What would the properties of an infinitely long wavelength of light be? And what about a wavelength of light that is infinitely short? What would that look like?
edit: light as in electromagnetic waves, not visible light. Sorry if it was not very clear
I mean, the expansion of the universe is a wave propagating with a potentially infinite wavelength. Not necessary for it to be any light stretching from the beginning of the universe, but also not impossible afaik.
The wave would probably interact weakly with anything making it very hard to detect. And depending on the initial burst it will probably also have it’s energy too spread out to be of any noticeable amplitude.