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December 16th |
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Our Christmas meeting was an occasion for mind-bending quiz questions, mince pies, and money-raising. The book auction raised £111.50, and the quiz was won by the Gremlins. |
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November 25th |
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We welcomed Fay Dowker from Imperial College back, to give us a talk on "The Science of Time". She explained how the classical everyday understanding of time was superceeded by the space-time view that comes from Einstein's theory of General Relativity, and how one of the problems with space-time is that it lacks the "now" that is part of our everyday understanding of time. She then told us about some of the ideas coming out of research around Quantum Gravity, and particularly from Causal Set Theory, which may be able to restore the "now" to space-time. This was a thought-provoking talk, and there were many questions from the floor afterwards. |
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October 28th |
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Our President, Gilbert Satterthwaite gave us a profusely illustrated talk about his experiences at various IAU/UAI General Assemblies entitled "Suns, Stars & Satchels". He wove historical information, memories of many astronomers, and photographs of may telescopes (especially transit instruments) into the story, and brought along various mementos (including the satchels given to attendees). At (and after) the most recent General Assembly in Sydney, Australia in 2003, he was able to visit the Sydney, Mt. Stromlo, Siding Spring and Perth observatories. His photographs of the remains of the Mt. Stromlo Observatory, which was destroyed during a firestorm in February 2003, were particularly poignant, since many historic instruments and Australia's prime optical workshop were lost. |
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September 23rd |
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Mike Leggett, a member of the Astrobiology Society of Britain came to High Elms to give us a talk with the title "Exobiology: Life Beyond the Earth?". From the start this engaged the interest of members, and there were several questions from the floor. Mike answered them while also keeping his talk on track. He took us through the history of the idea of life beyond Earth from the ideas of the ancient Greeks to modern times. He then gave us a brief explanation of the processes that are currently believed to be involved in the appearance of life and some estimates of the probability of it appearing elsewhere, and rounded the talk off with some speculation about whether there might be life on other moons and planets in our solar system. The subject is clearly one from which several more talks could be drawn, and discussions continued afterwards in the Change of Horses |
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August 23rd |
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Tony Buick gave a profusely illustrated talk about "The Moon and I" as part of this Members Evening. His pictures were all taken using his family digital camera and a second-hand 8" reflecting telescope from the heavily light-polluted skies in Orpington. He showed pictures of all visible areas of the Moon, including features he found particularly interestin, such as the Schroter Valley, the 'Jewelled Handle', and various other crater shadows, wrinkles, rills and domes. |
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July 22nd |
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Ken Harrison of Loughton A.S. came to talk to us about "Planetary Nebulae". He started by showing us an animated montage of images of planetary nebulae, and then went on to give us a brief potted history of the first recorded observations (by Messier), the naming (by Herschel) and the first spectral analysis (by Huggins, who ascribed the oxygen lines prominent in the spectra to "nebulium") of objects of this type. From there he led us through the initial fairly simple explanations for their formation to the much more complex explanations needed to esplain the details seen in these objects by the Hubble Space Telescope. These explanations were accompanied by animations, both computer-generated and from sequences of Hubble images. These objects are far more complex than early models suggested, and usually have a basically bi-polar form, a bit like an hourglass or a dumbell. The nearly circular ones are simply end-on views of these other more complex shapes. Detailed study of planetary nebulae promises to reveal much about the end stages of stellar evolution. |
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June 24th |
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Peter Hingley, Librarian of the Royal Astronomical Society, gave us an entertaining and profusely illustrated talk with the curious title "Astronomers & Oddities". The oddities were mostly items from the RAS library and archives connected with astronomers, and each one had a story to tell. Some were stories of astronomical discovery, while others showed us something of the character of an individual, and most of them in one way or another tied in with the history of the Royal Astronomical Society from its founding to the present day. |
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May 27th |
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Konrad Malin-Smith stepped in at short notice to give us a talk about "The Clouds of Magellan", starting with a few slides taken while on holiday in Western Australia, and then moving on to describe the history and significance of observations of these neighbouring galaxies. Because they are near enough for quite small telescopes to resolve into stars, and because they have been systematically observed for over a hundred years, they have been very useful in helping astronomers refine and confirm distance-measuring techniques. The most recent of these was the use of the light echos from the supernova 1987A, and the distance value it produced matched extremely well with distances measured by several other techniques. Through the talk it became apparent that the Magellanic Clouds are fascinating objects, and astronomers still have much to learn through studying them. |
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April 22nd |
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Our members' evening about "The Transit of Venus" started with Jeff, our Observing Officer, giving us a run-down on the night sky around the date of the transit. Then our President, Gilbert gave us a comprehensive talk about the history of Venus transits, from the first scientifically recorded one in 1631 to the most recent one in 1882. He explained the differences in techniques used and the accuracy of the measurements made. Transit observations were important in allowing the dimensions of Venus' and the Earth's orbits to be determined accurately, and thus provided a foundation from which the true scale of the universe could begin to be determined. Greg then gave a short talk on the techniques and perils involved in observing the transit, and Tony wound up the evening by showing us some of his excellent photographs of the Sun and Moon. |
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March 25th |
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In "When the Sun Lost its Spots", Tony Sizer first gave us some basic solar observing tips, went on to explain the main solar features that can be observed, with simple descriptions of the probable physical processes involved. Having described the series of observations that led first to the discovery of the 22 year solar cycle and then to the identification (first by Maunder) of the period of solar inactivity between 1645 and 1715 that's now called the Manuder Minimum, he then took a diversion through the fields of archaeological dating using carbon-14 and tree-ring counting, before bringing us back to the not entirely comfortable realisation that the Sun is quite noticably variable, and that this variability has had significant effects on the Earth's climate at several stages even in historical times. At present the Sun is very active but it is likely that it will become quiet again some day. |
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February 26th |
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Our Annual General Meeting was followed, as is traditional, by a talk from our retiring chairman, Greg Smye-Rumsby. He gave us a talk on "The Craig Telescope". He has been investigating the telescope's history for some time, and has managed to learn quite a bit about Craig and his telescope. He even managed to track down a photograph of the telescope, probably taken after it had fallen into dis-use. His talk was illustrated with computer-generated images of the scope, based on the photograph, known drawings and etchings, and information gathered from the small excavation performed on the site as part of Time Team's Big Dig. There is clearly still more to be learnt about this telescope, so we expect Greg will update us from time to time. |
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January 22nd |
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Our first meeting of 2004 was addressed by Piers Corbyn and was about "The Sun and the Weather". He started by explaining how the Sun's activity could be correlated with global temperatures, and went on to explain how it was possible to make long range forecasts by comparing the current solar cycle, stratospheric wind phase, lunar cycle and Hale cycle with past occasions when the same relative points in the cycles had been reached. He also showed how the method was particularly good at predicting extreme weather conditions like tropicals storms. |
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