating as clearly as I can. The induction follows. Fine enough. That’s a nice little induction proof.

But … what if we needed to do more work? What if we needed to do a lot of work? There is a corner of logic which considers infinitely long proofs, or infinitely long statements. They’re not part of the usual deductive logic that any mathematician knows and relies on. We’re used to, at least in principle, being able to go through and check every step of a proof. If that becomes impossible is that still a proof? It’s not my field, so I feel comfortable not saying what’s right and what’s wrong. But it is one of those lectures in your Mathematical Logic course that leaves you hanging your jaw open.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 27th is a joke about algorithms. These are the processes by which we know how to do a thing. Here, Hansel and Gretel are shown using what’s termed a “greedy algorithm” to follow pebbles back home. This kind of thing reflects trying to find an acceptable solution, in this case, finding a path somewhere. What makes it “greedy” is each step. You’re at a pebble. You can see other pebbles nearby. Which one do you go to? Go to some extreme one; in this case, the nearest. It could instead have been the biggest, or the shiniest, the one at the greatest altitude, the one nearest a water source. Doesn’t matter. You choose your summum bonum and, at each step, take the move that maximizes that.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 27th of February, 2019. There’s no mistaking this for a new tag. Saturday Morning Breakfast Cereal inspires many discussions at this link.

The wicked mother knows something about this sort of algorithm, one that promises merely a solution and not the best solution. And that is that all these solutions can be broken. You can set up a problem that the algorithm can’t solve. Greedy algorithms are particularly vulnerable to this. They’re called “local maximums”. You find the best answer of the ones nearby, but not the best one you possibly could locate.

Why use an algorithm like this, that can be broken so? That’s because we often want to do problems like finding a path through the woods. There are so many possible paths that it’s hard to find one of the acceptable ones. But there are processes that will, typically, find an acceptable answer. Maybe processes that will let us take an acceptable answer and improve it to a good answer. And this is getting into my field.

Actual persons encountering one of these pebble rings would (probably) notice they were caught in a loop. And what they’d do, then, is suspend the greedy rule: instead of going to the nearest pebble they could find, they’d pick something else. Maybe simply the nearest pebble they hadn’t recently visited. Maybe the second-nearest pebble. Maybe they’d give up and strike out in a random direction, trusting they’ll find some more pebbles. This can lead them out of the local maximum they don’t want toward the “global maximum”, the path home, that they do. There’s no reason they can’t get trapped again — this is why the wicked mother made many loops — and no reason they might not get caught in a loop of loops again. Every algorithm like this can get broken by some problem, after all. But sometimes taking the not-the-best steps can lead you to a better solution. That’s the insight at the heart of “Metropolis-Hastings” algorithms, which was my field before I just read comic strips all the time.

Dan Thompson’s Brevity for the 28th of February, 2019. This is another strip that’s inspired a host of essays. Brevity panels get shown off at this link.

Dan Thompson’s Brevity for the 28th is a nice simple anthropomorphic figures joke. It would’ve been a good match for the strips I talked about Sunday. I’m just normally reluctant to sort these comic strips other than by publication date.

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And there were some comic strips I didn’t think worth making paragraphs about. Chris Giarrusso’s G-Man Webcomics for the 25th of February mentioned negative numbers and built a joke on the … negative … connotations of that word. (And inaugurates a tag for that comic strip. This fact will certainly come back to baffle me some later day.) Art Sansom and Chip Sansom’s The Born Loser for the 2nd of March has a bad mathematics report card. Tony Rubino and Gary Markstein’s Daddy’s Home for the 2nd has geometry be the subject parents don’t understand. Bill Amend’s FoxTrot Classics for the 2nd has a mathematics-anxiety dream.

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And this closes out my mathematics comics for the week. Come Sunday I should have a fresh post with more comics, and I thank you for considering reading that.

