Every AI has a compass guiding its choices, from the shows Netflix recommends to the routes Google Maps suggests. That compass is the objective function—a mathematical scorecard telling the system what “success” looks like. By optimising this function, algorithms learn, adapt, and sometimes fail in unexpected ways. Understanding it reveals both AI’s power and its pitfalls.

In 2024, Google DeepMind's AlphaFold, an artificial intelligence system, won the Nobel Prize in Chemistry for solving the 50-year-old "protein folding problem"—a challenge crucial to understanding how proteins, vital molecular machines, achieve their precise 3D shapes, thereby transforming biological research and opening new frontiers in medicine.