Is a vector field a concept, a mathematical "description" if you will, that only comes to "reality" when it is disturbed by something else? Or is it a physical thing? Thanks again! The question was about electromagnetic waves so I answered appropriately. It seems to me the conceptual problem of the OP is with fields. Otherwise what is a photon? Its a quantum of a quantum field after all. The concept of a field is inevitable, you will always end up back to it. Show 5 more comments. Russall singh Russall singh 1.
There is no travel. Moonraker Moonraker 2, 1 1 gold badge 14 14 silver badges 25 25 bronze badges. I am not talking about a rest frame of a photon. Featured on Meta. Now live: A fully responsive profile. Linked 1. See more linked questions. Related 3. Hot Network Questions.
Question feed. Physics Stack Exchange works best with JavaScript enabled. Accept all cookies Customize settings. 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.
An instrument that diffracts light into a spectrum for analysis is an example of observing the wave-like property of light. The particle-like nature of light is observed by detectors used in digital cameras—individual photons liberate electrons that are used for the detection and storage of the image data. One of the physical properties of light is that it can be polarized. Polarization is a measurement of the electromagnetic field's alignment. In the figure above, the electric field in red is vertically polarized.
Think of a throwing a Frisbee at a picket fence. In one orientation it will pass through, in another it will be rejected. This is similar to how sunglasses are able to eliminate glare by absorbing the polarized portion of the light. The terms light, electromagnetic waves, and radiation all refer to the same physical phenomenon: electromagnetic energy.
This energy can be described by frequency, wavelength, or energy. All three are related mathematically such that if you know one, you can calculate the other two. Radio and microwaves are usually described in terms of frequency Hertz , infrared and visible light in terms of wavelength meters , and x-rays and gamma rays in terms of energy electron volts. This is a scientific convention that allows the convenient use of units that have numbers that are neither too large nor too small.
The number of crests that pass a given point within one second is described as the frequency of the wave. One wave—or cycle—per second is called a Hertz Hz , after Heinrich Hertz who established the existence of radio waves. A wave with two cycles that pass a point in one second has a frequency of 2 Hz.
How is imaging spectroscopy used in astronomy? What is spectroscopy? How does it detect the electromagnetic spectrum? What techniques are used to study the electromagnetic spectrum in space? See all questions in The Electromagnetic Spectrum. Impact of this question views around the world. You can reuse this answer Creative Commons License. This vibration creates a wave which has both an electric and a magnetic component.
An electromagnetic wave transports its energy through a vacuum at a speed of 3. The propagation of an electromagnetic wave through a material medium occurs at a net speed which is less than 3. This is depicted in the animation below.
The mechanism of energy transport through a medium involves the absorption and reemission of the wave energy by the atoms of the material.
When an electromagnetic wave impinges upon the atoms of a material, the energy of that wave is absorbed.
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