Chapter27

Brightm = 3m = 2m = 1m = 0m = 1m = 2m = 3Darkm = 3m = 2m = 1m = 0m = 0m = 1m = 2m = 3This is what a typical doubleslit interference patternwould look like.Notice there are alternatinglight and dark fringes.Also note that the centralfringe at θ = 0 is a brightfringe.It is also the brightest of thebright fringes.The order of the bright fringes starts at the central bright fringe.The order of the dark fringes starts right above and below the centralbright fringe.So, the second dark fringe on either side of the central bright fringe is the1 st order dark fringe, or m = 1.Remember, order means m.Young’s experiment provided strong evidence for the wave nature of light.If it was completely particle like, then we would only get two fringes on the screen, not aninterference pattern!