Free Astronomy Public Lectures

Presented by Dr Thomas E. Collett on Tuesday 14 November 2017.

Einstein's theory of general relativity predicts that light rays are bent when they travel past a massive object. In this talk, we will explore tests of this prediction and view some of the spectacular consequences of light bending: gravitational lenses. These gravitational lenses let us directly measure where the mass is in the Universe, and the results imply that the Universe is mostly made of an exotic substance called dark matter.

Presented by Dr Tiantian Yuan on Friday 29 September 2017.

One of the most prominent features of galaxies today is the manifestation of elegant spiral arms. We live in a beautiful grand-design spiral galaxy called the Milky Way. Our Solar System, including the Earth and the only life that we know, lies within the Orion spiral arm of our Milky Way galaxy. However, as we look back in time to the very early Universe, the frequency of spiral galaxies decreases dramatically. In fact, most galaxies in the distant past are messy and irregular in shape. Why is it so? When was the first appearance of spiral arms? How were they formed? In this talk, I will take us 11 billion years back in time through the distorted space surrounding nature's most massive structures. We will get a glimpse of earliest onset of spiral arms and directly witness the formation of a spiral galaxy that could later be home to billions of stars and planets like our earth.

Presented by Igor Andreoni on Friday 20 October 2017.

The ancients considered the Universe unchanging, and had a special name for the planets, which they regarded as “wanderers”. Any changes in the night sky were seen as portents of doom – and a reason to fear the Gods. The advent of modern astronomy means that we no longer fear changes in the night sky, indeed some of us make our living from them! In this lecture I will tell you the story of the modern transient sky, where stars live and die in spectacular explosions and amazing instruments such as the LIGO and Virgo gravitational wave interferometers probe the darkest depths of the Universe. The discovery of gravitational waves was awarded the Nobel Prize in Physics this month and has the power to reveal a plethora of new science from the merger of black holes and other exotic stars.

Presented by Prof. Patricia Vickers-Rich on Friday 7 July 2017.

We have been plotting the history of life around the world and climate over more than 1 billion years. Tonight we will zero in on a time when the Earth's first animals came into the picture - at a time when the planet was in the grips of a massive glaciation, Snowball Earth - which is likely better named Slushball Earth.

Presented by Dr Rebecca Allen on Friday 12 May 2017. Galaxies are the largest structures of matter in our Universe. Our own Milky Way has been studied in glorious detail. We know it has billions of stars, around most of which planets are likely to be found. There is a super massive black hole at its center where anything that gets too close will be consumed. There are intricate dust lanes that obscure the main disk of the galaxy. There is the life-force of stars, hydrogen gas. Finally, there is the mysterious dark matter that acts as a gravitational glue holding the ordinary matter together. But our galaxy is just one of many, and since their discovery, understanding how these complex objects form and evolve has been a focus of astronomers. There are many pathways to reveal more about the nature and evolution of galaxies. In this talk, Dr Rebecca Allen from the Centre for Astrophysics and Supercomputing, will share how she uses the sizes of galaxies to understand more about their growth.

Presented by Dr. Themiya Nanayakkara on 21st April 2017.

Over the last century, our understanding of the Universe has grown by leaps and bounds whilst posing new questions and testing our very fundamental knowledge and understanding of things around us. To answer these profound questions, scientists are planning ever more ambitious projects driven by human curiosity, to explore the unknown and comprehend our place in the vast senseless space. The Australian federal government in 2016-17 provided AUD 10 billion in support of science research and experiment development while NASA and ESA combined, plans to invest USD 25+ billion in 2017. Why is it important for governments to spend substantial amounts of money in fundamental science research? What are the benefits for the average tax payer, from governments investing billions of dollars into space science? How has our everyday lives been influenced by such investments? Together we shall discuss and explore how our investments in science has improved our way of living, and what the future may hold in store for us.

Presented by Assoc. Prof. Emma Ryan-Weber on 10 February 2017.

The whole Universe was in a hot dense state, then nearly 14 billion years ago expansion started. Wait... is the Bang Bang true and how do we know? In this talk Associate Professor Emma Ryan-Weber from the Centre for Astrophysics and Supercomputing will describe the observational evidence for Big Bang Cosmology and how it sets the initial conditions for every atom in the Universe. The talk is especially suitable for year 11 teachers and students studying VCE Physics Unit 1, area of study 3 "What is matter and how is it formed".

Presented by Dr. Tyler Bourke on 24th March 2017.

Australia is part of an international effort to build the World's largest radio telescope, the Square Kilometre Array (SKA). In fact, one of the two telescope arrays that make up the SKA will be built in the Western Australian outback near Murchison, about 800 km NNE of Perth, a remote area almost devoid of people, but already the location of two advanced radio telescopes. The other SKA telescope array will be in a similarly isolated location in South Africa. The telescopes of the SKA will provide more than an order-of-magnitude increase in performance over existing radio telescopes, to for example: address fundamental questions on the history of our Universe and the emergence of the first stars and galaxies ; detect the merger of super-massive black-holes at the centres of galaxies through their gravitational waves, and use these events to test Einstein's theories ; detect powerful bursts of radio emission whose origin and nature remain controversial.

