Black Holes Flip To White, Solving Cosmic Mystery
New theory sees black holes ending as long-lived white holes.
Scientists propose black holes tunnel into white holes, potentially solving the black hole information paradox.
The Cosmic Riddle: Information Paradox
For decades, physicists have wrestled with a cosmic riddle: What happens to stuff that falls into a black hole? The black hole information paradox challenges one of physics' most fundamental rules: that information can never truly be destroyed.
The Proposed Solution: White Hole Transformation
New research suggests a surprising solution might unfold at the very end of a black hole’s life.
A team of researchers explored the strange world where black holes shrink and eventually disappear due to Hawking radiation, a process where black holes slowly lose mass. They asked if, at the very end of this process, a black hole might not just fade away but transform into something entirely different: a white hole.
Think of a white hole as the opposite of a black hole — nothing can enter, and everything is pushed out.
How the Transformation Works
The scientists used complex theoretical models, blending established ideas like general relativity and quantum field theory with newer concepts from quantum gravity, particularly Loop Quantum Gravity. They focused on how a black hole could "quantum tunnel" into a white hole.
Quantum tunneling is a bizarre quantum phenomenon where a particle can pass through a barrier even if it doesn't have enough energy to do so, almost like a ghost walking through a wall.
Their findings are striking:
- As a black hole shrinks due to evaporation, the chances of it tunneling into a white hole skyrocket.
- This tunneling probability is very low for large black holes but becomes significant when the black hole's mass approaches the incredibly tiny Planck mass.
- The black hole's lifespan depends on its initial mass, while the resulting white hole could exist for an incredibly long time,
lasting much longer than the black hole itself.
"As a black hole evaporates, the probability to tunnel into a white hole increases," the authors noted. "Before reaching sub-Planckian size, the probability ceases to be suppressed and the black hole tunnels into a white hole."
This extended lifespan is key because it allows enough time for all the trapped information to eventually escape. The researchers say that an old black hole could have a surprisingly large interior volume, which would be preserved even after it morphs into a tiny, Planck-sized white hole. This massive internal space, despite the white hole's small external appearance, helps ensure its stability.
Challenges and Future Outlook
This theory still faces challenges as it relies purely on theoretical models and assumptions about how quantum gravity works. Critics might question the stability of these proposed long-lived white holes.
However, the researchers argue that their scenario bypasses these issues because the white hole is:
- Protected by a special "anti-trapping" horizon.
- Maintains a vast internal volume.
Future research will need to explore these concepts further and test the stability of such exotic objects.
This cosmic flip from black to white could elegantly explain how information thought lost in a black hole is ultimately preserved, maintaining the universe's fundamental bookkeeping.
Source:
E. Bianchi, M. Christodoulou, F. D’Ambrosio, H. M. Haggard, and C. Rovelli, "White Holes as Remnants: A Surprising Scenario for the End of a Black Hole," arXiv:1802.04264 [gr-qc].