No. In Modern Physics the theoreticians consider that light does not have a physical structure. Light is described mathematically by Maxwell’s equations, but they have no connection with a physical structure. We can say that light, according to Modern Physics, is like a ghost, an entity of another world different from the physical world in which we live.

This is the reason why some philosophers think that there is no such thing as physical reality, and we live a world of illusion.

When Einstein introduced the concept of a photon at the beginning of the 20th Century, he also introduced a new theoretical problem: the concept of the photon (a quantum of light) is not compatible with Maxwell’s Equations. Over several years Einstein tried, in vain, to find a solution to reconcile the concept of the photon with Maxwell’s Equations.

The concept of the corpuscular photon can be reconciled with Maxwell’s Equations through the adoption of the helical trajectory of the elementary particles. The helical trajectory, known as zitterbewegung, appears in the Dirac equation of the electron. This discovery was made by Schrödinger. He did not believe that the successes of Bohr’s theory could be accidental, and he tried to find the cause of some mysteries that appeared in the solution adopted by the theoreticians in the development of Quantum Mechanics.

The zitterbewegung was interpreted in Quantum Field Theory, the successor of Quantum Mechanics, in a different manner from that proposed by Schrodinger because according to QFT the zitterbewegung is not a helical trajectory. However, the theoreticians did not succeed in their attempt to eliminate the inconsistencies of Quantum Mechanics and several paradoxes still persist in the theory.

The zitterbewegung in the sense of Schrodinger is a new attempt that may be capable of eliminating these paradoxes of Modern Physics.

A new alternative for the explanation for the wave-particle duality of particles like the electron and proton has been proposed from a theory developed by considering the zitterbewegung. Such an alternative has been developed by several theoreticians, such as the physicist T. S. Natarajan, the mathematician Waldyr Rodrigues Jr., the physicist David Hestenes, and others.

But can the concept of zitterbewegung be applied to the photon?

The possibility of proposing a theoretical physical model of a photon was rejected by Einstein and Dirac at the beginning of the 20th Century because some experiments had shown that the photon appears to exhibit a statistical behavior in some light polarization phenomena. This restriction is the most fundamental argument against the viability of a theoretical proposal for a photon model. Nevertheless, in the paper regarding the EPR PARADOX, it is shown that there is a hidden variable in the structure of the photon, responsible for the statistical behavior. So, this fact implies the following: the statistical behavior can be explained through a physical model of the photon, something considered impossible during the 20th Century.

The theoreticians rejected theories based on the hypothesis of hidden variables because they consider that they violate a theorem known as Bell’s Inequalities. However, as we will see in the paper of the EPR PARADOX, Bell’s theorem would be acceptable if all the predictions of Quantum Mechanics were correct. But if the solution based on the zitterbewegung is the one used by Nature for the production of physical phenomena, this implies that Quantum Mechanics is not correct, and so Bell’s theorem cannot be taken into consideration for rejecting a physical model of the photon.

A paper on the zitterbewegung of the photon was written by D. H. Kobe and published in Physics Letters A in 1999.

A model of a photon is unacceptable if it is unable to satisfy the following premises:

1. To be able to yield Maxwell’s Equations.

2. To be compatible with the wave-particle duality of the light.

3. To be able to explain the transverse propagation of light.

4. To be able to explain light polarization (as we will see in paper on the EPR Paradox).

5. To be able to reconcile the quantum concept of light with Maxwell’s Equations; they may be reconciled through the present model of a photon, as shown in the paper on the EPR Paradox.

6. To be able to be fitted to a Lie group. As it’s impossible from a physical model of a photon constituted by ** matter** to fit it to any group of symmetry known as Lie Groups, it seems impossible, from the mathematical viewpoint, for the photon to have physical structure.

No. When Newton proposed that light is constituted of particles, he was thinking about a classical model of a particle. On the other hand, Quantum Ring Theory proposes that a non-classical model based on quantum mechanics can explain light: the photon is composed of two corpuscles, a particle and its antiparticle, in rotation, and they cross the aether.

