Quantum dispersion of light

Light dispersion is the decomposition of light into its constituent parts. This phenomenon was discovered experimentally in 1672 by Newton. Since then, everyone has tried to understand: why do color rays break in different ways? And smart heads have thought of it - each color has a different phase speed.

What is phase velocity? As Wikipedia writes:

“Phase velocity - the speed of movement of a point with a constant phase of oscillatory motion in space, along a given direction” .

Do you understand something? Where is this point? At the maximum of the wave, at the minimum of the wave, somewhere in between, or somewhere in a place incomprehensible to the mind? This point is some kind of wave element. If you do not go crazy, then this should be admitted. Now imagine that the whole wave is moving at the speed of light, and some point of it is moving at a lower speed. How long will it move like this? Will she break away from the wave? Such a point can be in a wave, but if it slowed down for some time, then in the next period its speed must be greater than the wave speed, that is, the average speed of the point must be equal to the wave speed. Consider Figure 1

The wave moves with the speed v , and the point К the intersection of the wave and the axis OX moves along the axis with the speed V . The smaller the angle between the wave and the axis, the faster the point К moves. This speed can be any, including more than the speed of light. But not a single wave element moves along the OX axis. All elements just cross the axis. The essence of phase velocity played a cruel joke with Einstein when he suggested that light propagates along the axes Y and Z speed.

As a result, the ball turned into an ellipsoid when the speed changes, which contradicts everything that is possible.

The physical speed of the elements is the same in red, and in green, and in ultraviolet and in any other stream of radiation. They all move at the same speed relative to the vacuum. Air also has a certain refractive index, that is, it traps the components of light. Moreover, different components are delayed in different ways.

But why did all the rays suddenly change their direction at the border of the media, regardless of the frequency? You can, of course, imagine a wave as some kind of comb with teeth from above and below, which is pushed into the hole at an angle, and with its lower teeth it clings to another medium earlier than the upper teeth and, as a result, will change the direction of movement. And when the upper teeth also reach another medium, then the movement of this comb will be rectilinear. All this would be so if it were not for the exit of the rays from the prism. At the exit, the prism presses on the lower teeth of the comb, but not on the upper ones, and therefore the comb must reverse the rotation. Experience shows that this is not the case. This can be seen in Figure 2. The mechanistic assumption is not correct. This is all the more obvious if you look at infrared radiation. Rice. 2.

What will the radiation measurement sensors located at points 1-7 show? Let each sensor be able to register all types of radiation. Sensor 1 will register ultraviolet light, but will not respond to the visible spectrum. Sensor 2 will register the visible spectrum, but will be indifferent to ultraviolet light. Sensor 3 will show signals of the infrared spectrum, other radiation simply does not fall on it. The same will be shown by sensors 4-6. Sensor 7 will show visible spectrum and infrared spectrum. More precisely, all sensors will show infrared radiation. Why is this so?

Yes, because for infrared radiation the laws of Thompson scattering come into play. And Thompson scattering is characterized by an almost circular scattering pattern. Can you show it somehow in a simpler way? Yes. If we put thermometers instead of radiation sensors, we will see that when the beam is not supplied with a prism, they will change their readings. Why is that? The prism heated up with infrared photons and began to relay infrared photons in all directions. Now the supposed combs turned in all directions, which is impossible. It is necessary to look for another model of the interaction of a photon and matter.

We will offer one of such models. It is based on the model photon as a sum of quanta and on a model light reflections . Nature is so arranged that a photon of any energy, coinciding in its orientation with the corresponding electron, will necessarily be absorbed by such an electron to the end. Otherwise, nothing will happen in nature. An electron without trying on a photon on itself cannot decide: to absorb this photon and go to another level, so that some reaction takes place, or to relay this photon.

During the periods of absorption and emission, the electron will travel a certain path. The photon began to be absorbed by the electron when it was at some point in its orbit in the atom, and will be emitted at another point in the orbit. This will create a kink in the beam.

