Undecidability: Recursive Languages and Turing Machines

This lecture delves into the concept of undecidability, focusing on recursive languages, Turing machines, and the halting problem. The instructor explains how certain languages cannot be decided by a Turing machine, leading to the notion of indescribable problems. Through examples and proofs, the lecture demonstrates the complexity of determining the acceptance of languages by machines, ultimately showcasing the limitations of computation. The discussion also touches on the universal language of Turing machines and the implications of decidability and undecidability in computational theory.