Optics Science Olympiad Flashcards

Reflection and Mirrors

• Law of reflection: incident ray, reflected ray, and normal lie in the same plane; angle of reflection equals angle of incidence.
• Specular reflection: light reflects off smooth surfaces at specific angles.
• Diffuse reflection: occurs on rough surfaces, scattering light in all directions.
• Plain mirrors: flat reflective surfaces where the angle of reflection equals the angle of incidence.

Refraction and Lenses

• Refraction: light deflection occurs when passing through different media; changes in speed affect wave direction.
• Refractive index: dimensionless number indicating how light moves through a medium (n = c/v).
• Snell's Law: formula relating angles of incidence and refraction at a boundary between different media.
• Critical angle: angle of incidence causing the angle of refraction to be 90°; essential for total internal reflection.
• Convex lenses: thicker in the center, they converge light rays to a principal focus.
• Concave lenses: thinner in the middle, they diverge light rays, making them appear to come from a virtual focus.
• Focal length: distance from lens/mirror center to its focus, influencing nearsightedness (long) and farsightedness (short).

Prisms and Dispersion

• Prisms: solid glass shapes that refract light, with geometric attributes defining their function.
• Dispersion: light separation into colors based on the prism's index of refraction and wavelength, with varying deviations for different colors.
• Deviation: prisms can alter ray paths, change image rotation, or displace images, optimizing imaging systems.

Image Formation

• Real images: formed at the convergence of light rays, visible on a screen when placed at the convergence plane.
• Virtual images: formed by diverging lenses or objects within the focal length of converging lenses.
• Erect images: appear right-side up, consistent with the object's orientation; formed by specific optical devices.
• Inverted images: have interchanged directions, formed by most astronomical telescopes.
• Magnified images: representation enlargement, determined by the image-to-object size ratio.

Optical Instruments

• Telescopes: capture distant objects using lens/mirror arrangements to produce magnified images.
• Microscopes: magnify small objects, enabling detailed viewing of cells and specimens.
• Cameras: devices for capturing visual images, producing photographs, films, or videos.

Light and Color

• Visible spectrum: range of electromagnetic spectrum visible to the human eye (390 to 700 nm).
• Primary colors: foundational colors that can combine to create a wide spectrum of hues.
• Secondary colors: derived from mixing two primary colors.
• Additive color model: creates colors by mixing light; red, green, and blue are the primary colors in this system.
• Subtractive color model: mixing pigments to absorb certain wavelengths, creating varied colors.
• Absorption: when light of a specific frequency is absorbed, it does not reach the observer, affecting color perception.

Advanced Light Properties

• Reflection: light, heat, or sound returns from a surface without being absorbed.
• Polarization: the direction of an electromagnetic wave's electric field; polarized light shows specific orientations.
• Polarization by scattering: light interacts with air molecules, creating polarized light in directions perpendicular to the original ray.
• Absorption spectra: dark lines in a spectrum indicate specific wavelengths absorbed by a substance.
• Absorption chemicals: specific chemical processes can be substituted for physical absorption methods, like carbon dioxide absorption by sodium hydroxide.