What makes a Black Hole?

21 Aug 2010

This is one of those uncomfortable pieces of emerging evidence that might result in an upset. At www.sciencedaily.com/releases/2010/08/100818085938.htm is a story that is being widely reported - it's just too good to ignore. European astronomers have demonstrated that a magnetar, an unusual form of a neutron star, was formed from a star with at least 40 times the mass of our Sun. The result presents a challenge as a star as enormous as this was thought to become a black hole - but that did not happen. The research is due to appear in Astronomy and Astrophysics.

Meanwhile, at www.sciencedaily.com/releases/2010/08/100819141917.htm is another story widely reported, Probing for Dark Energy. For example, you can see the story at www.physorg.com and at Nigel Calder's blog, http://calderup.wordpress.com on August 20th. Basically, a team of astronomers have published a paper in Science (August 20th issue) that claims to have probed the nature of dark energy - one of the big challenges in cosmology (and a reputation building block). They used gravitational lensing to try and measure its properties (which intrigued Calder) , a phenomenon predicted by Einstein's theory of general relativity. It was used to judge how distances, and space time, are modified by the elusive dark energy. A fascinating insight into the way scientists can home in, like tunnel vision, to a far point of the universe in order to try and understand what is happening.