5. Observe and comment on the patterns you see in the interference fringes as the spacing is changed. 6. Using our calibration of DO validated by the direct measurement with a scale in # 4, what is the slit separation h in each case for dial readings -- 43, 45, 47, 49, 51, 53, and 55 that produced the fringe patterns in these images? Note that the uncertainty in the dial reading is +1. What uncertainty will this introduce into a measurement of wavelength that depends on d? 7. Take notes on what you did to find the spacings, and then record the fringe spacing x for each case. Pair up the separation of the slit and its mirror image d with the spacing of the fringes Ax for that case. We will ask for the data, and for a description of how you made the measurement