X-ray astronomy: Polarimetry sees the light

Ethane is in the chemistry textbooks as a molecule that can switch between unstable and stable conformations by an internal rotation, with steric repulsion usually invoked to explain the preferred 'staggered' arrangement of its two methyl groups. A new look at the ethane molecule reveals a rather different picture, in which ethane�s structural state is determined principally by hyperconjugation. This is a quantum mechanical effect that involves charge delocalization due to transfer of electrons from occupied to unoccupied orbitals.

An efficient photoelectric X-ray polarimeter for the study of black holes and neutron stars
ENRICO COSTA, PAOLO SOFFITTA, RONALDO BELLAZZINI, ALESSANDRO BREZ, NICHOLAS LUMB & GLORIA SPANDRE
Nature 411, 662-665 (7 June 2001)
| First Paragraph | Full Text | PDF (231 K) |

Astronomy: A twisted look at the X-ray sky
WEBSTER CASH
By adopting technology developed for particle-physics experiments, astronomers have created a new X-ray tool for probing exotic parts of the Universe.
Nature 411, 644-647 (7 June 2001)
| Full Text | PDF (159 K) |

space: A hole lot of twisting

7 June 2001 table of contents