Light's ability to travel through a vacuum is supported by various pieces of evidence, including observations of light from celestial bodies that have traversed the vacuum of space. The discussion highlights that light can be seen after traveling through a vacuum, as evidenced by starlight reaching Earth. Additionally, Maxwell's equations provide a mathematical foundation, demonstrating that electromagnetic waves, including light, do not require a medium for propagation. The existence of a vacuum in space is a constant, further supporting this phenomenon. Overall, the evidence strongly indicates that light can indeed travel through a vacuum.