Friday, 21 November 2014

Radio Sculpture

A sculpture is a physical representation of an idea, a concept or even a feeling. In many ways, anything we can build becomes a sculpture of our thoughts.

Scott Mitchell is a Sculpture Artist and has many works to his name. As an entrant in the Melbourne Prize for Urban Sculpture 2014, Scott set his mind on a sculpture that would divert our attention to the sky. As a propositional work (for a larger version in Melbourne's Royal Park) he decided to build a working Radio Telescope.

Scott approached the Astronomical Society of Victoria and came along to one of the Radio Astronomy section monthly meetings. We spent several hours helping him understand some of the concepts, the science and the electronics behind Radio Astronomy. We also went over the History and the Pioneers of Radio Astronomy. Eventually Scott decided a Horn Antenna would be most appropriate and sculpturally pleasing.
The Horn Antenna has an opening at the wide end to allow radio waves to enter and funnels the waves down to a receiver element at the narrow end, usually just a short wire that is tuned to the particular frequency of interest. Then it connects to an amplifier to greatly increase the signal level. In Scotts design a receiver normally plugged into a computer to pick up Radio and TV signals is used to receive signals on the Hydrogen Line at 1.420 GHz.
The Hydrogen Line is the frequency where neutral Hydrogen atoms emit radio waves and allow us to see into the Cosmos. Other atoms also emit radio waves at different frequencies but Hydrogen is by far the most abundant element and therefore is the easiest to detect. Scott has named his sculpture 'The Listener' and has thoughtfully provided a pair of headphones as part of the display so that visitors can listen in on the static from the Stars much as Ellie Arroway did in the brilliant movie 'Contact'. The display also has a chart recorder under a perspex cover that draws lines representing the level of radio noise being received. From what I saw, the chart paper is replaced every morning at 10am which will give a permanent record of the two weeks that the display is available for viewing.
I visited the sculpture at Federation Square and took a few pictures. I even chatted with quite a few people that came to find out what it was. Being the friendly and knowledgeable fellow that I am I was more than pleased to tell them. I guess I was happy that Radio Astronomy was on display.