Colloids, Cathodic protection and corrosion and erosion

Looking at these trees (fig 1), the poet in me sees a palm tree in the morning mist in the garden of a maharaja's palace; the chemist in me sees a liquid-in-gas colloid.¹ Tiny droplets of water, floating in air, formed as the air cooled overnight and became saturated with water vapour. Because of the small size, there is little or no tendency for them to settle out. The slight pinkish/yellow tint is because this photograph was taken shortly after sunrise, so the sun was low in the sky. The colloidal particles are about the same size as the wavelength of light. They reflect light in all directions but the shorter (blue) wavelengths are scattered more and you see the transmitted light, ie the remaining longer (red) wavelengths, giving the sky a pinkish yellow colour.