ABC Wednesday O is for Orrery

This orrery was made in London in 1767 by Benjamin Martin and was used to teach astronomy at Harvard University. It is on display at the Putnam Gallery in the Harvard Science Center.

Image courtesy of Wikimedia Commons

An Orrery is a mechanical model of the solar system. Notwithstanding problems of scale it can be a useful tool in teaching children the relative positions of the planets. Orreries are also very beautiful. Brian Greig, in Victoria, Australia, recreates historical orreries and other scientific instruments and accepts commissions to make bespoke models. His site can be seen here.Until the 16^th century the unquestioned commonly and religiously held belief was that the earth was the centre of the universe and the sun, planets and stars revolved around it. Heaven was a fixed place and perfect. Any other opinion was considered to be heresy.
The Polish astronomer and mathematician Nicolaus Copernicus (1473 – 1543) posed the theory that the earth and other planets in the solar system orbited the sun.
Copernicus' view was promulgated by the German mathematician and astronomer Johannes Kepler (1571 – 1630)
Galileo Galilei (1564 -1642) the Italian philosopher, mathematician and astronomer, also supported the Copernican theory, but was accused of heresy by the Roman Catholic church and forbidden to advocate it. He remained under house arrest for the last ten years of his life for refusing to revoke his belief in the theory.

Orrery in the Vatican Museums

Image courtesy of Wikimedia Commons

The first model of the solar system was made about 1704 by George Graham (1674 – 1751) who was a renowned clockmaker. His tomb is in Westminster Abbey. An instrument maker called John Rowley made a copy of the model for his patron, Charles Boyle, 4^th Earl of Orrery. Henceforth any such model would be known as an Orrery.However, in the first century BC Cicero claimed that the Greek philosopher Posidonius, had built an orrery showing the daily movement of the sun, moon and five known planets. It may have resembled the Antikythera mechanism.

Main fragment of Antikythera Mechanism - probably the first known orrery

Image courtesy of Wikimedia Commons

There is a Human Orrery at the Armagh Observatory in Northern Ireland.
The University of St Andrews has an Electric Orrery showing the inner and outer solar systems.Thank you to Denise Nesbitt and her merry band for their work in organising and hosting this meme. To see more Os – and perhaps join in – please click here.