Posts from — April 2009

The cherry blossoms have come and gone now: two weeks of blooming and four days at the peak. A few pictures of my son enjoying the blossoms made their appearance on the Matthew Picture of the Day. The blooms are the most dramatic signal of the arrival of spring: there are a handful of other plants that bloom one way or another before the cherry trees do, but the cherry trees go from bare branches to large masses of fluffy pinkish-white rather dramatically.

Now the blossoms have blown away, and trees of every type are getting their leaves, and for a week or so the trees are all decorated in Spring Green. I had known about the Crayola color Spring Green since childhood, but it wasn’t until I was living in Ithaca that, after a characteristically long winter, I really understood what it meant. The very light and yellowish green of the nascent leaves on the trees across the street from my apartment were Spring Green; it was finally spring.

So now we begin the six or seven months in which the foliage and blooms of the plants around us make the city beautiful. This is capped by a month or so of fall foliage, after which nature’s beautification fades, slowly, and the seasonal decoration takes over. 

Between Thanksgiving and New Year’s, holiday lights make the otherwise bleak city beautiful. Strings of white lights outlining houses and filling in shrubs, some overdone, some very subtle: they compensate for the dwindling sunlight and dormant vegetation. In Ithaca, we got our first snow around Thanksgiving, here in DC it comes much later, usually in January. Snowfall is only very briefly beautiful, when it’s still piled up on otherwise bare branches, and while that on the ground hasn’t been disturbed very much. Then in a few hours, it drops from branches and twigs, and snowplows and other traffic have turned much of it into a dirty grey mush.

One thing I can’t understand is why it is that the holiday lights that made the streets seem so inviting in December look so tacky in the middle of January. The weather is the same, the hours of darkness are much the same, yet holiday lights, and the greens, golds, and reds of Christmas look fantastically out of place. I suppose we’ve been trained by the retail industry to appreciate bold reds and whites, à la Valentine’s day. Is there anyone who actually buys such seasonally-colored servingware from the yuppie housewares catalogs? And after Valentine’s day, as the dreary bleakness of winter presses on, we imagine spring in pastel colors. And then spring happens, like it’s happening now, here in DC.

I’ve been back from the 2009 APS March Meeting for two weeks now and so the window of relevance for writing about it is rapidly closing. It was held in Pittsburgh this year, following the same format as last year. The meeting seems to be getting bigger each year: when I first attended, in 2003, there were about 5600 attendees; this year’s meeting drew 7000.

Sessions
For a number of years now I’ve taken the online Epitome and Invited Speaker List and run them through tcl scripts to make TeX files that give me speaker and session information in a format I think is more useful. This also allows me to look at overall meeting statistics: There were more sessions this year, 558, than in previous years; last year there were 517 sessions. What seems to be growing most sharply are invited talks: there were 825 this year, compared to about 730 in each of the previous three years. Not surprisingly, this corresponded to an increase in the number of sessions with 5 invited talks: there were 95 such sessions this year, about 75 in each of the previous 3 years, and only 15 back in 2005.

Reunion
I only stayed through Wednesday of the meeting this year, taking an evening flight back home. I was rather irritated to find that the Cornell alumni reunion was held on Wednesday night, instead of Tuesday, like it always had been. I don’t know if this had even been published before I made my travel reservations, although I don’t know that I would have stayed an extra night just for that.

Projection
The disappearance of viewgraphs now appears complete. I was one of a handful of holdouts who was still using viewgraphs as late as 2006. Last year, I only saw one talk given using viewgraphs and this year I saw zero. There are still overhead projectors in the rooms, but they are kept on the floor beside the table upon which the computer projector sits. It’s amusing to read the note in the 2002 newsletter of the Division of Condensed Matter Physics:

More and more scientists want computer projection for their talks. This past year, computer projectors were available in invited session rooms only. Projectors are very expensive (~$400/ day/session) and would raise the registration fee at the conference significantly if placed in all rooms. Also, set-up time between talks makes staying on a 12 minute schedule for contributed talks very problematic. APS will continue to increase the availability of computer projection, but will not commit totally to them until price and technical interfacing problems become more tractable.

To be sure, there are problematic computers and I did see talks where roughly half of the time was taken up with computer fiddling. 

Context
On the topic of presentations, one thing that lots of speakers do, which really bugs me, is to show a graph of some raw data, usually a spectrum of something taken with a well-established experimental technique, but without giving any explanation. If I don’t use a technique myself, even if I know in principle how it works, I don’t know if it’s considered good or unexpected or interesting or disappointing if your graph has wiggles, or is flat, or has a bump in a particular place, or a big spike, or a big dip, or if it shifts a little as you twiddle some parameter, or shifts a lot. Context, my fellow physicists! Tell us what your measurement technique does, what shows up in your graph, what ordinary data would look like, and why your particular measurement is interesting.

Books
I also ended my one-year physics-book-buying drought. I buy interesting physics books knowing that I’m not also buying the time it takes to work through them. I have one book purchase from two years ago that I’ve made a concerted effort to actually work through, but am perhaps only 20% done with it. And it’s not even a very challenging book. But I went ahead this year anyway, and took advantage of Cambridge University Press’s Wednesday afternoon buy-2-get-50%-off sale to pick up an otherwise ridiculously overpriced Elasticity with Mathematica and Geometric Algebra for Physicists, and also bought Group Theory: Applications to the Physics of Condensed Matter.

On to Portland
I’m looking forward to visiting Portland for next year’s March Meeting. I consider Portland one of my favorite cities but in reality all I’ve only spend several hours there at a time, waiting to change trains. But with a streetcar and Powell’s, who couldn’t love Portland? I had been sure that, a couple of years ago, I also saw Seattle on the list of upcoming March Meeting locations, but it seems to be gone now.