If you look at light as a wave, then there no gaps unless specifically placed there on purpose. Of course, if you repeatedly turn on and off a flashlight, the light beam coming from your flashlight will have gaps. Similarly, if you shine a continuous beam of light through a shutter that is repeatedly opening and closing, you can create gaps. But if you shine a continuous beam of light into free space, the wave will start with no gaps and therefore develop no gaps as it travels. Waves are field oscillations that are spread out smoothly through space. Spreading out a wave over a larger area just causes the wave strength to weaken, but does not cause gaps to form. Therefore, if you look at photons as waves, spatial gaps never form in light as it travels through free space, no matter how dim it gets. The light from a distance star indeed spreads out and weakens as it travels, but this just reduces the wave strength and does not introduce gaps. Can momentum be hidden to human eyes like how kinetic energy can be hidden as heat?