Faster Than Light?
John David Best
The current official opinion is that nothing can travel faster than the speed of light in free space, called c to emphasize that it is constant, relative to anything else; This has even been proclaimed as an inviolable law of the universe. But just for fun, let’s imagine an object, say a massive and luminous object, headed directly toward earth, traveling at twice the speed of light. Would we be able to see it?
The first answer that comes to mind is no – the object is outrunning the light it emits, and will therefore splat against the earth before any light it emitted reaches the earth. However, if we regard the luminous object as stationary or at rest, with the earth moving toward it at twice the velocity of light, we get quite a different picture. According to the principle of relativity, in what we perceive as free space, either the earth or the luminous object could be regarded as stationary (or the anchor of the “rest frame”). If the luminous object is at rest, it should make no difference whether or not there are other objects in space or what their velocity is; it should emit light in the same manner. As an example, astronomical objects and their velocity have no influence on light being emitted by terrestrial sources. In this second case there would be light traveling away from the luminous object toward the earth as the earth approaches it. So, it makes a difference whether the earth is approaching the luminous object, or the luminous object is approaching earth.
This of course is not a real situation, but it offers food for thought: In the first case, light propagates away from the object at velocity c from the point where it was emitted, but since the object is traveling at 2c, it outruns the light it is emitting and reaches earth before its emitted light arrives. In the second case, since it is the earth that is in motion with the light source stationary, the earth is constantly passing through the light emitted by the object as it approaches the object. These two scenarios should be identical from a relativistic standpoint, but they are quite different. To resolve this paradox, we should first clarify exactly what is meant by the “speed of light” or c as it is commonly known.
Speed or velocity (the difference being velocity is directional, speed is not) has units of distance over time, or units of distance traveled divided by units of transit time. For there to be velocity, a distance traveled, and an elapsed time are needed. For there to be a distance, two points; a beginning, and an end are required. If we are measuring the distance traveled by something, say a propagating wavefront of light, then the location of the wavefront represents one end of the distance the light has traveled. We also need to know the location of the other end, or origin of the light. We might be tempted to think that this would be the same as the location of the emitting source. In the case of an emitting source that isn’t stationary, it is not. Instead, the origin of the light is where the emitting source WAS in the past at the time the light was emitted; not where the emitting source IS at the time the light reaches the receiver or “observer”. Once light is emitted, it travels independently of the emitting source. This can easily be seen in the case of the light reaching us from a lightning bolt. The source of the light no longer exists when the last of its light reaches us. If the light from the lightning bolt has some velocity away from the lightning bolt as it is released, and if the passing out of existence of the lightning bolt does not also somehow cause the light in transit to pass out of existence, then the light is seemingly propagating with a velocity that is relative to nothing at all; the place where the lightning was when it released the light before it passed out of existence.
light travels away from the place where it was emitted with velocity c, regardless of the velocity of the source or of the observer. This is the characteristic velocity of electromagnetic radiation in the medium of “free space”, not unlike the characteristic velocities that correspond to other mediums. A simplistic analogy may help to see the situation more clearly: Imagine a tanker truck filled with water, chugging up a hill. The tank has a leaky valve, so that a stream of water leaks from the back of the truck and runs down the road behind the truck as it continues up the hill. The velocity of the stream of water as it flows down the road has no dependence on the velocity of the truck, nor on the velocity of any observers downhill that the water has not reached yet.
Experiments such as one designed to detect the velocity of light by measuring how long it takes to travel from an emitting source to a detector show no directional dependence regardless of whatever direction of motion of the source. The situation can be illustrated using an analogy; a railroad car and a railroad track – an Einstein favorite: If there is a certain distance between the wheels of the railroad car, and a certain distance between the ties of the track, the distance between the wheels of the railroad car will always span the same number of ties regardless of the velocity of the train or how it appears to any observer.
Let’s say, for example, that the railcar spans 20 ties, and the ties are regularly spaced 1m apart. If the railcar were to move some distance, it could be any distance, the ends of the car will still be 20 ties apart. We can be assured of this, because since the railcar is a rigid object. The railcar could move a distance over a period of time, so there is velocity, but the ends of the car will remain 20 ties apart. This could represent an analogy to an experiment for the purpose of measuring the speed of light, if the light emitter and light detector were to be placed at opposite ends of the railcar. The distance that the railcar spans, 20 ties, represents the light path of the experimental apparatus. The railcar could be set in motion along the track, so that it would be traveling through a possible medium, and the transit time of light from the emitter to the detector could be measured by a super-precise clock. It would be found to be the same regardless of the speed of the railcar or the orientation of the track. This is true because in all cases, the light travels the same distance, the 20 tie (20m) span of the railcar, at the same velocity, the characteristic velocity of light in the medium (c in the case of “free space”).
