Answer the following question:
Ray optics is based on the assumption that light travels in a straight line. Diffraction effects (observed when light propagates through small apertures/slits or around small obstacles) disprove this assumption. Yet the ray optics assumption is so commonly used in understanding location and several other properties of images in optical instruments. What is the justification?
Ray optics is based on the assumption that light travels in a straight line. Diffraction effects (observed when light propagates through small apertures/slits or around small obstacles) disprove this assumption. Yet the ray optics assumption is so commonly used in understanding location and several other properties of images in optical instruments. What is the justification?
Exercise
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Typical sizes of the apertures involved in ordinary optical instruments are much large than the wavelength of light. Henceforth, the diffraction effects of light waves are negligibly small in these instruments and is of negligible or no significance. Thus, the assumption that light travels in straight lines can be safely used in the optical instruments.
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