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TheWiseFool
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Suppose a point charge is slowly oscillating simple harmonically. Does it emit an electromagnet wave and if not why not ? How does its field change with time. Does anyone know of a good animation ?
Thanks.
Thanks.
The field from an arbitrarily moving point charge is given by the Lienard Wiechert potentials.TheWiseFool said:How does its field change with time.
If you look at the Lienard Wiechert formulas (the fields, not the potentials) you will see that there are a couple of terms one term is proportional to ##r^{-1}## and one proportional to ##r^{-2}##. The former is the far field and the latter is the near field. More generally, any field term that falls off faster than ##r^{-1}## is considered part of the near field.TheWiseFool said:I have not yet seen a clear, explanation of these terms and their significance. Would anyone like to try
Electromagnetic radiation emitted by an accelerating charge is a form of energy that is produced when an electrically charged particle, such as an electron, is accelerated. This acceleration creates a fluctuation in the electric and magnetic fields, resulting in the emission of electromagnetic waves.
Unlike other types of radiation, such as thermal radiation or nuclear radiation, electromagnetic radiation emitted by an accelerating charge does not require a medium to travel through. It can travel through a vacuum and does not require particles to carry the energy.
Electromagnetic radiation emitted by an accelerating charge has several properties, including wavelength, frequency, and energy. These properties are related and determine the type of radiation emitted, such as radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Electromagnetic radiation emitted by an accelerating charge has many practical applications in everyday life. For example, radio waves are used for communication, microwaves are used for cooking, infrared is used for thermal imaging, visible light is used for vision, and X-rays are used for medical imaging.
Exposure to high levels of electromagnetic radiation emitted by an accelerating charge can be harmful to living organisms. This is why safety measures, such as shielding and distance, are important in certain situations. However, the levels of radiation emitted by most everyday devices, such as cell phones or Wi-Fi routers, are not considered harmful to humans.