## Reading the Comics, March 13, 2019: Ziggy Rerun Scandal Edition

I do not know that the Ziggy printed here is a rerun. I don’t seem to have mentioned it in previous Reading the Comics posts, but that isn’t definite. How much mathematical content a comic strip needs to rate a mention depends on many things, and a strip that seems too slight one week might inspire me another. I’ll explain why I’ve started to get suspicious of the quite humanoid figure.

Tom II Wilson’s Ziggy for the 12th is framed around weather forecasts. It’s the probability question people encounter most often, unless they’re trying to outsmart the contestants on Let’s Make A Deal. (And many games on The Price Is Right, too.) Many people have complained about not knowing the meaning of a “50% chance of rain” for a day. If I understand it rightly, it means, when conditions have been like this in the recorded past, it’s rained about 50% of the time. I’m open to correction from meteorologists and it just occurred to me I know one. Mm.

Few people ask about the probability a forecast is correct. In some ways it’s an unanswerable question. To say there is a one-in-six chance a fairly thrown die will turn up a ‘1’ is not wrong just because it’s rolled a ‘1’ eight times out of the last ten. But it does seem like a forecast such as this should include a sense of confidence, how sure the forecaster is that the current weather is all that much like earlier times.

I’m not sure how much of the joke is meant to be the repetition of “50% chance”. The joke might be meant to say that if he’s got a 50% chance of being wrong, then, isn’t the 50% chance of rain “correctly” a 50% chance of not-rain … which is the same chance of rain? The logic doesn’t hold up, if you pay attention, but it sounds like it should make sense, and having the “wrong” version of something be the same as the original is a valid comic construction.

So now for the promised Ziggy rerun scandal. To the best of my knowledge Ziggy is presented as being in new run. It’s done by the son of the comic strip’s creator, but that’s common enough for long-running comic strips. This Monday, though, ran a Ziggy-at-the-psychiatrist joke that was, apart from coloring, exactly the comic run the 2nd of March, barely two weeks before. (Compare the scribbles in the psychiatrist’s diploma.) It wouldn’t be that weird if a comic were accidentally repeated; production mistakes happen, after all. It’s slightly weird that the daily, black-and-white, original got colored in two different ways, but I can imagine this happening by accident.

Still, that got me primed to look for Ziggy repeats. I couldn’t find this one having an earlier appearance. But I did find that the 9th of January this year was a reprint of the Ziggy from the 11th of January, 2017. I wrote about both appearances, without noticing they were reruns. Here’s the 2017 essay, and over here is the 2019 essay, from before I was very good at remembering what the year was. Mercifully I didn’t say anything contradictory on the two appearances. I’m more interested in how I said things differently in the two appearances. Anyway this earlier year seems to have been part of a week’s worth of reruns, noticeable by the copyright date. I can’t begrudge a cartoonist their vacation. The psychiatrist strip doesn’t seem to be part of that, though, and its repetition is some as-yet-unexplained event.

Tony Rubino and Gary Markstein’s Daddy’s Home for the 13th has a much more casual and non-controversial bit of mathematics. Pete tosses out a calculate-the-square-root problem as a test of Peggy’s omniscience. One of the commenters points out that the square root of 532 is closer to 23.06512519 than it is Peggy’s 23.06512818. It suggests the writers found the square root by something that gave plenty of digits. For example, the macOS Calculator program offers me “23.065 125 189 341 592”. But then they chopped off, rather than rounding off, digits when the panel space ran out.

Olivia Jaimes’s Nancy for the 13th has Nancy dividing up mathematics problems along the equals sign. That’s cute and fanciful enough. One could imagine working out expressions on either side of the equals sign in the hopes of getting them to match. That wouldn’t work for these algebra problems, but, that’s something.

This isn’t what Nancy might do, unless she flashed forward to college and became a mathematics or physics major. But one great trick in differential equations is called the separation of variables. Differential equations describe how quantities change. They’re great. They’re hard. A lot of solving differential equations amounts to rewriting them as simpler differential equations.