Yes. The prediction that space is filled by particles and antiparticles was made by Dirac. His theory was confirmed by experiments. Thanks to his theory, physicists found antiparticles, such as the positron, antiparticle of the electron.

While particle model cannot be fitted to a Lie group because it is asymmetrical, a particle/antiparticle model can be fit to a Lie group because it is symmetrical and, therefore, it does not break the symmetry required by Lie Groups.

Let us analyze a physical model of a photon which works through the participation of its interaction with the aether.

Firstly, let us consider two macroscopic phenomena whose effects we need to consider for the explanation of a photon’s behavior. It is important to note that it is merely a macroscopic example with the object of considering the behavior of one particle with electric charge crossing a magnetic field.

Figure 2.1 shows that, when a particle with positive electric charge +q in rectilinear motion with speed v crosses a magnetic field B situated in a plane orthogonal to the motion, the particle executes circular motion with radius r = mv/qB.

If a particle with negative charge -q has speed v toward the line of flux of field B, but with a component of v orthogonal to x-axis, the particle acquires a helical trajectory (Figure 2.2).

Now let us consider a microscopic particle with charge +q emitted by an atom.
Figure 2.3 shows the particle with speed of light c and electric charge +q following a circular orbit orthogonal to the x-axis, with radius R and angular speed.

As the particle has a secondary motion transverse to the x-axis while its main motion is along the x-axis, it describes the trajectory shown in Figure 2.4.

Later we will see the reason why the particle follows an orbit with radius R.

Figure 2.4 shows a strong electric field ET in the z-direction, and a weak magnetic field B_{T} in the y-direction. The field E_{T} is strong because it is induced by the charge +q travelling with the faster speed c, while B_{T} is weak because it is induced by the charge +q with lower speed v=ω.R (see also Figure 2.5).

Figure 2.6 also shows that two other fields are induced: the field E_{L} is in the x-direction and is induced by the tangential speed v= ω.R and, therefore, it is weak, and B_{L} also in the x-direction but induced by the speed c and, therefore, is strong.

Let us verify the relation between the transverse fields E_{T} and B_{T}.
Figure 2.7 shows schematically an atom emitting two photons.

Let us suppose that photon “1” is composed of a quantity “m_{1}” of positive Dirac particles e(+) of the quantum vacuum. Thereby, m_{1} is a purely non-dimensional number. We will call “Phase P” (principal) such a photon with positive electric charge. If each particle e (+) of the quantum vacuum has charge +q, then m_{1}.q = Q_{1}1, which is the charge of photon 1. Using the same method for photon “2”, emitted with greater kinetic energy, m_{2}.q = Q _{2} is the charge, and m_{2} is the mass.

Concerning the relation between the spins of the two photons, it is reasonable to hope that the bigger the mass of a photon, then the higher the angular speed ω of the spin’s rotation; that is, it is reasonable to believe that, if K_{1} and K_{2} are the kinetic energies, then

Thus,

and for any photon:

The intensity of the transverse field B_{T} depends upon the values of Q and ω:

The intensity of the transverse field E_{T} depends upon the values of Q and c:

Compare the two situations in Figures 2.8 and 2.9:

• In Figure 2.8 there is no magnetic field B_{L} crossing the particle’s trajectory. From this condition we would have:

• However, the intensity of the field B_{L} depends upon the speed ω. In addition, the magnitude of the field B_{L} increases the influence of B_{T} (proportional to ω) in the relation between E_{T} and B_{T}. Therefore, in Figure 2.9, we need to consider the influence of the magnetic field B_{L} crossing the spiral. From this condition we have:

and then:

The expression above is a well-known relation between E_{T} and B_{T} in the propagation of electromagnetic waves. Now we can introduce an induced “Phase I” into our model of the photon:

• The atom emits a particle with charge +Q (Phase P), as we have seen already.

