While we take a break we are revisiting some of our favourite stories and interviews in our summer series. This week we revisit the interview with Young Australian of the Year Dr Katrina Wruck, a groundbreaking green chemist working to break down harmful "forever chemicals." As the first Torres Strait Islander to receive an Australian of the Year award in any category, Dr Wruck shares her journey, the science behind her research and how she is working to improve environmental and health outcomes in remote Indigenous communities.

Is it 2026 already? We farewell the year just gone, by remembering famous scientists who died in 2025, plus Chris tests our memory with his annual quiz of unforgettable science stories.

In this Christmas episode (our last for 2025!) the team looks at some Christmas adjacent science. Chris brings us up to date with the latest on our interstellar visitor 3I Atlas (spoiler, it's not aliens), Claire turns up the heat on the real reason Christmas cookies taste so good (hint: it's science) and Stu bags up some realities of the neuroscience of Holiday sales and how to avoid spending too much.

This week Linden interviews Tammy Lee, PhD student at UWA in Perth who was crowned the winner of FameLab International in Switzerland in November. This means Australia is officially home to the world's best science communicator! Tammy talks through her research, as well as the process of taking part in one of the world's oldest science communication competitions. Watch the FameLab International final on the FameLab YouTube channel, see the Australian final at the channel of the Foundation for the WA Museum, and follow Tammy on Instagram, @testtubetammy.

This week on Lost in Science, in the lead-up to Christmas — and before our official festive special — we’re diving into the archives to revisit two of our all-time favourite holiday stories. Cat crunches the numbers on Santa’s impossibly busy Christmas Eve, using maths and physics to reveal just how many children he visits (and how he might just pull it off). Then Stu takes us on a botanical adventure through the science of Christmas trees, exploring what makes them smell, sparkle and survive the season.

Linden and Chris talk about the funding cuts to Australian science, and Claire chats with A/Prof Jochen Kaempf from Flinders University about the algal bloom that continues off the South Australian coast.

This week, Stu lets us into the secret world of moss, how they're different to other plants, and how they're so hardy they can even survive on the outside of spacecraft; and Claire gets her teeth into a new, large longitudinal study that showed water fluoridation did not harm cognition or IQ. Maeng, Chang-hyun et al., Extreme environmental tolerance and space survivability of the moss, Physcomitrium patens. iScience, Volume 0, Issue 0, 113827 (2025). DOI: 10.1016/j.isci.2025.113827 John Robert Warren et al., Childhood fluoride exposure and cognition across the life course. Sci. Adv. 11, eadz0757 (2025). DOI:10.1126/sciadv.adz0757

Chris and Linden talk through the Prime Minister's Science prize, awarded in early November, and Linden chats with Dr. Grace Sethanant, and earthquake expert, about her work on Australia's weird earthquakes.

This week on Lost in Science Stu checks in on the cutting edge of CRISPR — the revolutionary gene-editing technology promising to change how we treat diseases. Is it living up to the hype? And as we head into the holiday season, Chris is getting practical with physics, applying maths and motion to the age-old problem of how to pack your bag efficiently.

Revisiting some past stories from episodes of Lost in Science Fiction, we look at the science contained in (and the science inspired by) Star Wars, 2001: a Space Odyssey, and Ad Astra