The scientific name for the phenomenon of light spreading through a narrow opening is called diffraction. This occurs when waves encounter an obstacle or a slit that is comparable in size to their wavelength, causing them to bend and spread out. Diffraction is observed commonly in optics and is a fundamental principle underlying various technologies such as lenses and diffraction gratings. The degree of diffraction depends on the wavelength of light and the dimensions of the opening. Understanding diffraction is crucial for applications in imaging and telecommunications.