image by SnowCrystals.com
You might be surprised to learn there is a Caltech professor studying snow crystals. (Or if you've ever been to a party at Caltech, it might actually make sense.) He runs a website and owns a database of some strikingly beautiful images of snow crystals. He writes:
Snowflakes and snow crystals are made of ice, and pretty much nothing more. A snow crystal, as the name implies, is a single crystal of ice. A snowflake is a more general term; it can mean an individual snow crystal, or a few snow crystals stuck together, or large agglomerations of snow crystals that form "puff-balls" that float down from the clouds... The water molecules in an ice crystal form a hexagonal lattice... There are two hydrogens for each oxygen, so the chemical formula is H2O. The six-fold symmetry of snow crystals ultimately derives from the six-fold symmetry of the ice crystal lattice.snapshot of a laser cut file
You might not be surprised to learn that I have a deep fascination with walled cities or 'star forts.' This military planning science originated in the 15th and 16th century and was taken to its "logical extreme" by architects such as Vauban and Menno van Coehoorn (via Wikipedia). And if you ever see the drawings that Michaelangelo did for Florence's earthworks, they are erotic, if a little impractical. Lets learn more about these things:
The original 'Italian' fortresses were comparatively simple structures. During the seventeenth century, however, the growing power of the cannon with which they were confronted, as well as their own logic, caused them to grow and become more complicated. At first, outlying or detached structures would be built to protect the corners of the basions; next, those structures themselves would require protection, and the whole lot would have to be linked with the main fortress, at which point the process repeated itself. Thus first-class fortresses, such as those constructed by Vauban or Coehoorn around 1690, became ever larger. They acquired ravelins and redoubts, bonnetttes and lunettes, tenailles and tenaillons, counterguards and crownworks and hornworks and cuvettes and fausse brayes and scarps and cordons and banquettes and counterscarps...
-from the Oxford History of Modern War
by Charles Townshend pp. 211-212
In October I was in Northern Italy and visited the walled city of Palmanova with Branner fellow Nicolette Mastrangelo
. The fortress, curiously enough, is a hexagon at the center and contains nine points. The logic is that a commander at the center can view the action on the ramparts and direct the cannon reinforcements with utmost speed. Contrary to what the plan might suggest, this is not a panoptic system in the pure sense. The commander at the center can't actually see over the ramparts - to build such a tower would be to invite decapitation. However, walled cities did function to project power over a large section of territory, which is a very panoptic concept. Imagine how the function of a walled city is now accomplished by satellites and drones today, a dramatic reduction in material though certainly not in engineering effort.Neuf Brisach, a walled city planned by Vauban
Tis' the season, right? Naturally, one needs Christmas ornaments... the most symmetrical walled cities could be done paper snowflake-style, but if you have access to a laser cutter in your neighborhood...
How does this Caltech professor study snow crystals? The production of snow crystals also embodies an architecture. We learn that they are grown in a convection chamber, shown schematically below. a convection chamber, image by SnowCrystals.com
Basically it is just a cold chamber about a meter tall, with two containers of heated water on the bottom. Convection mixes the water vapor into the cold air, creating supersaturated air for growing snowflakes. We nucleate crystals by dropping a speck of dry ice in the chamber, or by rapidly expanding some cold compressed air inside the chamber.
Can you imagine the sort of chamber that would grow walled cities? Exchange humidity for population, temperature for animosity with your neighbors, input available building materials...
Happy Holidays everyone! And email me if you want the CAD file.