Firewall Paradox Explored

In 2012, physicists Almheiri, Marolf, Polchinski, and Sully proposed the firewall paradox. If information must escape a black hole as quantum mechanics demands, then the event horizon cannot be the smooth, uneventful boundary that general relativity predicts. Instead, it might be a wall of high-energy particles — a firewall — that incinerates anything crossing it.

This contradicts Einstein's equivalence principle, which says a freely falling observer should notice nothing special at the horizon. The firewall paradox forces physicists to choose between two pillars of modern physics, and no consensus has been reached. Resolving it may require an entirely new framework.