How are electromagnetic waves generated? How are electromagnetic waves generated?

Why can we generate electricity through the relative motion of a wire and a magnet (by wrapping a closed wire into a rectangle and rotating it between the magnetic fields formed by the two poles, we can generate an electric current in the wire)? And why can we wrap a coil around the core to make a magnetic electromagnet? This is because there is a connection between magnetism and electricity.

Electromagnetic waves are generated because magnetism can produce electricity, and electricity produces magnetism, and so on, and propagates outward, forming electromagnetic waves.

In fact, the mechanism of electromagnetic wave generation is a little complicated, and the key is what kind of electricity can produce magnetism? What kind of magnetism can produce electricity?

It can be simply said that it is the changing electricity (field) that produces the magnetic field, and the changing (magnetic) field that produces the electric field. In order for the electric field and the magnetic field to alternate, this "change" must also have some characteristics, for example, it cannot be uniformly changed (because a uniformly varying electric field produces a constant magnetic field, while a constant magnetic field cannot produce an electric field, and the two cannot be "alternately generated"), and so on.

From 1855 to 1865, the British physicist James Maxwell summarized the results of the research of Ampère, Coulomb, Faraday and others, and gave a system of equations. This system of equations is available in both differential and integral forms, and requires the use of advanced mathematics to solve them, and in principle it is possible to solve some forms of expressions for electromagnetic wave fluctuations.

In general, except for the visible light band, electromagnetic waves cannot be seen or touched, and can propagate in a vacuum without a medium, which is a bit abstract compared to water waves. In middle school, it is difficult to have a thorough understanding of electromagnetic waves, and the most fundamental thing is to master its basic principles, characteristics, and applications.

Suppose there is an upright metal rod with a potential difference between the upper and lower ends that causes the electrons to accelerate towards the positive potential end, while the other end is positively charged due to the lack of electrons. Such a current creates a magnetic field in the surrounding space, and if the potential difference changes with time (e.g., as a sinusoidal function), the resulting magnetic field will also change with time.

The magnetic field changes with time and is induced by Faraday's law.

These electric fields also change again over time (as a sinusoidal function), and these changes in flux cause a magnetic field to form around them. In this interactive cycle, the alternating current electric field induces the alternating alternating magnetic field, and the alternating current magnetic field induces the alternating current electric field, thus forming electromagnetic waves.

LC Electromagnetic** can generate electromagnetic waves.

All objects with temperature are producing infrared rays, which are also electromagnetic waves.

Charge oscillations produce electromagnetic waves, it's simple!

The generation of electromagnetic waves, the family of electromagnetic waves, the discovery of electromagnetic waves, the strength of electromagnetic waves.

The principle of electromagnetic wave generation:

A changing electric field produces a changing magnetic field that exists not only in the original range of the changing electric field, but also in the adjacent range. A field that changes in the original range also creates a new field in the area around it.

The new field creates a field over a larger area of space, so that the energy is propagated into the distance, i.e., a wave containing electromagnetic energy travels outward. This wave source releases energy, and the process by which the energy is transmitted by electromagnetic waves is called the propagation process of electromagnetic waves.

Introduction to Electromagnetic Waves:

Electromagnetic waves are electric and magnetic fields that oscillate in phase and are perpendicular to each other in the form of waves in space, and their propagation direction is perpendicular to the plane composed of electric and magnetic fields, effectively transferring energy and momentum.

Electromagnetic radiation can be classified according to frequency, from low frequency to high frequency, including radio waves, microwaves, infrared, visible light, ultraviolet light, X-rays and gamma rays, etc.

The electromagnetic radiation that can be received by the human eye, with wavelengths between about 380 and 780 nanometers, is called visible light. Any object whose temperature is greater than absolute zero can emit electromagnetic radiation, and there is no object in the world with a temperature equal to or lower than absolute zero.

The principle of electromagnetic wave generation is that a changing electric field produces a magnetic field (i.e., an electric current produces a magnetic field), and a changing magnetic field produces an electric field. The changing electric field and the changing magnetic field constitute an inseparable and unified field, which is the electromagnetic field, and the propagation of the changing electromagnetic field in space forms electromagnetic waves.

When the frequency of electromagnetic waves is low, they are mainly transmitted by means of tangible conductors. The reason is that in the low-frequency electrical oscillation, the mutual change between magnetism and electricity is relatively slow, and almost all of its energy is returned to the original circuit without energy radiating out; When the frequency of electromagnetic waves is high, they can be transmitted in free space, or they can be transmitted in a tangible conductor.

