> Shouldn't we see light fill all of the sky at night No, due to the universe expanding, the wavelength of visible light gets longer as it travels massive dist

> Shouldn't we see light fill all of the sky at night No, due to the universe expanding, the wavelength of visible light gets longer as it travels massive distances, as such it moves out of the visible spectrum. This is why most of the deep field mapping of the universe is done via radio waves.