In post 19.9, I wrote that light and other forms of electromagnetic radiation, are propagated as waves. What is the evidence for this statement? In the picture above, water waves (blue) on the sea, meet the entrance to a harbour that is protected by walls (black). The walls prevent the waves from entering the harbour… Continue reading 19.20 Diffraction – light is propagated as waves

Before you read this, I suggest that you read post 19.9. We know that hot objects can emit electromagnetic radiation because sometimes they are “red hot”; then they emit red light – a form of electromagnetic radiation (post 19.9). The wavelength of emitted radiation shifts to shorter wavelengths (longer frequencies, post 19.9) as the temperature… Continue reading 19.19 Radiation of heat