Onionlike Layers of Exploding Stars with Prof. Geraint Lewis (447)

My go-to guy for all cosmic things Prof. Geraint Lewis, astrophysicist at the University of Sydney, returns to unpack a fascinating New York Times article on a newly observed “onionlike” space explosion that may reveal a new type of supernova. We dive into what actually happens when a star dies, the onion-layer buildup of elements through nuclear fusion, and how these cataclysmic blasts forge the building blocks of life on Earth. Plus, we explore what this might mean for the ultimate fate of our own Sun. www.geraintflewis.com/ Linkedin: Geriant Lewis

In this episode, friend of the show Geriant Lewis, Professor of Astrophysics at the Sydney Institute for Astronomy within the University of Sydney, joins us to unpack a fascinating New Scientist article theorising on how a strange line of dwarf galaxies may have formed.  We explore how high-speed collisions between dwarf galaxies can scatter gas and stars across space, sometimes giving rise to entirely new tidal galaxies. Geraint explains the latest thinking on where these dwarf galaxies come from and how these cosmic smash-ups might even shed light on one of the biggest mysteries in physics: the true nature of dark matter. www.geraintflewis.com/ Linkedin: Geriant Lewis Bluesky: cosmic_horizons

In part two, Associate Professor Marian-Andrei Rizoiu from the University of Technology Sydney explains how misinformation and toxic online cultures spread. We dive into the “manosphere pipeline” targeting boys as young as 10, its real-world impacts on schools and families, and how it can escalate into radicalisation. Rizoiu outlines his team’s six-stage pipeline - from passive curiosity to active involvement - and why simply giving people facts doesn’t solve the problem. Instead, this is a human challenge, and his lab is exploring new ways to diffuse and counter online misinformation before it turns dangerous. Linkedin: Marian-Andrei Rizoiu

In this episode, I sit down with Marian-Andrei Rizoiu, Associate Professor and head of the Behavioral Data Science Lab at the University of Technology Sydney. Drawing on a three-year research project into the misinformation ecosystem, he reveals that online conspiracies aren’t just about false facts. Instead, they meet deep human needs for belonging and identity.  We explore the idea that misinformation is less a content problem and more a human problem, fueled by the attention economy. Rizoiu also weighs in on the growing debate around restricting social media use, such as proposed bans for under-16s, unpacking the potential benefits and drawbacks. Keep your ears peeled for Part 2 next week Linkedin: Marian-Andrei Rizoiu

In this episode, we sit down with two of today’s most prominent defenders of science: Professor Michael Mann, world-renowned climate scientist, and Professor Peter Hotez, vaccine researcher and advocate for global health equity. Together, they’ve co-authored Science Under Siege, a powerful new book exposing the forces behind the global anti-science movement. We explore the surprising parallels between climate denial and vaccine misinformation, and how both Mann and Hotez have faced personal attacks simply for standing by the evidence. They break down the five key drivers of anti-science - plutocrats, professionals, propagandists, petrostates, and the press - and reveal how these forces shape public discourse and policy. This conversation is not just about diagnosing the problem, but about pathways forward: the urgent role of science communication, strategies to counter misinformation, and reasons to remain hopeful in the fight to reclaim trust in science. www.michaemann.net www.peterhotez.org www.scribepublications.com.au/books-authors/books/science-under-siege-9781761381669  

In part two of our conversation with Professor Carolyn Hogg, Research Manager of the Australasian Wildlife Genomics Group at the University of Sydney, we dive deeper into the science and strategy behind threatened species management. Carolyn shares how her team is developing crucial genetic data to guide conservation, including breed-and-release programs with species like the Tasmanian devil. We discuss the vital role of biodiversity in sustaining planetary health, and the ambitious Earth Biogenome Project, which aims to map the genomes of all 12 million species of eukaryotic life on Earth. Beyond the lab, Carolyn reveals how genetic insights are shaping real-world decisions—bridging the gap between cutting-edge science, social change, and the policies that determine the future of our ecosystems. Linkedin: Carolyn Hogg X: @HoggCarolyn, @BioplatformsAus, @ThreatenedSpGen https://wildlife-genomics.sydney.edu.au/ https://www.linkedin.com/company/bioplatforms-australia/      

From collecting urine samples in Antarctica to sampling whale snot to study reproduction, Dr. Carolyn Hogg's career is anything but ordinary. In this episode, she shares how her passion for protecting threatened species led her down some unexpected paths, including earning the nickname ‘Dr. Snot’. We chat about her PhD on whale behaviour, wild whale facts, and the creative ways scientists gather data in the field. There was so much to cover, we had to split it into two! Part 2 dives into her groundbreaking work in conservation genetics. Linkedin: Carolyn Hogg X: @HoggCarolyn, @BioplatformsAus, @ThreatenedSpGen https://wildlife-genomics.sydney.edu.au/ https://www.linkedin.com/company/bioplatforms-australia/  

In this episode, Professor PJ Cullen, Chemical Engineering expert from the University of Sydney, breaks down the global nitrogen challenge. We explore why nitrogen is essential for life, the history of fertiliser - from the Guano Wars to the energy-intensive Haber-Bosch process - and how today's nitrogen production is harming the planet. Cullen introduces PlasmaLeap, his startup using non-thermal plasma to mimic lightning and fix nitrogen sustainably. We also dive into the risks of nitrogen storage, the 2020 Beirut explosion, and the urgent need to electrify chemical industries.  https://www.plasmaleap.com/ Linkedin: PJ Cullen

In part two with Online Safety Consultant Troy Hunt (Have I Been Pwned), we unpack the risks of online age verification in light of Australia’s social media ban, including the personal data (often times photos or government documents) sites may demand, and how these security practices can be questionable.  Troy explains why we should be thinking more about data minimisation and the dangers of unnecessary data retention. We go through the safest multi-factor authentication methods, from SMS to physical keys, and Troy shares a personal phishing story, reminding us that no-one is immune to hacking thanks to increasingly sophisticated phishing techniques. https://haveibeenpwned.com/ Linkedin: Troy Hunt

In this episode, we’re joined by Troy Hunt, Australian online security consultant, creator of Have I Been Pwned, and one of the world’s leading voices on data breaches. He breaks down the key differences between encryption and hashing, and what they mean for keeping your data safe. We dive into infamous data breaches, including the Ashley Madison case, and explore the often hidden, long-term impacts these leaks can have on people’s lives. With online scams and breaches costing Australians over $3 billion every year, we also look at the rising threat of ransomware and why it’s so hard to fight. This conversation opened so many cans of worms, we had to save the rest for part two. https://haveibeenpwned.com/ Linkedin: Troy Hunt