22 December 2009

Perfect cinnamon twists

This is a great recipe for beginning bakers. They come out light and fluffy. If I can make them, so can you.

Bring to boil in large saucepan:

  • 1 cup sour cream

Remove from heat. Stir in until well blended:

  • 3 tbsp shortening
  • 1/4 cup sugar
  • 1/8 tsp baking soda
  • 1 tsp salt

Cool to lukewarm. Add:

  • 1 large unbeaten egg
  • 1 package of dry yeast

Stir until yeast is dissolved. (At this point you could also throw in a dash of vanilla, almond, or orange extract, but I didn't and they were great. The sour cream alone gives them plenty of flavor.) Mix in with spoon:

  • 3 cups sifted plain flour

Turn out onto a lightly floured board. Knead slightly a few seconds to form a smooth ball. Cover with a damp cloth and let stand five minutes to firm up. Meanwhile, in a small bowl mix:

  • 1/3 cup brown sugar
  • 1 tsp cinnamon
  • 1/2 cup finely chopped nuts (pecans work fine)

Roll dough 1/4 inch thick in a rectangle 6"×24". Spread the entire surface with

  • 2 tbsp soft butter or margarine

Sprinkle half of the dough (the long way) with the sugar-cinnamon mixture. Bring the unsugared half of the dough over the sugared half, pressing the top surface lightly to seal in the sugar mixture. Cut in strips 1/2 to 1 inch.

Grease 2 cookie sheets. Take each strip of dough, give each end a half twist (in opposite directions of course), and place on the cookie sheets about 2" apart, pressing both ends firmly and flatly to the baking sheet. Cover with a damp cloth and let rise at 85° or so until very light, about 1 hour 15 minutes.

Bake 12-15 minutes at 375°. While baking, mix in another bowl:

  • 1-2 tbsp milk
  • 1/2 cup powdered sugar

to make a fairly thick icing. Drizzle over the twists.

Makes about 2 dozen.

06 December 2009

Mathematicians in training

First off, if you haven't played Set, you really should, because you're just the sort of person who would love it. It's a clever idea elegantly executed, and it just happens to be great competitive fun. I taught the kids to play, and the four-year-old has a definite edge on the six-year-old. I couldn't be more pleased.

We had a bit of a drive yesterday, and along the way we gave the kids some analogies to puzzle over. You know the sort of thing: “Ice is to water as rock is to what?” This turns out to be engrossing and surprisingly fun. (I might try it with adults sometime. I sense opportunities for nerd humor.) Here the kids were not evenly matched at all. The four-year-old would get the easy ones (cow : moo :: pig : x) but would guess random related words on the harder ones, apparently with equal confidence. The six-year-old saw more clearly what the game was about, so he was able to bring his greater general knowledge to bear.

Why is this post titled “Mathematicians in training”? Well, Set is a transparently mathematical game. There are 81 cards because 81 is 34. The deck is the Cartesian product of four three-element sets. They form some kind of algebraic structure with extraordinary symmetry (of a kind I don't really know anything about—it's not a group—such that I'm tempted to get completely sidetracked here). But the kicker here is, the gameplay itself is mathematical. As far as I can tell, the only good strategy is to try to prove there are no sets.

Analogies are just little homomorphisms, which is to say, structure-preserving transformations. The idea that deep sameness is more interesting than superficial differences is more important to mathematics than numbers.

On the surface it seems like analogies are less mathematical than Set. Appearances can be deceiving.

(P.S. Figured it out. The sets in Set are the cosets of cyclic subgroups of (Z/3Z)4. The symmetry I was referring to above was that after you erase the underlying group operation, there's no privileged element. There are isomorphisms on the deck of cards, preserving the sets, mapping any given card to any other given card.)