Is 150000 flower and sword powerful

1. Ether (or ether); English: ether or aether) is a kind of material conceived by ancient Greek philosophers, which is a hypothetical medium of electromagnetic wave propagation and is considered to be ubiquitous
in ancient Greece, ether was the blue sky or upper atmosphere. In cosmology, ether is sometimes used to represent the matter occupying celestial space. Descartes in the 17th century was a philosopher who had a great influence on the development of scientific thought. He first introced ether into science and endowed it with some mechanical properties
according to Descartes, all forces between objects must be transferred through some intermediate medium, and there is no over distance effect. Therefore, space can not be empty, it is filled with the medium of ether. Although ether can't be felt by human senses, it can transmit forces, such as magnetic force and the force of the moon on the tide
later, as the load of light wave, ether was connected with the wave theory of light to a great extent. The theory of light fluctuation was first put forward by Huck and further developed by Huygens. For quite a long time (until the beginning of the 20th century), people's understanding of waves was limited to the mechanical vibration of a medium. This medium material is called the load of wave. For example, air is the load of sound wave
since light can propagate in vacuum, Huygens proposed that the medium material (ether) loaded with light wave should fill all the space including vacuum, and penetrate into the common material. In addition to being the load of light waves, Huygens also used ether to explain the phenomenon of gravity
although Newton did not agree with Hooke's theory of light wave, he also opposed the action of over distance like Descartes and acknowledged the existence of ether. In his view, ether is not necessarily a single substance, so it can transmit various effects, such as electricity, magnetism and gravity. Newton also believed that ether could propagate vibration, but the vibration of ether was not light, because the wave theory of time could not explain the polarization of light, nor why light propagated in a straight line
the 18th century was a time when etherism declined. Because the French descarterians rejected the law of inverse square of gravity, and made Newton's followers rise up against Descartes' philosophy system, so they joined the opposition together with his theory of ether
with the success of the inverse square law of gravity in celestial mechanics and the lack of practical results in the exploration of ether, the idea of over distance action has become popular. The wave theory of light has also been abandoned, and the particle theory has been widely recognized. By the late 18th century, it was proved that the force between charges (and between magnetic poles) was also inversely proportional to the square of distance. Therefore, the concept of electromagnetic ether was abandoned, and the idea of over distance action also occupied a dominant position in electricity
in the 19th century, the theory of ether was revived and developed, which started with optics, mainly as a result of the work of Thomas Young and Fresnel. Yang explained Newton's ring with the interference of light wave, and put forward a new viewpoint that light wave is shear wave in 1817, which solved the difficulty that wave theory could not explain the polarization of light for a long time. Scientists have graally found that light is a kind of wave, and most of the waves in life need propagation media (for example, the transmission of sound waves needs air, and the transmission of water waves needs water, etc.). Influenced by traditional mechanics, they assumed that there was a kind of matter called ether everywhere in the universe, and it was this kind of matter that played a role of medium in the transmission of light
the hypothesis of ether actually represents the traditional view: the propagation of electromagnetic wave needs an "absolutely static" reference frame. When the reference frame changes, the speed of light also changes< However, according to Maxwell's equations, the propagation of electromagnetic wave does not need an "absolutely static" reference frame, because the two parameters in the equation are non directional scalars, so the speed of light is constant in any reference frame

where ε 0 is the vacuum dielectric constant, μ 0 is the vacuum permeability
the absolute static system is the etheric system. The speed of light measured by observers in other inertial frames should be & quot; Etheric system & quot; The speed of light is the same as that of the observer at & quot; Etheric system & quot; The vector sum of the velocities on
ether is omnipresent, has no mass and is absolutely static. According to the conjecture at that time, the ether filled the whole universe, and electromagnetic waves could propagate in it. Suppose the sun is still in the etheric system. Since the earth is rotating around the sun, it has a velocity V relative to the ether. Therefore, if the speed of light is measured on the earth, the values measured in different directions should be different, with the maximum of C + V and the minimum of CV. If the sun is not stationary in the etheric system, the speed of light measured on the earth in different directions should also be different
Fresnel successfully explained the diffraction phenomenon of light with the passive theory. The theoretical method he proposed (now commonly known as Huygens Fresnel principle) can correctly calculate the diffraction pattern and explain the linear propagation of light. Fresnel further explained the birefringence of light and achieved great success
in 1823, based on Yang's theory that light wave is shear wave and his own assumption in 1818 that the density of ether in transparent matter is proportional to the second power of its refractive index, under certain boundary conditions, he deced the famous formula of reflected light and amplitude of refracted light, which well explained the results measured by Brewster several years ago