• However, suppose this particle induces the appearance of an antiparticle with electric charge -Q (Phase I).

• Then the antiparticle will have the same fields E_{T} and B_{T} , E_{L} and B_{L} as shown in Figure 2.4, 2.5, and 2.6

The induced antiparticle, with charge –Q and with motion in the x-direction, crosses the field B_{T} induced by the particle with charge +Q and, therefore, similar to the macroscopic phenomenon shown in Figure 2.1, the antiparticle acquires rotation around the flux B_{L}.

By the same method, the particle with charge +Q will cross the field B_{T} , which is induced by the antiparticle, and therefore, similar to the macroscopic phenomenon shown in Figure 2.1, the particle acquires rotation around the flux B_{L} too [U] but the rotation of the particle is in the opposite direction[/U] to the antiparticle’s rotation because the particle’s charge is positive and the antiparticle’s charge is negative.

Let us examine the combination of the fields in Figure 2.10-A.

The wavelength of light is

where c is the light speed and υ its frequency.

The wavelength λ shown in Figure 2.10-A depends upon the angular speed ω. Obviously, the lightest photons have lower ω, and, consequently, a longer wavelength. On the other hand, heavy photons such as gamma rays have faster ω, and their wavelengths are very short.

If T is the period for one complete revolution of the spin, then when t= 0 we have E=0, B=0; and when t=T/4 we have E=max, B=max; and so on..., as shown in Figure 2.10-A.

From these figures we can realize two things:

1. why the field E has a sine shape:

2. and why B with E are in phase:

where c = ω/k

From the three equations:

and starting from the mechanism of the present model of a photon, we can arrive at Maxwell’s Equations.

Figure 2.10-B shows three photons 1, 2, and 3. The polarization of a photon depends on the distance between the two particles that constitute the photon (in the photon 1 there is not a distance, in the photon 2 the distance is “a”, and in the photon 3 the distance is “b”). How such distance influences the polarization will be explained in the paper on the EPR Paradox.

Look at the Figure 2.11

Concerning the problem of the interference phenomenon of a photon crossing gaps in the wall, when the photon crosses the unique gap 1 of Figure 2.11 we do not have interference between Phase P and Phase I, because the field B_{L} is divided symmetrically by the centre line which divides the photon in the x-direction; i.e. in the direction of the photon’s motion. However, when the photon crosses gap 2 and gap 3, the magnetic field B_{L} is not divided symmetrically, and Phase P interferes with Phase I. This is the reason why a photon can interfere with itself, as experiments have shown, - a paradox described by Quantum Physics with the help of complex numbers.

__CONCLUSIONS__

It is possible that the model of a photon proposed herein could be the physical model used by Nature for the propagation of light. This is very important for science, because up to now a “physical” model (able to describe the phenomena of light) was considered an impossibility by scientists. Indeed, if we consider light as constituted by particles in the sense of Newton (with rectilinear trajectory), such a model cannot survive many theoretical restrictions against its hypothesis. Robert Lindsay and Henry Margenau, authors of the book Foundations of Physics, wrote:

*“It is also clear that, if the propagation of light is treated as being due to the motion of corpuscles moving with the velocity of light, the corpuscles do not move in accordance with the principle of least action. This situation has been discussed by L. de Broglie in his wave mechanics.” *

Such an objection is not applicable to two corpuscles , particle and anti-particle, moving in a helical trajectory.

__LIGHT, MATTER, AND ANTIMATTER__

When Einstein developed relativity at the beginning of the 20th Century, nobody considered it in relation to the existence of antimatter. The positron, that is the antiparticle of the electron, was a consequence of Dirac’s theory, and it was found experimentally later.

But what is antimatter ?

Antimatter is not something mysterious. A particle and its antiparticle have the same mass, the same spin; that is, they are identical particles, but with one difference: they have opposite electric charges. For example, the electron has negative electric charge, and the positron has positive charge.

