Mathematics
The Lambda Calculus and Its Role in Computability Theory
Quick fact
The lambda calculus is Turing complete, meaning it can compute exactly the same set of functions as a Turing machine, yet it uses only functions and their applications—no state, no memory, no numbers initially.
Why this is interesting
What if the only building block of all computation was a function? That's the radical idea behind the lambda calculus—a system so simple it can define everything, including numbers and logic.