Abstract. The reasons for the slowing down of light in matter are stated from the standpoint of the theory of the Elastic Universe. The reasons for the strong deceleration of photons in Bose-Einstein condensates are outlined.

   Lina Howe's experiments on slowing light in Bose-Einstein Condensates (BEC) sodium at low temperatures raised a lot of questions. The main question is: what is the reason for such a large slowdown of light (by a factor of millions) in sodium condensate at low temperatures in the Bose-Einstein state? The search for an answer to the question leads to a fundamental question: why does light slow down at all when passing through matter?

How is the universe and elementary particles arranged?

   Before starting the description of the slowing down of photons in matter, let us remind the reader how matter is arranged in the theory of the Elastic Universe. So the universe is an elastic continuum - Gukuum, filled with different wave objects. The question arises: what are the particles of this continuum made of? For a solid continuum, this question is meaningless. The continuum can be subdivided indefinitely. One of the wave objects in Gukuum is elementary particles, which are wave vortices (that is, without the transfer of matter, purely elastic waves). From the point of view of the theory of the elastic universe, elementary particles are axisymmetric wave vortices in Gukuum. Purely wave formations without any transfer of matter. Formulas for elementary particles have been found, portraits are drawn, there are even gifs of elementary particles. Full correspondence of all physical parameters of real elementary particles and their theoretical models has been proved. An electron is a real wave cloud with a void in the center.

   Here are the links to the formulas:

http://universe100.narod.ru/E200-Kandidats.html

GIF pictures of elementary particles:

http://universe100.narod.ru/E420-Electron-GIF.html

http://universe100.narod.ru/E430-Neutron-GIF.html

http://universe100.narod.ru/E440-Proton-GIF.html

   It should be noted that all processes in Gukuum obey the wave equation, and hence the discrete spectrum of solutions given by it. The discrete spectrum of solutions gives rise to quantization and all of quantum physics. In everyday language, all processes in Gukuum are of a quantum nature.

   A unified theory of all fields in Gukuum: http://universe100.narod.ru/u250/image032.jpg.

   The concept of a liquid or gaseous physical vacuum is erroneous. All objects formed in a liquid vacuum cannot maintain their shape. In addition, liquid vacuum transmits only longitudinal waves and does not transmit transverse ones. And the photon, according to modern concepts, is a transverse wave.

   In the elastic universe model, electrons are not small at all. Electrons are huge clouds, thousands of times the size of atomic nuclei. Electrons are much larger than commonly believed. And comparable to the size of a photon passing through matter. This is proven by mathematics, there are formulas. Atoms through which photons pass, they only slow down the photon, but do not change its vector, do not scatter photons. Just like when braking a car, it continues to move in the same direction.

How are photons arranged?

   In turn, the photons are not any kind of wave vortices. According to the theory of the elastic universe, the photon is not an electromagnetic entity. They arise in the processes of energy transitions inside atoms, as well as in the processes of mutual annihilation of elementary particles flying "head to head". In these processes, significant changes occur in the deformations of the surrounding areas, which lead to "scratches" inside Gukuum. According to the statements of mathematicians, such "scratches" in an elastic medium do not stand still, but once they arise, they then move at the speed of elastic waves in this medium. That is, in our case, at the speed of light. The shape of these "scratches" is determined by the process in which they occur. Due to the wave vortex structure of the sources of these "scratches", the shape of the "scratches" is most often similar to a spring or a flat sinusoid, with attenuation at the ends. These "scratches" spread along their main (long) axes, at the speed of light and are called photons. All observed in experiments wave or corpuscular properties of photons are determined by their shape. That is, when a photon passes through a substance, it can induce both electromagnetic processes in the substance and manifest itself as a corpuscle.

   Here are the links to the origin and shape of photons:

The entire chapter on photon:

http://universe100.narod.ru/E210-Photon.html

Mathematical solution for a photon:

http://universe100.narod.ru/u210/image023.jpg

Annihilation: http://universe100.narod.ru/u210/image017.gif

Photon form: http://universe100.narod.ru/u210/Photon-01.gif

   Photons, according to the solutions of the wave equation, are sometimes formed in pairs, and propagate while maintaining their shape, at the speed of light, in opposite directions. Allegedly, the wave properties of photons are determined when they collide with matter by their standard shape of a sinusoid or spring, which is determined by the process of photon production. The legend about "entangled" photons is apparently generated by the pairing of photons. Similarly, the legend about the wave "structure" of the photon was born, because of the properties they exhibit. In reality, this is a manifestation of the spring-like form of photons, which does not change during the flight of photons..

Common explanation for the slowing down of photons.

   Traditionally, the slowing down of light is interpreted as collisions of photons-particles with atoms of matter. That is, as it were, a manifestation of the corpuscular property of a photon. These collisions seem to scatter the photons at first, but because of their wave properties, the scattered photons then supposedly interfere, line up again and move in the same direction.

