Scientists from Google’s DeepMind subsidiary and the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland have shown that artificial intelligence (AI) can help control the delicate process of confining an ultra-hot plasma within a fusion reactor. They say their demonstration exploits a technique known as reinforcement learning to operate the magnetic coils in a tokamak. Tokamaks are doughnut-shaped chambers designed to produce energy by fusing light nuclei in the form of a plasma. The nuclei are heated to hundreds of millions of degrees to overcome their mutual repulsion, while the plasma is held in place using the fields from a series of magnetic coils. Those fields keep the plasma away from the chamber’s walls. . . .