Reading the Comics, January 30, 2019: Interlude Edition

I think there are just barely enough comic strips from the past week to make three essays this time around. But one of them has to be a short group, only three comics. That’ll be for the next essay when I can group together all the strips that ran in February. One strip that I considered but decided not to write at length about was Ed Allison’s dadaist Unstrange Phenomena for the 28th. It mentions Roman Numerals and the idea of sneaking message in through them. But that’s not really mathematics. I usually enjoy the particular flavor of nonsense which Unstrange Phenomena uses; you might, too.

John McPherson’s Close to Home for the 29th uses an arithmetic problem as shorthand for an accomplished education. The problem is solvable. Of course, you say. It’s an equation with quadratic polynomial; it can hardly not be solved. Yes, fine. But McPherson could easily have thrown together numbers that implied x was complex-valued, or had radicals or some other strange condition. This is one that someone could do in their heads, at least once they practiced in mental arithmetic.

John McPherson’s Close to Home for the 29th of January, 2019. Essays inspired by Close To Home should appear at this link.

I feel reasonably confident McPherson was just having a giggle at the idea of putting knowledge tests into inappropriate venues. So I’ll save the full rant. But there is a long history of racist and eugenicist ideology that tried to prove certain peoples to be mentally incompetent. Making an arithmetic quiz prerequisite to something unrelated echoes that. I’d have asked McPherson to rework the joke to avoid that.

(I’d also want to rework the composition, since the booth, the swinging arm, and the skirted attendant with the clipboard don’t look like any tollbooth I know. But I don’t have an idea how to redo the layout so it’s more realistic. And it’s not as if that sort of realism would heighten the joke.)

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 29th of January, 2019. Every Reading the Comics essay has a bit of Saturday Morning Breakfast Cereal in it. The essays with a particularly high Breakfast Cereal concentration appear at this link, though.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 29th riffs on the problem of squaring the circle. This is one of three classical problems of geometry. The lecturer describes it just fine: is it possible to make a square that’s got the same area as a given circle, using only straightedge and compass? There are shapes it’s easy to do this for, such as rectangles, parallelograms, triangles, and (why not?) this odd crescent-moon shaped figure called the lune. Circles defied all attempts. In the 19th century mathematicians found ways to represent the operations of classical geometry with algebra, and could use the tools of algebra to show squaring the circle was impossible. The squaring would be equivalent to finding a polynomial, with integer coefficients, that has as a root. And we know from the way algebra works that this can’t be done. So squaring the circle can’t be done.

The lecturer’s hack, modifying the compass and straightedge, lets you in principle do whatever you want. The hack isn’t new either. Modifying the geometric tools changes what you can and can’t do. The Ancient Greeks recognized that adding some specialized tools would make the problem possible. But that falls outside the scope of the problem.

Which feeds to the secondary joke, of making the philosophers sad. Often philosophy problems test one’s intuition about an idea by setting out a problem, often with unpleasant choices. A common problem with students that I’m going ahead and guessing are engineers is then attacking the setup of the question, trying to show that the problem couldn’t actually happen. You know, as though there were ever a time significant numbers of people were being tied to trolley tracks. (By the way, that thing about silent movie villains tying women to railroad tracks? Only happened in comedies spoofing Victorian melodramas. It’s always been a parody.) Attacking the logic of a problem may make for good movie drama. But it makes for a lousy student and a worse class discussion.

Ted Shearer’s Quincy for the 30th of January, 2019. It originally ran the 6th of December, 1979. I’m usually happy when I get the chance to talk about this strip. The art’s pretty sweet. When I do discuss Quincy the essays should appear at this link.

Ted Shearer’s Quincy rerun for the 30th uses a bit of mathematics and logic talk. It circles the difference between the feeling one can have about the rational meaning of a situation and how the situation feels to someone. It seems like a jump that Quincy goes from being asked about logic to talking about arithmetic. Possibly Quincy’s understanding of logic doesn’t start from the sort of very abstract concept that makes arithmetic hard to get to, though.