The upshot is that light will always take the same length of time to travel the distance from the emitter to the detector which are held a fixed distance apart when the light propagates with a characteristic velocity, regardless of directional orientation. The velocity depends only on the properties of the medium. Each medium has a certain characteristic velocity with which waves of certain types travel relative to it. It the case of light propagating in the medium of free space, the velocity is called c.
The same reasoning holds as true for wave theories of light propagation as well as for “machine gun bullet theories or any combination thereof.
If we allow that the velocity of light can actually vary, despite experiments showing it is constant, it becomes much easier to explain an observed effect:
While the velocity of light always appears to be c regardless of the motion of the source or observer, the wavelength of the observed light varies depending on the orientation of the motion. This is seen as the phenomena of redshift and blueshift.
The redshift/blueshift of light is thought to be caused by a phenomenon similar to the Doppler effect caused by velocity, and is used to measure the distance to astronomical objects. If you have ever driven on a highway or expressway, and passed a truck going in the opposite direction, you will have noticed how the roar of the truck increases in pitch as you approach it, then decreases in pitch when you pass it moving away. This is the Doppler effect. This effect is common to waves, but may be easiest explained by using another railroad track as an example: If the train goes faster, it passes more railroad ties per unit of time; if it goes slower, it passes fewer ties per unit of time. The railroad ties are an analogy for the nodes of a light wave, so the faster you go relative to the light wave, the more nodes you will pass in a unit time, which is blueshift; and the slower you go, the fewer nodes you will pass, which is redshift. The simple explanation for the observed redshift and blueshift of light is that it is caused by changes or differences in velocity between the observer and the beam of light.
This simple explanation is not possible according to proponents of Einsteinian relativity, of which a key tenet is that light always travels at the same velocity, c, relative to any observer, regardless of its redshift or blueshift. They tell us that something very unintuitive happens: According to them, the wavelength or distance between the nodes, of the light propagating from the origin, varies according to the velocity of any observers of the light, thereby maintaining its velocity at c when it arrives at any observer. This phenomenon seems to be regarded as a change to the light itself, not merely how it is viewed by an observer. If there are multiple observers moving at different velocities relative to the light, this seems impossible, because there can be and usually are many observers moving with all different velocities toward and away from the origin of the light. Does the source emit a customized version of light for each observer? Logic and the Occam’s Razor principle, favor the simpler explanation for the observed constancy of the speed of light, as well as its correspondence to the behavior of other traveling waves that we know of.
The official idea, that the wavelength of light emitted by a source varies according to the velocity of the observer, inherently places a speed limit on light, because if the faster the observer travels toward the emitter, and the shorter the emitted wavelength gets, until at speed c, the wavelength would be reduced to zero and the light (electromagnetic radiation) would not be able to propagate from its source. Einstein proclaimed c as an inviolable universal speed limit of nature.
According to proponents of Einsteinian relativity and related theories, this same concept applies to matter: There is said to be a “wave-particle duality”, so that matter “shrinks” or contracts in the direction of its motion in a similar manner to light and is therefore subject to the same “cosmic speed limit”, c, as light. They refer to this as the “Lorentz contraction”. Similar to the question of how the wavelength of light can actually change due to the velocity of an observer when there are multiple observers traveling at different velocities, is the question of how the actual physical dimensions of a solid object can vary according to the velocity of any observer when there are multiple observers traveling at different velocities. If there are multiple observers coming from different directions at different velocities, an object could Lorentz contract into something quite misshapen, maybe even a work of modern art could be produced using fast-moving observers.
Why would a simple and logical explanation for the behavior of light be discarded by mainstream science in favor of a confusing, and frankly, bizarre explanation? Maybe it is because a ray of light was seen as a stream of particles analogous to a stream of bullets being fired from a machine gun. This is at odds with the view of light as a wave propagating from the location where it was emitted. If the bullets are fired from a moving platform, say a fighter jet; they would conserve the momentum they acquire from the fighter jet whose velocity would be added to the muzzle velocity of the bullet. The idea that light is a stream of particles has been around for quite a long time; at least from the 6th century B.C. when Hindu thinkers regarded light as a stream of fast-moving particles. Isaac Newton shared this view of light and called the particles “corpuscles”. The prestige and popularity of Newton caused the corpuscular theory of light to be the dominant theory despite its failure to account for the experimental results that showed that light behaves as a wave. The failure of particle theories to account for optical phenomena eventually led to the view of light as a wave becoming the accepted view. However, all other waves that we know of require a medium in which to propagate.