Separation is a trick usable when there’s two quantities whose variation affect each other. If you can rewrite the differential equation so that one variable only appears on the left side, and the other variable only appears on the right? Then you can split this equation into two simpler equations. Both sides of the equation have to be some fixed number. So you can separate the differential equations of two variables into two differential equations, each with one variable. One with the first variable, one with the other. And, usually, a differential equation of one variable is easier than a differential equation with two variables. So Nancy and Esther could work each half by themselves. But the work would have to be put together at the end, too.

And for a truly marginal mathematics topic: Lincoln Pierce’s Big Nate: First Class for the 13th, reprinting the 2nd of March, 1994, mentions a mathematics test for Nate’s imminent doom.

And this wraps up the comic strips for the previous week. Come Sunday there should be a fresh new comic post. Yes, Andertoons is scheduled to be there.

## Reading the Comics, January 9, 2018: I Go On About Johnny Appleseed Edition

This was a slow week for mathematically-themed comic strips. Such things happen. I put together a half-dozen that see on-topic enough to talk about, but I stretched to do it. You’ll see.

Mark Anderson’s Andertoons for the 6th mentions addition as one of the things you learn in an average day of elementary school. I can’t help noticing also the mention of Johnny Appleseed, who’s got a weird place in my heart as he and I share a birthday. He got to it first. Although Johnny Appleseed — John Champan — is legendary for scattering apple seeds, that’s not what he mostly did. He would more often grow apple-tree nurseries, from which settlers could buy plants and demonstrate they were “improving” their plots. He was also committed to spreading the word of Emanuel Swedenborg’s New Church, one of those religious movements that you somehow don’t hear about. But there was this like 200-year-long stretch where a particular kind of idiosyncratic thinker was Swedenborgian, or at least influenced by that. I don’t know offhand of any important Swedenborgian mathematicians, I admit, but I’m glad to hear if someone has news.

Justin Thompson’s MythTickle rerun for the 9th mentions “algebra” as something so dreadful that even being middle-aged is preferable. Everyone has their own tastes, yes, although it would be the same joke if it were “gym class” or something. (I suppose that’s not one word. “Dodgeball” would do, but I never remember playing it. It exists just as a legendarily feared activity, to me.) Granting, though, that I had a terrible time with the introduction to algebra class I had in middle school.

Tom Wilson’s Ziggy for the 9th is a very early Pi Day joke, so, there’s that. There’s not much reason a take-a-number dispenser couldn’t give out π, or other non-integer numbers. What the numbers are doesn’t matter. It’s just that the dispensed numbers need to be in order. It should be helpful if there’s a clear idea how uniformly spaced the numbers are, so there’s some idea how long a wait to expect between the currently-serving number and whatever number you’ve got. But that only helps if you have a fair idea of how long an order should on average take.

I’ll close out last week’s comics soon. The next Reading the Comics post, like all the earlier ones, should be at this link.

## Reading the Comics, July 21, 2018: Infinite Hotels Edition

Ryan North’s Dinosaur Comics for the 18th is based on Hilbert’s Hotel. This is a construct very familiar to eager young mathematicians. It’s an almost unavoidable pop-mathematics introduction to infinitely large sets. It’s a great introduction because the model is so mundane as to be easily imagined. But you can imagine experiments with intuition-challenging results. T-Rex describes one of the classic examples in the third through fifth panels.

The strip made me wonder about the origins of Hilbert’s Hotel. Everyone doing pop mathematics uses the example, but who created it? And the startling result is, David Hilbert, kind of. My reference here is Helge Kragh’s paper The True (?) Story of Hilbert’s Infinite Hotel. Apparently in a 1924-25 lecture series in Göttingen, Hilbert encouraged people to think of a hotel with infinitely many rooms. He apparently did not use it for so many examples as pop mathematicians would. He just used the question of how to accommodate a single new guest after the infinitely many rooms were first filled. And then went to imagine an infinite dance party. I don’t remember ever seeing the dance party in the wild; perhaps it’s a casualty of modern rave culture.