On September 14, 2015, gravitational waves from the merger of two black holes rippled through the Laser Interferometer Gravitational-wave Observatory (LIGO). The measurement of these ripples would ultimately lead to the first direct detection of gravitational waves, the first observation of a binary black hole, and the birth of an entirely new field of astronomy. In this talk, Dr Eric Thrane from Monash University, will trace the history of gravitational waves from Einstein to the LIGO detection. Dr Thrane will describe how LIGO works and how we are using it to learn about black holes and other interesting objects. He'll also discuss the future of gravitational-wave astronomy in Australia and around the world. Presented on 16 December 2016.

Presented by Prof. Darren Croton on 21 October 2016.

Black holes are among the most bizarre objects predicted by Einstein's theory of General Relativity. Many people may not realise that our own galaxy hosts a supermassive black hole at its centre that is three million times more massive than our own Sun! In this talk Professor Darren Croton from the Centre for Astrophysics and Supercomputing will discuss the physics of black holes and their formation, how they can grow to become so massive, active black hole "quasars" in the distant universe, and the unexpected impact that a supermassive black hole can have on the evolution of an entire galaxy. Professor Croton will finish by side stepping into the exotic world of wormholes, the black hole's tormented cousin

Presented by Prof. Matthew Bailes on 30 September 2016. Almost 50 years ago Jocelyn Bell built a new telescope with her supervisor Antony Hewish that had an unusual property: it had high time resolution. The radio sky was thought to only change on long timescales but this new telescope's ability to explore a different regime of phase space meant that it made one of the greatest discoveries in astronomy, that of pulsars. Pulsars are neutron stars, the collapsed cores of once-massive stars. They have been used to perform some of the most accurate experiments in physics, and were the motivation for the construction of the LIGO telescope that recently discovered gravitational waves. In this talk Professor Matthew Bailes will explain how whilst trying to find new pulsars astronomers stumbled across a brand new phenomenon, the Fast Radio Bursts. These millisecond-duration radio flashes appear to be coming from half way across the Universe but nobody knows what they are.

Presented by on 22 July 2016 by Rebecca Allen.

In the vast cold reaches of space life has been able to gain a foothold and flourish on at least one planet- ours. We know that water is critical to life, but we do not know how Earth got it. In this talk, we will first explore the ongoing search for the source of Earth's water. Next, we will talk about some of the exciting ways in which we are utilising our knowledge of life on this planet to search for and possibly identify life in other parts of the Universe.

Presented on 17 June 2016 by Allan Duffy.

In the last 50 years astronomers have come to realise that there exists an invisible type of mass in the Universe, outweighing all of the atoms in every star, planet and person five times over. It's responsible for holding the galaxy together, for making the galaxies form where they do in the cosmos and is our best guide to physics beyond the Higgs boson, aka the 'god' particle. Yet astronomers are no nearer to understanding its nature. Using a combination of baby universes created on Australia's most powerful telescopes, next generation telescopes like the Australian SKA Pathfinder, and a wine glass, Alan will explore what we know about the invisible and how Australia may uncover the most sought after particle in physics with the world's first dark matter detector in the Southern Hemisphere, SABRE.

Presented on 20 May 2016 by Amanda Karakas.

Most of the elements in the periodic table heavier than hydrogen and helium were forged in stars. Through the combined studies of stellar spectroscopy, nuclear physics, geochemistry, and astrophysics, humans have been able to work out the origin of many of the chemical elements that naturally occur in our Solar System. We know for example that most of the oxygen in the air was forged in ancient supernova explosions, which are the end product of very massive stars. The carbon in our bodies was synthesized instead by stars covering a wide range of stellar masses, from solar-type stars like our Sun through to massive stars. The biggest mystery today concerns the origins of the elements heavier than iron. In this talk I will take you on a journey through the origin of the elements, with a special focus on where the heaviest elements in nature are formed. in order to do this, I will discuss some basics about the life cycle of stars, which is intimately connected to the story of the origin of the elements through the nuclear reactions that occur deep in their interiors. Presented on 20 May 2016.

Presented on 15 April 2016 by Dr Elisabete da Cunha.

Almost one hundred years ago, astronomer Edwin Hubble revolutionised our understanding of the Universe and our place in it when he discovered that it extends beyond the Milky Way. Since then, astronomers have identified millions of galaxies beyond our own, and developed sophisticated techniques to measure their distances and motions. In this talk, I will show how astronomers map the Universe using large surveys of galaxies, and how "cosmic maps" are an essential tool in Cosmology, allowing us to understand the physical nature and history of the Universe.