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There should be another Reading the Comics post this week. It should be here, when it appears. There should also be one on Sunday, as usual.

Reading the Comics, January 26, 2019: The Week Ended Early Edition

Last week started out at a good clip: two comics with enough of a mathematical theme I could imagine writing a paragraph about them each day. Then things puttered out. The rest of the week had almost nothing. At least nothing that seemed significant enough. I’ll list those, since that’s become my habit, at the end of the essay.

Jonathan Lemon and Joey Alison Sayers’s Alley Oop for the 20th is my first chance to show off the new artist and writer team. They’ve decided to make Sunday strips a side continuity about a young Alley Oop and his friends. I’m interested. The strip is built on the bit of pop anthropology that tells us “primitive” tribes will have very few counting words. That you can express concepts like one, two, and three, but then have to give up and count “many”.

Jonathan Lemon and Joey Alison Sayers’s Alley Oop for the 20th of January, 2019. I don’t seem to have had much cause to mention Alley Oop before; the only previous reference I can find is in this cameo in a different comic. Well, this and any other essays that write about Alley Oop at any length should be at this link. I don’t figure to differentiate between the weekday Alley Oop strip and the Sunday Little Oop line in using this tag.

Perhaps it’s so. Some societies have been found to have, what seem to us, rather few numerals. This doesn’t reflect on anyone’s abilities or intelligence or the like. And it doesn’t mean people who lack a word for, say, “forty-nine” would be unable to compute. It might take longer, but probably just from inexperience. If someone practiced much calculation on “forty-nine” they’d probably have a name for it. And folks raised in the western mathematics use, even enjoy, some vagueness about big numbers too. We might say there are “dozens” of a thing even if there are not precisely 24, 36, or 48 of the thing; “52” is close enough and we probably didn’t even count it up. “Hundred” similarly has gotten the connotation of being a precise number, but it’s used to mean “really quite a lot of a thing”. The words “thousands”, “millions”, and mock-numbers like “zillions” have a similar role. They suggest different ranges of what might be “many”.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 20th is a SABRmetrics joke! At least, it’s an optimization joke, built on the idea that you can find an optimum strategy for anything, whether winning baseball games or The War. The principle is hard to argue with. Nobody would doubt that different approaches to a battle affect how likely winning is. We can imagine gathering data on how different tactics affect the outcome. (We can easily imagine combat simulators running these experiments, particularly.)

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 20th of January, 2019. Pretty much every Reading the Comics brings up this strip. But the essays that specifically mention Saturday Morning Breakfast Cereal should be at this link.

The catch — well, one catch — is that this tempts one to reward a process. Once it’s taken for granted the process works, then whether it’s actually doing what you want gets forgotten. And once everyone knows what’s being measured it becomes possible to game the system. Famously, in the mid-1960s the United States tried to judge its progress in the Vietname War by counting the number of enemy soldiers killed. There was then little reason to care about who was killed, or why. And reason to not care whether actual enemy soldiers were being killed. There’s good to be said about testing whether the things you try to do work. There’s great danger in thinking that the thing you can measure guarantees success.

Mark Anderson’s Andertoons for the 21st is a bit of fun with definitions. Mathematicians rely on definitions. It’s hard to imagine a proof about something undefined. But definitions are hard to compose. We usually construct a definition because we want a common term to describe a collection of things, and to exclude another collection of things. And we need people like Wavehead who can find edge cases, things that seem to satisfy a definition while breaking its spirit. This can let us find unstated assumptions that we should pay attention to. Or force us to accept that the definition is so generally useful that we’ll tolerate it having some counter-intuitive implications.

Mark Anderson’s Andertoons for the 21st of January, 2019. Pretty much every Reading the Comics brings up this strip, at least since last fall’s weird gap has ended. But the essays that specifically mention Andertoons should be at this link.