Hilbert’s Hotel seems to have next seen print in George Gamow’s One, Two Three … Infinity. Gamow summoned the hotel back from the realms of forgotten pop mathematics with a casual, jokey tone that fooled Kragh into thinking he’d invented the model and whimsically credited Hilbert with it. (Gamow was prone to this sort of lighthearted touch.) He came back to it in The Creation Of The Universe, less to make readers consider the modern understanding of infinitely large sets than to argue for a universe having infinitely many things in it.

And then it disappeared again, except for cameo appearances trying to argue that the steady-state universe would be more bizarre than what we actually see. The philosopher Pamela Huby seems to have made Hilbert’s Hotel a thing to talk about again, as part of a debate about whether a universe could be infinite in extent. William Lane Craig furthered using the hotel, as part of the theological debate about whether there could be an infinite temporal regress of events. Rudy Rucker and Eli Maor wrote descriptions of the idea in the 1980s, with vague ideas about whether Hilbert actually had anything to do with the place. And since then it’s stayed, a famous fictional hotel.

David Hilbert was born in 1862; T-Rex misspoke.

Ernie Bushmiller’s Nancy Classics for the 20th gets me out of my Olivia Jaimes rut. We could probably get a good discussion going about whether giving an example of a sphere is an adequate description of a sphere. Granted that a bubble-gum bubble won’t be perfectly spherical; neither will any example that exists in reality. We always trust that we can generalize to an ideal example of this thing.

I did get to wondering, in Sluggo’s description of the octagon, why the specification of eight sides and eight angles. I suspect it’s meant to avoid calling an octagon something that, say, crosses over itself, thus having more angles than sides. Not sure, though. It might be a phrasing intended to make sure one remembers that there are sides and there are angles and the polygon can be interesting for both sets of component parts.

John Atkinson’s Wrong Hands for the 20th is the Venn Diagram joke for the week. The half-week anyway. Also a bunch of other graph jokes for the week. Nice compilation of things. I love the paradoxical labelling of the sections of the Venn Diagram.

Tom II Wilson’s Ziggy for the 20th is a plaintive cry for help from a despairing soul. Who’s adding up four- and five-digit numbers by hand for some reason. Ziggy’s got his projects, I guess is what’s going on here.

Glenn McCoy and Gary McCoy’s The Duplex for the 21st is set up as an I-hate-word-problems joke. The cop does ask something people would generally like to know, though: how much longer would it take, going 60 miles per hour rather than 70? It turns out it’s easy to estimate what a small change in speed does to arrival time. Roughly speaking, reducing the speed one percent increases the travel time one percent. Similarly, increasing speed one percent decreases travel time one percent. Going about five percent slower should make the travel time a little more than five percent longer. Going from 70 to 60 miles per hour reduces the speed about fifteen percent. So travel time is going to be a bit more than 15 percent longer. If it was going to be an hour to get there, now it’ll be an hour and ten minutes. Roughly. The quality of this approximation gets worse the bigger the change is. Cutting the speed 50 percent increases the travel time rather more than 50 percent. But for small changes, we have it easier.

There are a couple ways to look at this. One is as an infinite series. Suppose you’re travelling a distance ‘d’, and had been doing it at the speed ‘v’, but now you have to decelerate by a small amount, ‘s’. Then this is something true about your travel time ‘t’, and I ask you to take my word for it because it has been a very long week and I haven’t the strength to argue the proposition:

$t = \frac{d}{v - s} = \frac{d}{v}\left(1 + \left(\frac{s}{v}\right) + \left(\frac{s}{v}\right)^2 + \left(\frac{s}{v}\right)^3 + \left(\frac{s}{v}\right)^4 + \left(\frac{s}{v}\right)^5 + \cdots \right)$

