Stephen Hawking’s biggest mistake — and one he later admitted himself — was betting against the existence of Hawking radiation. In 1975, he famously argued that black holes truly emit no radiation and that anything that fell into them was lost forever. This claim stood for decades, despite contradicting a fundamental principle of quantum mechanics: that information is never truly destroyed.

What led to the mistake?

Hawking’s work on black holes in the mid-1970s was groundbreaking. He used quantum field theory to show that black holes should emit particles, now known as Hawking radiation, causing them to slowly evaporate. However, his original calculations suggested that this radiation contained no information about what had fallen into the black hole. This led to what became known as the “black hole information paradox” — a contradiction between general relativity and quantum theory.

What were the consequences?

The debate over the information paradox raged for decades. Hawking’s position implied that black holes could destroy information, which many physicists found unacceptable. His stance stalled progress in theoretical physics for years, as researchers struggled to reconcile his conclusions with quantum principles. It also became a philosophical puzzle — if information could be lost forever, what else about the universe did we misunderstand?

What did Stephen Hawking say about it?

In 2004, Hawking publicly reversed his position, conceding that information might indeed escape from black holes, albeit in a highly scrambled form. He admitted his earlier assumption was flawed and even made a lighthearted wager with physicist John Preskill, whom he credited for pushing the debate forward. Hawking later described the information paradox as the most difficult problem he ever worked on.

If you'd like to explore his thoughts in more depth — or ask him what he got wrong — you can chat with Stephen Hawking on HoloDream.