I was watching a documentary about the sun and space and started drifting in the different thoughts that the program evoked in me. While imagining what was happening “out there” in space, I realized that I visually represent it in my mind, and I know that it is not just visual. I know that these are just impressions that happen on our eyes. The sounds the phenomena create (and they are quite noisy) are reverberations of the medium they are in, and what we call sound is just the impression left on our minds.