• optical null method

प्रकाशिक:    optic optical

शून्य:    0 nil love vacuity zero nought nothingness vacuum

शून्य वक्रता:    air ratio zero curvature शून्य 0 nil

वक्रता:    curvature curve tortuosity camber incurvation

विधि:    act regularity regulation rite rule ceremony fate