Here's the second of a series of holiday photo-blog posts showing some of the ornaments we have, and providing explanations for how they're really all about the science. It starts to get a little harder here:
"Dude," you say, "that's a teapot. What does that have to do with science?"
Thermodynamics, of course. The making of tea is all about boiling water, and what is that, but applied thermodynamics? Heat transfer, the latent heat of vaporization, phase transitions-- it's all there, symbolized by this little teapot. There's a tea cup, too, which isn't in this picture because it doesn't symbolize anything.
I suppose you could also talk about the chemistry involved in tea, and extracting the flavors and nutrients from the leaves and all that. But there's no need to get all crazy just over a little teapot.
I thought it was Russells' orbiting teapot. And wouldn't a kettle be a better choice for thermodynamics? The teapot does represetn the chemistry stuff though.
Is that a porcelain teapot? If so, it is excellent. And plastic or porcelain, the chemistry of the materials is fascinating. Molten glass (a component of porcelain) is one of the most corrosive liquids known.
My first thought was Jim Blinn's "standard" 3D CAD model, used ever since to learn or demonstrate a new modelling technique or program.
Not to mention the sound effects: sound of water boiling, sound(s) of vortices (and those produced by the pharynx of someone who touches one(pot or the steam flow) when its hot)...
Carl, I believe it's porcelain. It's certainly not plastic and it's quite heavy.
I brought it (and the matching teacup, which is wildly out of scale, being as big as the pot) as a souvenir from England.
Also note the nice red ornament next to it; Chad bought a set of red and a set of blue when I requested something "small and intensely colored" to fill up the tree the first year we had it. He did good.
Heavy means porcelain, but better to distinguish, porcelain absorbs heat much better than plastic, and has a much greater Young's modulus. England is well known for porcelain, but based on the quality, I'd be willing to be it is made in China.
This shape would be slip (liquid clay) cast (in a plaster mold). Look for a big hole in the bottom where they poured the slip out.
If it were plastic, it would have parting marks where the mold meets. Porcelain will have these too, but they are so subtle only people familiar with the art will recognize them. (One sands them off in porcelain, but the little platelets of clay will end up not being parallel to the surface at the sanded spot.)
After casting, they carefully drilled the small holes. This is called "piercing" and it is not very easy. Dry porcelain clay is amazingly fragile, so people prefer to do it when it is a little wet. Then they "high fired" it to get that beautiful translucence that is visible even in the photograph (look at the soft edges to shadows, like the edges of shadows on skin) but will be more evident to the eye. Fire just a little too high and it melts into a mess. A little too low, no translucency. Then it is glazed and fired again, to a somewhat lower temp. Then the colors are applied, and then a final low temp firing.
It's somewhat amazing that the ancient and inefficient process is (a) still done, and (b) can be done without horrendous losses. A fascinating book on how the Chinese secret was reproduced in Europe is The Arcanum.
The first thing that the plastic industry did was to imitate fine white porcelain. They quickly destroyed the market. So when you see a porcelain tea set in simple white (which are so beautiful), you can be sure it is antique.
Modern procelain has surface decorations added to it, to make it distinguishable from plastic. But for a physicist / engineer, who sees deeper than the surface appearance, the old stuff cannot be beat. Hold it in your hands and sense the warmth of the hot tea. Feel the stone-like hardness with your fingernail. Hear the high frequency sound it makes when you set it back down.
You can't write about teapots, Christmas tree ornaments and science without mentioning Bradshaw, Baker, Bradshaw, Bray, Brignal, Clements & Cotter, "An Appraisal of the Utility of a Chocolate Teapot", PLOKTA, Issue 23 (2001)
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