What is Diffraction?
Diffraction occurs when a wave encounters an obstacle or slit. It bends around obstacles or spreads out after passing through small apertures, altering its path and intensity. This phenomenon demonstrates the wave nature of light.
Diffraction vs. Refraction
While both involve wave bending, they differ. Refraction is bending due to speed change in different mediums, like a pencil in water. Diffraction happens even without medium change, as waves spread out from openings or edges.
Single-Slit Diffraction
Single-slit diffraction illustrates wave interference. Waves passing through a slit create a pattern of bright and dark fringes on a screen, caused by waves overlapping – constructive interference for bright, destructive for dark fringes.
Diffraction Grating
Diffraction gratings, with thousands of parallel slits, disperse light into spectra. Each wavelength diffracts at a specific angle, enabling precise measurement of light's properties, crucial in spectrometry and understanding atomic structures.
X-Rays and Crystals
X-ray diffraction reveals crystal structures. Crystals cause X-ray waves to diffract in specific patterns, allowing scientists to deduce atomic arrangements. This technique was vital in discovering DNA's double helix.
Everyday Diffraction Examples
Diffraction isn't just in labs. It's in daily life: the pattern from a compact disc's surface, the rainbow colors in soap bubbles, and even the spreading of sound waves around corners.
Limitations of Diffraction
Diffraction limits resolution in imaging systems like microscopes and telescopes. As light waves spread out, details smaller than a certain threshold can't be distinguished, leading to the development of techniques to overcome this limit.