The basic difference between matter and antimatter is that our Universe is made of matter. Out of this, an electron and a positron behave in the same way, except in relation to their charges. If we create a positron in the laboratory, it immediatelly attempts to interact with an electron and they annihilate one another: when matter and antimatter interact, they annihilate and produce energy.

When the theoreticians were faced with the mystery of the nature of light at the beginning of the 20th Century, several pieces of theoretical evidence suggested that light could not be composed of matter; that is, light could not be composed of corpuscles. More than that, Einstein and Dirac were even convinced that it was impossible to find a physical model for light because the statistical behavior of light in polarization discarded that possibility.

In a certain way, Einstein was right in believing that the photon could not be a material particle; that is, the photon could not be matter because actually it is not matter, since a corpuscle, composed of matter and antimatter, is not matter. The combination of particle and antiparticle within the structure of a photon confers on it properties that matter does not possess; that is, the photon, because it is not matter, is not subject to the laws of Classical Mechanics.

No, when a force F is applied to a particle with mass m, it accelerates according to Newton’s law expressed by

The photon does not obey this law. The photon cannot be accelerated, because, being composed of matter and antimatter, it behaves as if it has no mass. If we create a magnetic field for accelerating a photon, a force F acts on the particle and a force –F on the antiparticle, and the two forces cancel one another in order that the total force on the photon is zero. Also, the photon is created with the speed of light, it does not accelerate. No particle of ordinary matter can do what the photon does.

To understand questions involving the nature of light, firstly we must consider the concept of rest mass. From the most famous Einstein equation E=mc^{2}, any energy can be converted to mass, and vice versa. If an electron has a speed V, it has then a total energy that is the sum of two energies:

In the case of photon, the theoreticians state that its rest mass is zero, it has its kinetic energy of movement only, which means that, if a photon collides with a surface and stops, no mass would be deposited on the surface.

Below are the restrictions imposed by the theoreticians on the hypothesis that light has a corpuscular nature:

1. Light composed of corpuscles would violate the principle of least action.

2. A corpuscular photon would have to have mass; in which case its rest mass could not be zero.

3. According to Relativity Theory the photon is massless.

4. A corpuscular photon would violate a mathematical concept known as gauge invariance.

Let us analyze these restrictions.

1. The least action principle would be violated by a corpusuclar photon if its trajectory was a classical rectilinear trajectory of a corpuscle. Nevertheless, the photon moves through a helical trajectory and, therefore, this restriction may be discarded.

2. A corpuscular photon would have to have mass if it was constituted by ordinary mass. But a photon composed of matter and antimatter has rest mass zero, because when the photon collides with a surface and stops, the particle and the antiparticle interact and annihilate.

3. A photon composed of matter and antimatter has no mass and, therefore, does not violate relativity. According to QRT, what the photon has is inertia, due to the particle and antiparticle, but not mass.

4. The gauge invariance is a mathematical concept that would be violated if the photon was composed of ordinary matter; that is, if it was composed of a particle only, without the antiparticle. This is because a photon with this structure of ordinary matter would not have symmetry and it would be impossible to fit it in one of the many groups of symmetry that receive the name Lie Groups. Not having symmetry, it would be impossible to find a mathematical equation for this photon independent of the reference frame, an indispensable condition for any model to be accepted. But a photon composed of matter and antimatter is symmetrical and, therefore, does not violate gauge invariance. Also, the most conclusive proof that this model of a photon has an equation independent of the reference frame is the following: in the paper A Model of Photon in QRT, it is demonstrated that this model of a photon generates the Maxwell equations. Thereby, the equation of a partnership between a particle and an antiparticle that moves along a helical trajectory is the Maxwell equations and, therefore, to reject this model of a photon would mean rejecting the Maxwell’s equations also.

One could comment that the helical trajectory appears in Dirac’s equation of the electron, and so we have a good theoretical reason for taking it into consideration.

