Lecture, Keynote
Do we live in a multiverse?
- The universe may extend far beyond the observable horizon, potentially stretching to infinity or being billions of times larger, with inflation possibly occurring at different times to create isolated "bubble" or "pocket" universes.
- Ongoing inflation could result in a self-reproducing, eternally growing fractal structure, generating an infinite number of pocket universes that may possess physical laws totally different from our own, potentially lacking gravity, a periodic table, or stable stars.
- Theoretical frameworks suggest that most universes within a multiverse will be sterile or stillborn due to laws that prevent complex structures, though string theory solutions not matching our universe may represent reality elsewhere.
- In Tegmark's third type of multiverse, physical laws remain constant while every quantum uncertainty outcome manifests, causing the universe to constantly split into daughter universes where each observer experiences only a single reality, such as a 50-50 chance of a photon passing through a polarizer at 45 degrees.
- The Level 4 multiverse posits that every coherent mathematical system may describe a physical reality, while the existence of the multiverse remains an empirical question that could potentially be confirmed by future observational data supporting inflation.
- Scientists face challenges in developing physics theories that predict only observed phenomena, and while direct observation of the multiverse may be impossible, future data may provide enough support to confirm its existence or the theories predicting it.
- Confirmation of the multiverse would provide a new perspective on the cosmos and humanity's place within it, though the scientific consensus remains that the jury is still out on its existence and it is currently regarded as a reasonable speculation rather than a proven fact.