Interview, Fireside Chat
War in space, grabby aliens, and the lifespan of civilisations | Anders Sandberg
- Civilizational collapse is predicted to result primarily from random bad luck rather than intrinsic decay, following an exponential hazard curve with a constant rate rather than age-related vulnerability.
- Long-term survival strategies involve creating multiple copies of civilizations or backup societies to facilitate resettlement after local crashes.
- Galactic dynamics project a collision between the Milky Way and Andromeda in approximately 5 billion years, with a subsequent dissolution of stars into outer darkness or central black holes over timescales exceeding $10^{20}$ years.
- Universal expansion will cause galaxies to move apart, making intergalactic travel impossible in a few hundred billion years and rendering communication across such distances potentially taking a billion years.
- Future life is expected to shift from biological to purely machine-based or virtual forms due to environmental flexibility, though virtual existence faces risks of societal disengagement.
- Human interstellar colonization is projected to rely on relativistic robots or nanobot-raised embryos grown from transported cells, as direct biological travel is deemed too unwieldy.
- Space habitats and ecosystems are forecasted to become the primary location for life due to superior surface area and resource access compared to planetary surfaces.
- Energy extraction capabilities may utilize black holes for up to 40% of mass-energy via accretion disks, or employ "black hole bombs" to extract rotational energy, surpassing fusion efficiency.
- Fundamental physical limits include a finite upper bound on information storage and value per unit of matter, while material shielding is constrained by the hardness of carbon monoxide and diamond structures.
- Resource constraints include eventual depletion of Big Bang-era deuterium and the potential for matter to spontaneously disintegrate over extremely long timescales due to thermodynamic principles.
- Warfare is anticipated to shift toward information-based weapons, computer viruses, and memes, with kinetic attacks becoming less effective as mobile spacecraft are harder to target than static planets.
- Scientific acceleration may be driven by AI overcoming human biological processing limits, though the current slowdown is attributed to static human cognitive capacity rather than institutional decline.
- Advanced technologies like room-temperature superconductors have an estimated 15% probability of revolutionizing long-term energy storage, while the existence of dark matter could alter current cosmological arguments.
- Cosmological scenarios favor standard exponential expansion (dark energy parameter 'w' near -1), making the "Big Rip" scenario unlikely, though the "Stelliferous era" offers a timeframe of 10 to 100 trillion years for stellar activity.
- The "grabby aliens" hypothesis suggests humans occupy a privileged time window just before rapid expansion settles the universe, potentially leaving future observers as the only surviving big minds.
- Existential risks such as false vacuum decay are viewed as local rather than universal due to cosmic expansion, while the simulation hypothesis offers no decision-relevant information without known constraints.
- Engineering challenges for interstellar travel include managing self-repair mechanisms for ultra-reliability and mitigating the risk of relativistic probes exploding upon impact with dust grains.
- Ethical and strategic behaviors of post-human civilizations may diverge from utility maximization, potentially adopting virtue-ethics that favor "satisficing" over infinite accumulation or expansion.
- Observational evidence for extraterrestrial intelligence, including UAP sightings, is largely compatible with mundane optical explanations or sophisticated hiding by nano-civilizations.
- Temporal concepts may be non-linear, with theories of retrocausation or "on the fly" universe construction challenging standard linear time views.