Basic charge is also called basic charge or elementary charge. In all kinds of charged particles, the size of electronic charge is the smallest. People call the smallest charge elementary charge, which is also one of the basic constants of physics. It is often expressed by the symbol E.
基本电荷又称“基本电量”或“元电荷（elementary charge）”。在各种带电微粒中，电子电荷量的大小是最小的，人们把最小电荷叫做元电荷，也是物理学的基本常数之一，常用符号 e 表示。基本电荷 e = 1.60217663410×10-19 库仑（通常取 e = 1.6×10-19C），是一个电子或一个质子所带的电荷量。任何带电体所带电荷都是 e 的整数倍或者等于 e。（夸克除外，它是已知唯一的基本电荷非整数的粒子）
Basic charge is also called “basic charge” or “elementary charge”. In all kinds of charged particles, the size of electronic charge is the smallest. People call the smallest charge elementary charge, which is also one of the basic constants of physics. It is often expressed by the symbol E. The basic charge e = 1.60217663410 × 10-19 Coulomb (usually e = 1.6 × 10-19c), which is the charge of an electron or a proton. The charge of any charged body is an integral multiple of or equal to E. (except for quark, which is the only known particle with non integer basic charge)
Accurate measurement of elementary charge
美国实验物理学家罗伯特·安德鲁·密立根（Robert Andrews Millikan,1868～1953）设计了油滴实验：将两块水平放置的金属板分别与电源正、负极相接，使两块金属板带上异种电荷。用喷雾器喷出带电油滴，带电油滴进入两平板之间时，调节电压使油滴电场力、重力平衡，由此就可以求出油滴所带电荷量。
Robert Andrews Millikan (1868-1953), an American experimental physicist, designed an oil drop experiment: two horizontally placed metal plates were connected to the positive and negative sides of the power supply respectively, so that the two metal plates were charged with different charges. When a charged oil droplet is ejected by a sprayer and the charged droplet enters the two plate, the electric field force and gravity balance of the droplet are regulated by adjusting the voltage, so that the electric charge quantity of the droplet can be obtained.
1910 年，他第三次作了改进，使油滴可以在电场力与重力平衡时上上下下地运动，而且在受到照射时还可看到因电量改变而致的油滴突然变化，从而求出电荷量改变的差值；1913 年，他得到电子电荷的数值：e=（4．774±0．009）×10-10esu，（通常取 e=1.6×10-19C）这样，就从实验上确证了元电荷的存在。他测得的精确值最终结束了关于对电子离散性的争论，并使许多物理常数的计算达到较高的精度。
In 1910, he made the third improvement, so that the oil droplets can move up and down when the electric field force and gravity are balanced, and the sudden change of the oil droplets caused by the change of electric quantity can be seen when they are irradiated, so as to calculate the difference of the change of electric charge quantity; in 1913, he obtained the value of electronic charge: e = (4.774 ± 0.009) × 10-10esu, (usually taken as In this way, the existence of elementary charge is confirmed experimentally. The precise values he measured finally ended the debate about the dispersion of electrons and made the calculation of many physical constants more accurate.
密立根由于测量电子电荷量等方面的杰出成就而荣获 1923 年诺贝尔物理学奖。
Millikan won the Nobel Prize in physics in 1923 for his outstanding achievements in measuring the amount of electronic charge.
Properties of basic charge
The understanding of the essence of electrical phenomena began hundreds of years ago, but the qualitative understanding of electrical phenomena and even the quantitative analysis of electrical phenomena 150 years ago, until the understanding of the interaction process of electricity in the field theory of modern physics, in addition to the attribute of electricity itself is attributed to attraction and exclusion, there is not much change in the attribute of electricity itself. Attraction and repulsion are two basic characteristics of electricity in the process of interaction, which can not be denied by empirical facts.
At first, people pay attention to the phenomenon of electricity generation by friction, which attracts or repels small objects by friction between two insulators, such as fur and amber. This is recognized and perceived as an empirical fact in people’s daily life. People’s understanding of the nature of electricity is first attributed to people’s empirical fact, which is not excessive.
From the generation of electricity by friction to the application of microscopic analysis to attribute the attraction and repulsion of two different kinds of electricity to the interaction between two basic charges, which is a great step forward in human understanding of the nature of electricity.
The interaction between charges is gradually used by people to determine the properties of charges by quantitative analysis. Coulomb’s torsion balance test is more famous. He established the relationship between the quantity and quantity of charge interaction from micro to macro. In addition to this empirical fact, there are two philosophical ideas that play a decisive role in the law of the interaction between charges. It is reflected in the empirical fact that “a conductor, when placed in the interior of a closed hollow conductor and contacted with it, will lose all its charges.”
The so-called charge quantization refers to the property that the electric quantity of any charged body can only take discrete and discontinuous values. That is to say, the charge of any charged body is an integral multiple of the elementary charge. Millikan’s experiment proved that the charge quantity of tiny particles does not change continuously, the charge quantity is always an integral multiple of a certain element charge, and the charge quantity follows the law of quantum change.
1964 年盖尔曼等人提出的夸克模型认为，质子和中子等，分别由具有-1/3e 和 2/3e 的夸克组成，这表明，目前，电荷必然是 e/3 的整数倍。这也被实验所证实。这虽不是元电荷的整数倍，但它依然是量子化的！
According to the quark model proposed by Gelman and others in 1964, protons and neutrons are composed of quarks with – 1 / 3E and 2 / 3E, respectively. This shows that at present, the charge must be an integral multiple of E / 3. This is also confirmed by experiments. This is not an integral multiple of the elementary charge, but it is still quantized!
A philosophical idea is the idea of conservation, which assumes that the external action of electric charge passes through different spheres with electric charge as the center, and the total amount of electric action remains unchanged.
Another philosophical idea is that in the process of external action of electric charge, the extension in space is the principle of equal distribution of action, that is, the attribute of tensor. (characteristics of space extension)
The above two methods and principles are established for the fact of testing Coulomb’s law. At the same time, it also shows that the traditional physical description of the electrostatic field is indirectly derived from these two philosophical concepts.