Black Hole Mysteries
Black holes are among the universe's most studied objects — yet fundamental mysteries remain.
The Information Paradox
The problem: Quantum mechanics says information can never be destroyed. But if something falls into a black hole and the black hole eventually evaporates (via Hawking radiation), where does the information go?
Hawking's original answer: It's lost. This violated quantum mechanics.
- Information escapes via subtle correlations in Hawking radiation
- Information is stored on the event horizon (holographic principle)
- Information escapes through wormholes
- Our understanding of quantum mechanics is incomplete
This remains unresolved. Solving it may require a theory of quantum gravity.
What's Inside?
The singularity: At a black hole's center, general relativity predicts infinite density — a point where space and time end.
But infinities in physics usually mean our theory is breaking down. What's really there?
- Our physics simply can't describe it
- Quantum effects prevent true singularity
- Something entirely unknown
We may never know — information can't escape to tell us.
Do Wormholes Exist?
General relativity permits wormholes — shortcuts through spacetime connecting distant points (or even different universes).
- No evidence they exist naturally
- Would require "exotic matter" with negative energy to stay open
- Time travel paradoxes if they work
Still, some physicists explore wormholes as possible solutions to the information paradox.
Firewall Paradox
A 2012 thought experiment suggested the event horizon might be a wall of fire that incinerates anything entering — contradicting general relativity's prediction of smooth passage.
This sparked intense debate still ongoing.
Dark Matter Connection?
Could primordial black holes (formed in the Big Bang) be dark matter? Some evidence is tantalizing, but observations haven't confirmed it.
What Black Holes Teach Us
- Quantum gravity
- The nature of spacetime
- The fate of information
- Perhaps the origin of the universe
They're laboratories for the most fundamental physics.
Related Reading
Listen to the Full Course
Explore the mysteries in Black Holes Explained.