one of Fresnel's important theoretical works on ether is to derive the velocity formula of light in a transparent object moving relative to the ether reference frame. In 1818, in order to explain Arago's experiment on the refraction behavior of starlight, he proposed on the basis of Yang's idea that the density of ether in transparent matter is directly proportional to the second power of the refractive index of the matter, and he also assumed that when an object moves relative to the etheric reference frame, only the part of the ether inside the object that exceeds the vacuum is driven by the object (etheric partial traction hypothesis). Using Fresnel's theory, it is easy to get the speed of light in a moving object
in the middle of the 19th century, some experiments were carried out to show the effect caused by the earth's motion relative to the etheric reference frame, and thus to determine the speed of the earth relative to the etheric reference frame, but the results were negative. These experimental results can be explained from Fresnel's theory. According to the formula of light speed in Fresnel's moving medium, when the experimental accuracy only reaches a certain level, the speed of the earth relative to the etheric reference frame will not be shown in these experiments, but the experiments at that time did not reach this accuracy
after the work of young and Fresnel, the wave theory of light established its position in physics. Later, ether gained its place in electromagnetism, mainly e to the contributions of Faraday and Maxwell
in Faraday's mind, the idea that function is graally passed on has a very strong position. He introced force lines to describe magnetic and electrical effects. In his view, the force line is the existence of reality, space is full of force line, and light and heat may be the transverse vibration of force line. He once proposed using force line to replace ether, and thought that matter atoms might be the force line field gathered near a point like center. He wrote in 1851: "if we accept the existence of light ether, then it may be the load of the force line." But Faraday's view was not accepted by the theoretical physicists at that time
in the early 1860s, Maxwell proposed the concept of displacement current, and proposed a set of differential equations to describe the general law of electromagnetic field, which was later called Maxwell equations. According to Maxwell's equations, we can dece that the disturbance of electromagnetic field propagates in the form of wave, and the speed of electromagnetic wave in the air is 310000 km / s, which is consistent with the known speed of light in the air of 315000 km / s in the range of experimental error< After pointing out that the propagation of electromagnetic disturbance is similar to that of light, Maxwell wrote: "light is the transverse vibration of the medium (ether) that proces electromagnetic phenomena.". Later, Hertz confirmed the existence of electromagnetic wave by experiment. The electromagnetic theory of light has successfully explained the nature of light wave. In this way, the ether has not only gained its position in electromagnetism, but also unified with the optical ether< In his 1855 paper, Maxwell compared the magnetic inction to the speed of ether. Later, he accepted Thomson's (Kelvin's) view and changed it to magnetic field for rotation and electric field for translation
he believes that the rotation of the ether around the magnetic line of force forms vortices, and there is a layer of charge particles between the adjacent vortices. He also assumed that when these particles deviate from their equilibrium position, that is, there is a displacement, they will proce a force on the matter in the vortex element, causing the deformation of the vortex element, which represents the electrostatic phenomenon
it is not a completely new idea that there is a certain correspondence between electric field and displacement. Thomson once compared electric field to displacement of ether. In addition, Faraday proposed earlier that when an insulating material is placed in an electric field, its charge will shift. Maxwell is different from Faraday in that he thinks that no matter there is insulating material or not, as long as there is an electric field, there will be the displacement of ether charge particles, and the displacement is proportional to the electric field strength. When the displacement of charge particles changes with time, an electric current will be formed, which is what he called displacement current. For Maxwell, the displacement current is the real current, and now we know that only a part of it (polarization current) is the real current
in this period, some other ether models were established, but there were some problems in the theory of ether. First of all, if light wave is shear wave, then ether should be elastic solid medium. So why do celestial bodies run without resistance? An explanation has been put forward: ether may be a plastic substance like wax or asphalt, which is elastic enough to vibrate as fast as light, like a solid, and as slow as a celestial body, like a fluid
in addition, in elastic media, there should be P-wave besides S-wave, but experiments show that there is no P-wave. How to eliminate the P-wave of ether and how to obtain the boundary conditions needed to dece the reflection intensity formula are long-term controversial problems for various ether models
in order to meet the needs of optics, people assume some very important properties of ether, such as the mccollah model and Cauchy model in 1839. Moreover, because the refractive index is different for different light frequencies, the drag coefficient will be different for different frequencies. In this way, each frequency of light will have to have its own ether and so on. These seemingly contradictory properties of ether are beyond people's understanding
from 1881 to 1884, Albert Michelson and Edward Murray concted the famous Michelson Murray experiment to measure the relative velocity of the earth and the ether. The experimental results show that there is no difference in the speed of light in different directions. In fact, this proves the principle of invariance of light speed, that is, the speed of light in real space has the same value in any reference frame, which has nothing to do with the relative speed of reference frame. In fact, ether does not exist. Later, there were many practical cases