Comments on: I was stumped. So of course, I asked Facebook.

I was stumped. So of course, I asked Facebook.

joseph conrad is fully awesome — Sun, 29 Mar 2015 12:42:21 -0800

"Let's talk about matter/anti-matter annihilation in the early Universe."

By: taff

taff — Sun, 29 Mar 2015 13:15:59 -0800

Bloody excellent idea. I wish everyone would try to do this for all their analogies. In fact, I say go further. Removing daily heteronormativity, gender and racial stereotypes, neuronormativity and assumptions about accessibility would go a long way to making people feel like they're not invisible or abnormal. There's seldom ever a need to use traits about groups of people in situations like this. The chair and the zipper are marvellous, and not at all othering. Would love to see more. Will be passing it around widely.

By: wintersweet

wintersweet — Sun, 29 Mar 2015 13:23:33 -0800

Great post. Sometimes I hear people claim that there's no "culture" in the hard sciences, which makes me grar because it's patently false--and claiming there isn't any causes the same issues as saying "I don't see race." It just makes it easier to ignore the problems.

By: StickyCarpet

StickyCarpet — Sun, 29 Mar 2015 13:25:13 -0800

Why talk about it when we can dance about it?

By: GenjiandProust

GenjiandProust — Sun, 29 Mar 2015 13:43:54 -0800

My takeaway from that metaphor is that boys and girls, when they dance together, are annihilated in a burst of x-rays. In order to preserve the population (and reduce stray gamma rays), I encourage only same-sex dancing and dating. It's the only safe thing to do.

By: mrjohnmuller

mrjohnmuller — Sun, 29 Mar 2015 13:48:31 -0800

A Brief History of the Early Universe by mrjohnmuller Shortly after the Big Bang, the universe was mostly a writing, expanding mass of ermines and stoats. Frightened and confused at their sudden existence, they immediately attacked one another. They grappled and bit with their tiny claws and teeth, but as they were so evenly matched, each battling pair invariable killed each other. Before long, the universe was replete with torn fur and weasel blood. Eventually, the carnage was concluded and the stoats stood victorious, but in vastly reduced numbers. It became apparent that the stoats had a very slight numerical advantage from the start, and although they endured a shocking loss of life (with only one in one-billion surviving), they went on to spread across the universe, filling the void with stoats forever.

By: GenjiandProust

GenjiandProust — Sun, 29 Mar 2015 13:51:29 -0800

So you believe in the Steady Stoat Universe Theory? I am pretty sure that has been discredited.

By: mmoncur

mmoncur — Sun, 29 Mar 2015 13:53:08 -0800

I don't like the zipper analogy at all. It just makes me think of questions like "Who's doing the zipping?" (now religion enters the discussion?) and "What does the zipper pull represent?" and it assumes an orderly, sequential process completely unlike the chaos of particles bouncing around. And there's no real difference in my head between "left zipper bits" and "right zipper bits". And it assumes all of the bits are connected to the others. Musical chairs is great though.

By: RedOrGreen

RedOrGreen — Sun, 29 Mar 2015 14:03:49 -0800

Great idea, but I hate both of his alternative analogies. The zipper immediately makes me think there's something special about the last few teeth. There's no interchangeability there. But every particle / antiparticle is identical - that's the point. If the zipper was randomly skipping teeth in the middle that would be one thing. As it stands - no. The musical chairs analogy is better except that there's no a priori distinction between particles and antiparticles - whatever is left over at the end is what we consider "normal matter", but of course that's not true for chairs and participants. If the chairs could sit on participants - or maybe if there were sometimes more chairs than participants - that might work. But again, it fails the simplicity requirement. Sadly enough, I think neither of these matches the analogy of a dance, where there may or may not be extra boys or extra girls left without partners at the end of the dance. It's too bad, but that's a good, intuitive, and reasonably accurate analogy. What else might work? Pets at the store? One owner can have multiple pets, so no. Gloves, maybe - a big lost and found collection of black gloves, and you are making pairs to put them back into circulation? That would avoid the weakness of socks, too. Yes, I'd go with gloves over zippers or musical chairs.

By: tecg

tecg — Sun, 29 Mar 2015 14:08:53 -0800

The zipper analogy is inferior because there is no random pairing; every time you open the zipper and closer it again, the exact same pairs of teeth form. The musical chairs analogy is better, but still not as good as the original ballroom dancing analogy because the chairs don't move randomly, but are standing still. How about introducing the ballroom analogy as a "1950s ballroom dance" with a little wink and nod to the fact that social norms have changed since then? That would be a better solution in my opinion.

