On the 29th December 2022, there was an opportunity to see a planetary phenomenon which will not happen again for eighteen years. (Too bad if you missed it.)
‘The planets of the solar system were lined up in the sky Wednesday night in an astronomical phenomenon, visible from Earth, known as a “planet parade.” ‘ https://www.cbsnews.com/news/every-planet-solar-system-visible-rare-planet-parade
Mercury, Venus, Mars, Jupiter and Saturn were all visible with the naked eye and Uranus and Neptune could be seen with a pair of binoculars. Fancy astronomical equipment was not needed.
There have been several opportunities for seeing stars at RMS. None of them involve knock-out punches but some of them do involve fancy instrumentation. Perhaps the most obvious is by using the Planetarium and the Observatory. Then there are more esoteric ways using an armillary sphere or an orrery.
An orrery is a mechanical model of the solar system. It is believed that the first one produced beyond ancient history was presented to Charles Boyle, 4th Earl of Orrery, which is how the name came to be applied generically.
They were used to represent the movement of the planets relative to the sun (heliocentric model) and the planets could be made to move by mechanical means to show their relative orbits and the orbits of various planetary satellites.
In the past, the School housed an orrery. It was a fascinating device which could be read by those who knew how and was totally baffling to everyone else.
The School has another method for seeing stars in the form of an armillary sphere in one of the Quads. Many armillary spheres are now used ornamentally or have a central rod acting as the gnomon of a sundial. The one at RMS does not. There is a sundial at the School but it is not near the armillary sphere.
The design. very much in keeping with the art nouveau/art deco period of the School’s architecture, this particular image is doing its own little skip in time as the young lady standing looking at it is in a photograph which predates 1970. If it were not, she would be encased in a wall in the Library/Resource Centre!
Apparently G A White was nicknamed ‘Geoger’ White presumably because he taught Geography but when spoken aloud, it sounds like Jogger White, thus presenting an entirely different mental image!
There are two kinds of armillary spheres: Ptolemaic and Copernican. The Ptolemaic view of the universe (after astronomer and mathematician Claudius Ptolemy of Alexandria) was that the earth was stationary at the centre and everything revolved around it. This was the belief from antiquity until the middle of the 16th century. The original geocentric design could be used ‘not only to model the movements and relative geometry of the heavens, but to carry out all sorts of calculations, such as the times of sunrise and sunset, the length of a day, and the altitude of the Sun or stars.’ https://www.hsm.ox.ac.uk/armillary-sphere authored by Chris Parkin – Secondary Education Officer
Then the Polish mathematician Nicolaus Copernicus – the Copperknickers name so beloved by schoolchildren everywhere – began to challenge the geocentric idea of the universe.
Presuming that the symbol in the centre is a stylised sun, it means that this is a Copernican sphere.
‘An armillary sphere such as this one might well have been used for education, aiding understanding of the 3-dimensional geometry of the celestial sphere …’ Adam Mosley, ‘Armillary spheres and teaching astronomy’, 2006 https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/astronomy/armillary-spheres-and-teaching-astronomy
An astrolabe is a hand held device which performs a similar function. Geoffrey Chaucer compiled A Treatise on the Astrolabe for his son so we have to assume that he understood its workings, unless it was just making it up as he went along on the basis that no-one would know what he was talking about anyway.
‘A Copernican armillary sphere generally illustrates the revolution of planets (and asteroids) within the solar system with a central sun sphere surrounded by concentric planetary’ from https://www.georgeglazer.com/
Slightly larger in size than the armillary sphere is the planetarium standing next to the Science block. This was erected as part of the new development in the late 1960s. Planetaria generally have domed roofs and these do not open whereas the roof of an observatory does. On this basis, the Building Committee minutes of March 1968 stated that the planetarium was to be in a separate building and the Observatory would be on the roof [of the new building].
The observatory is indeed separate to the Planetarium and has a retractable roof operated manually, allowing for either side to be open to access the night sky.
It houses a telescope, upgraded fairly recently, with which to view said night sky.
‘It was agreed that a Planetarium be included on the site plans and on the detailed specifications as it was thought that to fulfil present and future requirements, a Planetarium was essential’ (Minutes of Building Committee 1968)
Almost a year later (Feb 1969), presumably after someone totted up figures on the back of an envelope and realised with a jolt just how much everything was costing, it was decided that those costs were escalating beyond reasonable levels and savings were needed. The planetarium, at a construction cost of £12,000 containing equipment worth £5,750, was an obvious contender for the Chop. Possibly what saved it was not the declaration that ‘it was essential’ but the fact that just that one month earlier, an order had been placed with Messrs C Z Scientific Instruments for one Zeiss Jena Medium Planetarium. Slightly embarrassing to say now ‘Um? Could you cancel that?’ In today’s terms, the costs don’t sound great but they were the equivalent of almost £50,000 in today’s money so a substantial whack. It took a ‘Special Committee’ to overrule the nervous spenders and give the go ahead for the planetarium.
Interestingly, at the height of the Cold War, the scientific equipment necessary for the School’s planetarium came from East Germany. The Zeiss firm, like the country surrounding it, was split into two after WWII. Part of it remained in what was then called East Germany at Jena. Whilst the West German part of the company concentrated on large planetariums, in Jena, they were manufacturing the equipment for smaller planetariums. So not only on size but also by the fact that Jena was part of the name of the equipment, we surely have the understanding that the ‘gubbins’ came from beyond the ‘Iron Curtain’.
The planetarium has been serviced recently, with the ceiling re-painted and water leaks fixed in 2022. Updating the equipment to something digital would require a major injection of money and there are always demands on a limited supply although it would make use of the planetarium a lot easier: one button, press play …
A planetarium is, in effect, a theatre for showing the stars and constellations, projected onto the inside of the domed roof acting as a screen for whatever is being projected.
‘… stars, planets, and other celestial objects can be made to appear and move realistically to simulate their motion.’ (Wikipedia)
Like with so many things, one does not often stop and consider the how of these matters. Apparently, one of the most difficult aspects of construction of a planetarium roof is to make its seams invisible (not many seams in the sky, generally speaking.) Not only that, but it has to be painted after its construction. Ask Michelangelo what it’s like painting a complex ceiling.
Traditionally, planetarium domes were mounted horizontally, matching the natural horizon of the real night sky.
This does require highly inclined chairs for comfortable viewing if one is to avoid a severe crick in the neck. (Ask Michelangelo.) Either that or one lies on the floor. However
‘… increasingly domes are being built tilted from the horizontal by between 5 and 30 degrees to provide greater comfort’ (Wikipedia)
The Observatory and Planetarium means that GCSE Astronomy can be offered on the RMS curriculum so pupils can study such things as using star trails to measure Sidereal Day or finding the mass of an Exoplanet from Radial Velocity or studying Kepler’s 3rd Law. Apparently.
‘Historically, the word “planetarium” was used to describe what we now call an orrery, which is a mechanical model of the solar system.’ https://www.yhc.edu/academics/math-science/rollins-planetarium/faq-general-information.
So if a planetarium is an orrery and an orrery is a planetarium and an armillary sphere can be used as a sundial but not vice versa, it’s not really surprising we’re all seeing stars.
RMSG History Extra 