I love puzzles, at least certain kinds of puzzles.

I do the New York Times Sunday Crosswords when I have time.

I went from Sudoku to other logic puzzles from this cult favorite Japanese puzzle magazine

called Nikol-E.

My family gets into jigsaw puzzles around the holidays each year.

Now, I'm not a mathematician or a computer scientist, but I also appreciate the puzzle-like

solving and structure of some mathematical proofs. And I suspect that the people who solve them

might derive an even greater sense of satisfaction from doing it,

especially the puzzles that take decades or even generations to figure out.

Welcome to the Quantum Podcast, where we explore the frontiers of fundamental science and math.

I'm Samir Patel, editor-in-chief of Quantum Magazine.

This week marks the first anniversary of the discovery of a solution to an unusual intellectual puzzle,

one that our computer science staff writer Ben Brubaker wrote about right when it happened last year in a

story called With the Fifth Busy Beaver Researchers Approach Computations Limits. Ben is with us today

to dig into the elusive and strange busy beaver game and the unexpected source of the latest

solution. Welcome back, Ben. Thanks. It's good to be back.

This is one of my favorite topics to talk about.

Let's start with what's the big idea?

Where are we going with our conversation today?

The Busy Beaver game is a mathematical puzzle about the strangest and like most unpredictable

things that simple computer programs can do.

And one thing I like about it is that it's

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