By: KateViolet

KateViolet — Sun, 29 Mar 2015 14:21:52 -0800

How about sorting a cutlery drawer and pairing knives and forks?

By: Zalzidrax

Zalzidrax — Sun, 29 Mar 2015 14:24:59 -0800

Only the stoat analogy really encapsulates the fact that the anti-particles and particles annihilate each other violently and don't just form nice, stable pairs. Clearly it is the best analogy.

By: jackbishop

jackbishop — Sun, 29 Mar 2015 14:33:14 -0800

When I teach graph theory, I kind of have to cover Hall's marriage theorem, and give the traditional context it appears in. I strive for inclusiveness with a winking assertion that we'll dispense with heteronormativity soon --- which we do, since Tutte's theorem comes shortly afterwards.

By: officer_fred

officer_fred — Sun, 29 Mar 2015 14:36:25 -0800

An overlooked solution is to just talk about what happened to the particles without using metaphors. This is a pretty simple concept, and to me any analogy at all just introduces unnecessary detail and makes the actual lesson more confusing, not less. Now back to your regularly-scheduled grar about heteronormativity.

By: ardgedee

ardgedee — Sun, 29 Mar 2015 15:07:55 -0800

> Only the stoat analogy really encapsulates the fact that the anti-particles and particles annihilate each other violently and don't just form nice, stable pairs. Clearly it is the best analogy. The analogy exhibits an unconsidered mustelidist bias. We should be aiming for inclusionary language which is equally welcoming to stoats, weasels, and otters alike.

By: Anticipation Of A New Lover's Arrival, The

Anticipation Of A New Lover's Arrival, The — Sun, 29 Mar 2015 15:28:01 -0800

I don't find the two alternative analogies to be as strong, from a didactic sense, as the original dance analogy. That said, it is awfully heteronormative which is regrettable for both of the reasons that the author of TFA says it is: heteronormativity is intrinsically sub-optimal since it fails to accurately reflect reality, and also it is likely to turn off a certain portion of the class which means it's not an ideal teaching tool. Is it not possible to just mention, as an aside, that you know the upcoming analogy is awfully heteronormative but that you're going to use it because you've yet to find one that illustrates the concept better? Like, literally, "OK, now I'm going to try to put this whole matter/antimatter concept into terms that might help you understand and remember what it's about. By the way, the analogy I'm about to use is awfully heteronormative but I've yet to find a better one; if anybody thinks they have a good replacement that's less heteronormative then I'd be overjoyed if you'd email it to me, and in fact I'll give you two bonus points on the next test if I like it enough to use it in the future. Now, think of a dance..." I do stuff like that all the time in class, to clarify the limitations of the lesson that I'm giving. I've never had to do it for reasons of heteronormativity, but I don't think I'd hesitate. I feel like the whole thing would go right over the heads of most of my students (who don't know what "heteronormative" means) without doing any harm. The few students who do know what the term means are likely also to be those who would appreciate knowing that their teacher has explicitly considered gender and sexual issues in preparing their lessons, so it might actually increase their engagement because perhaps they'd identify with me more. I'm pretty inexperienced as a teacher, but from my naive perspective I don't see what's wrong with just confronting this problem head on. Obviously one would not want to get bogged down here (because gender norms are tangential to the main lesson) but I can't think of a reason not to just address it in a brief-and-to-the-point manner and then move on.

By: sfenders

sfenders — Sun, 29 Mar 2015 16:22:49 -0800

Oh sure, the musical chairs thing is fine, until there's someone in the class in a wheelchair, inwardly sighing as a situation where they do not exist is assumed as the norm. Also, people are not as much like chairs as particles are like anti-particles. Instead of girls and boys, why not just divide people into "people who prefer to pair up with girls" and "people who prefer to pair up with boys". No more heteronormativity, and you can throw in a joke about how the analogy isn't perfect since physicists haven't discovered any bisexual particles yet. Unless they have, in which case all the better.

By: Ignorantsavage

Ignorantsavage — Sun, 29 Mar 2015 16:24:41 -0800

The problem here is one of framing. The analogy could be seen a robust demonstration of a queer universe theory. The boys and girls pairing off, as a hetronormative process, remove themselves from the balance of the universe in which we live. It is only the non-normative particles that manage to persist. Thus an asymmetrical universe, a universe that allows for existence as we understand it establishes variation from the norm as the key to persistent existence. LGBTQ+ individuals are thus analogous to the surviving particles. The stuff of the universe is all queer. It is the normative which brings annihilation. It is the queer which bring life. Remember, we are all queer inside. -My girlfriend refers to me as the straightest man on Earth. I am in deep trouble now.-

By: PMdixon

PMdixon — Sun, 29 Mar 2015 17:08:03 -0800

Yeah, I don't get the zipper replacement at all. Elections in a 2 party system with votes cancelling each other?

