(WVS) Characteristics of Electromagnetic Waves Lesson

Characteristics of Electromagnetic Waves

If you watch a colony of ants walking up the wall, they look like a thin continuous black line. But as you look closer, you see that the line is made up of thousands of separated black ants.

Light and all other types of electromagnetic radiation seem like a continuous wave at first, but when one performs experiments with light, one can notice that light can have both wave- and particle-like properties. Just like the individual ants, light can also be made up of individual bundles of energy, or quanta of light.

Light has both wave-like and particle-like properties (wave-particle duality), but only shows one or the other, depending on the kind of experiment we perform. A wave-type experiment shows the wave nature, and a particle-type experiment shows the particle nature. One cannot test the wave and the particle nature at the same time. A particle of light is called a photon.  The amount of energy a photon has can cause it to behave more like a wave, or more like a particle. This is called the "wave-particle duality" of light. It is important to understand that we are not talking about a difference in what light is, but in how it behaves. Low-energy photons (such as radio photons) behave more like waves, while higher-energy photons (such as X-rays) behave more like particles.

Electromagnetic Wave description Links to an external site.

Unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost. Therefore, electromagnetic waves don't get weaker as they travel. However, the energy is "diluted" as it travels farther from its source because it spreads out over an ever-larger area.

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