CTR Wilson, the Ben Nevis Observatory, Cosmic Rays

The May, 2003 issue of Astronomy Now magazine included an article I wrote on CTR Wilson, the Ben Nevis Observatory (BNO) and Wilson's role at the inception of the study of cosmic rays. People in various parts of Scotland have heard me speak on these topics, or come across our Cosmic Way roadshow. Here are some resources and links that may interest anybody who enjoyed that story.

Resources I made

• Here's a slightly different retelling of the Wilson/BNO/cosmic ray story, a little bit lengthier and more 'popular', as well as much plainer looking (pdf format).
• Ben Nevis (flat summit to the left) and Carn Mor Dearg from the south: (click for a bigger version).
• Electron cloud chamber tracks may be simulated using almost the method that Ian Craig and I described, for a different purpose, in 1991 (paper). Here's a little movie (animated GIF - 2.2 MB) showing simulated tracks of 25 electrons. They all start out travelling vertically upwards, with the same speed, but each has a unique history of collisions with atoms and they follow increasingly different paths as they slow down. The colours don't mean anything, they just make it easier to see the separate paths.
• Wilson spent his first few years at the foot of Castlelaw
• in a certain sense the first ever experiment in cosmic ray physics was carried out in a railway tunnel near Peebles

Wilson and cloud chamber

• The Institute of Physics places blue plaques to commemorate the lives and work of well-known physicists. There is one for Wilson, at Flotterstone in the Pentland Hills, a short distance from his birthplace.
• Wilson was inspired to study the formation of water droplets in air by seeing the Brocken Spectre from Ben Nevis' summit while working at the Ben Nevis Observatory in September, 1894. Glories, the Brocken Spectre, and a host of other glows in the sky are beautifully illustrated and discussed in Les Cowley's website devoted to Atmospheric Optics.
• Wilson conceived and perfected the cloud chamber at the Cavendish Laboratory in Cambridge University. Cambridge has put excellent physics outreach resources online, including a section devoted to the cloud chamber with some original Wilson cloud chamber photographs.
• The Nobel Foundation has an excellent website with lots of information about all Nobel Prize winners. The autobiographical notes by more recent winners alone are fascinating. Wilson was awarded the Nobel Prize in Physics in 1927 (shared with A H Compton), and the page for that year includes a biography and his own Nobel Lecture, an overview of the development and employment of the cloud chamber told in a very nice narrative style.
• Also present there is the text of the short, charming speech he made at the Nobel Prize banquet. This seems to me to encapsulate key, distinctive aspects of his story: penetrating insights rooted in a love of the natural world, the role of accidents of place and personality in science. The 'other Scottish hill' he mentions was Carn Mor Dearg, Ben Nevis' eastern neighbour, and this incident took place in the summer of 1895.

Cosmic rays

• Anybody interested in science and its progress will find lots to interest them on the Nobel Foundation site, but for present purposes we should of course highlight Victor Hess, the Austrian scientist who first demonstrated the existence of penetrating radiation from the wider cosmos. Hess shared the Physics Nobel Prize in 1936. A biography of Hess is available at the website of the HESS project, a present-day cosmic ray experiment.
• NASA website devoted to cosmic rays with lots of news items, topical articles, etc.: Cosmicopia

Ben Nevis and Observatory

• The Scottish Antarctic explorer William Speirs Bruce spent some time on the summit of Ben Nevis, evidently in much harsher, winter conditions than those Wilson would have experienced. A website devoted to Scotland and the Antarctic includes a page briefly telling the story of the BNO.
• Ben Nevis is now owned by the John Muir Trust. Their website includes a section devoted to Ben Nevis.
• Marjory Roy's book, Weathermen of Ben Nevis tells the tale of the BNO very nicely, making excellent use of contemporary photographs. It used to be available directly from the website of the Royal Meteorological Society but seems to have disappeared. Second-hand copies are available on Amazon.co.uk but at significant expense. I'm amazed this valuable book would go out of print!

'Wider culture'

• Little Earth, a project of London Fieldworks, combined twinning ceremonies between Ben Nevis (Scotland) and Mount Haldde (Norway), and a video installation premiered in London in January 2005 and subsequently shown in Fort William. Mount Haldde was the site of another mountaintop observatory, established by Kristian Birkeland for the study of the aurora. The rather tragic tale of Birkeland and his observatory are told in Lucy Jago's book, The Northern Lights. This interview with her gives a nice peek at the book and story. Little Earth uses these two contrasting characters, their key locations and achievements to 'create an audio-visual poem reflecting upon how the "last of the natural philosophers" became the first of the big scientists.'
• A curiosity perhaps, in this context, but one that I at least enjoy: the American composer Harry Partch invented many new musical instruments to support his microtonal music, constructed in a 43-tone scale that implements just intonation. Cloud chamber bowls used tops and bottoms cut from large Pyrex flasks, intended originally for use in the construction of cloud chambers in the Radiation Laboratory of the University of California (now Lawrence Berkeley National Laboratory). More on Harry Partch is at Corporeal Meadows and also a page on cloud chamber bowls particularly. One website even lets you play a set of cloud chamber bowls.