By: rankfreudlite

rankfreudlite — Sun, 29 Mar 2015 17:19:51 -0800

I find it odd that there WERE more particles than anti-particles. If the creation of particles, anti and non-anti, was a function of time, perhaps particles came first, and anti-particles appeared later, addressing a mis-balance in the universe, similar to the way a mis-balance of electric charge produces lightning. As lightning does not occur until the disparity in charge reaches a critical level, perhaps the sliver of time needed to bring the particle imbalance to a critical level is responsible for the head-start that particles enjoyed.

By: Lexica

Lexica — Sun, 29 Mar 2015 17:43:09 -0800

I realize I was a touchy-feely-liberal-studies-dammit-poli-sci-is-not-a-science-major, but isn't the fact that neither the zipper nor the musical chairs analogy works kind of the point of the article? Hey! The analogy doesn't work! Groovy, let's come up with a better one! Or two, or three, or however many it takes to find one that works!

By: GenjiandProust

GenjiandProust — Sun, 29 Mar 2015 17:52:36 -0800

You start with a room full of Bonds and Blofelds. They kill each other off in a series of death traps and revenge murders. But, because you have more Bonds than Blofelds, you eventually have a room with only Bonds. But these are very tiny particles, remember, which is why we say that molecules are held together with atomic Bonds.

By: GenjiandProust

GenjiandProust — Sun, 29 Mar 2015 17:53:28 -0800

Unfortunately, Bond is pretty darned heteronormitive.

By: ardgedee

ardgedee — Sun, 29 Mar 2015 18:04:00 -0800

Let's not leap to conclusions, here.

By: BrotherCaine

BrotherCaine — Sun, 29 Mar 2015 18:21:34 -0800

Shoe pairs? It'd explain why there's occasionally just one shoe by the side of a road/freeway.

By: Jpfed

Jpfed — Sun, 29 Mar 2015 19:03:17 -0800

isn't the fact that neither the zipper nor the musical chairs analogy works kind of the point of the article? I don't think that's what he's thinking, though I may have missed something. Since he calls the original analogy "great", and the zipper and musical chairs analogies are "just as good" (plus the non-heteronormative bonus) it seems as though he really does think that these analogies work.

By: straight

straight — Sun, 29 Mar 2015 19:33:49 -0800

Count me as one who is baffled why you would need an analogy to explain this. The universe had two kinds of stuff. If a piece of the first kind bumped into a piece of the second kind, they would both be destroyed. This went on until the pieces of both kinds all destroyed each other, except there was a little bit more of one kind that was left over.

By: mmoncur

mmoncur — Sun, 29 Mar 2015 19:40:42 -0800

The more I think of this the more I think that *all* of the analogies* are terrible. Even the ballroom one implies the idea that the particles have desires and free will. And ballroom dancing follows strict rules instead of being chaotic. And what does the music represent? I'd just teach it without an analogy. Heck, this is a modern world, I'm sure we have some kind of CGI video that shows the particles and antiparticles bouncing around and annihilating each other. Wouldn't that make it perfectly clear? isn't the fact that neither the zipper nor the musical chairs analogy works kind of the point of the article? No. The article talks about how great (but offensive) the ballroom analogy is and then says "I think these are both just as good as the original analogy." Also, the author who "prides himself on his analogies" also says The expansion of the Universe is like the scene from Vertigo where the bottom of the tower stretches away from Jimmy Stewart. The "demotion" of Pluto is like an alien visiting a pet store and mistaking the first cat it sees for a strange dog. ...and all I can think is I'd be terribly confused if I was in his class. *except for ermines and stoats. That one is perfect.

By: Anticipation Of A New Lover's Arrival, The

Anticipation Of A New Lover's Arrival, The — Sun, 29 Mar 2015 20:16:15 -0800

I think a lot of folks (including the author of TFA) are missing a key point here. The reason the dance analogy works so well, and a major reason why it is better than proposed alternatives, is that it is more complete. The dance analogy covers not just the idea that particles and antiparticles annihilate each other, but also the important and oft-overlooked detail that the photons formed during annihilation then devolve into new particles and antiparticles in their turn (partners coming apart and back together for each song) and for a while everything flip-flops back and forth between matter and energy until the Universe cools down enough that the photons no longer transition back into matter (the dance ends, partners go home together). It's a two-part lesson which people frequently only remember one part of. The dance analogy covers both parts rather elegantly, while none of the competing alternatives do. It may help students remember an important detail which might be forgotten otherwise. It's still heteronormative and that's not great, but I still think it's the best analogy I've heard so far.