The more energy a photon has, that is, the longer the chain of quanta, the longer the period of time such a photon will be absorbed and emitted. Accordingly, during this longer period of time, the electron will pass most of the orbit, where the photon will be emitted. The direction of this photon will be further deviated from the original direction. For other wavelengths, there will be other directions.

If the substance of the prism is different, it may turn out that the atoms, including the surface ones, contain electrons that are at different energy levels, that is, at different speed modes. The time of emission and absorption of a quantum is constant, because it depends on the spin, but not on the substance. The same photon will interact with an electron for the same time in any substance. But in one substance during this time the electron will pass some segment of its orbit, and in another substance it will pass a larger or smaller segment of its orbit and, therefore, a different bend of the beam will be obtained. Moreover, the entire spectrum will be broken by this greater or lesser value. These are different refractive index values .

And what happens to infrared radiation, that it is detected at various points around the prism? The article "Electromagnetic radiation" it is said that radiation is a stream of photons with different frequencies. Approximately as shown in Fig. 3.

Photons 1, 2 and 3 of different energies move at the same frequency with a wavelength equal to λ, provided that we measure the wavelength correctly. It may be that the wavelength has to be taken to be λ1, λ2, or λ3. For this case, we do not care. Naturally, the same photons or photons of other energies can move with a different frequency. If you look at the radio range, there ?x can reach many meters. It can be assumed that the elementary photons themselves have higher energy (an electron in the LC circuit covers long distances) and, therefore, it is longer.

It is possible that in the infrared flux the photons are longer than the photons of the visible spectrum. This means that infrared photons are absorbed or emitted longer than photons in the visible spectrum. They are regenerated not for a part of the revolution of the electron around the nucleus, but for a revolution or revolution with some part or several revolutions of the electron around the nucleus. Accordingly, photons from these points of the orbits are emitted. And this can be any direction. And since thermal photons make electrons move at different speeds, these points of radiation float and therefore the radiation pattern (scattering) is blurred. This means that each electron has a different refractive index. If you imagine the antenna as a rod, then this diagram is almost a perfect circle. Other materials and designs of repeaters will give other diagrams, including a prism.

This is how Thomson scattering is formed without changing the radiation wavelength.

Between the dispersion of the visible spectrum and the dispersion of the infrared spectrum there is an observed intermediate phenomenon in the form of anomalous dispersion. For example, in iodine vapor (and in many other gases) the red ray breaks more than the blue one. Of course, we can say that the phase velocity of some imaginary point in a gas is different, so the rays break in a different way, but this will not clarify the physics of the phenomenon.

In a glass prism, a photon of the visible spectrum interacts with an electron along some part of its orbit in an atom. You can select a substance, prisms so that this path will be more or less, that is, the refractive index will be more or less. In a free atom, the length of the same orbit will always be less than in a bound one. When a bond is formed, the electron captures a part of the foreign territory. But a photon always interacts with an electron at the same time. And if the length of the orbit is relatively small, then it can happen that the photon is retransmitted into the body of the prism, up to the opposite direction, as in Thomson scattering. And then what is shown in Fig. 4 can happen.

On one of the iodine atoms, the beams were broken in the usual order, but the photons went into the prism. On the second atom, the rays hit points 4 and 5. And although the distance from 4-6 is greater than the distance 5-7, the emission of a blue ray can occur from point 6 earlier than the emission of a red ray at point 7. An inversion has occurred. If the rays after the first atom left the gas not inside the gas, but outside, then there would be a red ray on the right, and blue on the left. And after the second atom, the opposite happened. The beams are swapped.

Experience shows that the phenomenon of inverse anomaly is observed near absorption lines. Perhaps this is so, but you should still look for other rays in all directions. Maybe some will end up behind, below or on top of the prism.

Of course, this model, like many other models in my other articles, has many complaints. Why does the electron move in this direction, and not in some other, why does the photon hit the electron in this place, and not in another, etc. One can try to explain all this, but that is not the point. It is important to draw attention to the need to move to a quantum level of knowledge, and then, you see, someone will build a true model of this or that phenomenon.

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