Location:
United States
Description:
Dr Karl's a curious optimist – a great combination for a science lover. Join him and his guests for weird facts, amazing conversation and remember, it's never too late for a happy childhood. https://drkarl.com/
Language:
English
Episodes
The Rise In Nitrous Misuse with Assoc. Prof. Angela Chiew (463)
2/28/2026
Nitrous oxide (better known as "laughing gas") is widely used in medicine as a safe anaesthetic and pain reliever. It's also found in whipped cream canisters and even used in car engines. But Angela Chiew, toxicologist and Associate Professor at UNSW, joins me to set the record straight: the growing recreational misuse of this easily accessible gas is causing serious long-term harm, including nerve damage, cognitive damage, weakening of the spinal cord and mobility impairments.
Cases of misuse are rising globally, likely driven by how easy it is to legally purchase the drug in many countries. This episode unpacks the hidden dangers behind a gas many once thought was just a harmless high.
Linkedin: Angela Chiew
X: AngelaChiewA
Duration:00:27:55
Will AI Take Our Jobs? Part Three of the Great AI Safety Debrief with Dr. Petr Lebedev (462)
2/21/2026
In the final episode of the Great AI Safety Debrief series with Dr. Petr Lebedev, we discuss job eradication, AI alignment and the rise in cases of AI deceiving humans. Petr unpacks ideas like AI scheming, situation awareness, parasitic relationships between humans and machines, and even the possibility of AI developing belief systems of its own. We end by zooming out to existential risk, Alan Turing's early warnings, and why aligning AI with human values may be one of the most difficult (and urgent) challenges humanity must face.
Linkedin: Petr Lebedev
palisaderesearch.org/
Duration:00:28:44
Is AI Outsmarting Us? Part Two of the Great AI Safety Debrief with Dr. Petr Lebedev (461)
2/14/2026
In part two, Dr. Petr Lebedev and I dive deeper into how modern AI systems are grown, not programmed, and the emergence of Shutdown Resistance. We explore AI performance in math and coding competitions, the rapid evolution of ChatGPT models, and why companies are already letting AI write the majority of their code. Petr explains how huge investements globally are pushing these systems forward faster than we can fully understand or control.
The final episode in this 3 part series drops next week!
Linkedin: Petr Lebedev
palisaderesearch.org/
Duration:00:23:54
The Great AI Safety Debrief with Dr. Petr Lebedev - Part One (460)
2/7/2026
Intelligence is emerging from sand and less than 1% of the population seems to care!
Physicist and science communicator Petr Lebedev joins the podcast following his SXSW talk to explore why AI is advancing so fast, and why that should make us pause. From completing a PhD in physics and writing for Veritasium to leading science communication at Palisade Research, Petr steps in to bring some clarity to the weird, wild, and worrying sides of AI.
Did you know that no one truly understands how large language models actually work? We go deep on misaligned systems, humanoid and dog robots, and why many experts believe AI could pose a serious global risk. Is AI our greatest tool — or something we're slowly losing control of? This conversation is big, so we've split it into three parts. Part two drops next week.
Duration:00:24:10
The Milky Way's Mysterious Glow with Prof. Geraint Lewis (459)
1/31/2026
A mysterious glow from the centre of the Milky Way has scientists intrigued. Astrophysicist Geraint Lewis explains how this gamma-ray excess, first detected in 2009, could be evidence of dark matter particles interacting deep in our galaxy. With dark matter believed to make up a vast, invisible halo that holds galaxies together, uncovering the source of this glow may bring us closer to understanding what the universe is really made of.
www.geraintflewis.com/
Linkedin: geraint-lewis-4a499b1
Duration:00:32:28
Staying Safe Online Part 2 with Troy Hunt (439) [REPEAT]
1/17/2026
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
Duration:00:27:01
The Human Side of Misinformation Part 2 with Assoc. Prof. Marian-Andrei Rizoiu (445) [REPEAT]
1/10/2026
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
Duration:00:25:53
Rethinking Laundry for the Planet With Dr Holly Kaye Smith (430) [REPEAT]
1/3/2026
Most of us throw our clothes in the wash without a second thought, but what if that habit is doing more harm than good? In this episode, Dr. Holly Kaye-Smith, social change expert and communications specialist, challenges the way we think about cleanliness, climate action, and everyday laundry.
