Most Popular Books by Richard Gott

These copymasters for Key Stage 3 science pupils are designed to work alongside Science Connections or any other published science scheme. They include data/evidence activities, investigations, practical instruction sheets, and teacher and technician guidance notes, which cover equipment requirements, possible outcomes, assessment schemes, safety guidance and risk assessment information.

Reports on annual surveys of science performance of pupils, held 1980-1984.

The Sloan Digital Sky Survey (SDSS) started a new phase in 2008 August, with new instrumentation and new surveys focused on Galactic structure and chemical evolution, measurements of the baryon oscillation feature in the clustering of galaxies and the quasar Ly[Greek letter alpha] forest, and a radial velocity search for planets around ~8000 stars. This paper describes the first data release of SDSS-III (and the eighth counting from the beginning of the SDSS). The release includes five-band imaging of roughly 5200 deg2 in the southern Galactic cap, bringing the total footprint of the SDSS imaging to 14,555 deg2, or over a third of the Celestial Sphere. All the imaging data have been reprocessed with an improved sky-subtraction algorithm and a final, self-consistent photometric recalibration and flat-field determination. This release also includes all data from the second phase of the Sloan Extension for Galactic Understanding and Exploration (SEGUE-2), consisting of spectroscopy of approximately 118,000 stars at both high and low Galactic latitudes. All the more than half a million stellar spectra obtained with the SDSS spectrograph have been reprocessed through an improved stellar parameter pipeline, which has better determinationof metallicity for high-metallicity stars.

The current standard theory of the origin of the Moon is that Earth was hit by a giant impactor the size of Mars, causing ejection of iron-poor impactor mantle debris that coalesced to form the Moon. But where did this Mars-sized impactor come from? Isotopic evidence suggests that it came from 1 AU radius in the solar nebula, and computer simulations are consistent with its approaching Earth on a zero-energy parabolic trajectory. But how could such a large object form in the disk of planetesimals at 1 AU without colliding with Earth early on, before having a chance to grow large or before its or Earth''s iron core had formed? We propose that the giant impactor could have formed in a stable orbit among debris at Earth''s L4 (or L5) Lagrange point. We show that such a configuration is stable, even for a Mars-sized impactor. It could grow gradually by accretion at L4 (or L5), but eventually gravitational interactions with other growing planetesimals could kick it out into a chaotic creeping orbit, which we show would likely cause it to hit Earth on a zero-energy parabolic trajectory. We argue that this scenario is possible and should be further studied.