Markov Chain Norris =link= «Fully Tested»

He began to write a different chapter instead. He called it The Weight of Yesterday: Why the Past Always Returns .

On the last morning, the sun broke through the Cambridge rain. Chloe died at 7:43 a.m., with her hand in his. Alistair Norris returned to his college rooms. He sat at his desk. The silver die-shaped letter opener lay where he’d left it. He opened the drawer marked "Past States." Inside, beneath a folded program from a long-ago conference, was the postcard of the Maine lighthouse. markov chain norris

She reached out a thin hand. He took it. Her fingers were cold. And then, for the first time in eleven years, he did something that was not in any of his textbooks: he remembered. He began to write a different chapter instead

His wife, Eleanor, had left him eleven years ago. He did not dwell on it. The past is irrelevant , he would tell himself. Today I am alone. Tomorrow I may not be. No need to carry the weight of yesterday. Chloe died at 7:43 a

He was a man who believed in the elegance of forgetting. Not memory loss, but conditional independence : the future should depend only on the present, not the past. It was the central tenet of his life’s work—the Markov chain. And for twenty-three years, he had applied it to everything: the movement of gas molecules, the rise and fall of stock prices, the shuffling of a deck of cards. Even to himself.