Through the lens: the contribution of Defence scientists to the history of optical glass in Australia
From smartphone screens and optical fibres to Erlenmeyer flasks in the lab, glass plays a significant role in science, and in our everyday lives. But what you may not know is that Defence scientists have made a significant contribution to the history of glass in Australia ... and we've been there from the very beginning.
As Australia's annual celebration of science and technology, National Science Week provides a wonderful opportunity for us to come together to celebrate and acknowledge the significant contributions that Australians have made in the world of science, technology, engineering, and maths (STEM).
This year's school theme for National Science Week is Glass: More than meets the eye, to celebrate the many roles that glass plays in our lives, and to investigate glass as a part of our sustainable future. For Defence scientists in Australia, glass remains crucial to the science, technology, and innovation eco-system in which we work. But Defence scientists also played a major role in pioneering the optical glass industry in Australia.
Pioneering a sovereign optical industry
Optical glass is used to make optical instruments, and differs from regular glass in its transparency, purity, and hardness; it needs to be completely transparent, superbly flawless, AND able to be ground into shape. Its main properties, such as refractive index (a measure of how light propagates through a material), dispersion (the change of refractive index versus wavelength), and transmission (the amount of incident light that successfully passes through the material) also need to be completely predictable and reproducible. Any impurities in the glass, for example, can scatter light rays, reducing the transparency of the glass.
Prior to the outbreak of World War II, any optical equipment needed to provide optical sighting for Australian-manufactured defence weapons had to be imported from overseas. Optical munitions (or optical instruments associated with weapons) are just as important as the weapons themselves – a Browning M2 Aircraft Machine Gun is of little use without the ability to aim it accurately.
In 1938, the Munitions Supply Laboratories (MSL), at Maribyrnong, had begun to establish glass-making facilities to manufacture lens assemblies. At the time, Australia had no optical equipment manufacturing industry, nor any local supply of optical-quality glass, and MSL became the only organisation in Australia possessing any skills in optical technology.
When supplies from Britain ceased with the collapse of France, Australia found itself in dire circumstances when providing optics for its expanding war-time munitions manufacture. The Optical Munitions Panel (OMP) was formed, in June 1940, bringing together university-based scientists, representatives from government laboratories, and the armed services, to assist organisations and industries involved in the optical munitions effort. Senior Physicist Eric Loxton Sayce from the Munitions Supply Laboratories was there from the OMP's inception and, along with Herbert John (Jim) Frost, Norman Abraham Esserman and John James McNeil, was integral to MSL's involvement in the optics industry. The first optical glass was produced in Australia in December of that year, demonstrating a new sovereign capability that was vital to the success of Australian defence production during World War II.
The production of optical glass requires a high-grade, iron-free source of silica (sand), along with various mixtures of oxides to produce the desired optical properties. As a country rich in natural resources, most components required for production could be sourced locally, including aeolian sand and calcite from New South Wales, zinc oxide from Tasmania, and lead oxide and sodium carbonate from South Australia.
All in all, forty-three different types of optical instruments (and more than 26,000 individual objects) were produced for the war effort in Australia, including angle of sight instruments, periscopes, telescopes, range finders, parabolic reflectors, stereoscopes, camera lenses and prisms, spirit and optical levels, theodolites, collimators, glide path indicators, reconnaissance and flash spotting instruments, just to name a few.
The OMP became the Scientific Instruments and Optical Panel near the end of WWII in an attempt to widen and continue their work after the war, however the government decided that an optical industry was not viable and withdrew its support despite the enormous industrial and scientific successes. However, the success of the OMP helped demonstrate the practical value of science to government and the military.
Using glass to understand human decision-making
These days, glass is still vital to Defence science, technology, and innovation. From flow visualisation in tempered-glass water tunnels to combining diamond with glass to create a new quantum sensor, glass supports many of our vital technologies.
For Dr Alexander Kalloniatis, a military command and control expert and 2021 recipient of the Defence Minster's Award for Achievement in Science and Technology, understanding how glass works at the atomic level was crucial in finding solutions to the problem of synchronisation of decision making in human organisations.
"Coming from academic theoretical physics where my natural language for understanding nature was Quantum Field Theory, I struggled through the summer of 2005-6 to identify what toolset to bring to bear on 'Command and Control'," said Dr Kalloniatis.
Since Complex Systems Theory was already being considered in this space, Dr Kalloniatis looked at the phenomenon of 'Spin Glasses' – a theoretical approach to understanding how glass works at the atomic level, as an extension of the physics of crystals and magnetic systems.
"Eventually I chanced upon a beautiful model for synchronisation of oscillators on networks – which I was able to translate into the problem of synchronisation of decision making in human organisations. So, the model I have developed over the last 17 years sees Command and Control between two adversary systems as a form of very dynamical 'glassy' system." Dr Kalloniatis also pointed out that, fittingly, "the Nobel Prize for Physics in 2021 was awarded to Giorgio Parisi for the development of some of the theoretical tools to precisely understand Spin Glass systems."
The uses for and intrinsic nature of glass in science make it an important theme for National Science Week this year. And a big shout out to the glass-fibre cables that underpin the internet for bringing you this online story.