‘d’ divided by ‘v’ is how long your travel took at the original speed. And, now, $\left(\frac{s}{v}\right)$ — the fraction of how much you’ve changed your speed — is, by assumption, small. The speed only changed a little bit. So $\left(\frac{s}{v}\right)^2$ is tiny. And $\left(\frac{s}{v}\right)^3$ is impossibly tiny. And $\left(\frac{s}{v}\right)^4$ is ridiculously tiny. You make an error in dropping these $\left(\frac{s}{v}\right)$ squared and cubed and forth-power and higher terms. But you don’t make much of one, not if s is small enough compared to v. And that means your estimate of the new travel time is:

$\frac{d}{v} \left(1 + \frac{s}{v}\right)$

Or, that is, if you reduce the speed by (say) five percent of what you started with, you increase the travel time by five percent. Varying one important quantity by a small amount we know as “perturbations”. Working out the approximate change in one quantity based on a perturbation is a key part of a lot of calculus, and a lot of mathematical modeling. It can feel illicit; after a lifetime of learning how mathematics is precise and exact, it’s hard to deliberately throw away stuff you know is not zero. It gets you to good places, though, and fast.

Morrie Turner’s Wee Pals for the 21st shows Wellington having trouble with partitions. We can divide any counting number up into the sum of other counting numbers in, usually, many ways. I can kind of see his point; there is something strange that we can express a single idea in so many different-looking ways. I’m not sure how to get Wellington where he needs to be. I suspect that some examples with dimes, quarters, and nickels would help.

And this is marginal but the “Soul Circle” personal profile for the 20th of July — rerun from the 20th of July, 2013 — was about Dr Cecil T Draper, a mathematics professor.

You can get to this and more Reading the Comics posts at this link. Other essays mentioning Dinosaur Comics are at this link. Essays that describe Nancy, vintage and modern, are at this link. Wrong Hands gets discussed in essays on this link. Other Ziggy-based essays are at this link. The Duplex will get mentioned in essays at this link if any other examples of the strip get tagged here. And other Wee Pals strips get reviewed at this link.

## Reading the Comics, May 8, 2018: Insecure http Edition

Last week had enough mathematically-themed comics for me to split the content. Usually I split the comics temporally, and this time I will too. What’s unusual is that somewhere along the week the URLs that GoComics pages provide switched from http to https. https is the less-openly-insecure version of the messaging protocol that sends web pages around. It’s good practice; we should be using https wherever possible. I don’t know why they switched that on, and why switch it on midweek. I suppose someone there knew what they were doing.

Tom Wilson’s Ziggy for the 6th of May uses mathematical breakthroughs as shorthand for inspiration. In two ways, too, one with a basically geometric figure and one with a bunch of equations. The geometric figure doesn’t seem to have any significance to me. The equations … that’s a bit harder. They’re probably nonsense. But it’s hard to look at ‘a’ and not see acceleration; the letter is often used for that. And it’s hard to look at ‘v’ and not see velocity. ‘x’ is often a position and ‘t’ is often a time. ‘xf – xi‘ looks meaningful too. It almost begs to be read as “position, final, minus position, initial”. “tf – ti” almost begs to be read as “time, final, minus time, initial”. And the difference in position divided by a difference in time suggests a velocity.

So here’s something peculiar inspired by looking at the units that have to follow. If ‘v’ is velocity, then it’s got units of distance over time. $\left(\frac{av}{V}\right)^2$ and $\left(\frac{av}{I}\right)^2$ would have units of distance-squared over time-squared. At least unless ‘a ‘or ‘V’ or ‘I’ are themselves measurements. But the square root of their sum then gets us back to distance over time. And then a distance-over-time divided by … well, distance-over-time suggests a pure number. Or something of whatever units ‘R’ carries with it.

