Introduction
Gaussian unit system (Gaussian Units) is a system of measurement units, which belongs to the metric, from centimeter - gram - second system-derived, electromagnetic The most common unit system in the unit system. In centimeter - gram - second system, there are several groups of mobilized electromagnetic units, not only there is a Gaussian unit. Therefore, the term "centimeter-gram - second unit" is likely to cause a divergence, it must be avoided as much as possible.
In addition to the Gaussian unit system, the most common option is the international unit system. In many fields, the international unit system is the main unit system. With the flow of time, more and more people choose to abandon the Gaussian unit system, and the international unit system is used. The unit conversion between the Gaussian unit system and the international unit system is not as simple as the usual unit conversion. For example, electromagnetic physical law equation, like the Maxwell equation, which type of unit is used, need to do related adjustments; in the Gaussian unit system is the infinite physical quantity, like a capacitor or magnetore, for international unit Making, it may become a dimension.
At present, the Gaussian unit system must have experimental significance to the international unit system, because only the international unit system has precise definitions of each physical quantity. Gaussian units make the formula simple in certain areas, such as the geometric physics field of the ball symmetry. However, in the field of engineering, the international unit system, which often needs to handle the straight line, is more simple.
A variety of different centimeters-grams-seconds system
in centimeter-gram-second system, there are several electromagnetic unit systems, the Gaussian unit system is only one of them. Other electrostatic units, electromagnetic units, Lorentz-Heaviside Units (Lorentz-HEAVISIDE Units).
There is also a system called a natural unit system, including atomic unit system, Prance, etc. From some aspects, between centimeter-gram - second system and international unit system, these natural units are relatively close to the former. For example, assume that the natural unit system or centimeter-gram-second system is selected, then there is a factor
Today, the international unit system is the most commonly used unit system. In the field of engineering, the international unit system is almost universally adopted, which is the fact of many years. In the scientific literature, like the theoretical physics and astronomical literature, until recent years, Gaussian unit system is the main unit, but now it is increasingly used.
Natural unit system is relatively common in a more theoretical, more abstract physical field, especially particle physics and chord theory.
Gaussian unit system and international unit system is important difference
has a physical and chemical unit system
Gaussian unit system and international unit system, one difference is Some factors in the equation 4π. The international unit system is classified as "systematic unit system", because there is no factor 4π in the Maxwell equation, but in the equation of Coulomb's law and Bio Salvalence, there is a factor 4π. The status of the Gaussian unit system is completely opposite. There is 4π in the Maxwell equation group, but there is no factor 4π in the equation of Coulomb's Law and Bio Saal. Therefore, the Gaussian unit system is classified as "orthocular unit system".
charge unit
For the Gaussian unit system and the international unit system, the definition of charge unit has a great difference. The international unit system sets a basic unit for electrical phenomena - ampere, this action is that electric charge is a unique amount of physical quantity, (1 Couromb = 1ampere × 1second) cannot be used The mechanical unit (kg, m, s) is expressed. Coulomb Law Equation is
Vacuum dielectric constant
In the Gaussian unit, the unit Statc of the charge can be written in
-
1 statc = 1 g 1/2 < / sup> cm 3/2 s -1
Coulomb Law Equation is quite simple:
< P>Magnetic quantity of the unit
Different from the international unit system, in the Gaussian unit system, the electric field E is the dimension of the magnetic induction strength (B field) B. This totaled the difference in optical speed factor C in two units in two units. The same factor also occurs in other magnetic physical quantities, like magnetic field strength (h field) and magnetization intensity. For example, for a flat electromagnetic wave propagating on a vacuum, in the Gaussian unit,
electrode vector, magnetization vector
Different from the international unit system, in the Gaussian unit, electric field E, potential movement D, electrode strength P, magnetic induction strength B, magnetic field strength H, the magnetization intensity M has the same dimension. Another focus is that the electrodelation rate and magnetization of the substance are not equipped in the Gaussian unit system, and the magnetization rate is not equipped. However, they are different in the two units. Later, they will list equations.