80,000 Hours Podcast

When James Smith first heard about mirror bacteria, he was sceptical. But within two weeks, he’d dropped everything to work on it full time, considering it the worst biothreat that he’d seen described. What convinced him?Mirror bacteria would be constructed entirely from molecules that are the mirror images of their naturally occurring counterparts. This seemingly trivial difference creates a fundamental break in the tree of life. For billions of years, the mechanisms underlying immune systems and keeping natural populations of microorganisms in check have evolved to recognise threats by their molecular shape — like a hand fitting into a matching glove.Learn more, video, and full transcript: https://80k.info/js26Mirror bacteria would upend that assumption, creating two enormous problems:Many critical immune pathways would likely fail to activate, creating risks of fatal infection across many species.Mirror bacteria could have substantial resistance to natural predators: for example, they would be essentially immune to the viruses that currently keep bacteria populations in check. That could help them spread and become irreversibly entrenched across diverse ecosystems.Unlike ordinary pathogens, which are typically species-specific, mirror bacteria’s reversed molecular structure means they could potentially infect humans, livestock, wildlife, and plants simultaneously. The same fundamental problem — reversed molecular structure breaking immune recognition — could affect most immune systems across the tree of life. People, animals, and plants could be infected from any contaminated soil, dust, or species.The discovery of these risks came as a surprise. The December 2024 Science paper that brought international attention to mirror life was coauthored by 38 leading scientists, including two Nobel Prize winners and several who had previously wanted to create mirror organisms.James is now the director of the Mirror Biology Dialogues Fund, which supports conversations among scientists and other experts about how these risks might be addressed. Scientists tracking the field think that mirror bacteria might be feasible in 10–30 years, or possibly sooner. But scientists have already created substantial components of the cellular machinery needed for mirror life. We can regulate precursor technologies to mirror life before they become technically feasible — but only if we act before the research crosses critical thresholds. Once certain capabilities exist, we can’t undo that knowledge.Addressing these risks could actually be very tractable: unlike other technologies where massive potential benefits accompany catastrophic risks, mirror life appears to offer minimal advantages beyond academic interest.Nonetheless, James notes that fewer than 10 people currently work full-time on mirror life risks and governance. This is an extraordinary opportunity for researchers in biosecurity, synthetic biology, immunology, policy, and many other fields to help solve an entirely preventable catastrophe — James even believes the issue is on par with AI safety as a priority for some people, depending on their skill set.The Mirror Biology Dialogues Fund is hiring!Deputy director: https://80k.info/mbdfddOperations lead: https://80k.info/mbdfopsExpression of interest for other roles: https://80k.info/mbdfeoiThis episode was recorded on November 5-6, 2025.Chapters:Cold open (00:00:00)Who's James Smith? (00:00:49)Why is mirror life so dangerous? (00:01:12)Mirror life and the human immune system (00:15:40)Nonhuman animals will also be at risk (00:28:25)Will plants be susceptible to mirror bacteria? (00:34:57)Mirror bacteria's effect on ecosystems (00:39:34)How close are we to making mirror bacteria? (00:52:16)Policies for governing mirror life research (01:06:39)Countermeasures if mirror bacteria are released into the world (01:22:06)Why hasn't mirror life evolved on its own? (01:28:37)Why wouldn't antibodies or antibiotics save us from mirror bacteria? (01:31:52)Will the environment be toxic to mirror life? (01:39:21)Are there too many uncertainties to act now? (01:44:18)The potential benefits of mirror molecules and mirror life (01:46:55)Might we encounter mirror life in space? (01:52:44)Sounding the alarms about mirror life: the backstory (01:54:55)How to get involved (02:02:44)Video and audio editing: Dominic Armstrong, Milo McGuire, Luke Monsour, and Simon MonsourMusic: CORBITCamera operators: Jeremy Chevillotte and Alex MilesCoordination, transcripts, and web: Katy Moore

