Reading the Comics, February 9, 2019: Garfield Outwits Me Edition


Comic Strip Master Command decreed that this should be a slow week. The greatest bit of mathematical meat came at the start, with a Garfield that included a throwaway mathematical puzzle. It didn’t turn out the way I figured when I read the strip but didn’t actually try the puzzle.

Jim Davis’s Garfield for the 3rd is a mathematics cameo. Working out a problem is one more petty obstacle in Jon’s day. Working out a square root by hand is a pretty good tedious little problem to do. You can make an estimate of this that would be not too bad. 324 is between 100 and 400. This is worth observing because the square root of 100 is 10, and the square root of 400 is 20. The square of 16 is 256, which is easy for me to remember because this turns up in computer stuff a lot. But anyway, numbers from 300 to 400 have square roots that are pretty close to but a little less than 20. So expect a number between 17 and 20.

Jon swipes his card at a supermarket checkout. The reader asks: 'Would you like to donate a dollar to charity today?' (Boop.) 'Enter PIN.' (boop boop boop boop.) 'Your total is $3.24. Is this correct?' (Boop.) 'What is the square root of 324? Please show your work.' Jon: 'ALL I WANT IS A BAG OF CHEESE DOODLES!' Garfield: 'DON'T WE ALL?!!'
Jim Davis’s Garfield for the 3rd of February, 2019. Other essays featuring Garfield would be at this link. But somehow this is the first time I’ve had something to write about based in Garfield. Huh.

But after that? … Well, it depends whether 324 is a perfect square. If it is a perfect square, then it has to be the square of a two-digit number. The first digit has to be 1. And the last digit has to be an 8, because the square of the last digit is 4. But that’s if 324 is a perfect square, which it almost certainly is … wait, what? … Uh .. huh. Well, that foils where I was going with this, which was to look at a couple ways to do square roots.

One is to start looking at factors. If a number is equal to the product of two numbers, then its square root is the product of the square roots of those numbers. So dividing your suspect number 324 by, say, 4 is a great idea. The square root of 324 would be 2 times the square root of whatever 324 ÷ 4 is. Turns out that’s 81, and the square root of 81 is 9 and there we go, 18 by a completely different route.

So that works well too. If it had turned out the square root was something like 2\sqrt{82} then we get into tricky stuff. One response is to leave the answer like that: 2\sqrt{82} is exactly the square root of 328. But I can understand someone who feels like they could use a numerical approximation, so that they know whether this is bigger than 19 or not. There are a bunch of ways to numerically approximate square roots. Last year I worked out a way myself, one that needs only a table of trigonometric functions to work out. Tables of logarithms are also usable. And there are many methods, often using iterative techniques, in which you make ever-better approximations until you have one as good as your situation demands.

Anyway, I’m startled that the cheese doodles price turned out to be a perfect square (in cents). Of course, the comic strip can be written to have any price filled in there. The joke doesn’t depend on whether it’s easy or hard to take the square root of 324. But that does mean it was written so that the problem was surprisingly doable and I’m amused by that.

T-Rex: 'Say the average person can expect to live for 81 years. That's a little over 2.5 billion seconds. 2.5 billion is not that much! I thought I'd compare the seconds in a life to the molecules in a glass of water, but even a gram of water has over ten sextillion molecules in it. Even if I measure my life in NANOSECONDS I'm still not on par with a gram of boring ol' WATER.' Dromiceiomimus: 'Molecules are super tiny, T-Rex! You should measure yourself in bigger units.' T-Rex: 'like ... cubic millimeters?' Utahraptor: 'That'd give you 2500 litres, that's a lot!' T-Rex: 'Dude, that's just a GIANT BATHTUB! I want to visualize my lifespan as something impressive!' Utahraptor: 'OK. 2.5 billion kilometers is enough to make a one-way trip to Saturn and get most of the way back before dying, OR to travel part of the way to Uranus, but again, dying well before you arrive.' LATER: T-Rex: 'Dear audio diary! Today I learned why we measure lifetimes in years and not in 'failed trips to Uranus where only corpses show up at the end'. It's, um, for the reasons you'd expect, basically.'
Ryan North’s Dinosaur Comics for the 4th of February, 2019. Some of the many essays inspired by Dinosaur Comics appear at this link.

