Fine-grained analysis of a molecular biology how-to video reveals significant features of rationality in practice. https://metarationality.com/rational-pcr   This is one of several standalone essays by David Chapman I'm incorporating into the unwritten sections of In The Cells Of The Eggplant, for the audiobook version.   The Britannica entry on PCR: https://www.britannica.com/science/polymerase-chain-reaction   The Khan Academy explainer on PCR: https://www.youtube.com/watch?v=nHi-3jP6Mvc&ab_channel=KhanAcademy   You can support the podcast and get episodes a week early, by supporting the Patreon: https://www.patreon.com/m/fluidityaudiobooks   If you like the show, consider buying me a coffee: https://www.buymeacoffee.com/mattarnold   Original music by Kevin MacLeod.   This podcast is under a Creative Commons Attribution Non-Commercial International 4.0 License.