From surprising stats (over 90% of washed clothes aren't even dirty!) to the hidden environmental cost of every wash cycle, we dive into the myths, microplastics, and mindsets that shape our laundering routines. Holly shares practical refreshing techniques that save water, and why she recommends everyone have a "rewear chair."
Connect with Dr Holly Kaye Smith on Linkedin
Instagram - www.instagram.com/drhollyphd/
Youtube - www.youtube.com/@drhollyphd
Duration:00:21:44
Climate Overshoot: The World Beyond 1.5 Degrees with Dr. Andy Reisinger (458)
12/26/2025
In this episode, we speak with Dr. Andy Reisinger, an internationally recognized expert in climate change science and policy, with a focus on mitigation and agricultural emissions. Together, we unpack the concept of climate overshoot - why the world is set to exceed the 1.5°C warming limit within the next five years, and what that means for people and the planet. Dr. Reisinger explores whether the damage already done is reversible, what it would take to get back on track, and, hypothetically, the bold actions he would take if he had the power to drive real societal change to combat climate change.
Linkedin: Andy Reisinger
Duration:00:30:01
More Everyday Consumer Good Facts Part 2 with Ashley Iredale (457)
12/20/2025
Consumer technology expert Ashley Iredale returns for part two, bringing more surprising facts about everyday household appliances. We break down why your fridge actually contains more heaters than coolers, demystify the Energy Star rating system, and settle the debate on whether front-loading or top-loading washers are more efficient at cleaning clothes.
Duration:00:17:40
Cooking Dinner In Your Dishwasher?! & Other Fun Facts with Ashley Iredale (456)
12/13/2025
This episode i'm joined by Ashley Iredale, a consumer technologist and content producer whose winding career through industrial design has armed him with a trove of quirky tips and practical wisdom.
Ashley breaks down the real efficiency of hand-washing versus dishwashers, explains how a dishwasher can double as an oven, and settles the age-old question of how toilet paper should hang. We also dig into his non-linear career journey and how it led to his deep well of surprising insights. There was so much to cover that Part Two lands next week!
Linkedin: Ashley Iredale
Duration:00:18:35
The Discovery That Changed Astrophysics with Prof. Dame Jocelyn Bell Burnell (455)
12/6/2025
In this episode, I'm joined by the legendary Dame Susan Jocelyn Bell Burnell - the pioneering astrophysicist who discovered pulsars, launching an entirely new field of astrophysics.
She began her PhD searching for quasars, but soon noticed a strange, repetitive signal appearing night after night - so peculiar she jokingly labelled it LGM ("Little Green Men"). That signal would become one of the most important astronomical discoveries of the century, though the credit and Nobel Prize were controversially awarded to her supervisor.
Dr Bell Burnell also shares why she donated $4.3 million of her own prize money to support underrepresented researchers in physics, especially women and girls, and the work she's doing to make the field more inclusive.
We dive into her views on religion, her life in science since that landmark discovery, and her mission to help more young women pursue careers in physics.
Duration:00:32:01
Sunscreen Safety in Australia with John Staton (454)
11/29/2025
This week I'm joined by John Staton, one of Australia's leading sunscreen-testing experts, to unpack the big headlines surrounding sunscreen safety. A recent Choice report revealed that 16 out of the 20 tested sunscreen products failed to meet their advertised SPF rating by a significant figure. John helps us to understand what is really going on. He breaks down how sunscreens actually work, the science behind SPF testing and why so many products fell short.
Duration:00:24:29
What are Time Crystals? with Prof. Geraint Lewis (453)
11/22/2025
In this episode, friend of the show and astrophysicist Professor Geraint Lewis returns to help me wrap my head around one of the strangest ideas in modern physics: Time Crystals.
After stumbling across a Nature article that left my brain pleasantly scrambled, I called up Geraint for a deep-dive into what time crystals are and why physicists are so excited about them.
We explore why Time Crystals don't have real-world applications yet, but how they could open entirely new frontiers in future technology.
