2Thought QuestionConsider a single slit diffraction pattern. At the first dark fringe above the middle bright fringe, what is the phase difference between the contribution to the field from the topmost and bottommost edges of the slit?A : 45 degreesB : 90 degreesC : 180 degreesD : 360 degreesE : None of the above
6Light impinges on a single slit but suffers no significant diffraction Light impinges on a single slit but suffers no significant diffraction. We conclude that the wavelength of the light ismuch shorter than the slit width.much longer than the slit width.c. on the order of the slit width.
13KNIFE FIGHTS AND MISSILES MATTHEW 6 26 Behold the fowls of the air: for they sow not, neither do they reap, nor gather into barns; yet your heavenly Father feedeth them. Are ye not much better than they? 34 Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day is the evil thereof.
14Why larger scale features in two-slit interference?
19Circular aperture resolution In the printed figure, the lines are separated by 2 mm. Viewed at a distance, the two patterns look identical, but as you approach them, there is a point at which you can barely resolve the lines and tell the difference between the two images. From this distance L, you can calculate the angular resolution of your eyes:angular resolution = (2 mm)/L (in radians). Classroom demonstration: Hold up the figure and ask who can see the lines in one of the patterns. Usually no one beyond 4 meters will raise their hands. (This works best in a classroom which is 8 meters or more deep.) Using the above equation, L = 4 m corresponds to an angular resolution of 0.03 degrees.The diffraction limit of the eye can be calculated using Rayleigh's criterion:angular resolution = (1.22)(lambda)/D,where lambda is the wavelength of light (on the average, about 550 nm) and D is the diameter of the eye's pupil, which is about 5 mm indoors. This calculation results in an angular resolution of degrees. If your eyes could resolve images at the diffraction limit, you could resolve the lines in the printed pattern at a distance of 15 m!
20What can a spy satellite resolve? Low earth orbit: Too much drag below 300 kmDelta IV max payload size ~5 mVery little light in x-ray, deep uv bandsStrong atmospheric absorption below 300 nm. Fairly good transmission in visible band.
22Cat’s eyes have pupils that can be modeled as vertical slits Cat’s eyes have pupils that can be modeled as vertical slits. At night, would cats be more successful in resolvingTwo headlights on a distant carVertically separated lights on the mast of a distant boatIf the two sets of lights are the same distance away, the ability to resolve them would be the same.
23Diffraction Gratings (Resolving power means something different here) 𝑅= 𝜆 Δ𝜆