Virtual Particles and the Speed of Light


[the following series of questions came in one email, but represent a number of similar questions]

Question: I understand why the transmission of light would be slowed down.  The concept of light being absorbed and then re-emitted by a dense "sea" of particles would increase the time it takes for a beam of light to get from Point A to Point B.    Thus the velocity would decrease.  By my understanding, the increase in time to travel a given distance will be the summation of the time it takes to be absorbed and then re-emitted by each particle along the way.  Is this correct?

Setterfield:  The answer is basically yes. There are a number of other ways of looking at this, but that is a good picture. 


Question: If I understand this theory correctly, the actual speed of travel of the light from one particle to the next remain the same?

Setterfield:  Again the answer is bascially yes on this approach. You might consider that the speed of light has always remained the same, except for the interference from the virtual particles.  


Question: In other words light speed slows down as it travels large distances because of the added time for the light to be absorbed and then re-emitted.

Setterfield: Yes


Question: However, for the short distance between two particles (not counting the absorption and re-emission by the particles), is the speed the same today as it was [many] years ago.

Setterfield: Yes. On this approach, the speed of a light photon between interactions with virtual particles has remained unchanged since the origin of the universe.


Question: As a side note, does this theory indicate that light will diffuse in a vacuum? 

Setterfield:  The answer is NO! The intrinsic impedance of the vacuum is fixed. This means that the electric and magnetic properties of the vacuum change synchronously. If only the electric property of space changed and the magnetic properties were fixed (or vice versa), there would THEN be dispersion. But this does not happen, and dispersion does not occur.


Question: Does this also contribute to the wave nature of light?

Setterfield:  NO! it has nothing to do with the wave nature of light, nor does it contribute to it. 


Question: In your response to my first set of questions you indicated that 'As the mass of an electron increases, it can be shown that its kinetic energy, as it goes in its orbit, must remain the same.  This means that as the mass increases, the velocity must decrease, and so the rate at which it orbits the nucleus also decreases.'  I understand the mathematical relationship between mass, velocity, and kinetic energy, but what is it that physically slows down the electron? Do the virtual particles interfere with the electron?  Using a water analogy, is it kind of like a person running on a track and then running in a swimming pool filled with water?  Do the virtual particles form a resistance to motion?

Setterfield:  You are heading in the right direction here. The important key is that SED physics has shown that inertial mass on a subatomic level (such as with an electron) is due to the retarding force exerted by the waves of the Zero Point Energy (ZPE). As an electron is accelerated, it encounters an increasing number of waves which offer resistance to acceleration and so impede motion. This manifests as inertial mass. Thus, when an electron's mass increases, it is because there are more ZPE waves in a given volume. At the same time, this increased number of waves offers a greater resistance to the motion of the electron (or other subatomic particles) and so it travels more slowly. This is probably a better picture to present than one using virtual particles, as the virtual particle interaction you suggested would be (at the atomic level) an intermittent one, whereas the ZPE waves are acting against the electron continuously. However, your analogy using the swimming pool is good.


Question: Lastly, why does lowering the velocity of an orbiting electron also result in lowering the rate of radioactive decay?

Setterfield:  In answer to this question, it must be realized that we are not only dealing with electrons when masses increase with the resultant velocity decrease. The same is true of all sub-atomic particles including protons and neutrons. Let us here give the illustration of alpha decay. Picture the alpha particle moving back and forth within the nucleus of an atom that undergoes alpha decay. The alpha particle is constrained by the potential energy barrier of the nucleus. The motion of the alpha particle within the nucleus causes it to strike the barrier, or knock at the gate to be let out, a certain number of times per second. Each time it hits the barrier, there is a finite probability that it will penetrate the barrier and escape. When the ZPE is lower, subatomic masses are also lower, but their total kinetic energy is unchanged. This means that the speed of the alpha particles within the nucleus is higher, which results in more hits at the barrier per second, and so it escapes sooner. Conversely, as the ZPE strength increases, alpha particle masses increase and their velocity decreases. This means fewer hits per second at the barrier, and so a reduced escape rate results. This means that the rate of radioactive decay is also reduced.