What’s the opposite of cancer? If you answered “cure,” “antidote,” or “antivenom” — you’ve obviously been reading the antonym section at www.merriam-webster.com/thesaurus/cancer.But today’s guest Athena Aktipis says that the opposite of cancer is us: it's having a functional multicellular body that’s cooperating effectively in order to make that multicellular body function.If, like us, you found her answer far more satisfying than the dictionary, maybe you could consider closing your dozens of merriam-webster.com tabs, and start listening to this podcast instead.Rebroadcast: this episode was originally released in January 2023.Links to learn more, video, and full transcript: https://80k.link/AA As Athena explains in her book The Cheating Cell, what we see with cancer is a breakdown in each of the foundations of cooperation that allowed multicellularity to arise: Cells will proliferate when they shouldn't. Cells won't die when they should. Cells won't engage in the kind of division of labour that they should. Cells won’t do the jobs that they're supposed to do. Cells will monopolise resources. And cells will trash the environment.When we think about animals in the wild, or even bacteria living inside our cells, we understand that they're facing evolutionary pressures to figure out how they can replicate more; how they can get more resources; and how they can avoid predators — like lions, or antibiotics.We don’t normally think of individual cells as acting as if they have their own interests like this. But cancer cells are actually facing similar kinds of evolutionary pressures within our bodies, with one major difference: they replicate much, much faster.Incredibly, the opportunity for evolution by natural selection to operate just over the course of cancer progression is easily faster than all of the evolutionary time that we have had as humans since Homo sapiens came about.Here’s a quote from Athena:“So you have to shift your thinking to be like: the body is a world with all these different ecosystems in it, and the cells are existing on a time scale where, if we're going to map it onto anything like what we experience, a day is at least 10 years for them, right? So it's a very, very different way of thinking.”You can find compelling examples of cooperation and conflict all over the universe, so Rob and Athena don’t stop with cancer. They also discuss:Cheating within cells themselvesCooperation in human societies as they exist today — and perhaps in the future, between civilisations spread across different planets or starsWhether it’s too out-there to think of humans as engaging in cancerous behaviourWhy elephants get deadly cancers less often than humans, despite having way more cellsWhen a cell should commit suicideThe strategy of deliberately not treating cancer aggressivelySuperhuman cooperationAnd at the end of the episode, they cover Athena’s new book Everything is Fine! How to Thrive in the Apocalypse, including:Staying happy while thinking about the apocalypsePractical steps to prepare for the apocalypseAnd whether a zombie apocalypse is already happening among Tasmanian devilsChapters:Rob's intro (00:00:00)The interview begins (00:02:22)Cooperation (00:06:12)Cancer (00:09:52)How multicellular life survives (00:20:10)Why our anti-contagious-cancer mechanisms are so successful (00:32:34)Why elephants get deadly cancers less often than humans (00:48:50)Life extension (01:02:00)Honour among cancer thieves (01:06:21)When a cell should commit suicide (01:14:00)When the human body deliberately produces tumours (01:19:58)Surprising approaches for managing cancer (01:25:47)Analogies to human cooperation (01:39:32)Applying the "not treating cancer aggressively" strategy to real life (01:55:29)Humanity on Earth, and Earth in the universe (02:01:53)Superhuman cooperation (02:08:51)Cheating within cells (02:15:17)Father's genes vs. mother's genes (02:26:18)Everything is Fine: How to Thrive in the Apocalypse (02:40:13)Do we really live in an era of unusual risk? (02:54:53)Staying happy while thinking about the apocalypse (02:58:50)Overrated worries about the apocalypse (03:13:11)The zombie apocalypse (03:22:35)Producer: Keiran HarrisAudio mastering: Milo McGuireTranscriptions: Katy Moore

