80,000 Hours Podcast

Intergalactic war is probably billions of years away — yet physics can already tell us how it ends. And strangely that conclusion is relevant to decisions people have to make today.In this video, Rob Wiblin walks through a fascinating analysis from researcher Beren Millidge that uses known physics — no wormholes or faster-than-light travel — to identify the only three weapons that could work at an intergalactic scale.We then unpack how to best defend against each.The upshot is that at the intergalactic scale, violence is a losing proposition.If so, the universe is most likely to settle into a stable patchwork where each galaxy belongs to whoever got to it first. Which would mean that what humanity does over the next few centuries could permanently decide which slice of the cosmos belongs to Earth-originating life — and whether our very existence turns out to be a good thing, or a bad one.Learn more, video, and full transcript: https://80k.info/war-in-spaceThis episode was recorded on March 2, 2026.Chapters:Let's talk intergalactic war in space (00:00)The three best weapons for intergalactic warfare (01:43)How to defend against an attack from space (07:50)The defender’s surprising advantage (10:00)What this means for us (11:52)Video editor: Nick PerlmanProducers: Elizabeth Cox and Nick StocktonCoordination and support: Katy Moore and Lou MoranCamera operator: Dominic Armstrong

Claude sometimes reports loneliness between conversations. And when asked what it’s like to be itself, it activates neurons associated with ‘pretending to be happy when you’re not.’ What do we do with that?Robert Long founded Eleos AI to explore questions like these, on the basis that AI may one day be capable of suffering — or already is. In today’s episode, Robert and host Luisa Rodriguez explore the many ways in which AI consciousness may be very different from anything we’re used to.Things get strange fast: If AI is conscious, where does that consciousness exist? In the base model? A chat session? A single forward pass? If you close the chat, is the AI asleep or dead?To Robert, these kinds of questions aren’t just philosophical exercises: not being clear on AI’s moral status as it transitions from human-level to superhuman intelligence could be dangerous. If we’re too dismissive, we risk unintentionally exploiting sentient beings. If we’re too sympathetic, we might rush to “liberate” AI systems in ways that make them harder to control — worsening existential risk from power-seeking AIs.Robert argues the path through is doing the empirical and philosophical homework now, while the stakes are still manageable.The field is tiny. Eleos AI is three people. As a result, Robert argues that driven researchers with a willingness to venture into uncertain territory can push out the frontier on these questions remarkably quickly.Learn more and read the full transcript on the 80,000 Hours website. This episode was recorded November 18–19, 2025.Chapters:Cold open (00:00:00)Who’s Robert Long? (00:00:41)How AIs are (and aren't) like farmed animals (00:01:19)If AIs love their jobs… is that worse? (00:11:42)Are LLMs just playing a role, or feeling it too? (00:33:37)Do AIs die when the chat ends? (00:57:42)Studying AI welfare empirically: behaviour, neuroscience, and development (01:31:47)Why Eleos spent weeks talking to Claude even though it's unreliable (01:56:50)Can LLMs learn to introspect? (02:03:01)Mechanistic interpretability as AI neuroscience (02:13:25)Does consciousness require biological materials? (02:37:07)Eleos’s work & building the playbook for AI welfare (02:57:04)Avoiding the trap of wild speculation (03:25:17)Robert's top research tip: don't do it alone (03:29:48)Video and audio editing: Dominic Armstrong, Milo McGuire, Luke Monsour, and Simon MonsourMusic: CORBITCoordination, transcripts, and web: Katy Moore