My favorite counter-intuitive implication is in analysis. The field has a definition for what it means that a function is continuous. It’s meant to capture the idea that you could draw a curve representing the function without having to lift the pen that does it. The best definition mathematicians have settled on allows you to count a function that’s continuous at a single point in all of space. Continuity seems like something that should need an interval to happen. But we haven’t found a better way to define “continuous” that excludes this pathological case. So we embrace the weirdness in exchange for general usefulness.

Charles Brubaker’s Ask A Cat for the 21st of January, 2019. Although I’ve mentioned this comic before, it wasn’t when I was putting up tags naming each comic. I’ll fix that now. This and future essays mentioning Ask A Cat (or its Fuzzy Princess sideline, as long as that hasn’t got its own GoComics presence) should appear at this link. And this strip previously ran the 19th of June, 2016.

Charles Brubaker’s Ask A Cat for the 21st is a guest appearance from Brubaker’s other strip, The Fuzzy Princess. It’s a rerun and I did discuss it earlier. Soap bubbles make for great mathematics. They’re easy to play with, for one thing. That’s good for capturing imagination. And the mathematics behind them is deep, and led to important results analytically and computationally. It happens when this strip first ran I’d encountered a triplet of essays about the mathematics of soap bubbles and wireframe surfaces. My introduction to those essays is here.

Benita Epstein’s Six Chix for the 25th I wasn’t sure I’d include. But Roy Kassinger asked about it, so that tipped the scales. The dog tries to blame his bad behavior on “the algorithm”, bringing up one of the better monsters of the last couple years. An algorithm is just the procedure by which you do something. Mathematically, that’s usually to solve a problem. That might be finding some interesting part of the domain or range of a function. That might be putting a collection of things in order. that might be any of a host of things. And then we go make a decision based on the results of the algorithm.

Benita Epstein’s Six Chix for the 25th of January, 2019. The essays wherein I mention Six Chix, from any of the shared strip’s authors, should appear at this link.

What earns The Algorithm its deserved bad name is mindlessness. The idea that once you have an algorithm that a problem is solved. Worse, that once an algorithm is in place it would be irrational to challenge it. I have seen the process termed “mathwashing”, by analogy with whitewashing, and it’s a good one. The notion that because something is done by computer it must be done correctly is absurd. We knew it was absurd before there were computers as we knew them, as see anyone for the past century who has spoken of a “Kafkaesque” interaction with a large organization. It’s impossible to foresee all the outcomes of any reasonably complicated process, much less to verify that all the outcomes are handled correctly. This is before we consider that there will always be mistakes made in the handling of data. Or in the carrying out of the process. And that’s before we consider bad actors. I’m sure there must be research into algorithms designed to handle gaming of the system. I don’t know that there are any good results yet, though. We certainly need them.

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There were a couple comics that didn’t seem to be substantial enough for me to write at length about. You might like them anyway. Connie Sun’s Connie to the Wonnie for the 21st shows off a Venn Diagram. Hector D Cantú and Carlos Castellanos’s Baldo for the 23rd is a bit of wordplay about what mathematicians do. Jonathan Lemon’s Rabbits Against Magic for the 23rd similarly is a bit of wordplay built around percentages. (Lemon is the new artist for Alley Oop.) And Keith Tutt and Daniel Saunders’s Lard’s World Peace Tips features Albert Einstein, and a joke based on one of the symmetries which make relativity such a useful explanation of the world’s workings.

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I don’t plan to have another Reading the Comics post until next Sunday. But when I do, it’ll be here.

Reading the Comics, January 16, 2019: Young People’s Mathematics Edition

Today’s quartet of mathematically-themed comic strips doesn’t have an overwhelming theme. There’s some bits about the mathematics that young people do, so, that’s enough to separate this from any other given day’s comics essay.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 14th is built on a bit of mathematical folklore. As Weinersmith’s mathematician (I don’t remember that we’ve been given her name) mentions, there is a belief that “revolutionary” mathematics is done by young people. That isn’t to say that older mathematicians don’t do great work. But the stereotype is that an older mathematician will produce masterpieces in already-established fields. It’s the young that establish new fields. Indeed, one of mathematics’s most prestigious awards, the Fields Medal, is only awarded to mathematicians under the age of forty. I was cheated of mine. Long story.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 14th of January, 2019. I have many essays inspired by something said in Saturday Morning Breakfast Cereal. You can find them at this link.