Yes. The helical trajectory of a photon appears in the Schrödinger-like equation, as shown in the paper Zitterbewegung of a Photon, by D.H. Kobe , published in Physics Letters A, Vol. 253, No. 1-2, March 1999, where in the absrtract he writes:

*“A single photon, satisfying a relativistic Schrödinger-like equation, has a velocity operator that undergoes oscillations in a direction orthogonal to its momentum. This Zitterbewegung has a spatial amplitude equal to the classical wavelength. The spin of the photon is the orbital angular mometum due to the Zitterbewegung ” *

This model of a photon is, therefore, theoretically viable. It is not merely viable but eliminates paradoxes from the theories of Modern Physics. Indeed, as well as wave-like properties, this model also has corpuscular characteristics, such as are confirmed by Compton’s experiments. In these experiments, a photon collides with an electron and the event occurs exactly as if they were two billiard balls. This does not fit in with the undulatory hypothesis. Besides, this photon has momentum. In Physics, the momentum “P” of a body is the product of its mass and velocity: P=mV. Not having mass, how is the momentum of a photon explained and how is the Compton Effect explained?

When an atomic nucleus emits a photon of large energy, for example a gamma ray, the nucleus suffers a withdrawal, as happens with the boat in figure 2-12, in the instant when the man throws the watermelon to the other man in the other boat. Which indicates that the photon follows the law of action-reaction, that is applied to the bodies.

Yes, there is a controvery over the question of whether or not the photon possesses mass. But mass is a concept created by Newton, who proposed laws for matter. The photon is not matter, since it is a combination of matter and antimatter. As said already, the photon does not follow the law F=ma, because it does not accelerate, just because it is not matter. Hence, the discussion on whether or not it has mass does not seem appropriate. But there is no doubt that it possesses something that is equivalent to mass. Perhaps we have to propose a new concept, even a new mechanics for the alliance of matter and antimatter, just as Newton proposed the concept of mass for the matter.

Perhaps instead of calling it mass we should simply call it inertia, since:

a) the total energy of the combination of matter and antimatter at rest is zero because the matter has positive energy and the antimatter negative energy,

b) however, the total inertia of the combination of matter and antimatter is the sum of the inertias of the separate matter and antimatter.

It is not a case of the classical Newtonian inertia, which is applied to matter, because this refers to the inherent tendency of the bodies to continue in their state of motion in a straight line or rest as stated in Newton’s first law. Rather, it is the case of an inertia tied to the momentum. At the instant of creation, a photon is created with momentum P = i.c, where “i” is the inertia of the photon. After a collision, the photon transmits this momentum equal to the product of the inertia i and the velocity c of the photon. The momentum of a photon is the product of its frequency f and Planck’s constant h:

An experiment performed by Jung Luo in 2003, published by the American Institute of Physics, made with a very sensible torsion balance, detected a sediment of mass when light falls down on a surface. Does this imply that the mass of photon is not zero ?

As already explained, the controversy appears because we want to approach the question of a photon through Classical Mechanics using the Newtonian concept of mass. Consider the following:

1. A particle of matter has mass “m”, as a particle of antimatter has mass “m” too. So, when both are within the structure of a photon, each one of them has mass m.

2. But, while in the Classical Mechanics the sum of two masses m is 2m, the mass of a corpuscle in which are packed one particle of matter and one particle of antimatter, both with mass m, is not 2m. When they are packed together, the two particles behave as though they have zero mass.

3. When light falls on a surface and is absorbed by it, the structure of the photon is broken, and the two particles are unpacked. Then the individual characteristics of each one of them emerges and, as consequence, a mass 2m is deposited on the surface.

4. One has to note that, when the photon is absorbed by a surface, with the absorption the particle and antiparticle no longer constitute a photon because the structure of the photon has been broken with the lost of packing. With the unpacking, the two corpuscles lose the electromagnetic properties derived from the partnership between matter and antimatter inside the structure of the photon, and from that point on, they begin to manifest the individual properties of each corpuscle, which individually has mass.

