Big Think

The Universe in 90 minutes: Time, free will, God, & more | Sean Carroll

25 snips
Nov 6, 2025
In this engaging discussion, theoretical physicist Sean Carroll delves into the intricacies of the multiverse, revealing how quantum mechanics leads to infinite possible worlds. He explores profound questions of time and entropy, linking them to the structure of the universe and the emergence of life. Carroll also tackles free will, defending a compatibilist view and examining how human agency fits within a scientifically understood reality. His insights make complex concepts accessible and spark deep reflection on existence and decision-making.
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INSIGHT

Multiverse In Culture Versus Physics

  • Popular culture imagines multiverses as narratively interactive alternate timelines, but scientists mean theories that predict other regions or branches.
  • Hollywood often ignores the physics constraints that determine which alternatives are possible.
INSIGHT

Multiverse Emerges From Physics, Not Wishful Thinking

  • Physicists accept multiverse ideas when simple theories that explain observations unavoidably predict other universes.
  • We test theories by comparing their predictions for what we observe, not by directly observing other universes.
INSIGHT

Many-Worlds Means Local Branching

  • Many-worlds quantum mechanics says every possible measurement outcome that the equations allow happens in different branches.
  • Those branches coexist here and can lead to very different macroscopic outcomes if quantum events amplify.
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