General Meeting: Speaker: Chris Mathews

On the 3rd Tuesday of the month (February to November) at 7:30pm, we meet on zoom or at Regis Hall in the grounds of St Ignatius’ College, Riverview Street, Riverview (Lane Cove) which features a presentation from a Guest Lecturer. These presentations generally focus on the theoretical aspects of Cosmology, Astrophysics and Astrophotography and can include some of the most up-to-date research and scientific findings. We are fortunate to be able to obtain speakers from Australia’s top universities and scientific community – our past Guest Lecturers have included the likes of Dr Fred Watson and Nobel Prize winner Prof. Brian Schmidt. Our speaker this month is Chris Mathews from Western Sydney University who will be talking on the following: "More accurately than Others: Eratosthenes and the Circumference of the Earth".

SYNOPSIS: In the third century BC, the Greek Polymath, Eratosthenes – then chief librarian of the Great Library of Alexandria – attempted to calculate the circumference of the Earth based upon observations of the Sun, the shadows cast by the solar light, and the distance between two locations in Egypt. Debate has raged ever since Eratosthenes undertook this experiment over how accurate his results were. This presentation will delve into this mire of scholarly debate, present new evidence and new understandings, and demonstrate that Eratosthenes was one of the first hyper-accurate observers in the history of astronomy.

The format of the evening consists of a welcome to Members and Visitors, a quick discussion on general business of NSAS, the presentation from our Guest Speaker and then members usually stay and have a chat with a cup of tea or coffee.

These meetings are an excellent opportunity to get to know fellow members.