The reason for the transmission in free space is that in the high-frequency electrical oscillation, the magnetoelectric interchange is very fast, and the energy cannot all return to the original oscillation circuit, so the electrical energy and magnetic energy propagate to space in the form of electromagnetic waves with the periodic changes of the electric field and the magnetic field, and the energy can be transmitted to the outside without the need for medium, which is a kind of radiation.

For example, the distance between the sun and the earth is very long, but when you are outdoors, you can still feel the light and heat of the sun, just like the principle that electromagnetic radiation transmits energy through the phenomenon of radiation.

To know how electromagnetic waves are generated, one must know what electromagnetic waves are.

The mainstream believes that electromagnetic waves are moving electromagnetic fields, in fact, electromagnetic waves and electromagnetic fields are incompatible, waves are the vibration of the medium, and the field is the space with a certain physical effect, the wave is the propagation of energy, and the field is the property of matter, the wave is generated by the vibration of the object, and the field is the innate nature of the object. For example, the electric field is generated by electric charge, is the property of the charged particle itself, as long as the charged beam calling beam particles exist, there is an electric field, the magnetic field is the motion effect of the electric field, as long as the charged particle chain is manual, there is a magnetic field, there is no magnetic field without the movement of charged particles.

The existence of an electric field must have the presence of an electric charge, and without a charge there is no electric field. There is indeed a certain relationship between the electric field and the magnetic field, physicists have also summarized the law of electricity and rubber magnetism, under certain conditions, electricity and magnetism also conform to Maxwell's equations, however, we cannot say that the electric field is generated by the changing magnetic field, if so, I must ask: the changing magnetic field comes from **?

Without the motion of charged particles, ** comes from the magnetic field? In fact, when charged particles move, there must be differences in the speed of motion, which leads to a change in the density of charged particles, and the electric field is generated due to the different densities of charged particles.

In short, electromagnetic field is a general term for electric field and magnetism, the movement of the electric field can produce a magnetic field, but the strength of the magnetic field is related to the reference frame, but the changing magnetic field can produce an electric field is a false proposition. If there is no charge, no field exists.

If the existence of the ether is recognized, electromagnetic waves are the waves propagating in the ether, which, like sound waves, are generated by the vibration of electrons, and the reason for this is that there can be no net charge in the conductor, and the electrons output by the power supply to the antenna, like bubbles in water, float to the surface of the conductor, and when they reach the surface, they will vibrate, and the propagation of this vibration in the ether is electromagnetic waves.

Causes of electromagnetic waves.

The source of electromagnetic waves can be many physical phenomena, such as changes in electric current, oscillations of electrons, vibrations of molecules, etc. Electromagnetic waves are a form of energy propagation produced by the interaction of electric and magnetic fields. When the charge moves, there is a change in the electric and magnetic fields, which interact and propagate through space, forming electromagnetic waves.

Electromagnetic waves are a transverse wave that travels through space at the speed of light. Electromagnetic waves do not require a medium and can propagate in a vacuum.

Electromagnetic waves have a series of characteristics, such as wavelength, frequency, energy, polarization, etc. Wavelength refers to the distance that an electromagnetic wave needs to travel through a cycle in space, usually expressed in meters. Frequency refers to the number of cycles that an electromagnetic wave completes per unit of time, usually expressed in hertz.

Wavelength and frequency are interchangeable, and the relationship between them is that the speed of the wave is equal to the wavelength multiplied by the frequency. The energy of an electromagnetic wave is related to the frequency, and the higher the frequency, the greater the energy. Polarization refers to the characteristics of the electric field and the direction of the magnetic field vibration in an electromagnetic wave.

Electromagnetic waves are an indispensable physical phenomenon in modern communications, electronics, and many other fields. Radio communication, for example, is a technology that uses electromagnetic waves to transmit information. In addition, electromagnetic waves can also be used in medical, aerospace, energy, materials science, and other fields.

With the continuous development of science and technology, the application range of electromagnetic waves will become more and more extensive.

Recent studies have also found that electromagnetic waves can also be used to detect material in distant galaxies. Since electromagnetic waves travel extremely fast in space, it is possible to study the properties of matter in distant galaxies by observing the frequency and polarization state of electromagnetic waves. The study of this area is called radio astronomy, and it has become an important part of modern astronomy.