Charged particle fields, electromagnetic and electrostatic fields and their components
Particles and fields are two types of matter. A characteristic feature of the interaction of particles is that it takes place not in their direct contact, but at a certain distance between them.
This is due to the fact that the particles are related to the field that surrounds them and determines the interaction between them. Thus, the particles interact through their fields.
Fields are distributed in space, unlike discrete particles, continuously. Some interactions are dual in nature. So, for example, an electromagnetic field propagating through space in the form of waves is detected simultaneously in the form of discrete particles - photons.
In nature, there are fields of various types: gravitational (gravitational), magnetostatic, electrostatic, nuclear, etc. Each field is characterized by distinctive, inherent properties.
Between two types of matter — particles and fields — there is an internal connection, which is manifested primarily in the fact that any change in the state of the particles is directly reflected in the field (and conversely, any change in the field affects the particles), as well as in the presence of general properties: mass, energy, momentum or momentum, etc.
Also, particles can turn into a field, and the field into the same particles. All this shows that matter and field are two types of matter.
In addition, there is a difference between fields and particles, which allows us to consider them as different types of matter.
This difference consists in the fact that elementary particles are discrete and occupy a certain volume, they are impervious to other particles: the same volume cannot be occupied by different bodies and particles. The fields are continuous and have high permeability: fields of different types can be located simultaneously in the same volume of space.
Particles and bodies can move in space under the influence of external forces, accelerated or slowed down, that is, the speed of movement of particles in space can be different. Fields propagate through space at the same speed, for example in a vacuum - at a speed equal to the speed of light.
Since particles and fields are closely related to each other and constitute a whole, it is impossible to establish an exact boundary between a particle and its field in space.
However, it is possible to specify a very small region of space in which the properties of a discrete particle are manifested. In this sense, it is conditionally possible to determine the dimensions elementary particles… In the space outside the specified region, it can be assumed that there is only a field associated with an elementary particle.
The electromagnetic field and its components
In electrical engineering, a field is considered that is caused by the movement of carrying particles electrical charges… Such a field is called electromagnetic. The phenomena associated with the propagation of this field are called electromagnetic phenomena.
Electrons circulating in an atom around a nucleus interact with protons through an electric field, while at the same time their movement is equivalent to an electric current, which, as experience shows, is always associated with the presence of a magnetic field.
Therefore, the field through which the elementary particles of the atom interact with each other, that is, the electromagnetic field, consists of two fields: electric and magnetic. These fields are interconnected and inseparable from each other.
Externally, the electromagnetic field under macroscopic examination manifests itself in some cases in the form of a stationary field, and in other cases in the form of an alternating field.
In the stationary state of the atoms of a given substance, both the electric field (in this case the field in the atoms is completely connected with equal charges of different signs) and the magnetic field (due to the chaotic orientation of electron orbits) in outer space is not detected.
However, if the equilibrium in the atom is disturbed (an ion is formed, directed motion is superimposed on chaotic motion, elementary currents of magnetic substances are oriented in one direction, etc.), then outside this substance the field can be detected.Additionally, if the specified state is maintained unchanged, then the field characteristics have a value that is constant over time. Such a field is called a stationary field.
The stationary field during macroscopic examination in a number of cases occurs in the form of only one component: either in the form of an electric field (for example, the field of stationary charged bodies), or in the form of a magnetic field (for example, the field of permanent magnets).
The components of a stationary electromagnetic field are inseparable from moving charged particles: the electric component is associated with electric charges, and the magnetic component accompanies (surrounds) moving charged particles.
A variable electromagnetic field is formed as a result of the changing or oscillating motion of charged particles, systems or constituents of stationary fields. A characteristic of such a high-frequency field is that after it has arisen (after being emitted from a source), it is separated from the source and enters the environment in the form of waves.
The electric component of this field exists in a free state, separated from the material particles and has a vortex character. The same field is the magnetic component: it also exists in a free state, not associated with moving charges (or electric current). However, both fields represent an inseparable whole and in the process of movement in space are constantly transformed into each other.
The variable electromagnetic field is detected by the impact on particles and systems located in the path of its propagation, which can be set in an oscillating motion, as well as by means of devices that convert the energy of the electromagnetic field into energy of another type (for example, thermal) .
A special case is the action of this field on the visual organs of living beings (light is electromagnetic waves).
Components of the electromagnetic field — electric and magnetic fields were discovered and studied before the electromagnetic field, and independently of each other: no connection was then discovered between them. This led to the fact that both areas were considered independent.
Theoretical considerations, then confirmed by experiment, show that there is an inextricable connection between electric and magnetic fields, and any electric or magnetic phenomenon always turns out to be electromagnetic.
See also: Electric and Magnetic Field: What are the Differences?
Electrostatic field
Only an electric field is detected in a vacuum or a dielectric medium around isolated bodies that are stationary relative to the observer with an excess unchanged in space and time (in the macroscopic sense) electric charges of the same sign obtained during the ionization of atoms ( as a result of electrification look - Electrification of bodies, interaction of charges).Such a field is called electrostatic.
An electrostatic field is a type of stationary electric field and differs from it in that the elementary charged particles that cause the electrostatic field are only in chaotic motion, while the stationary field is determined by the directed motion of electrons superimposed on the chaotic motion.
In this field, the constancy of the characteristics is due to the continuous reproduction of the distribution of charges in the field (equilibrium process).
In an electrostatic field, the general action of a large number of uniquely charged particles in continuous chaotic motion in different directions is perceived outside a charged body as a field with an electric charge of the same sign that does not change over time.
The effect of the magnetic component in the electrostatic field is mutually neutralized due to the chaotic movement of charge carriers in outer space and is therefore not detected.
A distinctive feature of the electrostatic field is the presence of source and drain bodies, which are given excess charges of different signs (bodies from which this field appears to flow and into which it flows).
The electrostatic field and the electrified bodies, which are sources and sinks of the field, are inseparable from each other, representing one physical entity.
In this, the electrostatic field differs from the electric component of the alternating electromagnetic field, which, existing in a free state, has a vortex character, has no source and drain.
No energy is expended to maintain this state of the electrostatic field. It is only necessary when this field is established (it takes energy to continuously emit an electromagnetic field).
An electrostatic field can be detected by the mechanical force acting on stationary charged bodies placed in this field, as well as by inducing or directing electrostatic charges on stationary metallic bodies and by polarization of stationary dielectric bodies placed in this field.
See also:
Electric field characteristics