Tall, Dark, and Mysterious


Drinking (tea) with mathematicians

File under: I Made It Out Of Clay, Queen of Sciences. Posted by Moebius Stripper at 9:02 pm.

This morning, I made myself some tea in one of the matching mugs from my dinner set, waited an inordinately long time for it to start to cool down, and then downed the rest of it in a few gulps because it was quickly becoming too cold to drink. Not the most satisfying tea-drinking experience, but that’s what I get (I think) for throwing narrow cylinders.

So I started to wonder what shape of mug, made out of clay of constant thickness, would be ideal for drinking hot beverages. Specifically: I would like to pour myself some tea, wait a fixed time t for the surface of the tea to cool down to a drinkable temperature before beginning to sip, and then sip at a fixed (and preferably constant) rate until the tea is gone, with the tea remaining at a constant temperature. It seems like this should be doable; at the very least, I don’t think it’s not a ridiculous thing to ask for: the surface of the tea cools much faster than the tea below, and so there should be a way to sip tea from the appropriate vessel in such a way that each sip exposes another layer of tea that cools down to the temperature of the previous layer, just as I’m drinking it. It also seems clear that the top should be wider than the bottom, as the tea at the bottom will not be completely insulated by the tea above. Also, the heat transfer through the mug cannot be ignored: the specific heat capacity of clay is around a third of that of water, and only a third more than that of air.

…that’s as far as I got: I don’t have the physics background to set up this problem, though I spoke with someone who did, and he came up with some rather grisly equations that I don’t have the calculus background to solve. I also don’t know what simplifications could reasonably be made. But if anyone does, and can come up with a reasonable shape of mug that is conducive to tea-drinking, I’ll make you such a mug.


Playing with fire

File under: 1000 Words, I Made It Out Of Clay, Know Thyself. Posted by Moebius Stripper at 7:10 pm.

I’ve said before that throwing is by far my favourite part of making pottery. And for the most part, it is.

I’m almost never terribly happy with the way the surfaces of my pots turn out, and I’ve always felt somewhat cheated by the firing process: load the electric kiln, and then wait patiently for two days as a machine transforms your work without any input from you.

Raku is different.

The raku firing process isn’t very demanding in terms of money and materials. If you can get your hands on a propane tank, a torch, some bricks, a bit of insulation, a few metal garbage cans, and a bag of sawdust, and some open space, you can set up a raku kiln and some reduction chambers. And it’s a quick process: as little as an hour, compared to the day and a half to two days that stoneware spends in the electric kiln. But raku demands careful attention and input from the potter: a premature removal of wares, or a slight delay covering the pots can dramatically alter the outcome. And even when done properly, it’s not for conservative potters.

The payoff is huge: bright colours, dramatic metals, and the coolest chemistry lesson you’ll ever experience.

I’ve chronicled this weekend’s raku fire at my pottery gallery, and I’ve got some photos of the finished products.


Ode to general knowledge

File under: I Made It Out Of Clay, No More Pencils, No More Books. Posted by Moebius Stripper at 9:55 pm.

I’ve stated before that I don’t believe that college is for everyone. For example, college is not for Stacy Perk, who just wants to write for Glamour magazine, but her dumbass school is making her learn stuff, and she doesn’t care enough about stuff to actually go to class and do her homework and shit, so her GPA is suffering and so she might get kicked out of j-school, OH THE INJUSTICE OF IT ALL. (Where did I find this again?) There’s cheap dig about Glamour magazine (Americans spell ‘glamour’ with a U? Who knew?) just asking to be made, but I can’t be bothered to make it. As for the rest of the piece - it’s been a long day, and fisking is a delicate art as it is, and fisking something that so spectacularly transcends parody? Forget it.

So I’m going to talk about how a broad and general technical background has served me in the place where I most flagrantly avail myself of the right hemisphere of my brain: the pottery studio.

For instance, I minored in physics for a spell - more than long enough that I can answer the question that every beginner potter asks: “why is everything I make turning into a bowl?” That’s Newton’s first law in action: if you pull the clay directly upward, it’ll bowl out, because as soon as you lose contact with your form, you’re releasing the centripetal force that keeps your clay close to the centre of the wheel. Compensate by pushing inward, toward the centre of the wheel, if you want to throw forms that don’t widen at the top.

…A solid background in elementary geometry was enough to enable to me to help a fellow potter who was throwing a drum. On top of the thrown drum body she planned to stretch a circle of drum skin, which she’d tie on by looping a string through “twelve or fourteen” holes spaced equally on the perimeter. Twelve, I explained, would be better than fourteen, and we could space them equally using nothing but pencil and a straightedge. And I understood the reflection properties of conics deeply enough to explain why it was suggested that drum bodies be paraboloids.