When light passes from one medium to another, it changes its velocity; a phenomenon that receives the name refraction. For instance, in glass the speed of yellow light is 200.000km/s, while in the vacuum the speed is 300.000km/s. In this case is there accleration of light when it passes from a medium to another? **No, the light does not accelerate**. Although the light speed is greater in the vacuum than in the glass, it does not accelerate when it passes from the glass to the vacuum. Let’s see why.

First of all we have to understand what acceleration, which is a Newtonian concept inferred from the relation a=F/m, is. We realize that the acceleration is a property of matter, because a body composed of matter has mass “m”.

Consider a car moving with constant speed v=50km/h. Suddenly the driver accelerates so that, in an interval of time “t”, the speed increases from 50km/h to 100km/h. In the time interval “t”, the car has experienced all speeds between 50km/h and 100km/h, as for instance 50.1km/h, 50.2km/h...62.8km/h...77.03km/h...100km/h. This happens because the mass “m” has a Newtonian inertia and, when a force is applied to that body with mass “m”, its speed increases **continuously**. Any body, composed of matter, **requires a time** “t” to be accelerated. A body composed of matter cannot be accelerated from a speed v to another faster speed V in zero time.

So, let us suppose that a photon is a particle with mass “m”. Then, it is obvious that, when the speed of such a photon passes from 200.000km/s to 300.000km/s, its speed experiences all the intermediary speeds between 200.000km/s and 300.000km/s, because any particle composed of matter suffers acceleration.

However, consider a photon composed of a particle and antiparticle. Such aphoton has no inertia in the Newtonian sense, which means that such a photon is not accelerated; when it passes from the glass to the vacuum, its speed changes **instantaneously** from 200.000km/s to 300.000km/s. In another words, such a photon does not experiences the intermediary speeds between 200.000km/s and 300.000km/s, because this change of speed does not waste time. The time of speed changing is zero.

In the Compton Effect, a photon with momentum

collides with an electron at rest.

The photon transfers a portion of its momentum to the electron, which gets a momentum p_{e}=m_{e}.v, and the momentum of the photon decreases from p to p’, in order that there is a conservation of momentum: p = p’ + p_{e}. The phenomenon is similar to a collision between two billiards balls. As in Modern Physics the photon is considered massless, its momentum before the collision would have to be p=m.c = 0 , since its mass is m=0. Therefore, the equation p=m.c cannot be reconciled with the equation p=h/λ from the concepts of Modern Physics.

Besides, from the philosophical viewpoint, it makes no sense to consider a particle with mass m=0 capable of supplying momentum p_{e}=m_{e}.v to an electron at rest.

One could say that a massless photon has relativistic kinetic energy, but the kinetic energy of a particle is a result of its velocity. Again, we can think of velocity only if we consider a corpuscle composed of matter, because without matter it makes no sense to speak about velocity, since something that does not exist materially cannot have velocity. Therefore, a particle with no mass cannot have relativistic kinetic energy.

No. It’s known that the Compton Effect is incompatible with the wave concept of light because two waves cannot collide like two billiard balls. But, even if one wished to say that a photon’s relativistic energy is related to its wave nature, a wave is a disturbance of a medium and its propagation would require a massive feature of such medium.

As we realize, there is no way to reconcile the concept of a massless photon with the Compton Effect, from the viewpoint of Modern Physics.

Firstly, we have to understand: what a massless particle is? A massless particle is one that does not interact with matter. Also, if it has no inertia, then it is not subject to Newton’s law F=ma. For instance, before the confirmation of Einstein’s special relativity, where space is considered empty, scientists believed the space would be filled by an aether composed of massless particles because, if they were not massless, the velocity of the planets about the Sun would decrease slowly due to the friction of the particles and the matter that constitutes the planets.

