Geometric Optics
Understanding reflection, refraction, and how light travels in straight lines
Topics
How do lenses work?
Lenses work by refracting (bending) light as it passes through. Convex lenses converge light rays to a focus point, while concave lenses diverge them. This bending occurs because light slows down when entering the lens material.
Read more →How does a camera work?
A camera works by using a lens to focus light onto a light-sensitive sensor or film. The lens creates an image, and the sensor/film captures it. A shutter controls how long light enters, and an aperture controls how much light enters.
Read more →Why do mirrors reflect?
Mirrors reflect because they have smooth, polished surfaces that bounce light back. When light hits a mirror, it reflects at the same angle it arrived (angle of incidence equals angle of reflection), creating a clear reflection.
Read more →Why do we see rainbows?
We see rainbows when sunlight is refracted (bent) and reflected inside water droplets. Different colors bend at different angles due to their wavelengths, separating white light into the spectrum of colors we see as a rainbow.
Read more →Why is the sky blue?
The sky is blue because of Rayleigh scattering—sunlight is scattered by tiny particles in the atmosphere, and blue light scatters more than other colors because it has shorter wavelength. This scattered blue light reaches our eyes from all directions, making the sky appear blue.
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