There’s intuitive appeal in the idea that revolutions in thinking are for the young. We think that people get set in their ways as they develop their careers. We have a couple dramatic examples, most notably Évariste Galois, who developed what we now see as foundations of group theory and died at twenty. While the idea is commonly held, I don’t know that it’s actually true. That is, that it holds up to scrutiny. It seems hard to create a definition for “revolutionary mathematics” that could be agreed upon by two people. So it would be difficult to test at what age people do their most breathtaking work, and whether it is what they do when young or when experienced.

Is there harm to believing an unprovable thing? If it makes you give up on trying, yes. My suspicion is that true revolutionary work happens when a well-informed, deep thinker comes to a field that hasn’t been studied in that way before. And when it turns out to be a field well-suited to study that way. That doesn’t require youth. It requires skill in one field, and an understanding that there’s another field ready to be studied that way.

Will Henry’s Wallace the Brave for the 14th of January, 2019. I have only had a few chances to talk about Wallace the Brave so far, but the chances I’ve taken are at this link. (It and Breaking Cat News are the two recently-launched comics I’m most excited by.)

Will Henry’s Wallace the Brave for the 14th is a mathematics anxiety joke. Wallace tries to help by turning an abstract problem into a concrete one. This is often a good way to approach a problem. Even in more advanced mathematics, one can often learn the way to solve a general problem by trying a couple of specific examples. It’s almost as though there’s only a certain amount of abstraction people can deal with, and you need to re-cast problems so they stay within your limits.

Yes, the comments turn to complaining about Common Core. I’m not sure what would help Spud work through this problem (or problems in general). But thinking of alternate problems that estimated or approached what he really wanted might help. If he noticed, for example, that 10 + 12 has to be a little more than 10 + 10, and he found 10 + 10 easy, then he’d be close to a right answer. If he noticed that 10 + 12 had to be 10 + 10 + 2, and he found 10 + 10 easy, then he might find 20 + 2 easy as well. Maybe Spud would be better off thinking of ways to rewrite a problem without changing the result.

Wiley Miller’s Non Sequitur for the 15th of January, 2019. Essays mentioning Non Sequitur should appear at this link.

Wiley Miller’s Non Sequitur for the 15th mentions calculus. It’s more of a probability joke. To speak of a calculated risk is to speak of doing something that’s not certain, but that has enough of a payoff to be worth the cost of failure. But one problem with this attitude is that people are very, very bad at estimating probabilities. We have terrible ideas of how likely losses are and how uncertain rewards can be. But even if we allow that the risks and rewards are calculated right, there’s a problem with things you only do once. Or only can do once. You can get into a good debate about whether there’s even a meaningful idea of probability for things that happen only the one time. Life’s among them.

Bob Weber Sr’s Moose and Molly for the 16th of January, 2019. I haven’t had the chance to talk about Moose and Molly before. But now I have the tag, and will be putting essays mentioning it at this link.

Bob Weber Sr’s Moose and Molly for the 16th is a homework joke. It does actually depend on being mathematics homework, though, or there’d be no grounds for Moose’s kid to go to the savings and loan clerk who’ll help with “money problems”.

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I think there’s one more batch of comic strips to discuss this week. When I’ve published it, you should find the essay at this link. And then there’ll be Sunday again.

