Hello, I got a question about this famous graph of the spectrum given by a heated body, showing the classical line (which goes up) and planck's line (which gives the hill shape). How is this line continuous? Let's say my body is a lump of hydrogen, the only points on the graph should be the balmer, lyman, paschen etc wavelength. So I understand that the hotter the body is, the emission is more energetic and has shorter wavelength. But why it shows the entire spectrum and not only the allowed emission lines?