All posts for the month August, 2012
A mysterious warming of the climate was slowly manifesting itself in the Arctic, Dr. Ahlmann said, and, if the Antarctic ice regions and the major Greenland ice cap should reduce at the same rate as the present melting in the Arctic, oceanic surfaces would rise to catastrophic proportions and people living in the lowlands along their shores would be inundated.
He said that temperatures in the Arctic had increased 10deg. Fahrenheit since 1900—an “enormous” rise from a scientific standpoint. The waters in the Spitsbergen area in the same period had risen three to five degrees in temperature and one to one and a half millimeters yearly in level.
“The Arctic change is so serious that I hope an international agency can speedily be formed to study the conditions on a global basis,” he added. He pointed out that whereas in 1910 the navigable season along western Spitsbergen lasted three months it now lasted eight months.
Yowsa, sounds serious! We’d better… oh, wait. The quote is from May 30, 1947. You know, back when the CO2 concentration was around 316 ppm.
Posted by Fred on August 20, 2012
https://ninthlaw.wordpress.com/2012/08/20/evidence-of-arctic-warming-from-the-uc-geophy/
So, should we worry or not about the warming climate? It is far too binary a question. The lesson of failed past predictions of ecological apocalypse is not that nothing was happening but that the middle-ground possibilities were too frequently excluded from consideration. In the climate debate, we hear a lot from those who think disaster is inexorable if not inevitable, and a lot from those who think it is all a hoax. We hardly ever allow the moderate “lukewarmers” a voice: those who suspect that the net positive feedbacks from water vapor in the atmosphere are low, so that we face only 1 to 2 degrees Celsius of warming this century; that the Greenland ice sheet may melt but no faster than its current rate of less than 1 percent per century; that net increases in rainfall (and carbon dioxide concentration) may improve agricultural productivity; that ecosystems have survived sudden temperature lurches before; and that adaptation to gradual change may be both cheaper and less ecologically damaging than a rapid and brutal decision to give up fossil fuels cold turkey.
I couldn’t have said it better myself. In the midst of a rather good Wired (yes, Wired!) article, this is a spot on description of the lukewarmist stance.
Posted by Fred on August 18, 2012
https://ninthlaw.wordpress.com/2012/08/18/the-case-for-lukewarmers-in-a-nutshell/
Yet the results Witten obtained led to the Britto, Cachazo, and Feng papers, including the one written with Witten himself, which managed to pull from the string theory developments some key insights that were needed for more general calculations. From there we follow the results to BlackHat, whose leaders all did some amount of string theory early in their careers but who turned by choice to practical calculations and invented many new techniques themselves. They’re exactly the sort of people you’d expect to dismiss these efforts by string theorists as naive. But no. They credit Britto et al. prominently for a key insight that makes BlackHat possible. And finally we arrive back at the dinner table, with me listening to Joe Incandela, who, fresh from the completion of the CMS paper on the observation of the Higgs-like particle, is praising BlackHat for its contribution to searches for new phenomena in CMS data. It’s only a few steps from Incandela to Witten — from experiment to the most apparently-useless edge of string theory.
This is a really insightful article describing the place of String Theory in physics today. If you are at all interested in the combination of physics and computation, you’ll learn something about current high energy physics research, the place of computation in understanding physical theories, and the worth of String Theory as a sub-discipline in physics.
Highly recommended. Read the whole thing.
Posted by Fred on August 16, 2012
https://ninthlaw.wordpress.com/2012/08/16/computations-from-string-theory-to-the-large/
The Ninth Law 