So this equation seems arbitrary, and of course the expression doesn’t need to make sense for the joke. But it’s odd that the most-obvious choice of meanings for v and x and t means that the symbols work out so well. At least almost: an acceleration should have units of distance-over-time-squared, and this has units of (nothing). But I may have guessed wrong in thinking ‘a’ meant acceleration here. It might be a description of how something in one direction corresponds to something in another. And that would make sense as a pure number. I wonder whether Wilson got this expression from from anything, or if any readers recognize something that I should have seen right away.

Todd Clark’s Lola for the 7th jokes about being bad at mathematics. The number of days left to the end of school isn’t something that a kid should have trouble working out. However, do remember the first rule of calculating the span between two dates on the calendar: never calculate the span between two dates on the calendar. There is so much that goes wrong trying. All right, there’s a method. That method is let someone else do it.

Bud Fisher’s Mutt and Jeff for the 7th uses the form of those mathematics-magic games. You know, the ones where you ask someone to pick a number, then do some operations, and then tell you the result. From that you reverse-engineer the original number. They’re amusing enough tricks even if they are all basically the same. It’s instructive to figure out how they work. Replace your original number with symbols and follow the steps then. If you just need the number itself you can replace that with ‘x’. If you need the digits of the number then you’d replace it with something like “10*a + b”, to represent the numerals “ab”. Here, yeah, Mutt’s just being arbitrarily mean.

Paul Gilligan and Kory Merritt’s Poptropica for the 7th depicts calculating stuff as the way to act like a robot. Can’t deny; calculation is pretty much what we expect computers to do. It may hide. It may be done so abstractly it looks like we’re playing Mini Metro instead. This is a new comics tag. I’m sad to say this might be the last use of that tag. Poptropica is fun, but it doesn’t touch on mathematics much at all.

Gene Mora’s Graffiti for the 8th mentions arithmetic, albeit obliquely. It’s meant to be pasted on the doors of kindergarten teachers and who am I to spoil the fun?

Scott Hilburn’s The Argyle Sweater for the 9th is the anthropomorphic-numerals joke for this week. Converting between decimals and fractions has been done since decimals got worked out in the late 16th century. There’s advantages to either representation. To my eyes the biggest advantage of fractions is they avoid hypnotizing people with the illusion of precision. 0.25 reads as more exact than 1/4. We can imagine it being 0.2500000000000000 and think we know the quantity to any desired precision. 1/4 reads (to me, anyway) as being open to the possibility we’re rounding off from 0.998 out of 4.00023.

Another advantage fractions do have is flexibility. There are infinitely many ways to express the same number as a fraction. In decimals, there are at most two. If you’re trying to calculate something that would be more easily done with a denominator of 30 than of 5, you’re free to do that. Decimals can have advantages in computing, certainly, especially if you’re already set up to manipulate digits. And you can tell at a glance whether, say, 14/29th is greater or less than 154/317th. In case you ever find reason to wonder, I mean. I’m not saying either is always the right way to go.

## Reading the Comics, January 14, 2017: Maybe The Last Jumble? Edition

So now let me get to the other half of last week’s comics. Also, not to spoil things, but this coming week is looking pretty busy so I may have anothe split-week Reading the Comics coming up. The shocking thing this time is that the Houston Chronicle has announced it’s discontinuing its comics page. I don’t know why; I suppose because they’re fed up with people coming loyally to a daily feature. I will try finding alternate sources for the things I had still been reading there, but don’t know if I’ll make it.

I’m saddened by this. Back in the 90s comics were just coming onto the Internet. The Houston Chronicle was one of a couple newspapers that knew what to do with them. It, and the Philadelphia Inquirer and the San Jose Mercury-News, had exactly what we wanted in comics: you could make a page up of all the strips you wanted to read, and read them on a single page. You could even go backwards day by day in case you missed some. The Philadelphia Inquirer was the only page that let you put the comics in the order you wanted, as opposed to alphabetical order by title. But if you were unafraid of opening up URLs you could reorder the Houston Chronicle page you built too.

