July Lectures in Physics

Scientists sometimes need to go to extreme lengths to find answers about the cosmos. This is exemplified by the new Stawell Underground Physics Laboratory (SUPL) located a kilometre underground in regional Victoria. The motivation for SUPL began with the surprising discovery in the 20th century that ordinary matter makes up less than 5% of the mass of the universe. The rest of the universe appears to be made of a mysterious, invisible substance named dark matter (25%), and a force that repels gravity known as dark energy (70%). So far, neither has been directly detected, though physicists know dark matter must exist because of its gravitational effects on galaxies and other astrophysical phenomena. Finding dark matter requires a very sheltered environment deep underground – far from cosmic ray-induced particles – to observe deep space phenomena far below the surface of Earth: this is what SUPL provides. Creating this new underground lab as an extreme project, which now provides the home for the SABRE South experiment: a new detector designed to catch the rare dalliances of these elusive cosmic messengers with ordinary matter. From the depths of a mine shielded from cosmic rays, we will get a glimpse of one of the deepest mysteries of the universe.

In Melbourne’s southeast, a powerful particle accelerator is generating beams of light a million times brighter than the Sun. Scientists from all over the country travel to this accelerator, the Australian Synchrotron, to use this light in their research. In this lecture, we will explore the brilliant world of synchrotron light and its applications to studying crystals. From deciphering the structures of complex molecules to conducting life-saving medical research, synchrotron light can illuminate nature’s secrets.

The evolution of the very early universe is described by quantum mechanics and particle physics. The first moments after the big bang saw the creation of an asymmetry between matter and antimatter, the production of dark matter, and the formation of light elements in ‘primordial nucleosynthesis’. This lecture looks at the way quantum processes created the matter in our universe.

Quantum computers are beginning to emerge from decades of development in physics research labs around the world – prototypes are here, and you can access them via the cloud. But what are they, and what are they good for? To answer these questions we will take a brief tour through the world of quantum computers – covering their origins, current status and outlook. The talk will be augmented by quantum programming examples, both in a simulation environment and on physical quantum computer systems.

Quantum chemistry had humble beginnings - in 1927 quantum mechanics was applied to chemistry for the first time, to describe the chemical bonds of the hydrogen molecule. Since then, advancements in quantum chemistry has gone hand in hand with advancements in computing. By the 1990s quantum chemistry methods could solve problems from thermodynamics and kinetics of chemical reactions to excited states of biological systems. The arrival of petascale computing has resulted in an explosion of studies to understand the properties of organic,  emiconductor and metallic materials used in our everyday life. We now have quantum chemical software that solves the Schrödinger equation for chemical systems consisting of nearly half a million atoms… a mighty achievement almost unthinkable a few decades ago.

It is hard now to imagine that before the 1930s, the source of the Sun’s power was not known for sure. After the reveal of mechanism of thermonuclear fusion, prospects for controlled fusion as a source of power on Earth were proposed, but the main nuclear reaction in the Sun uses the weak nuclear reaction and this is too feeble for an engineered reactor. This lecture looks at the prospects for a breakthrough and the role of quantum mechanics that may provide new insights to address the difficult challenges. Lecture dedicated to the memory of Prof Tony Klein.