What was the incorrect assumption about how distant starlight could reach Earth, according to the astronomy expert in the film?

The assumption that light is created in every place between two points is considered incorrect because it implies that light does not travel through space in a continuous manner but rather appears or is generated spatially throughout the journey from distant stars to Earth. This idea contradicts the well-established understanding of physics that light travels as a wave or particle through the vacuum of space at a speed determined by the laws of physics.

This concept touches upon the fundamental principles of how light behaves and the nature of space-time. According to the current scientific understanding, light emitted from a star travels through the vacuum of space following the laws of physics, rather than being spontaneously generated at various points along its path. Recognizing that light originates from a specific source and propagates over distance helps to maintain the integrity of astronomical observations and interpretations of the universe.