And those have all faded away. In the interests of whatever interest is served by web site redesigns all these papers did away with their user-buildable comics pages. The Chronicle was the last holdout, but even they abolished their pages a few years ago, with a promise for a while that they’d have a replacement comics-page scheme up soon. It never came and now, I suppose, never will.

Most of the newspapers’ sites had become redundant anyway. Comics Kingdom and GoComics.com offer user-customizable comics pages, with a subscription model that makes it clear that money ought to be going to the cartoonists. I still had the Chronicle for a few holdouts, like Joe Martin’s strips or the Jumble feature. And from that inertia that attaches to long-running Internet associations.

So among the other things January 2017 takes away from us, it is taking the last, faded echo of the days in the 1990s when newspapers saw comics as awesome things that could be made part of their sites.

Lorie Ransom’s The Daily Drawing for the 11th is almost but not quite the anthropomorphized-numerals joke for this installment. It’s certainly the most numerical duck content I’ve got on record.

Tom II Wilson’s Ziggy for the 11th is an Early Pi Day joke. Cosmically there isn’t any reason we couldn’t use π in take-a-number dispensers, after all. Their purpose is to give us some certain order in which to do things. We could use any set of numbers which can be put in order. So the counting numbers work. So do the integers. And the real numbers. But practicality comes into it. Most people have probably heard that π is a bit bigger than 3 and a fair bit smaller than 4. But pity the two people who drew $e^{\pi}$ and $\pi^{e}$ figuring out who gets to go first. Still, I won’t be surprised if some mathematics-oriented place uses a gimmick like this, albeit with numbers that couldn’t be confused. At least not confused by people who go to mathematics-oriented places. That would be for fun rather than cake.

I can’t promise that the Jumble for the 11th is the last one I’ll ever feature here. I might find where David L Hoyt and Jeff Knurek keep a linkable reference to their strips and point to them. But just in case of the worst here’s an abacus gag for you to work on.

Corey Pandolph, Phil Frank, and Joe Troise’s The Elderberries for the 12th is, I have to point out, a rerun. So if you’re trying to do the puzzle the reference to “the number of the last president” isn’t what you’re thinking of. It is an example of the conflation of intelligence with skill at arithmetic. It’s also an example the conflation of intelligence with a mastery of trivia. But I think it leans on arithmetic more. I am not sure when this strip first appeared. “The last president” might have been Bill Clinton (42) or George W Bush (43). But this means we’re taking the square root of either 33 or 34. And there’s no doing that in your head. The square root of a whole number is either a whole number — the way the square root of 36 is — or else it’s an irrational number. You can work out the square root of a non-perfect-square by hand. But it’s boring and it’s worse than just writing “$\sqrt{33}$” or “$\sqrt{34}$”. Except in figuring out if that number is larger than or smaller than five or six. It’s good for that.

Dave Blazek’s Loose Parts for the 13th is the actuary joke for this installment. Actuarial studies are built on one of the great wonders of statistics: that it is possible to predict how often things will happen. They can happen to a population, as in forecasts of how many people will be in traffic accidents or fires or will lose their jobs or will move to a new city. We may have no idea to whom any of these will happen, and they may have no way of guessing, but the enormous number of people and great number of things that can combine to make a predictable state of affairs. I suppose it’s imaginable that a group could study its dynamics well enough to identify who screws up the most and most seriously. So they might be able to say what the odds are it is his fault. But I imagine in practice it’s too difficult to define screw-ups or to assign fault consistently enough to get the data needed.

Zach Weinersmith’s Saturday Morning Breakfast Cereal for the 14th is another multiverse strip, echoing the Dinosaur Comics I featured here Sunday. I’ll echo my comments then. If there is a multiverse — again, there is not evidence for this — then there may be infinitely many versions of every book of the Bible. This suggests, but it does not mandate, that there should be every possible incarnation of the Bible. And a multiverse might be a spendthrift option anyway. Just allow for enough editions, and the chance that any of them will have a misprint at any word or phrase, and we can eventually get infinitely many versions of every book of the Bible. If we wait long enough.