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Jul 16, 2024 · Determine if light is absorbed, transmitted, or emitted in a given interaction with matter. What happens when an electromagnetic wave impinges on a material? There are a variety of possibilities depending on the characteristics of that material as well as the frequency of the electromagnetic wave.
- 25.1: The Ray Aspect of Light
In the situations shown here, light interacts with objects...
- 25.1: The Ray Aspect of Light
- Light
- Waves
- Particles
- Matter
- Interactions Between Light and Matter
Gamma rays, X-rays, ultraviolet light, visible light (the visible rainbow), infrared light, microwaves, and radio waves are all forms of light, also called electromagnetic radiation. Together, they make up the electromagnetic spectrum. (That’s right, the radio waves that carry music from the station to your radio, the microwaves that heat up your f...
Light behaves like a wave. You are probably familiar with waves: water waves that ripple across a pond, sound waves that vibrate air and ear drums, and seismic (earthquake) waves that cause the ground to shake. These are all mechanical waves—energy that propagates through matter, causing it to move up and down, back and forth, or side to side. Ligh...
Light also behaves like a particle. A particle of light is called a photon. Each individual photon has a very specific amount of energy (no more, no less), which corresponds to its wavelength. Blue photons carry more energy than red photons. Ultraviolet photons carry more energy than infrared photons. Sometimes photons are described as “packets of ...
Matter is the scientific catch-all word for stuff—anything that has mass and takes up space. Matter is made of microscopic particles called atoms. Atoms are made of even smaller, or subatomic, particles known as protons, neutrons, andelectrons. Atoms can combine to formmolecules. Solids, liquids, and gases are all forms of matter. Planets, stars, n...
As you may have gathered, light and matter are intricately linked. Matter gives off light. Every object emits, or gives off, light of one sort or another simply because of its temperature. Glowing objects like stars, galaxies, light bulbs, and lava are all sources of visible light. Cooler objects like planets, dust grains, rocks, trees, animals, an...
Nov 14, 2024 · Light - Reflection, Refraction, Physics: Light rays change direction when they reflect off a surface, move from one transparent medium into another, or travel through a medium whose composition is continuously changing.
The manner in which visible light interacts with an object is dependent upon the frequency of the light and the nature of the atoms of the object. In this section of Lesson 2 we will discuss how and why light of certain frequencies can be selectively absorbed, reflected or transmitted.
In the situations shown here, light interacts with objects large enough that it travels in straight lines, like a ray. Experiments, as well as our own experiences, show that when light interacts with objects several times as large as its wavelength, it travels in straight lines and acts like a ray.
The changing of a light ray’s direction when it passes through variations in matter is called refraction. The speed of light in vacuuum c = 2.99792458 × 108 ∼ 3.00 × 108m / s. Index of refraction n = c v, where v is the speed of light in the material, c is the speed of light in vacuum, and n is the index of refraction.
The part of optics dealing with the ray aspect of light is called geometric optics. Light can travel in three ways from a source to another location: (1) directly from the source through empty space; (2) through various media; and (3) after being reflected from a mirror.