John McWhorter is a linguistics professor at Columbia University specialising in research on creole languages. He's also a content-producing machine, never afraid to give his frank opinion on anything and everything. On top of his academic work, he's written 22 books, produced five online university courses, hosts one and a half podcasts, and now writes a regular New York Times op-ed column.Rebroadcast: this episode was originally released in December 2022.YouTube video version: https://youtu.be/MEd7TT_nMJELinks to learn more, video, and full transcript: https://80k.link/JMWe ask him what we think are the most important things everyone ought to know about linguistics, including:Can you communicate faster in some languages than others, or is there some constraint that prevents that?Does learning a second or third language make you smarter or not?Can a language decay and get worse at communicating what people want to say?If children aren't taught a language, how many generations does it take them to invent a fully fledged one of their own?Did Shakespeare write in a foreign language, and if so, should we translate his plays?How much does language really shape the way we think?Are creoles the best languages in the world — languages that ideally we would all speak?What would be the optimal number of languages globally?Does trying to save dying languages do their speakers a favour, or is it more of an imposition?Should we bother to teach foreign languages in UK and US schools?Is it possible to save the important cultural aspects embedded in a dying language without saving the language itself?Will AI models speak a language of their own in the future, one that humans can't understand but which better serves the tradeoffs AI models need to make?We’ve also added John’s talk “Why the World Looks the Same in Any Language” to the end of this episode. So stick around after the credits!Chapters:Rob's intro (00:00:00)Who's John McWhorter? (00:05:02)Does learning another language make you smarter? (00:05:54)Updating Shakespeare (00:07:52)Should we bother teaching foreign languages in school? (00:12:09)Language loss (00:16:05)The optimal number of languages for humanity (00:27:57)Do we reason about the world using language and words? (00:31:22)Can we communicate meaningful information more quickly in some languages? (00:35:04)Creole languages (00:38:48)AI and the future of language (00:50:45)Should we keep ums and ahs in The 80,000 Hours Podcast? (00:59:10)Why the World Looks the Same in Any Language (01:02:07)Producer: Keiran HarrisAudio mastering: Ben Cordell and Simon MonsourVideo editing: Ryan Kessler and Simon MonsourTranscriptions: Katy Moore

It’s that magical time of year once again — highlightapalooza! Stick around for one top bit from each episode we recorded this year, including:Kyle Fish explaining how Anthropic’s AI Claude descends into spiritual woo when left to talk to itselfIan Dunt on why the unelected House of Lords is by far the best part of the British governmentSam Bowman’s strategy to get NIMBYs to love it when things get built next to their housesBuck Shlegeris on how to get an AI model that wants to seize control to accidentally help you foil its plans…as well as 18 other top observations and arguments from the past year of the show.Links to learn more, video, and full transcript: https://80k.info/best25It's been another year of living through history, whether we asked for it or not. Luisa and Rob will be back in 2026 to help you make sense of whatever comes next — as Earth continues its indifferent journey through the cosmos, now accompanied by AI systems that can summarise our meetings and generate adequate birthday messages for colleagues we barely know.Chapters:Cold open (00:00:00)Rob's intro (00:02:35)Helen Toner on whether we're racing China to build AGI (00:03:43)Hugh White on what he'd say to Americans (00:06:09)Buck Shlegeris on convincing AI models they've already escaped (00:12:09)Paul Scharre on a personal experience in Afghanistan that influenced his views on autonomous weapons (00:15:10)Ian Dunt on how unelected septuagenarians are the heroes of UK governance (00:19:06)Beth Barnes on AI companies being locally reasonable, but globally reckless (00:24:27)Tyler Whitmer on one thing the California and Delaware attorneys general forced on the OpenAI for-profit as part of their restructure (00:28:02)Toby Ord on whether rich people will get access to AGI first (00:30:13)Andrew Snyder-Beattie on how the worst biorisks are defence dominant (00:34:24)Eileen Yam on the most eye-watering gaps in opinions about AI