Notes on Time’s Enigma

Part of the Fundamental Theories of Physics book series (FTPH, volume 172)


Scientists continue to wrestle with the enigma of time. Is time a dynamic or a fundamental property of spacetime? Why does it have an arrow pointing from past to future? Why are physical laws time-symmetric in a universe with broken time-reversal symmetry? These questions remain a mystery. The hope has been that an understanding of the selection of the initial state for our universe would solve such puzzles, especially that of times arrow. In this contribution, I discuss how the birth of the universe from the multiverse helps to unravel the nature of time and the reasons behind the time-reversal symmetry of our physical laws. I make the distinction between a local emerging arrow of time in the nucleating universe and the fundamental time with no arrow in the multiverse. The very event of nucleation of the universe from the multiverse breaks time-reversal symmetry, inducing a locally emergent arrow. But, the laws of physics imprinted on this bubble are not processed at birth. Time-reversal symmetry of laws in our universe is inherited from its birth in the multiverse, since these laws originate from the arrowless multiversal time.


Local Observer Bubble Nucleation High Energy State Fundamental Building Block Superselection Rule 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



L.M-H is grateful to DAMTP for their hospitality during the time this work was done. LM-H is supported in part by DOE grant DE-FG02-06ER1418, NSF grant PHY-0553312 and FQXI.


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© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Department of Physics and AstronomyUNC-Chapel HillChapel HillUSA
  2. 2.Department of Applied Mathematics and Theoretical PhysicsCambridge UniversityCambridgeUK

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