By: GenjiandProust

GenjiandProust — Mon, 30 Mar 2015 07:50:01 -0800

The dance analogy covers not just the idea that particles and antiparticles annihilate each other, but also the important and oft-overlooked detail that the photons formed during annihilation then devolve into new particles and antiparticles in their turn I will point out that Bonds and Blofelds often are only thought to be dead, reappearing when it is least convenient. (As a bonus point, they also emit photons.)

By: odinsdream

odinsdream — Mon, 30 Mar 2015 07:50:03 -0800

I find it really strange that this situation even requires an analogy. It's not that complex of an idea to communicate, and adding the layer of any analogy just adds further confusion as a result of awkward matching between the analogy and the concept being described. This is already troublesome enough with things like electron orbits ('it's a little solar system!") and particle-wave duality ("it's both! it's neither! It's like a gun and bullet!"). Granted, the core concept of removing heteronormativity is most excellent. I'm just not sure why the teacher insists on a metaphor for such an easily-explained concept.

By: Shutter

Shutter — Mon, 30 Mar 2015 09:12:36 -0800

If you don't get why an analogy would be helpful for teaching this then you're neither the teacher of this material nor the student for whom the analogy is intended. He's dealing with a student population with a wide range of abilities and backgrounds. Some of them are not as smart as you for whatever reason. He's thinking carefully about how to reach out to those students. Doing whatever you can to convey a concept is a key part of teaching.

By: Atom Eyes

Atom Eyes — Mon, 30 Mar 2015 10:02:27 -0800

Science without analogies would be like Carl Sagan without a turtleneck and wide lapels.

By: Anticipation Of A New Lover's Arrival, The

Anticipation Of A New Lover's Arrival, The — Mon, 30 Mar 2015 16:16:23 -0800

Also, varying your teaching techniques helps keep students' attention. As a university teacher, especially at a public university, your job often involves teaching introductory courses to large groups of new college students from a huge range of backgrounds and levels of academic accomplishment, most of whom don't have any intrinsic interest in the subject (they're just taking the course for a requirement) and many of whom would probably rather just not be there. You have to hold their attention for over an hour while explaining difficult and often rather dry concepts to them, trying to keep them engaged enough to understand and absorb the lesson and just maybe even spark a little interest here and there. It's a tough room, but an important job. If you care about your students, you don't want to get up there and just drone off a list of facts and concepts in a totally literal, humorless fashion. Sometimes the direct approach may be best ("I am going to write some words on the board, and give you their definitions. You will be responsible for these definitions for next week's quiz, so take notes.") but you need to break it up. Using analogies, images, anecdotes, minor tangents, etc. gives your lecture some variety and helps hold the class's attention. It keeps them engaged. If you've ever had to teach a three-hour biodiversity lab at eight in the morning to a roomful of thirty hungover first-year psychology majors at an underfunded state university (a pretty standard teaching scenario for the kind of lessons we're talking about here—physics people can correct me if I'm wrong, but I feel like learning about matter and antimatter in the early universe is kinda on a level with learning about the stages of mitosis in biology, i.e. pretty standard intro college fare) then you'd understand that you gotta put on at least a little bit of a show if you don't want to find yourself lecturing to a room full of young adults, all pouting into their smartphones and texting each other about how lame this class is.

By: straight

straight — Mon, 30 Mar 2015 20:37:40 -0800

Yeah, that's a good point. Even if the dance metaphor isn't easier to understand, it might be more vivid and memorable.

By: Jpfed

Jpfed — Fri, 03 Apr 2015 07:13:58 -0800

I feel like learning about matter and antimatter in the early universe is kinda on a level with learning about the stages of mitosis in biology I think it must be different for different majors. Starting out in EE and going to CS, my intro to physics course was mostly just classical mechanics, with not an antiparticle in sight. (Actually, I don't think any of my physics courses ever officially covered antiparticles; they came up informally from time to time but it was just kind of assumed people knew about them). most of whom don't have any intrinsic interest in the subject (they're just taking the course for a requirement) and many of whom would probably rather just not be there. I have very mixed feelings about this. On a practical level, putting on a show might help more students learn more, so yay positive utility. But on a "get off my lawn" level it feels like it shouldn't be necessary. These are adults we're talking about; they are fully capable of choosing to motivate themselves. The only reason why we can't just say "your level of motivation is your responsibility" is course evaluations.