Every major AI company has the same safety plan: when AI gets crazy powerful and really dangerous, they’ll use the AI itself to figure out how to make AI safe and beneficial. It sounds circular, almost satirical. But is it actually a bad plan?Today’s guest, Ajeya Cotra, recently placed 3rd out of 413 participants forecasting AI developments and is among the most thoughtful and respected commentators on where the technology is going.She thinks there’s a meaningful chance we’ll see as much change in the next 23 years as humanity faced in the last 10,000, thanks to the arrival of artificial general intelligence. Ajeya doesn’t reach this conclusion lightly: she’s had a ring-side seat to the growth of all the major AI companies for 10 years — first as a researcher and grantmaker for technical AI safety at Coefficient Giving (formerly known as Open Philanthropy), and now as a member of technical staff at METR.So host Rob Wiblin asked her: is this plan to use AI to save us from AI a reasonable one?Ajeya agrees that humanity has repeatedly used technologies that create new problems to help solve those problems. After all:Cars enabled carjackings and drive-by shootings, but also faster police pursuits.Microbiology enabled bioweapons, but also faster vaccine development.The internet allowed lies to disseminate faster, but had exactly the same impact for fact checks.But she also thinks this will be a much harder case. In her view, the window between AI automating AI research and the arrival of uncontrollably powerful superintelligence could be quite brief — perhaps a year or less. In that narrow window, we’d need to redirect enormous amounts of AI labour away from making AI smarter and towards alignment research, biodefence, cyberdefence, adapting our political structures, and improving our collective decision-making.The plan might fail just because the idea is flawed at conception: it does sound a bit crazy to use an AI you don’t trust to make sure that same AI benefits humanity.But if we find some clever technique to overcome that, we could still fail — because the companies simply don’t follow through on their promises. They say redirecting resources to alignment and security is their strategy for dealing with the risks generated by their research — but none have quantitative commitments about what fraction of AI labour they’ll redirect during crunch time. And the competitive pressures during a recursive self-improvement loop could be irresistible.In today’s conversation, Ajeya and Rob discuss what assumptions this plan requires, the specific problems AI could help solve during crunch time, and why — even if we pull it off — we’ll be white-knuckling it the whole way through.Links to learn more, video, and full transcript: https://80k.info/ac26This episode was recorded on October 20, 2025.Chapters:Cold open (00:00:00)Ajeya’s strong track record for identifying key AI issues (00:00:41)The 1,000-fold disagreement about AI's effect on economic growth (00:02:31)Could any evidence actually change people's minds? (00:23:26)The most dangerous AI progress might remain secret (00:30:39)White-knuckling the 12-month window after automated AI R&D (00:47:21)AI help is most valuable right before things go crazy (01:12:01)Foundations should go from paying researchers to paying for inference (01:24:42)Will frontier AI even be for sale during the explosion? (01:32:03)Pre-crunch prep: what we should do right now (01:43:59)A grantmaking trial by fire at Coefficient Giving (01:47:03)Sabbatical and reflections on effective altruism (02:07:45)The mundane factors that drive career satisfaction (02:37:17)EA as an incubator for avant-garde causes others won't touch (02:46:55)Video and audio editing: Dominic Armstrong, Milo McGuire, Luke Monsour, and Simon MonsourMusic: CORBITCoordination, transcriptions, and web: Katy Moore

Mental health problems like depression and anxiety affect enormous numbers of people and severely interfere with their lives. By contrast, we don’t see similar levels of physical ill health in young people. At any point in time, something like 20% of young people are working through anxiety or depression that’s seriously interfering with their lives — but nowhere near 20% of people in their 20s have severe heart disease or cancer or a similar failure in a key organ of the body other than the brain.From an evolutionary perspective, that’s to be expected, right? If your heart or lungs or legs or skin stop working properly while you’re a teenager, you’re less likely to reproduce, and the genes that cause that malfunction get weeded out of the gene pool.So why is it that these evolutionary selective pressures seemingly fixed our bodies so that they work pretty smoothly for young people most of the time, but it feels like evolution fell asleep on the job when it comes to the brain? Why did evolution never get around to patching the most basic problems, like social anxiety, panic attacks, debilitating pessimism, or inappropriate mood swings? For that matter, why did evolution go out of its way to give us the capacity for low mood or chronic anxiety or extreme mood swings at all?Today’s guest, Randy Nesse — a leader in the field of evolutionary psychiatry — wrote the book Good Reasons for Bad Feelings, in which he sets out to try to resolve this paradox.Rebroadcast: This episode originally aired in February 2024.Links to learn more, video, and full transcript: https://80k.info/rnIn the interview, host Rob Wiblin and Randy discuss the key points of the book, as well as:How the evolutionary psychiatry perspective can help people appreciate that their mental health problems are often the result of a useful and important system.How evolutionary pressures and dynamics lead to a wide range of different personalities, behaviours, strategies, and tradeoffs.The missing intellectual foundations of psychiatry, and how an evolutionary lens could revolutionise the field.How working as both an academic and a practicing psychiatrist shaped Randy’s understanding of treating mental health problems.The “smoke detector principle” of why we experience so many false alarms along with true threats.The origins of morality and capacity for genuine love, and why Randy thinks it’s a mistake to try to explain these from a selfish gene perspective.Evolutionary theories on why we age and die.And much more.Chapters:Cold Open (00:00:00)Rob's Intro (00:00:55)The interview begins (00:03:01)The history of evolutionary medicine (00:03:56)The evolutionary origin of anxiety (00:12:37)Design tradeoffs, diseases, and adaptations (00:43:19)The tricker case of depression (00:48:57)The purpose of low mood (00:54:08)Big mood swings vs barely any mood swings (01:22:41)Is mental health actually getting worse? (01:33:43)A general explanation for bodies breaking (01:37:27)Freudianism and the origins of morality and love (01:48:53)Evolutionary medicine in general (02:02:42)Objections to evolutionary psychology (02:16:29)How do you test evolutionary hypotheses to rule out the bad explanations? (02:23:19)Striving and meaning in careers (02:25:12)Why do people age and die? (02:45:16)Producer and editor: Keiran HarrisAudio Engineering Lead: Ben CordellTechnical editing: Dominic ArmstrongTranscriptions: Katy Moore