Reading the Comics, November 29, 2018: Closing Out November Edition

Today, I get to wrap up November’s suggested discussion topics as prepared by Comic Strip Master Command.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 27th mentions along its way the Liar Paradox and Zeno’s Paradoxes. Both are ancient problems. The paradoxes arise from thinking with care and rigor about things we seem to understand intuitively. For the Liar Paradox it’s about what we mean to declare a statement true or false. For Zeno’s Paradoxes it’s about whether we think space (and time) are continuous or discrete. And, as the strip demonstrates, there is a particular kind of nerd that declares the obvious answer is the only possible answer and that it’s foolish to think deeper. To answer a question’s literal words while avoiding its point is a grand old comic tradition, of course, predating even the antijoke about chickens crossing roads. Which is what gives these answers the air of an old stage comedian.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 27th of November, 2018. Other essays mentioning topics raised by Saturday Morning Breakfast Cereal are at this link. Well, all right, this link, if you want to avoid the maybe four times it hasn’t turned up.

Mark Tatulli’s Lio for the 28th features a cameo for mathematics. At least mathematics class. It’s painted as the most tedious part of the school day. I’m not sure this is quite right for Lio as a character. He’s clever in a way that I think harmonizes well with how mathematics brings out universal truths. But there is a difference between mathematics and mathematics class, of course.

Mark Tatulli’s Lio for the 28th of November, 2018. Essays discussing topics raised by Lio should be at this link.

Tom Toles’s Randolph Itch, 2am for the 28th shows how well my resolution to drop the strip from my rotation here has gone. I don’t seem to have found it worthy of mention before, though. It plays on the difference between a note of money, the number of units of currency that note represents, and between “zero” and “nothing”. Also I’m enchanted now by the idea that maybe some government might publish a zero-dollar bill. At least for the sake of movie and television productions that need realistic-looking cash.

Tom Toles’s Randolph Itch, 2am rerun for the 28th of November, 2018. It first appeared the 12th of April, 2000. Other instances of Randolph Itch, 2 am that I thought worth discussing are at this link.

In the footer joke Randolph mentions how you can never have enough zeroes. Yes, but I’d say that’s true of twenties, too. There is a neat sense in which this is true for working mathematicians, though. At least for those doing analysis. One of the reliable tricks that we learn to do in analysis is to “add zero” to a quantity. This is, literally, going from some expression that might be, say, “a – b” to “a + 0 – b”, which of course has the same value. The point of doing that is that we know other things equal to zero. For example, for any number L, “-L + L” is zero. So we get the original expression from “a + 0 – b” over to “a – L + L – b”. And that becomes useful is you picked L so that you know something about “a – L” and about “L – b”. Because then it tells you something about “a – b” that you didn’t know before. Picking that L, and showing something true about “a – L” and “L – b”, is the tricky part.

Dan Collins’s Looks Good On Paper for the 29th of November, 2018. Other appearances by Looks Good On Paper should be at this link.

Dan Collins’s Looks Good On Paper for the 29th is back with another Möbius Strip comic strip. Last time it was presented as the “Möbius Trip”, a looping journey. This time it’s a comic strip proper. If this particular Looks Good On Paper has run before I don’t seem to have mentioned it. Unlike the “Möbius Trip” comic, this one looks more clearly like it actually is a Möbius strip.

The Dumpties in the comic strip are presented as getting nauseated at the strange curling around. It’s good sense for the comic-in-the-comic, which just has to have something happen and doesn’t really need to make sense. But there is no real way to answer where a Möbius strip wraps around itself. I mean, we can declare it’s at the left and right ends of the strip as we hold it, sure. But this is an ad hoc placement. We can roll the belt along a little bit, not changing its shape, but changing the points where we think of the strip as turning over.

