Physics and Astronomy

Telltale X-rays from iron may reveal if black holes are spinning or not, according to astronomers using NASA’s Chandra X-ray Observatory and the European Space Agency’s XMM-Newton Observatory. The gas flows and bizarre gravitational effects observed near stellar black holes are similar to those seen around supermassive black holes. Stellar black holes, in effect, are convenient `scale models’ of their much larger cousins.

Black holes come in at least two different sizes. Stellar black holes

Philosophical transactions a November issue

Organised and edited by Carlos Frenk, George Kalmus, Nigel Smith and Simon White

What is the universe made of? How is it expanding? What is the origin of galaxies and other cosmic large-scale structures? These questions and some tentative answers were the focus of the discussion meeting on The search for dark matter and dark energy in the Universe, held at The Royal Society on 22-23 January 2003.

Astronomers have known fo

The universe may have been created by an explosion within a black hole, according to a new theory by two mathematicians recently published in the Proceedings of the National Academy of Sciences of the U.S.A..

“It’s a mathematically plausible model which refines the standard model of the Big Bang,” said Blake Temple, professor of mathematics at UC Davis and co-author of the paper with Joel Smoller, professor of mathematics at the University of Michigan.

In the standard model o

Measurements of 11 exploding stars spread throughout the visible universe made by the Hubble Space Telescope confirm an earlier, ground-based study which produced the first evidence that the universe is not only expanding, but expanding at an increasing rate.

The new study, which has been posted online [http://www.arxiv.org/abs/astro-ph/0309368] and will soon appear in the Astrophysical Journal, also provides some tantalizing new insights into the nature of the mysterious repulsive force, d

Observations of the bright side of the Moon with NASA’s Chandra X-ray Observatory have detected oxygen, magnesium, aluminum and silicon over a large area of the lunar surface. The abundance and distribution of those elements will help to determine how the Moon was formed.

“We see X-rays from these elements directly, independent of assumptions about the mineralogy and other complications,” said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass, at a

Galileo, the NASA space probe in which UK scientists have played a key role, will dramatically end its 14-year mission when it plunges into Jupiter’s dense atmosphere on the 21st September. The spacecraft, which has revealed a wealth of scientific data on Jupiter and its moons, with fuel and power exhausted, will vaporize like a meteor as its descends through the giant planet’s turbulent atmosphere (an artist’s impression of what this might look like is available – please see notes to