Archive for September, 2009

Winter Solstice at Stonehenge

Sunday, September 27th, 2009

Sunset at Stonehenge

Sunday, 27 September 2009

Its well known that there is a connection between Stonehenge and sunrise and sunset on the longest and shortest days of the year. To celebrate this connection between the stones and the sky, in the International Year of Astronomy 2009, a special event has been organised by the Royal Astronomical Society together with English Heritage.

Events include; free talks and tours by leading archaeologists and astronomers, the “From Earth to the Universe” exhibition, an opportunity to view the sunset itself, and a chance to see the night sky from the stones (advance bookings only).

To find out more, visit our website at http://www.astronomy2009.co.uk/index.php/news-mainmenu-37/22-announcements/129-winter-solstice-event-at-stonehenge

Carolin Crawford – “Cosmology and Dark Energy”

Wednesday, September 2nd, 2009

Wednesday 2nd September 2009

Cosmology has always been of interest to Club members and therefore the talk by Carolin Crawford on “A Beginners Guide to Cosmology and Dark Energy” was much enjoyed and appreciated. As well as being a staff scientist at the Institute of Astronomy, Carolin is also a public outreach officer, and her talk reflected the care she takes to make complex information understandable by a lay audience.

The talk started with an introduction to the discoveries in the mid 20th century that led to our current understanding of the universe. Einstein’s General Theory of Relativity produced different scenarios for the fate of the universe depending on a mathematical device, the Cosmological Constant. Subsequent observational work by Edwin Hubble showed that in fact the universe is expanding. Given that it started out at the Big Bang, the universe was estimated to be over 14 billion years old.

More recent observations of supernovae and galaxy clusters were described, which imply that the rate of expansion is actually increasing, giving a revised figure of 13.7 billion years for the age of the universe. The force driving this expansion is known as Dark Energy, but the nature of this energy is one of the great mysteries of modern cosmology. Carolin’s talk prompted a range of questions, some of which inevitably verged on the philosophical given the nature of the subject. The evening gave us plenty to think about as we looked up at the Papworth night sky on the way home!