Ninth Lunchtime Rendezvous of the Seniors Group in Glasgow
The ninth Lunchtime Rendezvous in the Melville Room, Gilbert Scott Building, University of Glasgow on Tuesday 24 January 2012 had a capacity attendance of 24 Members and Guests.
The lecture From spectres to meteorology and particle physics – on the life and work of C. T. R. Wilson was given by Mr Jim Jamieson, Senior Associate, Scottish Schools Equipment Research Centre, Dunfermline.
Mr Jamieson gave an interesting account of the development of the cloud chamber by C. T. R. Wilson. Initially, Wilson was interested in the natural phenomena, such as the glory, a colourful optical phenomenon consisting of concentric rings, and electricity in thunderclouds, which he observed while staying at the Ben Nevis Weather Observatory. He was determined to reproduce some of these phenomena back in the Cavendish Laboratory at Cambridge for fuller study.
In order to simulate the production of a cloud, he rapidly reduced the pressure in a flask containing water by suddenly connecting it to a previously evacuated much larger flask. He realized at the beginning of his experiments that either dust particles or ions were needed to initiate the formation of a cloud.
Wilson determined that an expansion ratio greater than 1.252 was necessary for condensation. He progressively refined the construction of the cloud chamber, progressing from the original spherical form to a cylindrical form in order to facilitate the photography of the clouds.
When he irradiated the cloud chamber with alpha and beta particles he was able to produce a photographic record of their tracks. Amongst his many achievements he was able to make an estimate of e, the electronic charge.
Ms Marjory Gibson Roy, Formerly Superintendent of the Edinburgh Meteorological Office, presented the lecture The Ben Nevis Weather Observatory, 1883-1904.
This lecture involved an examination of the history of the Ben Nevis Weather Observatory set up by the Scottish Meteorological Society in 1883 until its closure in 1904.
The observations, which were published in full in the Transactions of the Royal Society of Edinburgh, provide the most complete set of mountain weather data in the UK. Comparison observations were made at sea-level at Fort William.
From 1890 hourly observations were made using photographic recording instruments at a purpose-built observatory at Fort William.
Manual recording had to be used at the summit of Ben Nevis because of the severe icing conditions.
C. T. R. Wilson's brief period as a relief observer in 1894 led to laboratory research on clouds and eventually to the Wilson cloud chamber.
Several excellent photos were shown of the Observatory being covered in ice and snow during the winter.
A dramatic account of extreme observing conditions was given by Angus Brown on the 26th of June 1883 “The wind began to blow at force 10. I had three times to lie down and take hold of stones until the squall had passed”.
A brief visit to the Chapel was then followed by a four course seated lunch with fine wines and waitress service.
The ninth Lunchtime Rendezvous in Edinburgh is to be on Wednesday the 21st of March 2012 at the Clubhouse, Daniel Stewart’s and Melville College, Inverleith Playing Fields, 525 Ferry Road, Edinburgh.
The fifth Lunchtime Rendezvous in Aberdeen is to be held in the Aberdeen Maritime Museum on Friday the 26th of October 2012.
Full details, including booking forms, menus and prices will be published under the Seniors’ Section heading on the IOPS website and will also be sent by e-mail to all Senior Members who have an e-mail address and by mail to those without an e-mail address in the Edinburgh and Aberdeen areas, respectively.
Suggestions for lecture topics and speakers for the Lunchtime Rendezvous of the Seniors Group are always welcome.
For further information, please contact
Dr John Higinbotham, CPhys, FInstP, FAIP
Seniors Group Coordinator
The Institute of Physics in Scotland
12 (1F2) Bruntsfield Gardens