Experimental study on visualisation of the Zeeman effect based on flame shadows

Abstract When sodium chloride granules are introduced into a flame illuminated by a sodium lamp, a shadow forms behind the flame. Under the influence of an externally applied steady magnetic field, the Zeeman effect can be directly observed through changes in the shadow’s brightness. This experimental design demonstrates that the Zeeman effect causes the shadow’s colour to lighten as the degree of energy level splitting increases, thereby achieving a visualisation of the Zeeman effect. This experimental approach enables visual observation of the Zeeman effect using low-cost apparatus, thereby resolving the issue of expensive traditional experimental equipment.