We can guess what intergalactic war would look like. And strangely, it matters.

We can guess what intergalactic war would look like. And strangely, it matters.

Author: The 80,000 Hours team June 18, 2026 Duration: 15:16

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-space

This 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 Perlman

Producers: Elizabeth Cox and Nick Stockton

Coordination and support: Katy Moore and Lou Moran

Camera operator: Dominic Armstrong


The 80,000 Hours Podcast, from The 80,000 Hours team, digs into the complex and often overlooked questions surrounding how we can best use our careers to tackle the world's most pressing problems. While artificial intelligence is a recurring and critical theme, framing some of the most important conversations you won't hear elsewhere, the discussions range far wider into the intersections of technology, policy, philosophy, and global priorities. Hosts Rob Wiblin, Luisa Rodriguez, and Zershaaneh Qureshi guide in-depth interviews with researchers, policymakers, and practitioners, breaking down daunting ideas into actionable insights. You'll hear nuanced analyses of career paths, ethical dilemmas in emerging tech, and evidence-based strategies for creating a positive impact. This isn't about quick tips; it's about deep, substantive exploration of how specific choices and systemic changes can lead to a better future. The podcast lives in the Education and Technology categories because it fundamentally aims to equip listeners with the knowledge and perspective to navigate a rapidly changing world thoughtfully. Each episode is built on rigorous research, challenging assumptions while maintaining a conversational and accessible tone. Tune in for a consistently engaging and intellectually honest look at the forces shaping our century and the practical steps individuals can take within their own 80,000-hour working lives to make a meaningful difference.
Author: Language: English Episodes: 50

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