…My studies of chemistry ended when I graduated high school - something that I didn’t start regretting until I started working regularly with clay. But I stuck around long enough to learn the difference between temperature and quantity of heat - a difference that is paramount to everyone who works with kilns. Potters talk about firing at various cones rather than at various temperatures - whether your kiln temperature rises at 50 degrees per hour or 150 degrees per hour makes a huge difference in how your glazes will come out. I stuck around long enough to understand that the evaporation of the water molecules in wet clay - which happens when clay is left in the air to dry - is a physical change, whereas the driving off chemically bonded water from clay molecules - which happens in the bisque firing - is a chemical change. This distinction explains why clay will disintigrate if you dip it in glaze - a suspension of insoluble particles in water - before it’s been fired, but not after; it also explains why unfired clay can be recycled, but bisqueware can’t. I don’t know enough chemistry, however, to make glaze-mixing anything other than random, which is why I’m positively salivating over this book. (I do know enough to remember that copper turns green when it’s been exposed to oxygen - witness the roofs of our Parliament buildings, among countless others - which is why I’m not surprised that copper oxide in glazes only gives brilliant reds in reduction firings, such as raku, in which the interior of the kiln is starved of oxygen.)

…And damned if I have the physics/kinesiology background to explain this one adequately, but every time I teach a beginners’ workshop, I recall a certain experiment that I found in one of the children’s science magazines I used to read when I was a kid. Try this one at home: have a partner - preferably a strong one - extend his or her arms, with elbows locked, and fists pressed together as tightly as possible. You won’t have much trouble knocking your partner’s fists apart, regardless of how strong they are or how weak you are. Now have your partner try this again, but with his or her elbows bent and fists pressed together close to the body. That’s a much more stable position, and it’s how I motivate the throwing posture: you use your entire upper body - not just your hands - when you’re on the wheel. You tuck your elbows into your hips, you bring your chair right up to the wheel, and you lean downward into the clay; otherwise you’re no match for it when you try to centre it. Take it from a certain beginner I taught once: he was six inches taller and nearly a hundred pounds heavier than me; he had biceps the size of my thighs; and when he sat back at the wheel with arms extended, he was no match for a 500g lump of clay.

That’s how my “useless general knowledge” has come up in the pottery studio alone. I owe a huge debt not only to the artists, but to the mathematicians and scientists who have laid the groundwork for my craft. I suppose I don’t really need to know why I need to lean inward why I throw; why I can’t seem to control a pound of clay unless I tuck my elbows into my hips; why we can’t get bright red glazes with our electric kilns…but my time in the studio is richer because I do.

Similarly, Ms. Perk technically doesn’t need to know damn near anything outside how to write a sentence if she wants to write. But she sure won’t have enough perspective to write anything worth reading. Not even in Glamour magazine.


Potteryblog, redux: the Hollywood North edition

File under: 1000 Words, I Made It Out Of Clay, Talking To Strangers. Posted by Moebius Stripper at 9:10 pm.

So, we’ve established that no one’s interested in my pottery. Tough crowd, but I’ve been spending nearly all of my time in the studio lately, so that’s all I’ve got. How about a story about my pottery and Al Pacino, then?

Gallery Show this week. Here’s my stuff. Those of my readers who follow the amateur pottery scene will note that the bulk of my work does not conform to the preferences of the consumer, who will pay good money for a turd dipped in blue glaze after rejecting every other colour of bowl, mug, vase, or plate, regardless of how skillfully made and well priced. I’m not kidding; every single one of my pieces that sold in the past two days was blue. Someone bought the fifth piece I made, ever. It was crap, but it was blue. Don Davis, author of one of my pottery bibles, once remarked that potters tend to focus on form, while non-potters pay closer attention to the surface of a pot. This certainly holds true in my experience, and it’s a shame, because glazing is my weak suit, and it shows. Throwing is my strength and my passion, but only other potters seem to recognize that.

But, Al Pacino. Sales were slow at the gallery yesterday morning, and the other studio member who was manning the tables with me decided to duck out for a few minutes to promote our show. A few minutes turned into half and hour, and when K returned, she explained that she had had trouble getting across campus, what with the movie being filmed around the science building (*), and what with every student and their dog trying to get a piece of the star, Al Pacino, who was six feet from her, and her without her camera!

I had my camera. K dispatched me to the scene, and I had no trouble finding it. Or, as it turns out, walking into it: I soon found myself six feet from Al Pacino while a handful of security guards idly looked on, but I convinced myself that it wasn’t actually him, because wouldn’t the security guards have held me back? As I turned a corner, a stagehand called out to me, “Hey! Get back! Only extras are allowed in here!”

