Extinction might be the rule in the universe, not the exception.

Charley Lineweaver studied history and English before switching to physics — and ended up on the NASA team whose 1992 discovery of fluctuations in the cosmic microwave background, the oldest light in the universe, helped earn his PhD supervisor a Nobel Prize. He's now an astrobiologist and cosmologist at the Australian National University. With his student Aditya Chopra, he proposed the Gaian Bottleneck: the idea that most life goes extinct before it learns to regulate its own planet, and that this, not the difficulty of starting life, may explain why the universe looks so empty.

We talk about:

• Why extinction, not emergence, might be the hard part of staying alive on a planet
• His case, built on isolated ecosystems like Australia and Madagascar, that human-like intelligence may never have been an inevitable outcome of evolution
• Why he thinks maths is useless for talking to aliens, and what trying to communicate with dogs, dolphins and plants actually teaches us
• Where he agrees, and where he sharply disagrees, with his hero Carl Sagan on humanity's place in the universe

A Melbourne psychiatrist spent decades building the case for psychedelic therapy — and became one of the psychiatrists pushing for Australia to legalise it.

Nigel Strauss has been a psychiatrist for over 45 years, trained at the Jung Institute in Zurich, and was among the first Australian psychiatrists trained by MAPS in psychedelic‑assisted therapy in the UK in 2014. He ran Melbourne's Millswyn Clinic for around forty years, worked as a psychedelic psychotherapist on Australia's first approved psilocybin trial for end‑of‑life anxiety and depression, and personally sponsored a Monash University trial giving MDMA‑assisted therapy to 25 veterans and first responders with severe PTSD — results are being presented in Amsterdam this year, and by his account most participants have done very well. His own experience with LSD as a depressed medical student set him on this path decades before any of it was legal.

We talk about what changed in the science and the culture to make Australia the first country to allow authorised psychiatrists to prescribe MDMA for PTSD and psilocybin for treatment‑resistant depression, what actually happens in a psychedelic session, what shifts in someone facing death, and why an urban psychiatrist ended up planting thousands of trees and spending decades helping protect the Great Otway region.

Concussion isn’t just “getting your bell rung” — it’s a mild traumatic brain injury that disrupts how your brain’s electrical system works, often long after the obvious symptoms settle.

Neurophysiologist Professor Alan Pearce has spent more than a decade using non-invasive brain stimulation to study how the brain recovers — or doesn’t — after repeated impacts in Australian Rules football, rugby and other contact sports.

Fresh from appearing on ABC’s Four Corners investigation Collision, which revealed a far higher number of former players diagnosed with CTE than previously known, Alan joins Uncomfortably Curious to dig into what’s really happening in the brain during concussion and chronic traumatic encephalopathy.

We talk about the mismatch he’s found between symptom resolution and physiological recovery, why a player can feel fine while their nervous system is still compromised, and what his research shows about 12–14 day return-to-play rules versus the roughly 26-day window the brain often needs to genuinely recover.

We also explore how many concussions might be “too many”, why CTE isn’t simply a concussion disease, and the cultural habits that keep athletes saying “just one more” even as the risks mount.

Along the way, Alan touches on the current push to develop clinical diagnostic criteria for CTE, and where listeners can go to support the Australian Sports Brain Bank and the Concussion & CTE Foundation’s work.