Hence, consider the model proposed in Quantum Ring Theory. The photon is composed of two corpuscles: a particle and its antiparticle. They move with a helical trajectory, a motion that confers to light its wave-particle feature. Each corpuscle has mass m/2, in order that the photon’s mass is m/2+m/2= m.

The Compton equation

has been developed from the energy of the photon given by:

where the greek letter "ν" is the frequency, and it has been assumed that the rest mass of the photon is zero, so that eq. (1) becomes:

From eq. (2) we get the momentum of the massless photon:

As the momentum of a particle is the product of its mass and its velocity, from eq. (3) we have:

and so we get the photon’s mass from eq. (4):

Let’s consider the model proposed in Quantum Ring Theory.

The photon’s mass is actually composed of two masses hν/2c^{2}, one due to the particle with positive electric charge and the other due to the anti-particle with negative electric charge.

Now let’s interpret

which had been the starting point of Compton’s mathematical development, as follows:

and we see that from the model of photon proposed in Quantum Ring Theory we arrive at Compton’s starting point E=hν by considering a photon with mass m, because the positive energy +(hν/2c^{2}).c^{2} of the particle is cancelled by the negative energy –(hν/2c^{2}).c^{2} of the antiparticle.

**Conclusions: **

1. From the viewpoint of the photon’s **“energy”** as considered by Compton in his formalism, we see that the energy due to the rest mass of the two particles is cancelled, because they have opposite electric charges.
So we understand that the photon is massless as far as the “energy aspect” is concerned.

2. From the viewpoint of the photon’s **“momentum”**, we realize that the photon is not massless because actually it has a mass m = hν/c^{2}

Minkowski introduced the idea of the light cone into Relativity Theory. This is illustrated in the figure 2-13:

The Light Cone represents the idea that *“the direction of the light-flash does not depend on the motion of the source but just on the event at which the light-flash is emitted.” *

In addition, from the Einstein Principle of Relativity, all observers, regardless of their motions, must (because of Maxwell's Laws) measure the speed of light to be the same constant in all directions; that is to say, **"all observers will universally agree on the Light Cones at each event." ** This means that each observer drawing a spacetime diagram in which he is at rest must have the worldlines of light-flashes at the same angle of 45^{0} from his world line - his time axis - and 45^{0} from his plane of simultaneity - his space axes.

The world lines for photons have inclination +/-1. That means that photons cannot be accelerated or retarded.

Ordinary matter is composed only of particles and not by particles and antiparticles. That is why ordinary matter is subject to Newton’s law F=m.a. But a photon composed of a particle and its antiparticle is not subject to Newton’s law. At the instant of photon creation - for example, emitted by an atom - the two corpuscles are created with the speed of light c.

We can accelerate ordinary matter, as for instance the electron and the proton, in accelerators where they are under the action of electromagnetic fields, and so subject to an electromagnetic force but, if we put a photon in such an accelerator, the particle will be submitted to a force +F, while the antiparticle will be submitted to a force –F and the total force applied to the photon will be null.

Therefore:

1. From the viewpoint of relativity, the photon behaves as if massless because it cannot be subject to acceleration since it does not obey Newton’s law F=ma; that is, the photon behaves as if it has no mass.

2. From the viewpoint of momentum, the photon is not massless because the particle contributes a mass m = hν/2c^{2} and the antiparticle contributes a mass m = hν/2c^{2} for the effect of momentum.

In conclusion, we may say that the photon is not matter and that is why it is not subject to Newton’s law F=ma. Actually, the photon is a combination of matter and antimatter and the combination of matter and antimatter does not behave like matter alone. That is why, among other mysteries of light, such as its dual behavior which however can be well explained by considering the helical trajectory of the two corpuscles that constitute the photon, the essence of light was not understood even in the 20th Century.

