IT seems very improbable that the bright line spectrum of the inner corona can be attributed to thermal excitation of the coronal matter. We may seek its cause in the process of photoelectric ...

THE following way of showing the reversal of the bright line spectrum of metals may be of some interest to lecturers. I have not, so far, seen the method described.

Hot gases don’t produce a continuous emission spectrum. Black hydrogen absorption lines are at the same wavelength as the bright hydrogen emission lines. Key fact Line emission spectra are ...

gave a bright line spectrum, proving that they are gaseous in nature. Helium was discovered in the sun in 1869 and a green line was observed in the spectrum, which proved to be unaccounted for in ...