Ryan North’s Dinosaur Comics for the 4th goes in some odd directions. But it’s built on the wonder of big numbers. We don’t have much of a sense for how big truly large numbers. We can approach pieces of that, such as by noticing that a billion seconds is a bit more than thirty years. But there are a lot of truly staggeringly large numbers out there. Our basic units for things like distance and mass and quantity are designed for everyday, tabletop measurements. The numbers don’t get outrageously large. Had they threatened to, we’d have set the length of a meter to be something different. We need to look at the cosmos or at the quantum to see things that need numbers like a sextillion. Or we need to look at combinations and permutations of things, but that’s extremely hard to do.

Tube Sock: a white cylinder with two blue stripes near the top. Inner Tube Sock: a white torus with two blue stripes around the narrow radius.
Tom Horacek’s Foolish Mortals for the 4th of February, 2019. This is a new tag. When I am next moved to write about Foolish Mortals the results should be this link. This might be a while. I can find some examples of writing about this strip in 2014, before I tagged the comic strips by name, but not since then.

Tom Horacek’s Foolish Mortals for the 4th is a marginal inclusion for this week’s strips, but it’s a low-volume week. The intended joke is just showing off a “tube sock” and an “inner tube sock”. But it happens to depict these as a cylinder and a torus and those are some fun shapes to play with. Particularly, consider this: it’s easy to go from a flat surface to a cylinder. You know this because you can roll a piece of paper up and get a good tube. And it’s not hard to imagine going from a cylinder to a torus. You need the cylinder to have a good bit of give, but it’s easy to imagine stretching it around and taping one end to the other. But now you’ve got a shape that is very different from a sheet of paper. The four-color map theorem, for example, no longer holds. You can divide the surface of the torus so it needs at least seven colors.

Wiley's Dictionary, as read by Peter: 'Logarithm. A downed tree with dance moves.'
Mastroianni and Hart’s B.C. for the 5th of February, 2019. Essays describing some aspect of B.C., whether the current run or the vintage 1960s reruns, appear at this link.

Mastroianni and Hart’s B.C. for the 5th is a bit of wordplay. As I said, this was a low-volume week around here. The word “logarithm” derives, I’m told, from the modern-Latin ‘logarithmus’. John Napier, who advanced most of the idea of logarithms, coined the term. It derives from ‘logos’, here meaning ‘ratio’, and ‘re-arithmos’, meaning ‘counting number’. The connection between ratios and logarithms might not seem obvious. But suppose you have a couple of numbers, and we’ll reach deep into the set of possible names and call them a, b, and c. Suppose a ÷ b equals b ÷ c. Then the difference between the logarithm of a and the logarithm of b is the same as the difference between the logarithm of b and the logarithm of c. This lets us change calculations on numbers to calculations on the ratios between numbers and this turns out to often be easier work. Once you’ve found the logarithms. That can be tricky, but there are always ways to do it.

Mother: 'Maggot, help Otis with his math homework. Explain fractions to him.' Maggot, to Otis: 'Well, it's like when you drop a beer bottle and it breaks into a lot of pieces.'
Bill Rechin’s Crock rerun for the 8th of February, 2019. I have no information about when this strip previously appeared. Essays based on things mentioned in Crock appear at this link. Somehow this isn’t the first time I’ve tagged this comic.

Bill Rechin’s Crock for the 8th is not quite a bit of wordplay. But it mentions fractions, which seem to reliably confuse people. Otis’s father is helpless to present a concrete, specific example of what fractions mean. I’d probably go with change, or with slices of pizza or cake. Something common enough in a child’s life.

And I grant there have been several comic strips here of marginal mathematics value. There was still one of such marginal value. Mark Parisi’s Off The Mark for the 7th has anthropomorphized numerals, in service of a temperature joke.


These are all the mathematically-themed comic strips for the past week. Next Sunday, I hope, I’ll have more. Meanwhile please come around here this week to see what, if anything, I think to write about.

Author: Joseph Nebus

I was born 198 years to the day after Johnny Appleseed. The differences between us do not end there. He/him.

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