Maybe as an analogy to water, whose waves are familiar, and because it would have to be something that matter can pass through, this unseen medium was thought to be like some type of liquid or gas. Numerous attempts to detect such a medium were made, such as the famous Michelson-Morley experiment. This experiment attempted to show a directional dependence of the velocity of light due to the motion of the earth through the supposed medium, which became known as luminiferous aether. All such experiments failed to detect any directional dependence of the velocity for the reasons argued earlier in this discussion. This failure to detect a medium created quite a dilemma for those who viewed light as a wave. The modern theory overcame this by claiming that light or electromagnetic waves don’t need a medium to propagate.
Two types of fields have been identified: magnetic, and electric. It was discovered that a time-varying magnetic field results in an electric field, and vice versa. A time-varying or oscillating electric field is what generates the magnetic fields that are radio transmissions. Apparently, these radio waves are evidently part of the same electromagnetic spectrum as light.
The dominant theory purporting (viewed as fact by some) to explain how EM radiation propagates, I call the “Lego-block” theory. The reason that I call it the “the Lego-block theory” is that a graphical representation of an electromagnetic wave predicted by this theory resembles a stack of Lego blocks of alternating colors, say red for blocks representing magnetic fields and green for electric fields or links of a chain.
It is thought that an oscillating magnetic field produces an oscillating electric field, which in turn generates another oscillating magnetic field…ad infinitum. This fields are are said to stack against each other aligned along one direction, sort of like a stack of Lego blocks. In some literature, it is claimed that this mechanism was proposed by James Clerk Maxwell. It is odd this mechanism which purports to require no medium, has been attributed to James Clerk Maxwell, although in his 1864 paper, “A Dynamical Theory of the Electromagnetic Field”, he wrote: “We have therefore some reason to believe from the phenomena of heat and light, that there is an aethereal medium filling space, and permeating bodies, capable of being set in motion, and transmitting that motion from one part to another, and of communicating that motion to gross matter, so as to heat it, and affect it in various ways.”
One thing we can note about this mechanism is that there is resistance to overlap between the electric and magnetic fields. This must be the case for the radiation to be able to propagate outward, because each successive field must arise from the preceding field in a manner that adds distance from the origin. This picture of electromagnetic fields is quite different from the classical description of an electromagnetic field as existing in a region surrounding an electric charge, with the strength of the field decreasing with distance from the charge. In the classical view a magnetic field is the same field as an electric field. The difference is the motion of the observer relative to the field; when the observer is static, it is has the characteristics of an electric field, but when the observer is in motion, it has the characteristics of a magnetic field.
Maybe the most radical departure of this mechanism from previous thought is that the alternating EM fields that comprise the radiation are self-replicating, and independent of any electric charge, with the apparent exception of somehow energetically driven initial charge at the origin. In theory, they could go on replicating forever without any charge to produce them. These “lego blocks” carry energy (both waves and bullets transfer energy) At some distance from the original charge, these fields are called “far fields”. These far fields are said to be immortal unless they encounter something in their path. A question is do the electromagnetic fields that comprise light continue to replicate if they are disconnected from their energy source by becoming detached from the chain of fields from which they sprang? Or because the chain of fields is detached from its energy source.
According to proponents of the “Big Bang” theory, the universe is filled with such far fields left over from a stage of the “Big Bang”. One wonders however, what happens to all the far fields resulting from production of EM radiation, such as light. Do they become “orphaned” when the source of energy causing them to propagate is turned off and start traveling around a c independently? Do they get added to the cosmic soup, or Cosmic Background Radiation (CMB) as it is called? Are these fields isotropic, or anisotropic like the field at the origin they replicated from? What sort of cohesion would keep the links together?
The crux of the matter is: Does the chain of fields that is a beam of light extend from where a moving source was when the light was emitted, or does it always extend from the current location of the source? If the far fields are truly independent of the original charge that produced them, then we must choose the first answer, that light propagates from the place where it was emitted, not the current location of the source, unless the source is static. As noted earlier in this discussion, such a wave will always be experimentally determined to have an invariant velocity, if it is measured by timing the distance it takes to traverse two points a fixed distance apart.