Einstein’s equation E = mc^{2} does not depend on the reference frame. So, we cannot find any reference frame in which the equation E = mc^{2} becomes independent of the mass. Such an absolute feature of the equation, E = mc^{2}, means that the photon cannot be massless because the energy of the photon is given by the equation E = mc^{2}; that is, the photon obeys Einstein’s equation E = mc^{2}.

Actually, it would be correct to say that the photon provides striking proof of Einstein’s equation E = mc^{2} because:

1. At the instant of light emission, the energy of the atom is converted to matter-antimatter, a photon.

2. At the instant when the light hits a surface and is absorbed, matter-antimatter (photon) is converted to energy in the form of heat.

When Newton developed his theory, he could not have imagined the existence of antimatter. So, he proposed the fundamental equation F=m.a by considering all particles in the universe would be composed of matter and, therefore, every particle would have to have mass. As the photon is not matter, then we cannot apply Newton’s concept of mass to the photon. Actually, when we deal with the photon, we have to consider a new Physics in which the concept of mass must be changed, by considering that such a concept cannot be applied to a particle composed of matter and antimatter. The concept of mass must be replaced by the concept of inertia. So the photon is massless when the particle and antiparticle are packed together in the body of the photon but, when the two particles are parted, - for example, when the light falls on a surface - and the photon is destroyed, the two particles individually behave as if not massless. In this sense, the photon is massless while it it is travelling in the space or within a medium, but acts as if possessing mass when it collides with a surface.

Before 2001 theoreticians considered the neutrino as massless. So, according to Quantum Mechanics, the neutrino could not have interaction with the matter. But, in 2001, an experiment showed that the neutrino interacts with matter and the theoreticians had to change their understanding of the features of the neutrino.

Consider this incoherence of Modern Physics:

1. The theoreticians consider that a neutrino cannot be massless because it interacts with the matter.

2. However, light interacts with the matter too, as in the photo-electric phenomenon and the Compton Effect. Despite the interaction of light with matter, the photon is considered massless, although the neutrino is not considered massless simply because it interacts with the matter.

As we see, the criterion applied to the neutrino is different from that applied to the photon. Why two different criteria?
This seems to be an inconsistency that Modern Physics is unable to eliminate.

First of all, we have to remember that repulsive gravity is not considered in Modern Physics. But suppose that repulsive gravity really exists, and consider the hypothesis that in short distances it may have influence in the interaction between two elementary particles that constitute the body of a photon.

**Well, then obviously from the concepts of Modern Physics it’s impossible to understand the structure of the photon.**

Figure 2.14 shows the particle (blue) surrounded by repulsive gravitational particles G(-), and the antiparticle (red) surrounded by repulsive gravitational particles G(+).
The particle and the antiparticle girate about the line center L_{C} of the helical trajectory.

The particles G(+) and G(-) have repulsion, and so the particle and antiparticle of the photon does not attract one each other.

As we will see in another scripts, **the repulsive gravity also actuates into the nucleus and into the electrosphere of the atoms**. That's why the atoms have so strange behavior, and that's why the physicists did not get yet a deeper understanding of the atoms working.

The experiment made by the Nobel Laureate Hans Dehmelt has shown that the electron travels the space between two levels of energy, and so from his experiment we realize that the model of atom of Quantum Mechanics is wrong. However, instead of to realize that somethig is very wrong with some foundations of Quantum Mechanics, they prefer to neglect some experiments, so that to keep the theory.
In the case of the Dehmelt experiment, they alleged that the atom was "dressed", and by this way they avoid to recognize there are errors in Quantum Mechanics.

The explanation for the result of Dehmelt experiment requires a new model of atom in which the repulsive gravity actuattes into the electrosphere, as we will se in the script on the **new hydrogen atom** proposed in Quantum Ring Theory.

**The missing of the repulsive gravity in the models of Quantum Mechanics is probably the stronger reason why the theorists did not get yet a complete theory, and that's why Quantum Mechanics cannot explain cold fusion occurence.**