Interesting science reading for the day:
For those of you interested in astrophysics, this week's
Science has a very interesting set of articles about pulsars, magnetars and neutron stars. Particularly interesting are the news articles "The Pulsar Menagerie" (1) and "Crushed by Magnetism," (2) and Lattimer and Prakash's review article "The Physics of Neutron Stars." (3) The latter includes a great discussion of the state of our understanding of type II supernovae and how neutron stars are formed.
(Interesting thought from this: The typical total energy release in a type II SNa is ~3*10
53 erg, about 10% of the total mc
2 for the star. Of this, about 1% is kinetic energy, 0.01% is photons, and the overwhelming remainder is a wall of neutrinos. During one key stage in the collapse, a region of star becomes sufficiently dense to become opaque to neutrinos (! - mean free path of about 10cm over a 20km region) so energy can build up in this form, and it's the sudden release of that which triggers the primary explosive shock wave. There's just something neat about that.)
And on another side, there's a new report out by Laumann
et al titled
The Sexual Organization of the City. (4) It discusses how cities tend to split into several independent "sexual marketplaces," often with radically different customs, leading to questions about how cities need to manage things like health and social issues with more refined tools. So far, I've only read the
NY Times review, but I intend to get my hands on a copy of the full report asap - it looks like a good read.
(1) Science, 23 April 2004, vol. 304 pp. 532-3
(2) Science, ibid., pp. 534-5
(3) Science, ibid., pp. 536-41
(4) E. O. Laumann et al., (eds.) The Sexual Organization of the City, Univ. of Chicago Press, Chicago, Ill., 2004.
