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Danyon
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Does the magnetic component of light emitted by an antenna arise from the effects of length contractions or from the fundamental magnetic moment of the electron?
phyzguy said:Neither. The source of the magnetic field in EM radiation is the changing electric field. This is how EM radiation works - the changing electric field gives rise to a changing magnetic field which gives rise to a changing electric field which gives rise to ...
Drakkith said:Wouldn't that explanation require that the magnetic and electric field vectors be out of phase with one another?
Not in a plane wave in vacuum.PeterDonis said:Yes. They are.
DaleSpam said:Not in a plane wave in vacuum.
phyzguy said:the following vectors are solutions:
$$
E = E_x \cos (kz - \omega t)
$$
$$
B = B_y \cos (kz - \omega t)
$$
In electromagnetism, displacement current is a quantity appearing in Maxwell's equations that is defined in terms of the rate of change of electric displacement field. Displacement current has the units of electric current density, and it has an associated magnetic field just as actual currents do. However it is not an electric current of moving charges, but a time-varying electric field.
pervect said:I've usually heard the magnetic field of light being described as coming from the displacement current.
pervect said:I've usually heard the magnetic field of light being described as coming from the displacement current.
PeterDonis said:Apparently we are using "in phase" to mean different things.
PeterDonis said:This is true in the sense that it is the displacement current term in Maxwell's equations that makes electromagnetic waves a possible solution with zero source.
pervect said:the process has nothing to do with the magnetic moment of the electron.
Yes, it appears so. I refer to the phase shift in time. What you are calling "out of phase" I would call "perpendicular", but your point is good and I can see your usage is reasonable although it is different from what I am used to.PeterDonis said:Apparently we are using "in phase" to mean different things.
Yes, although at this level I prefer to not even speak of electrons, but just current and charge.Danyon said:When the electrons accelerate up to the top of the transmission antenna the electric field emits one wavelength, all the while the magnetic field produced by the current rotates clockwise around the wire, Which is orthogonal to the electric field change. When the electrons accelerate downward the magnetic field rotates anti-clockwise and is orthogonal to the next wavelength of electric field change, the magnetic fields produced by the wire travel outward with the electric fields forming electromagnetic waves
The magnetic component of light is generated by the movement of charged particles, such as electrons, within atoms. These moving charged particles create oscillating electric and magnetic fields, which together make up electromagnetic radiation - including light.
The electric and magnetic components of light are both essential parts of the electromagnetic spectrum. While the electric component is responsible for the brightness and color of light, the magnetic component is responsible for the direction and polarization of the light waves.
Yes, the source of the magnetic component of light can be altered or manipulated by changing the movement of charged particles. This can be achieved through various methods such as applying an external magnetic field or passing light through certain materials that can alter the direction of the magnetic field.
Yes, the magnetic component is present in all types of light, including visible light, infrared light, ultraviolet light, and other forms of electromagnetic radiation. However, the strength and direction of the magnetic component may vary depending on the type of light and its source.
The magnetic component of light plays a crucial role in how light interacts with matter. It can determine the absorption, reflection, and scattering properties of light, which are essential for various applications such as imaging, communication, and energy conversion. The magnetic component can also influence the behavior of charged particles within matter, leading to phenomena like magnetism and induction.