Nikodem Popławski (born 1975) is a theoretical physicist at the University of New Haven, most widely noted for the theory that every black hole is a doorway to another universe and that the Universe was formed within a black hole which itself exists in a larger universe. This theory was listed by National Geographic and Science magazines among their top ten discoveries of 2010. Popławski appeared in Episode 5 of a Discovery Channel show Curiosity, titled "Parallel Universes - Are They Real?", which was hosted by Morgan Freeman and aired in 2011.
Popławski's theory is based on the Einstein-Cartan-Sciama-Kibble theory of gravity which extends general relativity to matter with intrinsic angular momentum (spin). Spin in curved spacetime requires that the affine connection cannot be constrained to zero and its antisymmetric part, the torsion tensor, must be a variable in Hamilton's principle of stationary action which gives the field equations. Torsion gives the correct generalization of the conservation law for the total (orbital plus intrinsic) angular momentum to the presence of the gravitational field, but also modifies the Dirac equation for fermions.
Gravitational effects of torsion on fermionic matter are significant at extremely high densities which exist inside black holes and at the beginning of the Universe. Popławski theorizes that torsion manifests itself as a repulsive force which causes fermions to be spatially extended and prevents the formation of a gravitational singularity within the black hole's event horizon. Because of torsion, the collapsing matter on the other side of the horizon reaches an enormous but finite density, explodes and rebounds, forming an Einstein-Rosen bridge (wormhole) to a new, closed, expanding universe. Analogously, the Big Bang is replaced by the Big Bounce before which the Universe was the interior of a black hole. This scenario also explains why the present Universe at largest scales appears spatially flat, homogeneous and isotropic, providing a physical alternative to cosmic inflation, and may explain the arrow of time and solve the black hole information paradox. Torsion may also be responsible for the observed asymmetry between matter and antimatter in the Universe. The rotation of a black hole would influence the spacetime on the other side of its event horizon and result in a preferred direction in the new universe. Popławski suggests that the observed anomalies in the cosmic microwave background might thus provide evidence for his theory.
- National Geographic Daily News: "Every Black Hole Contains Another Universe?"
- Science Now: "Does Our Universe Live Inside a Wormhole?"
- Space.com: "Our Universe Was Born in a Black Hole, Theory Says"
- Telegraph: "A universe could exist 'inside every black hole,' claims scientist"
- "Every black hole may hold a hidden universe" in New Scientist, Vol. 207, No. 2770, p. 9 (2010)
- "Cosmologist's theory about black holes puts a new spin on the universe", Washington Post
- Inside Science: "Every Black Hole Contains a New Universe"
- Fox News: "Every black hole contains a new universe"
- National Geographic Daily News: "Top Ten Discoveries of 2010: Nat Geo News's Most Popular"
- Science Now: "Top 10 ScienceNOWs of 2010"
- Discovery Channel: Curiosity: "Parallel Universes - Are They Real?"
- N. J. Popławski (2010). "Nonsingular Dirac particles in spacetime with torsion". Physics Letters B 690 (1): 73–77. arXiv:0910.1181. doi:10.1016/j.physletb.2010.04.073.
- N. J. Popławski (2010). "Radial motion into an Einstein-Rosen bridge". Physics Letters B 687 (2–3): 110–113. arXiv:0902.1994. doi:10.1016/j.physletb.2010.03.029.
- N. J. Popławski (2010). "Cosmology with torsion: An alternative to cosmic inflation". Physics Letters B 694 (3): 181–185. arXiv:1007.0587. doi:10.1016/j.physletb.2010.09.056.
- N. Popławski (2012). "Nonsingular, big-bounce cosmology from spinor-torsion coupling". Physical Review D 85 (10): 107502. arXiv:1111.4595. doi:10.1103/PhysRevD.85.107502.
- N. J. Popławski (2011). "Matter-antimatter asymmetry and dark matter from torsion". Physical Review D 83 (8): 084033. arXiv:1101.4012. doi:10.1103/PhysRevD.83.084033.