Talking Science

Extinction is the normal fate of almost every species that has ever lived — but five times in Earth's deep history, the losses spiked into catastrophe, wiping out huge fractions of all life in a geological instant. This episode explores the Big Five mass extinctions, what caused them, and the hard question of whether we're now living through a sixth.

You'll come away understanding the difference between everyday extinction and a mass extinction, what drove the great dyings of the past, why the end-Permian event nearly ended life altogether, and how scientists weigh the evidence about today.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Natural History Museum (London) – "Mass extinctions"; Smithsonian – "The Big Five"; Elizabeth Kolbert, *The Sixth Extinction*.

A million and a half kilometres from Earth, a golden telescope the size of a tennis court's sunshield sits in the cold and dark, catching faint infrared light from the edge of time. This episode explores the James Webb Space Telescope — how it works, why it sees in infrared, and what it has already found.

You'll come away understanding why Webb had to travel so far and stay so cold, how it can look back toward the very first galaxies, and how it reads the atmospheres of planets around other stars.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: NASA – "James Webb Space Telescope"; European Space Agency – "Webb"; Space Telescope Science Institute – Webb image galleries.

We call it dirt, we scrape it off our shoes, and we rarely give it a thought — yet almost all of our food, and much of life on land, depends on the thin skin of soil covering the planet. This episode digs into what soil actually is, and why it matters far more than its humble reputation suggests.

You'll come away understanding how soil forms over centuries, why a single handful teems with billions of living things, how it stores water and carbon, and why soil erosion is one of the quiet threats to feeding the world.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: CSIRO – "Soil" research pages; FAO – "The state of the world's soil resources"; Australian Government – "Soil health".

From the checkout scanner to eye surgery to the internet itself, lasers are woven through modern life — yet most of us have no idea what makes laser light different from the light of a torch. This episode explains the surprisingly elegant physics of light marching in perfect step.

You'll come away understanding what makes a laser beam so pure and tight, the quantum trick called stimulated emission that Einstein predicted, and why this one invention quietly runs so much of the modern world.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Britannica – "Laser"; American Physical Society – "This Month in Physics History: Maiman builds first laser"; *The Feynman Lectures on Physics*, Vol. I.

Every breath you take and nearly every meal you eat traces back to a single quiet chemical trick that plants, algae and some bacteria perform: turning sunlight, water and air into food. This episode unpacks photosynthesis, arguably the most important chemical reaction on Earth.

You'll come away understanding how a leaf captures light, where the oxygen we breathe actually comes from, why plants are green, and how this one process built our breathable atmosphere and underpins almost every food chain.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Khan Academy – "Photosynthesis"; NASA Earth Observatory – "The carbon cycle"; David Attenborough, *The Green Planet*.

Scattered through the solar system are billions of leftover scraps from its birth — rocky asteroids and icy comets that never got swept up into a planet. This episode explores what they are, why comets grow glowing tails, and how a stray one wiped out the dinosaurs.

You'll come away understanding the difference between an asteroid and a comet, where each comes from, why a comet's tail always points away from the Sun, and how humanity has begun to defend itself against an impact.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: NASA – "Asteroids" and "Comets" overview pages; NASA/APL – "DART mission"; ESA – "Rosetta".

When a massive star dies, it can leave behind an object so dense that a sugar-cube-sized piece would weigh as much as a mountain: a neutron star. Some spin hundreds of times a second and sweep the sky with beams of radiation like cosmic lighthouses. This episode explores the most extreme form of matter we know of, short only of a black hole.

You'll come away understanding how neutron stars form, just how unimaginably dense they are, what a pulsar is, and how colliding neutron stars forge the gold and platinum in the universe.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: NASA – "Neutron Stars"; Jodrell Bank Observatory – pulsar resources; LIGO/Virgo – neutron star mergers.

The water in your glass is older than the dinosaurs, older than the planet's first life — the same finite supply, recycled endlessly through ocean, sky, land and living things. This episode follows a drop of water on its journey through the water cycle, the great engine that shapes weather, carves landscapes, and delivers the fresh water all life depends on.

You'll come away understanding evaporation and condensation, how clouds and rain form, where groundwater fits in, why fresh water is surprisingly scarce, and how the cycle connects the whole planet.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Bureau of Meteorology (Australia) – "The water cycle"; USGS – "The Water Cycle"; NASA Earth Observatory – water cycle resources.

Cool certain materials below a critical temperature and something almost magical happens: they carry electricity with no resistance at all, and they can levitate magnets in mid-air. Superconductors already power MRI machines and cutting-edge physics, and the century-long hunt for one that works at room temperature could transform how we move and store energy. This episode explains what superconductivity is and why it's so hard to achieve.

You'll come away understanding what electrical resistance is, what changes in a superconductor, why they usually need extreme cold, how they levitate magnets, and what a room-temperature superconductor would mean.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: CERN – "Superconductivity"; Royal Institution – superconductivity explainers; Nature Physics – reviews on high-temperature superconductors.

Every one of the roughly thirty-seven trillion cells in your body traces back to a handful of unspecialised cells that could become anything. Those are stem cells, and their remarkable flexibility has made them one of the most promising — and most over-hyped — frontiers in medicine. This episode separates the real science from the marketing.

You'll come away understanding what makes a stem cell special, the difference between embryonic and adult stem cells, the breakthrough of reprogramming ordinary cells, and where the genuine therapies end and the hype begins.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: International Society for Stem Cell Research – "A Closer Look at Stem Cells"; Nature – "Induced pluripotent stem cells"; Australian Government NHMRC – stem cell information.