What is the effect of light traveling through a vacuum?

Light traveling through a vacuum is unique because it does not require a medium to propagate. In a vacuum, there are no particles to interact with the light waves, allowing them to travel at their maximum speed, which is approximately 299,792 kilometers per second (or the speed of light in a vacuum). This characteristic distinguishes light from sound, which needs a medium like air or water to move through.

The other effects mentioned do not apply in the context of a vacuum: light does not slow down, as it maintains its speed; it is not absorbed in a vacuum as there are no particles to absorb it; and there is no deflection or bending since light typically changes direction only when interacting with a medium or gravitational field. Thus, the fact that light does not require a medium to travel is fundamental to understanding its behavior in a vacuum.