“I’m an extra,” I lied, because, why not? I had nothing better to do yesterday than be in a movie.

The stagehand didn’t buy it. “No, you’re not,” he proclaimed with such conviction that I couldn’t help but feel hurt. What gave it away? I surveyed the actual extras across from me as I tried to assess what separated me so obviously from them. Was it my glasses? My aspherical breasts? My underwear-covering jeans?

The stagehand was forthcoming: “Our extras are not covered in dirt,” he sneered.

“Clay,” I corrected, self-consciously fingering the dried bits of slip in my hair. Nevertheless: point well taken.

I apologized for walking onto the scene, and explained that the security guards on the set had seen me and hadn’t tried to stop me, so I had assumed that the filming was taking place elsewhere. The stagehand sighed heavily. “Those are not security guards,” he explained slowly, “Those are actors playing security guards.”

I excused myself from the set. Off to the side, two female students were chatting up another assistant. The topic of conversation was something along the lines of Al Pacino is here? Like, right here? Can we see him? Can we get his autograph? I injected myself into the discussion long enough to ask what the movie was called, because on the off-chance that its editors suck, then they’ll leave in the scene that was filmed when I accidentally wandered onto the set. Look for the clay-covered girl, appearing soon in a theatre near you!

“It’s called 88 Minutes,” replied the assistant. “It’s about a guy who has 88 minutes to find three people .”

“What three people?” asked one of the girls.

And at this, the assistant gave a lopsided grin, and said, “If it were up to me”- here he pointed - “it would be you, you,” - eyes settling on me, and a huge wink - “and you.”

A few hours later, when I’d gotten myself to a computer, I looked for some more information about 88 minutes. Here’s a plot summary:

[88 Minutes is a] thriller about a college professor who, while moonlighting as a forensic psychiatrist for the FBI, receives a death threat telling him that he has only 88 minutes to live. In narrowing down possible suspects, he frantically seeks to communicate with a problem student, an ex-girlfriend, and a serial killer on death row. (**)

Which makes “and you” a contender for the worst pick-up line ever. Regardless, I have been really low on bloggable material lately, so I giggled and smiled back at the assistant, and handed him a promotional postcard for the gallery show. “You’ll have a lot longer than eighty-eight minutes to find us,” I said, and winked back at him.

I spent this morning in the studio attaching handles to mugs, and just after lunch I wandered up to our display to see how sales were going. “You sold some stuff,” the studio secretary informed me. “Some guy came in and asked for you specifically. He didn’t know your name, just told me what you looked like. It was weird. I told him where your stuff was.”

“Dude in his thirties or so, tanned, light brown hair?” I asked.

“Yeah,” replied the secretary.

Son of a gun. “Did he buy anything?” I asked, incredulous.

He did. He bought a mug.

It was blue.


(*) There have been many movies filmed on campus. The one that I remember best was this dreck, which is hands-down the worst movie I have ever seen in my life. I watched it only because I had heard that part of it was filmed in the very classroom where I had taught a first-year calculus class. The movie opened with a scene featuring high school students in that classroom writing their SATs, an acronym that the narrator informed us stood for “the Suck-Ass Tests”, and if you still think that this looks to be quality cinema after reading that, then you are not welcome here anymore.

(**) Does anyone else find it amusing that the problem student is apparently just as likely a suspect as the serial killer?



File under: I Made It Out Of Clay, Meta-Meta. Posted by Moebius Stripper at 9:10 pm.

Those of my readers who desperately hang onto my every word, who begin to twitch when the rate of updates wanes, and who, lost when confronted by this utter absence of new and interesting content, cast their eyes rightward in the hopes of finding something, anything of mine that they can read - those strange, strange folks recently had their creepy devotion validated when they found a new link to photos of my pottery in the sidebar. The rest of you had to wait until today.

Everything in that gallery was made in the past three weeks, by the way - I recently renewed my membership in my beloved old studio, and have spent four to five days there each week ever since I signed the club contract and reclaimed my old cubby. I start my new job soon, and am sad that [above] won’t last much longer. There will be pictures of my older stuff up soon - my studio is holding a big show/sale soon, and I’ll want to get shots of the older pots before I part with them.


There are advantages to planning things carefully

File under: 1000 Words, I Made It Out Of Clay. Posted by Moebius Stripper at 7:18 pm.

How am I spending my last few weeks of unemployment? By making a dinner set, complete with teacups:

…and saucers:

The astute reader will observe that there is no bijection between the set of teacups and the set of saucers. This is true, but more frustratingly, there isn’t even a morphism between the two sets: all but one of the saucers are too small for most of the teacups.

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