Eon

This book by Greg Bear came up once on Lex Fridman in the episodes we index. That mention was a genuine on-air recommendation, not just a passing reference. The people who brought it up: Adam Frank. Every occurrence below links to the episode page and to the exact second it was said on YouTube.

"Perhaps it wasn't from our time, perhaps it wasn't even from our universe, but perhaps the arrival of the 300 km long stone was the answer to humanity's desperate plea to end the threat of nuclear war. Inside the deep recesses of the stone lies Thistledown: the remnants of a human society, versed in English, Russian and Chinese. The artifacts of this familiar people foretell a great Death caused by the ravages of war, but the government and scientists are unable to decide how to use this knowledge. Deeper still within the stone is the Way.