10 September 2018
Speaker at our meeting of 14th September was Prof Eric Priest FRSE, FRS: mathematician and Emeritus Professor at St Andrews University. He took as his topic ‘The Sun’.
Professor Priest is a recognised authority in solar magnetohydrodynamics - the study of the interaction between the Sun's magnetic field and its plasma interior. Admittedly not a subject that is much discussed in Rotary circles - but we were treated to the most fascinating, entertaining, wonderfully enthusiastic and humorous - illustrated tour de force about this centre to our part of the universe.
Profound concepts were effortlessly explained, as we learned about our ionosphere, about plasma, sunspots, granulated and tubular magnetic fields, several million degree temperatures in the Sun’s corona and supersonic solar winds.
Photographs by spacecraft of the Sun’s surface and photosphere were stunning, where movement and flares could clearly be seen to be shaped by the Sun’s magnetic field. Terrestrial pictures taken during a full eclipse were also impressive with flares visible at the Sun’s surface. Prof Priest spoke of his expedition to Egypt (complete with a most impressive photograph of he and his wife riding a camel and with pyramids in the background!) to see a total solar eclipse. He described the increasing darkness, cold, sharpening shadows and then, in the last ten minutes, a view of all the planets in a line.
We heard that solar flares take one or two days to reach Earth whilst ‘fast’ particles cover the 93 million miles in an hour. This gives us the majestic ‘Northern Lights’ spectacle - but can also disrupt spacecraft, satellites and electronic equipment on Earth.
We learned too something of Prof, Priest’s current work interest in magnetic instabilities, magnetic waves and the conversion of magnetic energy to heat.
Altogether we were privileged to enjoy a stimulating and exciting talk, where ‘profound’ feels like an understatement. Following many questions, an appreciative vote of thanks was proposed by club member Ian Kennedy.