But suppose you were a flat creature, wandering a Möbius strip. Would you have any way to tell that you weren’t on the plane? You could, but it takes some subtle work. Like, you could try drawing shapes. These let you count a thing called the Euler Characteristic, which relates the numer of vertices, edges, and faces of a polyhedron. The Euler Characteristic for a Möbius strip is the same as that for a Klein bottle, a cylinder, or a torus. You could try drawing regions, and coloring them in, calling on the four-color map theorem. (Here I want just to mention the five-color map theorem, which is as these things go easy to prove.) A map on the plane needs at most four colors to have no neighboring territories share a color along an edge. (Territories here are contiguous, and we don’t count territories meeting at only a point as sharing an edge.) Same for a sphere, which is good for we folks who have the job of coloring in both globes and atlases. It’s also the same for a cylinder. On a Möbius strip, this number is six. On a torus, it’s seven. So we could tell, if we were on a Möbius strip, that we were. It can be subtle to prove, is all.

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All of my regular Reading the Comics posts should all be at this link. The next in my Fall 2018 Mathematics A To Z glossary should be posted Tuesday. I’m glad for it if you do come around and read again.

Reading the Comics, November 24, 2018: Origins Edition

I’m not sure there is a theme to the back half of last week’s mathematically-based comic strips. If there is, it’s about showing some origins of things. I’ll go with that title, then.

Bill Holbrook’s On The Fastrack for the 21st is another in the curious thread of strips about Fi talking about mathematics. She’s presented as doing a good job inspiring kids to appreciate mathematics as a fun, exciting, interesting thing to think about. It’s good work. And I hope this does not sound like I am envious of a more successful, if fictional, mathematics popularizer. But I don’t see much in the strip of her doing this side job well. That is, of making the case that mathematics is worth the time spent on it. That’s a lot to ask given the confines of a syndicated daily newspaper comic strip, yes. What we can expect is some hint of what the actual good argument would look like. But this particular day’s strip rings false to me, for example. I don’t see how “here’s some pizza — but first, here’s a pop quiz” makes mathematics look as something other than a chore.

Bill Holbrook’s On The Fastrack for the 21st of November, 2018. Essays mentioning topics raised by On The Fastrack are at this link.

Pizza area offers many ways into mathematical ideas. How the area depends on the size of the pizza, for example. How the area depends on the shape, even independently of the size. How to slice a pizza fairly, especially if it’s not to be between four or six or eight people. What is the strangest shape you could make that would give people equal areas? Just the way slices intersect at angles inspires neat little geometry problems. How you might arrange toppings opens up symmetries and tilings, which are surprisingly big areas of mathematics. Setting problems on a pizza gives them a tangibility that could help capture young minds, surely. But I can’t make myself believe that this is a conversation to have when the pizza is entering the room.

Mike Peters’s Mother Goose and Grimm for the 22nd of November, 2018. Other essays which mention Mother Goose and Grimm should be at this link. I had thought this was a new link, but it turns out there was a strip in early 2017 and another in mid-2015 that got my attention here.

Mike Peters’s Mother Goose and Grimm for the 22nd is a lottery joke. So if we suppose this was written about the last time the Powerball jackpot reached a half-billion dollars we can work out how far ahead of publication Mike Peters is working. One solid argument against ever buying a lottery ticket is, as Grimm notes, that you have zero chance of winning. (I’m open to an argument based on expectation value. And even more, I don’t object to people spending a reasonable bit of disposable income “foolishly”.) Mother Goose argues that her chances are vastly worse if she doesn’t buy a ticket. This is true. Are her chances “astronomically” worse? … That depends. A one in three hundred million chance (to use, roughly, the Powerball odds) is so small that it won’t happen to you. Is that any different than a zero in three hundred million chance [*]? Or than a six in three hundred million chance? In any case it won’t happen to you.

[*] Do you actually have zero chance of winning if you don’t have a ticket? I say no, you don’t. Someone might give you a winning ticket. Maybe you find one as a bookmark in a library book. Maybe you find it on the street and figure, what the heck, I’ll check. Unlikely? Sure. But impossible? Hardly.

Johnny Hart’s Back to BC for the 22nd of November, 2018. It originally appeared the 27th of May, 1961. Essays which discuss topics brought up by B.C., both the current-run and the half-century-old reruns, are at this link.