Presented on 18 March 2016 by Elodie Thilliez and Matthew Agnew.

The Solar system is a remarkable place filled with wonderfully varied worlds. Travelling outwards from the sun we first encounter the hellish, rocky bodies of Mercury and Venus, continue to the cooler, water bearing world of Earth and our close neighbour Mars. Beyond the asteroid belt we hit the majestic gas giants of Jupiter and Saturn and continuing on our voyage we finally reach the cold ice giants of Uranus and Neptune. The Solar system is our home and our starting point for understanding planetary systems and their architectures. Until the late 20th century these were the only planets known to us, however, in the last two decades, there has been enormous and rapid progress in the discovery and understanding of planets beyond our Solar system, dubbed Exoplanets. As we discover more and more of these exoplanets, and the planetary systems to which they belong, our understanding of planet formation and planetary architectures has changed and raised several questions. Where did these Jupiter-sized, gas giants orbiting their stars in as little as 3 days come from? What is a 'super Earth'? Will we find another habitable world? In this lecture we will answer some of these questions as we explore our very own Solar system, look at how we observe and discover Exoplanets, and examine how these other planetary systems differ to our own.

Presented by Dr Pablo A. Rosado on 18th February 2016.

One of the greatest scientific discoveries of all times was achieved last week: the first detection of gravitational waves, emitted by a black hole binary. This discovery follows decades of intense work, and opens a new window to the Universe. This talk, for scientists and for non-scientists, is about black hole binaries, and the dawn of gravitational wave astronomy. This talk is about the curious romance of Alice and Bob. Nobody has heard it before, but we can speculate about what happened: how they were born, how they grew, how they first met, and how they finally became one forever. The true story is actually written in space-time, has been traveling across the Universe for more than a billion years, and is reaching Earth now. This is the story of two distant black holes merging into one. You may be wondering how we can hear it: is there really a way to listen to the voice of space-time? I will endeavour to answer this question, and explain how we attempt to discover new sounds of the Universe that we have never been able to listen to before. The talk will involve the loudest events in the Universe, like supernovae or collisions of neutron stars and black holes. In other words, I will speak about the dawn of gravitational wave astronomy, and pose that the mysterious love story of Alice and Bob might soon be finally heard, loud and clear.

Presented on 4 December 2015 by Dr Lisa Harvey-Smith.

What is Dark Matter? How did the solar system form? Was Einstein right about the nature of gravity? Are we alone in the universe? To tackle these fascinating questions and more, an international consortium of eleven nations is currently designing the 'Square Kilometre Array' (SKA) telescope. Comprising thousands of radio receivers located in Africa and Australia, the SKA will be the world's most powerful radio telescope. It will revolutionise our understanding of the universe, from the first stars and galaxies formed after the Big Bang to the formation of planet Earth. In preparation for this mega-science project, the CSIRO has built the Australian SKA Pathfinder (ASKAP) telescope which is due to start early science operations next year. In this talk, CSIRO astronomer Dr. Lisa Harvey-Smith will reveal early results from ASKAP, explain the science and technology behind the telescope and describe many scientific mysteries it will tackle.

Presented by Dr Laura Wolz on Friday 23 October 2015.

Radio telescopes have made numerous appearances in media and films due to their huge, mechanical appearances contrasting with the natural background. The gigantic size of the dishes are essential for observing cosmic objects in high resolution following the basic rule: the longer the wavelength, the bigger the dish. The construction efforts are worthwhile because radio waves can pass our atmosphere nearly unobscured and thus allow us to view the Universe whether it is sunny or cloudy. But what are we looking at? Every galaxy emits a wide range of radio waves, including our own Milky Way, allowing us to measure the positions of the galaxies in space. Radio waves also carry information about the interior of galaxies, namely their hydrogen content. Radio telescopes can be used as cartographers to map the cosmic landscape by their hydrogen emission. This allows us to see areas unobtainable through visible light and take a glimpse how the Universe looked when it was less than half of its age. We can use both, galaxy catalogues and cosmic maps, to explore how the Universe evolved to the present state. We can learn how space floated apart after the Big Bang, how gravity pulls structures together and how dark energy is mysteriously speeding up the expansion of the cosmos

Presented by Associate Professor Kim-Vy Tran on Friday 9 October 2015.

Since Galileo's time, our ability to study the universe has been driven by our ability to collect light from distant objects. Due to tremendous technological advances in the last few decades, we can now study the most distant galaxies known in the universe. In addition to seeing fainter objects at higher resolution, we can also view the universe at many different wavelengths ranging from gamma rays to radio waves. I highlight the major advances that have been made with, e.g. the Keck telescopes and Hubble Space Telescope, and discuss why we need to continue pushing our limits by developing and building new observatories like the Giant Magellan Telescope.