How to Optimize Rust for Slowness: Inspired by New Turing Machine Results

Up to this point, we’ve been talking about Turing machines — specifically, the longest-known 5- and 6-state machines that eventually halt. We ran the 5-state champion to completion and built visualizations to explore its behavior. But the discovery that it’s the longest halting machine with 5 states — and the identification of the 6-state contender — came from extensive research and formal proofs, not from running them step-by-step. That said, I’ve built a Rust-based visualizer that can emulate these machines for trillions of steps — just enough to explore their early behavior. But even 10 trillion steps isn’t an atom in a drop of water in the ocean compared to the full runtime of the 6-state machine. And running it as far as we did doesn’t get us any closer to understanding why it runs so long. Aside: Rust “interpreted” the Turing machines up to some point — reading their transition tables and applying the rules step by step. You could also say it “emulated” them, in that it reprodu ... Read full article.