between experts and the US public (00:39:41)Will MacAskill on what a century of history crammed into a decade might feel like (00:44:07)Kyle Fish on what happens when two instances of Claude are left to interact with each other (00:49:08)Sam Bowman on where the Not In My Back Yard movement actually has a point (00:56:29)Neel Nanda on how mechanistic interpretability is trying to be the biology of AI (01:03:12)Tom Davidson on the potential to install secret AI loyalties at a very early stage (01:07:19)Luisa and Rob discussing how medicine doesn't take the health burden of pregnancy seriously enough (01:10:53)Marius Hobbhahn on why scheming is a very natural path for AI models — and people (01:16:23)Holden Karnofsky on lessons for AI regulation drawn from successful farm animal welfare advocacy (01:21:29)Allan Dafoe on how AGI is an inescapable idea but one we have to define well (01:26:19)Ryan Greenblatt on the most likely ways for AI to take over (01:29:35)Updates Daniel Kokotajlo has made to his forecasts since writing and publishing the AI 2027 scenario (01:32:47)Dean Ball on why regulation invites path dependency, and that's a major problem (01:37:21)Video and audio editing: Dominic Armstrong, Milo McGuire, Luke Monsour, and Simon MonsourMusic: CORBITCoordination, transcripts, and web: Katy Moore

Most debates about the moral status of AI systems circle the same question: is there something that it feels like to be them? But what if that’s the wrong question to ask? Andreas Mogensen — a senior researcher in moral philosophy at the University of Oxford — argues that so-called 'phenomenal consciousness' might be neither necessary nor sufficient for a being to deserve moral consideration. Links to learn more and full transcript: https://80k.info/am25For instance, a creature on the sea floor that experiences nothing but faint brightness from the sun might have no moral claim on us, despite being conscious. Meanwhile, any being with real desires that can be fulfilled or not fulfilled can arguably be benefited or harmed. Such beings arguably have a capacity for welfare, which means they might matter morally. And, Andreas argues, desire may not require subjective experience. Desire may need to be backed by positive or negative emotions — but as Andreas explains, there are some reasons to think a being could also have emotions without being conscious. There’s another underexplored route to moral patienthood: autonomy. If a being can rationally reflect on its goals and direct its own existence, we might have a moral duty to avoid interfering with its choices — even if it has no capacity for welfare. However, Andreas suspects genuine autonomy might require consciousness after all. To be a rational agent, your beliefs probably need to be justified by something, and conscious experience might be what does the justifying. But even this isn’t clear. The upshot? There’s a chance we could just be really mistaken about what it would take for an AI to matter morally. And with AI systems potentially proliferating at massive scale, getting this wrong could be among the largest moral errors in history.In today’s interview, Andreas and host Zershaaneh Qureshi confront all these confusing ideas, challenging their intuitions about consciousness, welfare, and morality along the way. They also grapple with a few seemingly attractive arguments which share a very unsettling conclusion: that human extinction (or even the extinction of all sentient life) could actually be a morally desirable thing. This episode was recorded on December 3, 2025.Chapters:Cold open (00:00:00)Introducing Zershaaneh (00:00:55)The puzzle of moral patienthood (00:03:20)Is subjective experience necessary? (00:05:52)What is it to desire? (00:10:42)Desiring without experiencing (00:17:56)What would make AIs moral patients? (00:28:17)Another route entirely: deserving autonomy (00:45:12)Maybe there's no objective truth about any of this (01:12:06)Practical implications (01:29:21)Why not just let superintelligence figure this out for us? (01:38:07)How could human extinction be a good thing? (01:47:30)Lexical threshold negative utilitarianism (02:12:30)So... should we still try to prevent extinction? (02:25:22)What are the most important questions for people to address here? (02:32:16)Is God GDPR compliant? (02:35:32)Video and audio editing: Dominic Armstrong, Milo McGuire, Luke Monsour, and Simon MonsourCoordination, transcripts, and web: Katy Moore