Analyzing the Physics Behind Lightsaber Blades in Star Wars

Mon, 04 May 2026 19:43:00 +0200

On Star Wars Day, the question of whether lightsaber blades have mass is examined through the lens of physics. While characters in the movies often call them 'laser swords,' lightsabers cannot be simple lasers, since real lasers are invisible from the side, do not stop at a fixed length, and cannot interact like physical objects. By considering mass and motion, the article explains that a lightsaber’s behavior during duels suggests it has mass. Using the concept of angular motion and the moment of inertia, it demonstrates that swinging a blade with mass behaves differently than a massless light beam. The article also references the rotation of a thrown lightsaber in 'Return of the Jedi,' showing that the center of mass indicates the blade contributes to its motion. In short, lightsabers must have a physical mass component to move convincingly as seen in the movies, though the glowing blade effect is likely a visual effect. This physics-based analysis clarifies why lightsaber duels appe