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Apr 24, 2017 · Light always takes the shortest path between a source and destination. A line drawn from the source to the destination, perpendicular to the wave-fronts, is called a ray. Far from the source, spherical wave fronts degenerate into a series of parallel lines moving in the direction of the ray.
- Overview
- Electromagnetic Energy
- Sun & Atmosphere
- Beyond our Atmosphere
This article is about the Electromagnetic energy and its uses. It explains how electromagnetic energy travels in waves, spans a broad spectrum from radio waves to gamma rays, and how NASA's scientific instruments use it to study the Earth, solar system and universe beyond. The article also mentions that our atmosphere protects us from exposure to h...
Electromagnetic energy travels in waves and spans a broad spectrum from very long radio waves to very short gamma rays. When you tune your radio, watch TV, send a text message, or pop popcorn in a microwave oven, you are using electromagnetic energy. You depend on this energy every hour of every day. Without it, the world you know could not exist.
The Earth's atmosphere protects us from exposure to harmful higher-energy waves that can be ionizing and cause damage to cells in organic matter but is not helpful when studying sources of high-energy radiation in space as instruments have to be positioned above Earth's atmosphere.
NASAspacecraft provide scientists with a unique vantage point helping them "see" at higher-energy wavelengths that are blocked by the Earth's protective atmosphere while some microwaves can even pass through clouds making them best for transmitting satellite communication signals.
- Theory of Light in the 19th Century: During the Scientific Revolution, scientists began moving away from Aristotelian scientific theories that had been seen as accepted canon for centuries.
- Double-Slit Experiment: By the early 19th century, scientists began to break with corpuscular theory. This was due in part to the fact that corpuscular theory failed to adequately explain the diffraction, interference and polarization of light, but was also because of various experiments that seemed to confirm the still-competing view that light behaved as a wave.
- Electromagnetism and Special Relativity: Prior to the 19th and 20th centuries, the speed of light had already been determined. The first recorded measurements were performed by Danish astronomer Ole Rømer, who demonstrated in 1676 using light measurements from Jupiter's moon Io to show that light travels at a finite speed (rather than instantaneously).
- Einstein and the Photon: In 1905, Einstein also helped to resolve a great deal of confusion surrounding the behavior of electromagnetic radiation when he proposed that electrons are emitted from atoms when they absorb energy from light.
20 hours ago · According to Sapienza, this isn't the right question to be asking. "Light is not sometimes a particle and sometimes a wave," he said. "It is always both a wave and a particle. It's just that we ...
Jul 16, 2020 · Visible light — which, like all electromagnetic radiation, travels in waves — includes wavelengths between about 380 nanometers (violet) and about 740 nanometers (red). Radiation with wavelengths shorter than visible light includes gamma rays, X-rays and ultraviolet light.
Sep 30, 2022 · On one end of the electromagnetic spectrum are radio waves, which have wavelengths billions of times longer than those of visible light. On the other end of the spectrum are gamma rays, with wavelengths billions of times smaller than those of visible light.
People also ask
How does electromagnetic energy travel?
Why is light a form of energy?
How does light travel in waves?
Are light waves and radiation the same thing?
Is light a particle or a wave?
What is the difference between gamma rays and radio waves?
Aug 10, 2016 · YES! Light is made of discrete packets of energy called photons. Photons carry momentum, have no mass, and travel at the speed of light. All light has both particle-like and wave-like properties. How an instrument is designed to sense the light influences which of these properties are observed.