   Why do photons slow down when passing through transparent substances? Which substances are transparent and which are not? Nontransparent substances are substances in which there are quantum energy levels equal to the energy of a passing photon. For example, in metals there are many free electrons, which have millions of energy levels, and such substances are capable of absorbing almost any photons. Transparent substances are substances in which there are no energy levels equal to the energy of the passing photons.

   Reflection of photons is a separate issue. It is determined by the structure of the substance on which the photon falls, as well as by the energy of the photon. Here we do not touch on this phenomenon.

The reasons for the slowing down of photons in the theory of an elastic universe.

Why are passing photons slowing down in substances? The reasons for the slowing down of photons are different from the reasons for deflecting light near massive stars. From the standpoint of the theory of the elastic universe, the picture of the slowing down of photons in matter looks like this. A photon is a deformation of the Gukuum that moves at the speed of light. Atoms of matter are wave vortices in which the wave runs in a circle around the axis. Mathematical solutions for wave vortices are found and given in the theory of the Elastic Universe. In these wave vortices, there is a predominance of one (of the two) directions of rotation, which is why the spin and charge of the particles arise. The following is a simplified picture. When colliding with a photon, one half of the electron cloud rotates in the same direction that the photon is traveling. And this half does not slow down the photon. But the second half rotates in the opposite direction to the movement of the photon, and this half slows down the photon. As a result, after summation over all particles of matter, the resulting deceleration of the photon is created. This is the reason for the slowing down of the photon. After leaving the substance, the photon moves again with the speed of light, because the speed of the photon is determined by the elastic properties of Gukuum.

   A similar interaction between an electron and a photon occurs at each turn of the photon's "spring" or at each wave of the photon's sinusoid. The photon is not perceived by matter as something whole. The substance slows down every turn of the photon, every bend. And there are millions of such bends in a photon. In this case, the wave laws are such that the photon does not break into pieces and retains its integrity.

   The interaction of a photon with a half of an electron occurs for any size of a photon, because the other half of an electron rotates in the same direction in which the photon moves. The electron cloud slows down the photon with its other half. But the first half cannot accelerate the photon because it rotates at the same speed as the photon.

   Since the outermost electrons in the atom have the form of clouds with the size of the atom itself, then it makes sense to talk about the deceleration of a photon by an atom of matter.

   In a gas, molecules are rare and the deceleration of a photon is very weak. In matter, the deceleration of a photon is stronger. But due to the relatively large distances between the atoms of matter in crystals, the deceleration of photons in matter is very limited by a few percent of the speed of light.

Where does such a huge deceleration of photons in Bose-Einstein Condensates (BEC) come from?

   It seems that the reason for such a slowdown is that in BEC all atoms are aligned in the same way, freeze, and slow down the light together, together, everything is the same. Moreover, a passing photon cannot change their orientation. All atoms and nuclei are frozen in one state. And at ordinary temperatures in transparent substances there is a distribution of atoms according to the orientation of the spins, and the passing photon is able to change the orientation of the spins of the atoms of the substance. Just like a running elephant pushing aside bushes.

   In other words. In transparent substances, light is retarded by the atoms of this substance. And these atoms act not on the main body of the photon, but on its deformation shell. On the "skin" of the photon. And for every turn of this "skin". Since in this deformation shell there are tensor elements that interact with the tensor elements of the electron shells of the atom. It is obvious that in the tensor of deformations (stresses) of electron wave vortices there are components that are capable of making electrons from different atoms interact with each other. This is observed experimentally in the interaction of atoms. We cannot yet select and write these components in the form of formulas. But they obviously exist and will be found by mathematicians. The photon is in the form of a spring that moves along the axis on which the spring is wound. In the same way, by analogy, the strain (stress) tensors in the turns of the photon spring have similar components that are capable of interacting with the components of the electron deformations (stresses). There are many coils of the spring, each coil has its own front and its rear. Each turn of a photon passing through an electron is decelerated by this electron due to the interaction of its front and rear with the electron cloud. That, in the sum for all electrons and for all turns of the photon, gives the interaction between the photon and the electron. It is also possible that a photon passing through a substance is able to change the orientation of counterpropagating electrons in order to reduce their deceleration. Just like an elephant running through a bush changes the orientation of the bushes. At the same time, dense bushes can greatly slow down the movement of an elephant and even completely slow down it, which we observe in Lina Howe's experiments.

   Thus, I think, if Lena House's experiments are carried out with different orientations of spins in the BEC, with different polarizations of transmitted photons, then a spread in the magnitude of the slowing down of photons can be observed. Up to a complete lack of deceleration. And also all kinds of variations of the effect of the polarization of the photon on the slowing down.