Johnny Hart’s Back to BC for the 22nd has the form of the world’s oldest story problem. It could also be a joke about the discovery of the concept of zero and the struggle to understand it as a number. Given that clams are used as currency in the BC setting it also shows how finance has driven mathematical development. So the strip actually packs a fair bit of stuff into two panels. … And I’ll admit I’m not quite sure the joke parses, but if you read it quickly it looks like a good enough joke.

Johnny Hart’s Back to BC for the 24th of November, 2018. It originally appeared the 30th of May, 1961. If this strip has inspired any essays oh wait, I already said where to find them, didn’t I? Well, you know what to look for, then.

Johnny Hart’s Back to BC for the 24th is a more obvious joke. And it’s built on the learning abilities of animals, and the number sense of animals. A large animal stomping a foot evokes, to me at least, Clever Hans. This is a horse presented in the early 20th century as being able to actually do arithmetic. The horse would be given a question and would stop his hoof enough times to get to the right answer. However good the horse’s number sense might be, he had quite good behavioral sense. It turned out — after brilliant and pioneering work in animal cognition — that Hans was observing his trainer’s body language. When Wilhelm von Osten was satisfied that there’d been the right number of stomps, the horse stopped. This is sometimes presented as Hans `merely’ taking subconscious cues from his trainer. But consider how carefully the horse must be observing an animal with a very different body, and how it must have understood cues of satisfaction. I can’t call that `mere’. And the work of tracking down a signal that von Osten himself did not know he was sending (and, apparently, never accepted that he did) is also amazing. It serves as a reminder how hard biologists and zoologists have to work.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 24th of November, 2018. The many essays mentioning topics raised by Saturday Morning Breakfast Cereal are at this link.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 24th gives a bit of Dad History about perspective. And, particularly, why artists didn’t seem to use it much before the 16th century. It gets more blatantly tied to mathematics by pointing out how it took ten thousand years of civilization to get Cartesian coordinates. We can argue about how many years civilization has been around. But it does seem strange that we went along for certainly the majority of that time without Cartesian coordinates. They seem so obvious it’s almost hard to not think of them. Many good ideas have such a legacy.

It’s easy to say why older pictures didn’t use perspective, though. For the most part, artists didn’t think perspective gave them something they wanted to show. Ancient peoples knew of perspective. It’s not as if ancient peoples were any dumber than we are, or any less able to look at square tiles held at different angles and at different distances. But we can convey information about the importance of things, or the flow of action of things, using position and relative size. That can be more important than showing that yes, an artist is aware that a square building far away looks small.

I’m less sure what I know about the history of coordinate systems, though, and particularly why it took until René Descartes to describe them. We have a legend of Descartes laying in bed, watching a fly on the tiled ceiling, and realizing he could describe where the fly was by what row and column of tile it was on. (In the past I have written this as though it happened. In writing this essay I went looking for a primary source and found nobody seems to have one. I shall try not to pass it on again without being very clear that it is just a legend.) But there have been tiled floors and walls and ceilings for a very long time. There have been flies even longer. Why didn’t anyone notice this?

One answer may be that they did. We just haven’t heard about it, because it was found by someone who didn’t catch the interest of a mathematical community. There’s likely a lot of such lost mathematics out there. But still, why not? Wouldn’t anyone with a mathematical inclination see that this is plainly a great discovery? And maybe not. What made Cartesian coordinates great was the realization that arithmetic and geometry, previously seen as separate liberal arts, were duals. A problem in one had an expression as a problem in the other. If you don’t make that connection, then Cartesian coordinates don’t solve any problems you have. They’re just a new way to index things you didn’t need indexed. So that would slow down using them any.

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All of my regular Reading the Comics posts should all be at this link. Tomorrow should see the posting of my next my Fall 2018 Mathematics A To Z essay. And there’s still time to put in requests for the last half-dozen letters of the alphabet.