Lecture by Paul Hill – “Fred, Carol and John and the birth of modern astronomy”

Paul Hill with his later explained ironic opening slide!

Paul Hill with his later explained ironic opening slide!

What do have the following in common? Uranus, the moons of Saturn and Uranus, Planetary Nebulae, Asteroids, Mars’s atmosphere, polar ice caps and rotational period, and Infra-Red light.
 
Answer – they were all discovered by a Herschel. Specifically William Herschel (1738-1822), his sister Caroline (1750-1848) and William’s son John (1792-1871) – their lives covering a period of 133 years during a critical and burgeoning period of scientific curiosity, innovation and discovery.
 
Paul Hill’s lecture, given in his usual humorous, illuminating and authoritative style, followed the lives of these three pioneers. Starting with William who started as a musician (he wrote 24 symphonies for example) Paul described how William Herschel made a career change to astronomy. He found his first encounters with the subject unsatisfactory because of the poor quality of the telescope he was using which led him to develop and build his own off-axis Herchelian instrument. Indeed he went on to build about 60 telescopes (and the multiple speculum mirrors for each one!) which became recognised as the best instruments in the world at the time – judged so by no less than the Astronomer Royal at the time, Nevil Maskelyne.
 
And none of his work would have been possible without the dedicated support of his sister, Caroline. Not only did she attend to all the domestic matters in their house in Bath (including feeding William while he ground his mirrors!), she also became William’s note-keeper during his observing sessions and mathematical workhorse after that to plot and position all the new objects they had found. Paul Hill contrasted their output with that of Charles Messier whose one hundred and ten Messier Objects have earned such repute: William and Caroline Herschel between them catalogued over 2,500 objects!
 
William gave Caroline a telescope of her own in 1783 and she went on to make an independent discovery of M110, eight comets, eleven nebulae and, at her brother's suggestion, updated (and corrected!) Flamsteed's work detailing the positions of stars. William became George III’s Court Astronomer earning a salary of £200/year; Caroline as his assistant earned £50/year – as far as we know, the first paid female scientist!
 
John Herschel, William’s son, followed in their footsteps – his mathematics so good that he became a Senior Wrangler at Cambridge University. He was a polymath, mathematician, astronomer, chemist and an early developer of photography. He named seven moons of Saturn and four of Uranus. He investigated colour blindness and the chemical power of ultraviolet rays; he described an inductive approach to science (experiment and theory building) which became an important contribution to the philosophy of science. His wife, Margaret, was a botanist and together they visited South Africa where she studied the flora of the region whilst he mapped the southern skies.
 
During their lives, the “Herschel Dynasty” as Paul Hill dubbed them, listed over 5,000 astronomical objects between them. This formed the “General Catalogue of Nebulae and Clusters of Stars” – the precursor of the New General Catalogue (NGC) that we all use today.