33 weeks LMP

There is a certain irony to being to a researcher who studies mortality risk early in life, and also a soon-to-be father. Sometimes I feel I know way too much about certain topics.

Decreasing population, increasing density

The Institute where I work is built on land that used to be part of huge East German ship building facility. The facility folded shortly after the German Democratic Republic did. The buildings were, for the most part, left derelict. One of the former factory buildings has been converted into an indoor shopping center. Each store is its own single story box built into the bottom of the cavernous factory building, with walkways and cranes still hanging overhead. Most of the other buildings have been torn down, and ~15 waterfront apartment buildings have been built (or are being built) on the land, most just within the two years I have been here. Apartments in these new buildings are on the expensive side for Rostock, but are filling up fast. One or two huge windowless cement monstrosities (one holds a dance club called The Bunker) remain, as well as a couple of older brick warehouses that have been refurbished. One is being used as a temporary home for the Rostock Volkstheater (community theater) while their main hall is closed for fire-code violations. It feels as though a new, fairly fancy, neighborhood is simply sprouting from the root-system of the old shipyards, among the remaining shells, foundations and train tracks to nowhere.

The demand for housing that fuels all this building is a story of migration. Rostock is Mecklenberg-Vorpomern, the least densely populated state in Germany, and a state that has steadily lost population since reunification. Many of the outylying villages are dominated by abandoned buildings. Apartment complexes on the outer edges of Rostock, plunked down in the middle of fields by the communist planners, now offer multiple months of free rent to anyone who will move in and still are emptying out. Rostock is full of college students, who don’t want to be on the outskirts in half empty buildings, and an aging population of long-term residents, who don’t either. The more abandoned the outskirts get, the strong the incentive to move toward the city center. So the center of Rostock is becoming denser even as the state loses population.

A name but no face

The first time I saw one? I was out in the rowboat, only a couple of hundred feet from our dock, and had, for whatever reason, dropped an oar over the side. I was probably 11, so there is a good chance I had dropped it on purpose, so as to be able to retrieve it. As I was reaching for the oar, I noticed a little white circle, mostly translucent, maybe the size of a dime, floating just under the oar. My hand retracted as the word 'jellyfish' formed in my brain. But I had swum in this lake many hundreds of times and never been stung, or heard that anyone else had. It wafted back and forth in the wavelets I created as I wiggled down in the boat to get a closer look. I held still and eventually so did it. Definitely a jellyfish, or something very similar to one. I watched it until it sank down into the dark silky water and out of view. I imagined it going back down to its secret world and hidden life. I imagined following it and learning.

The oar by this time was far enough away that I had to jump in and get it. I did this with some reluctance, having been stung too many times before, by jellyfish at summer camp on the Chesapeake Bay, and the previous winter in Florida by a Portuguese Man-o-War. Like every swim in the lake before and since, no stings.

My mother afterwards told me that there were freshwater jellyfish in the lake, but only occasionally, and not as many as my grandfather described from when he was a boy. I’ve seen them occasionally since, usually only on really hot days, one or two at a time. I only recently learned their name, Craspedacusta sowerbyi, when they were suggested to me as a possible study organism. Looking them up, finding that they had been studied down to the molecular, I realized I already knew this organism, but only as scattered phantasms floating by on summer days.

name for a principle?

There is a principle that I want to refer to in an upcoming talk, but I can't find a name for it. Someone must have named it after themselves by now. It is related to Ockham's razor, and to parsimony, but is distinct.

The principle is that an explanation for a pattern should preferably be applicable as broadly as the pattern is observed, but not more broadly. For example, an evolutionary explanation for group living that can be applied to all the group-living insects is preferable to an explanation that works only for one species of ant. The explanation should preferably not explain the pattern more broadly than it occurs. For example, an explanation for the fusion reaction of the sun merely in terms of the presence of hydrogen would also tend to predict fusion in many other contexts where it does not generally occur, making this explanation less desirable than a more complex one which also specifies the need for the physical conditions which encourage the hydrogen to fuse.

This is the sort of logical statement that is so obvious as to rarely need to be said, yet I need to say it for this talk. If you know what I should call it, please let me know.