If all this wasn’t complicated enough, in 1905, Albert Einstein added to the confusion by resurrecting the particle theory of light.in his paper on the “Photoelectric effect” in which light is viewed as a stream of particle-like entities which later were called “photons”. His motivation for doing this was apparently observations by Max Planck, that heat radiation was only absorbed and emitted by matter in discrete quantities, or “quanta”, and thinking that these quanta were analogous to particles. If such particles had mass, this would certainly explain how EM radiation can transfer energy, since then, the particles would have momentum just like bullets from a machine gun. This caused a problem with wave theories of light, since a wave has no mass. This problem was resolved by declaring that a photon was a unique sort of “relativistic” particle that could have momentum without having mass, despite mass appearing in the definition of momentum.
So, there was a choice between two not entirely compatible views of light. This problem was dealt with by proposing a similar “wave-particle duality” for light as is proposed for matter, so that light can have the characteristics of either a wave or a particle depending on the circumstances. Why not consider a photon just as a section of a wave? Maybe a photon corresponds to a certain length of a light wave along its direction of motion. After all, the expression for the energy of a photon depends on the wavelength. Defenders of the “machine gun” idea claim that some experimental observations such as the Compton effect require a particle with momentum. Why couldn’t wave energy, which in itself could be regarded as a propagation of momentum of whatever comprises the medium, equally explain the results?
Velocity or speed requires something to be relative to, because velocity is the time rate of change of the distance between two points, so the velocity of something would be impossible to specify or measure, and meaningless, without something external to it that serves as a second point for it to be relative to. The question is what is the velocity of light relative to after it leaves its emitting source if the emitting source is in motion? To say that light propagates from some point at a certain velocity is the same as saying that the velocity of the light is relative to that point which is taken to be stationary. It cannot be relative to the moving source, because a moving source moves somewhere else after the light leaves. We must conclude that it can only be traveling relative to a point in empty space where the emitting source was in the past. But how can something be moving relative to nothing? It can’t.
An idealized scenario makes the situation very clear: Imagine a luminous object traveling through space. If all other entities in space which could serve as reference points to specify the velocity of the luminous object were blinked out of existence, say by Samantha the witch; would the luminous object still have velocity? Common sense says yes, but to have velocity, we must have two points in order to establish a distance. If one point is the luminous object, what would the other point be?
There have been a number of proposals for something unseen for wave velocity to be relative to. Something that would be convenient is a Cartesian coordinate system that that extends infinitely. This author has proposed something that could serve as such an unseen coordinate system. It is presented in the paper entitled “Universal lattice theory” by John David Best. It is described as being a simple cubic lattice that extends infinitely. It is comprised of elementary electric charges at the intersections of the lattice, and its structure is maintained by attraction and repulsion between the charges. Unlike an “aether” similar to a fluid, this lattice is extremely rigid, due to the close spacing of the charges that comprise it, and the enormous forces between them. Electrically neutral matter can move through the lattice. Because of the electric neutrality of the matter, there is limited interaction between the matter and the lattice, such that our human experience is what it is, but there is some: There is enough drag to prevent perpetual motion of matter. Inertia is postulated to be due to interaction between matter and the lattice. The lattice could also serve as a medium for the propagation of EM radiation. It would be an alternative that doesn’t require momentum without mass, the warping of space and time, or the shrinking of matter. Because of its extreme rigidity, it should be capable of supporting ultra-high frequency waves or vibrations in the lattice. An analogous paradox exists for rotary motion to the one described above for linear velocity: Linear velocity requires a reference point to exist; rotary motion requires a reference direction. Such a real analogue of a Cartesian coordinate system would provide both.
Returning to the question that was asked at the beginning of this treatise, “If a massive, luminous object was headed directly toward earth, traveling at twice the speed of light. Would we be able to see it? Answer: probably not – the light would propagate toward us at c from where it was emitted, while the object is traveling toward us at 2c. The object would win the race. At least we would never know what hit us 🙂
Fortunately, there doesn’t appear to be any natural process capable of accelerating masses to such velocities. Due to slight drag exerted between matter and the lattice, we would expect most masses to be closer to stationary relative to the lattice than at extreme velocities.Click to view contributions to this theory