USC Physicist's Two-Time Theory Tackles Black Hole Paradox — SkimNews
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- Itzhak Bars at the University of Southern California unveiled "two-time physics" in 1998, a framework with four space dimensions and two time dimensions built on treating position and momentum as interchangeable descriptions of reality.
- A 2013 collaboration with Paul Steinhardt at Princeton and Neil Turok (now at Edinburgh) predicted particle masses dwindle toward zero as a collapsing universe approaches a "big crunch," then pass through a phase of repulsive gravity before a new big bang.
- Bars returned to the framework in 2025, arguing particles falling into a black hole continue through the singularity into a region where gravity flips to become repulsive — preserving information that Stephen Hawking's 1970s radiation result suggested should disappear.
- Federica Muscolino at the University of Milan-Bicocca called the approach "highly innovative," saying it "resolves the problems posed by singularities in the universe and provides a solution to the black hole information paradox."
- The framework sidesteps the usual pitfalls of multiple time dimensions because once you choose one vantage (position vs. momentum), one space and one time dimension effectively drop out — leaving familiar space-time and eliminating causal paradoxes.
- Chris Hull at Imperial College London warned that naive two-time models would let an observer "go around any event you wanted to avoid," making "biology as we know it…very hard to envisage."
Why it matters: Bars's two-time physics is unusually testable for speculative work — astronomers can search for varying particle masses and other supposedly fixed constants in extreme cosmic environments. Confirmation would offer rare empirical evidence for hidden geometric structure beneath ordinary physics and resolve an information paradox that has stumped quantum gravity researchers since Hawking flagged it in the 1970s.
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