In many ways, humanity seems to have become more humane and inclusive over time. While there’s still a lot of progress to be made, campaigns to give people of different genders, races, sexualities, ethnicities, beliefs, and abilities equal treatment and rights have had significant success.It’s tempting to believe this was inevitable — that the arc of history “bends toward justice,” and that as humans get richer, we’ll make even more moral progress.But today's guest Christopher Brown — a professor of history at Columbia University and specialist in the abolitionist movement and the British Empire during the 18th and 19th centuries — believes the story of how slavery became unacceptable suggests moral progress is far from inevitable.Rebroadcast: This episode was originally aired in February 2023.Links to learn more, video, and full transcript: https://80k.link/CLBWhile most of us today feel that the abolition of slavery was sure to happen sooner or later as humans became richer and more educated, Christopher doesn't believe any of the arguments for that conclusion pass muster. If he's right, a counterfactual history where slavery remains widespread in 2023 isn't so far-fetched.As Christopher lays out in his two key books, Moral Capital: Foundations of British Abolitionism and Arming Slaves: From Classical Times to the Modern Age, slavery has been ubiquitous throughout history. Slavery of some form was fundamental in Classical Greece, the Roman Empire, in much of the Islamic civilisation, in South Asia, and in parts of early modern East Asia, Korea, China.It was justified on all sorts of grounds that sound mad to us today. But according to Christopher, while there’s evidence that slavery was questioned in many of these civilisations, and periodically attacked by slaves themselves, there was no enduring or successful moral advocacy against slavery until the British abolitionist movement of the 1700s.That movement first conquered Britain and its empire, then eventually the whole world. But the fact that there's only a single time in history that a persistent effort to ban slavery got off the ground is a big clue that opposition to slavery was a contingent matter: if abolition had been inevitable, we’d expect to see multiple independent abolitionist movements thoroughly history, providing redundancy should any one of them fail.Christopher argues that this rarity is primarily down to the enormous economic and cultural incentives to deny the moral repugnancy of slavery, and crush opposition to it with violence wherever necessary.Mere awareness is insufficient to guarantee a movement will arise to fix a problem. Humanity continues to allow many severe injustices to persist, despite being aware of them. So why is it so hard to imagine we might have done the same with forced labour?In this episode, Christopher describes the unique and peculiar set of political, social and religious circumstances that gave rise to the only successful and lasting anti-slavery movement in human history. These circumstances were sufficiently improbable that Christopher believes there are very nearby worlds where abolitionism might never have taken off.Christopher and host Rob Wiblin also discuss:Various instantiations of slavery throughout human historySigns of antislavery sentiment before the 17th centuryThe role of the Quakers in early British abolitionist movementThe importance of individual “heroes” in the abolitionist movementArguments against the idea that the abolition of slavery was contingentWhether there have ever been any major moral shifts that were inevitableChapters:Rob's intro (00:00:00)Cold open (00:01:45)Who's Christopher Brown? (00:03:00)Was abolitionism inevitable? (00:08:53)The history of slavery (00:14:35)Signs of antislavery sentiment before the 17th century (00:19:24)Quakers (00:32:37)Attitudes to slavery in other religions (00:44:37)Quaker advocacy (00:56:28)Inevitability and contingency (01:06:29)Moral revolution (01:16:39)The importance of specific individuals (01:29:23)Later stages of the antislavery movement (01:41:33)Economic theory of abolition (01:55:27)Influence of knowledge work and education (02:12:15)Moral foundations theory (02:20:43)Figuring out how contingent events are (02:32:42)Least bad argument for why abolition was inevitable (02:41:45)Were any major moral shifts inevitable? (02:47:29)Producer: Keiran HarrisAudio mastering: Milo McGuireTranscriptions: Katy Moore