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High-school physics students on the rise A third of all US high-school students enrol on a physics course, according to a report from the American Institute of Physics (AIP). The report, “Reaching the Critical Mass”, found that in 2005 some 1.1 million people, or 30% of the student body, had taken at least one physics class before they got jobs or went to university. In 1987, in contrast, that figure stood at only 620 000 pupils or 20% of the student body. The report also reveals that high-school physics is no longer dominated by white men. In 2005 nearly 50% of physics students were women, while between 1990 and 2005, the proportion of AfricanAmerican and Hispanic students in highschool physics classes rose from 10% in each case to 23% and 24%, respectively. “There is really no chance for the figure [for female students] to rise much since it

The number of high-school students who have taken physics and then do physics at university remains stuck at barely 0.5%

is near parity now and has been for quite some time,” says Michael Neuschatz, a statistician at the AIP, who co-wrote the report with Susan White and Mark McFarling. “But as for minorities, I have no reason to doubt that the recent trend will continue.” The AIP report also shows that the proportion of female high-school physics teachers rose from 23% in 1993 to 30% three years ago and that numbers taking more difficult “advanced placement” courses, which many high schools offer to university-bound students, also increased from about 106 000 to roughly 308 000 over the same period. However, the actual number of high-school students who have taken physics and then do physics at university remains stuck at barely 0.5%. Peter Gwynne Boston, MA

Astronomy

Telescope to clean up echo of Big Bang One of a pair of telescopes that will help in the search for signatures of gravitational waves in the cosmic microwave background (CMB) will be inaugurated next month at the Teide Mountain Observatory on the island of Tenerife in Spain. The project, named Quijote and costing 71.5m, will produce a map of photon polarization of the CMB at frequencies of 10–30 GHz. Although it will not directly detect gravitational waves, Quijote will characterize the signals that contaminate CMB measurements. The second, larger telescope will open later next year. One way to search for gravitational waves is to look at the polarization of photons from the CMB as they scattered off free electrons when stars first formed and re-ionized the surrounding gas. Although gravitational waves have never been directly measured, it is in principle possible to tease out their existence by mapping in detail the temperature and polarization of photons in the CMB. Until now, however, it has only been possible to measure the temperature fluctuations using the space-based Wilkinson Microwave Anisotropy Probe (WMAP). The polarization of the CMB can be characterized in terms of “E-modes” as measured by WMAP, which are fluctuations in the density of matter, Physics World December 2008

Cosmic dreams The Quijote telescopes will help in the search for gravitational waves.

and “B-modes”, which have not been measured yet and are linked to gravitational waves produced when the early universe rapidly expanded. Quijote, which will cover 10 000 square degrees of sky with an angular resolution of 1 degree, will be able to characterize unwanted microwaves from the rotation of charged particles along the magnetic field lines of the Milky Way that contaminate CMB measurements and then subtract them. Quijote will complement the European Space Agency’s Plank satellite, due to be launched in April 2009, with the information on the sources of contamination. “Within three to five years we expect to have 1000 microwave maps of the northern sky at five frequencies,” says Quijote’s director Rafael Rebolo. Michele Catanzaro Barcelona

LHC on the mend after accident Two months after an electrical fault put CERN’s Large Hadron Collider (LHC) out of action, the first damaged sections of the machine began making their way out of the tunnel for repair. Last month, seven of the LHC’s magnets (mostly 15 m-long, 35 tonne “dipoles”) were lifted out of the LHC tunnel to be inspected. Although some equipment was ready to be transported out within a couple of weeks of the original incident, only one of the LHC’s access shafts – located n the middle of sector 12 – is wide enough to handle the LHC’s dipoles, thus forcing engineers to wait until the sector was purged of helium. In total, 50 magnets are expected to come to the surface, the last shortly before Christmas. About 20 of the magnets will be replaced with spares, while the rest will be repaired.

Physics of medicine centre launches A new centre for the physics of medicine will be officially opened on 16 December at the University of Cambridge in the UK. The multidisciplinary centre, which has cost £12.5m to build, is located next to the Cavendish Laboratory. It will provide lab space for a core team of physicists from the Cavendish who will work with researchers from the biological and clinical sciences. The centre will initially have eight full-time staff and be home to more than 100 postdocs and students. A full-time director is still being sought, as is funding for a second building for offices and lecture theatres. The centre’s interim director is Cavendish physicist Athene Donald, who last month was given one of this year’s L’Oréal-UNESCO awards for women in science, worth $100 000.

Comic-ray observatory is inaugurated The $53m Pierre Auger Observatory in Argentina’s Mendoza province east of the Andes was inaugurated last month. The observatory studies high-energy cosmic rays – charged particles that shower the Earth at energies 10 times higher than can be produced at today’s most powerful particle accelerators – via an array of 1600 water tanks spread over 3000 km2. These tanks will detect radiation produced when a incoming cosmic ray is slowed down by the water. The inauguration marks the completion of the southern site in Argentina and the beginning of planning for a second “northern” site in Colorado, US. The collaboration, consisting of 350 physicists from 70 institutions worldwide, last year found that the direction of the highest energy cosmic rays matches the position of nearby active galaxies with black holes at their centre.

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