Guildford Astronomical Society

John Lancashire

John Lancashire BSc ACA
John graduated in Mathematics from Bristol University, where he studied general relativity and quantum mechanics in his final year. Torn between an academic career or a life in business he chose the latter, although he always retained his enthusiasm for science and mathematics.
He spent many years working in IT for international companies as a software designer, risk manager and programme director. He retired 3 years ago.
His interest in the Antikythera Mechanism was sparked back in 2006 and he has been following the developments and research ever since.
In his project to create a modern reconstruction of the machine he's bult on his expertise in computer aided design and learnt much about modern manufacturing and prototyping techniques.
He believes the Mechanism is a fascinating instrument which still has relevance and value today. Although a small number of bronze reconstructions of the Mechanism have been built by researchers, these are all now sitting in glass cases in museums. People cannot see the engineering inside or explore the functionality of the machine. Hence his aim has been to bring the Mechanism to life by creating a version using modern materials which can be reproduced in small numbers. He would like people to be able to "get inside" the mechanism, understand how it works and actually use it in real life.
DateTalk at GAS meeting
7 Feb 2019The Antikythera Mechanism

I’ll start by explaining the history of the early loss of the Mechanism in around 70BC, and then its discovery in 1900AD by Greek divers. I’ll show how the recent research and X-rays have revealed far more about the construction of the Mechanism and its purpose.
Then I’ll work my way through the Mechanism, explaining the astronomical theories behind each part of it and showing, with the aid of videos, how the theories have been implemented and how the instrument works. I’ll also identify some of the engineering challenges the Ancient Greek craftsmen must have faced.
As part of this I’ll describe with the aid of a timeline the key steps in the development of astronomical theories in the Hellenistic era during the period from 500BC through to the time when the Mechanism was lost. I’ll describe the thinking behind their first models of the Universe and how they evolved over time.
I’ll then demonstrate how my version of the complete Mechanism works and illustrate some of the challenges associate with calibrating it for the present day.
Topics which will be covered include:
1. Astronomy in the ancient world and the need for a “Calendar Computer”
2. How the Mechanism predicts eclipses
3. The first Lunar Anomaly
4. The apparent motion of the Sun from a Geocentric perspective
5. The motions of the Inferior planets
6. The motions of the Superior planets

To see the handout from John's presentation here [PDF: 432Kb, Members only].