Duration:00:28:59
Science in Oz: The Good, The Bad and The Ugly with Dr. Catherine Ball (452)
11/15/2025
In this episode, futurist and award-winning scientist Dr Catherine Ball dives into the state of science in Australia, uncovering the good, the bad, and the overlooked. From humanoid robotics and wearable exoskeletons transforming healthcare, to Australia's lagging space economy, Ball offers an unflinching look at where we stand. She also highlights world-class cancer detection research happening in Australia, like PROCAN and early ovarian cancer screening innovations that deserve far more recognition. Passionate about inspiring the next generation, Ball shares her advice for young Australians ready to shape the future of science
ww.drcatherineball.com/
Duration:00:31:08
Food Additives: What's Safe, What's Not? with Prof. Clare Collins (451)
11/8/2025
In this episode, I'm joined by Professor Clare Collins, Australian dietitian and Professor of Nutrition and Dietetics at the University of Newcastle. Clare is my go-to expert when it comes to all things nutrition, and today she's here to unpack the often confusing world of processed and ultra-processed foods.
We dive into what really separates the two, explore the role of additives, emulsifiers, and flavour enhancers, and discuss how some of these ingredients, designed to make foods more appealing, may be doing our health more harm than good. Plus, she shares practical, no-nonsense tips to help you make smarter choices next time you're wandering the grocery aisles.
Check out Clare's free online resource, No Money No Time, for simple, budget-friendly recipes and nutrition advice - nomoneynotime.com.au/
Follow Clare on X: @ProfCCollins and LinkedIn: Clare Collins.
Duration:00:28:27
Innovative Nanotechnology for Cancer Detection with Dr. Renee Goreham (450)
11/1/2025
In this episode, we chat with Dr. Renee Goreham, a physicist and nanotechnologist at the University of Newcastle, and passionate science communicator. Renee is an experimental physicist exploring how our breath could hold the key to detecting lung cancer early—by identifying specific proteins as biomarkers. We also delve into her PhD student's exciting research into a new red-light laser diagnostic tool for breast cancer. Along the way, Renee breaks down the basics of cell biology and shares her inspiring, non-linear journey through physics, nanotech, and beyond. A brilliant example of multidisciplinary science in action.
Follow Renee on TikTok: @dr_renee_goreham
Duration:00:25:41
Gene Therapy & Rare Diseases with Assoc. Prof Leszek Lisowski (449)
10/25/2025
In this episode, we speak with Associate Professor Leszek Lisowski, Head of the Translational Vectorology Unit at the Children’s Medical Research Institute (CMRI), about the cutting-edge world of gene therapy. He explains how viral vectors are engineered to deliver life-saving treatments for rare genetic diseases - many of which are so uncommon, they’re only known by the name of the affected gene. Despite being often overlooked, genetic diseases impact 10% of adults and 30% of children in hospitals. Leszek sheds light on the challenges of diagnosis, the promise of emerging genetic testing, and how his work is paving the way for more accurate, effective therapies.
Linkedin: Children's Medical Research Institute, Leszek Lisowski
Facebook: @jeansforgenes
Instagram: @jeansforgenesau
Duration:00:33:16
The Brain’s Energy Bill: From Childhood to Old Age with Assoc. Prof Sharna Jamadar (448)
10/18/2025
In this episode, we’re joined by Associate Professor Sharna Jamadar, a cognitive neuroscientist at Monash University, to explore how the brain uses energy, and how that changes across the lifespan. Did you know that a 10-year-old’s brain uses over 50% of the body’s total energy, compared to just 20% in adults? We dive into why younger brains work harder, the role of synaptic pruning and proliferation, and how the brain’s organisation impacts cognitive efficiency. We also touch on the importance of glucose metabolism and its connection to age-related disorders like Alzheimer’s. A fascinating look at the energy demands of our most complex organ!
Bluesky: @SharnaJamadar
Linkedin: Sharna Jamadar
www.sharnajamadar.com
Email: Sharna.jamadar@monash.edu
Duration:00:30:55
Onionlike Layers of Exploding Stars with Prof. Geraint Lewis (447)
10/11/2025
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
Duration:00:29:15
