Journal of Theoretics

  A Method for Determining Distant Simultaneity and Whether Light is One-way Isotropic


Author: Jones, BD



Abstract: A new definition and classification of motion is presented and elaborated herein along with a method of clock synchronization.  Additionally, Einstein's clocks are shown to be asynchronous.  The impact of this on special relativity theory and one-way light isotropy is discussed.

Keywords: special relativity, time, light, synchronization, Einstein.


The postulation that light's unidirectional speed is isotropic is based on the assumptions that clocks of different frame of reference cannot be synchronized and that any synchronization attempt will result only in "standard synchronization." Standard synchronization being the specific "synchronization" of special relativity theory [SRT] that by design yields one-way light speed isotropy. This condition is at times referred to as "the conventionality of distant simultaneity,"1 which is a much more accurate label than "standard synchronization," which (not surprisingly) has misled many to believe that Einstein's clocks (in an arbitrary frame) are synchronous.

Since synchronous clocks would disprove SRT, it is obviously important to realize that Einstein's clocks are asynchronous. Since this fact is unknown to many relativists, I will first prove the asynchronicity of Einstein's clocks and subsequently present a clock synchronization procedure (i.e., a one-way test of SRT).2 This proof is based upon a concept of which Einstein was aware but did not explicitly state, much less label, thereby making it all too easy to overlook this critical concept, which I will call "frame independency." I will discuss further in three parts: I)Defining the Three Categories of Motion, II)Proof That Einstein's Clocks Are Asynchronous, and III)Method for Determining Distant Simultaneity.

Part I -- The Three Categories of Motion

Although everyone knows that light and sound somehow differ motionwise, no one has ever explicitly defined (much less labeled) the specific physical cause of this difference. Source independency is insufficient because both light and sound possess this attribute. Only this new concept of "frame independency" allows us to distinguish between the motions of light and sound and is best outlined with the following single axis examples.

There are three types of movement:

[a] Source-dependent, frame-dependent motion (inertial object). Given two frames traveling at different velocities with respect to a wall, as the frames pass, an observer in each frame fires a gun towards the wall. The fact that the bullets reach the wall at different times proves the source dependent nature of inertial objects. Source dependency is obvious as any two different objects propelled will be dependent upon the source, such as firing a gun versus throwing a baseball.

[b] Source-independent, frame-dependent motion (sound wave). Given two frames moving at different velocities relative to a wall, as the frames pass, an observer in each frame yells towards the wall. The fact that the sound waves reach the wall at the same time proves the source-independent nature of sound waves. Though sound is source independent, it is also medium dependent.

[c] Source-independent, frame-independent motion (light). Given two frames moving with respect to a wall at different velocities, as the frames pass, an observer in each frame fires a laser towards the wall. The fact that the light photons reach the wall at the same time proves the source-independent nature of light waves. Like sound, light is source-independent, but it is not medium-dependent for its existence/travel. Sound waves are the movement of a medium (e.g., air) which is carried along with Earth, but light waves have no need for a medium to exist/propagate and are therefore not carried along by the Earth, but instead move independently of it. That is, light waves are not only source-independent, but also frame-independent.

The key result of light's frame independency is the fact that a light source in any given frame is equivalent to a light source in any other frame as far as the speed of the emitted light is concerned. This fact is the basis for my proof that Einstein's clocks are asynchronous. It is also worth noting that light's frame independency leads to frame movement relative to light, which in turn leads to Einstein's relativity of simultaneity, and thus we have for the first time revealed the direct physical cause of this uniquely Einsteinian or relativistic phenomenon.


Part II -- Proof That Einstein's Clocks Are Asynchronous

Given a long table A with a clock at each end, and a light bulb in the middle, we want to start the clocks by using light signals emitted by the bulb. Accepting the commonly held belief that this procedure (Einstein's definition of synchronization) will synchronize the clocks, we will assume this to be the outcome in this case. Although this will be the only frame whose clocks are synchronized by Einstein's procedure, many are not able to see this because they invariably use separate light sources for each frame, which in itself is not improper, but certainly can mislead one into thinking that the use of more than one frame is redundant and can tell us nothing new. But all this has been changed given our new concept, and the best way to see that each case is unique, is to simply let all frames use the same light source. Continuing with our example, let a second table B roll past the first table. This table B has its own clocks at each end, but will significantly and enlighteningly depart from tradition by using the light from the table A's source to start its clocks. According to all observers in all frames, table B's rear clock will be started before table A's rear clock, and table B's front clock will be started after table A's front clock, so if table A's clocks were started simultaneously, table B's cannot be. For example, if table A's clocks start at high noon, then table B's rear clock would start at 11 am, whereas its front clock would start at 1 pm.

Einstein of course was aware that his clocks were not synchronized, but this is obviously not something one would advertise about one's theory, so Einstein never explicitly stated (at least not publicly) that his clocks are not synchronized. Ironically, there is nothing improper, inconsistent, or illogical about Einstein's use of asynchronous clocks; he simply extrapolated one-way isotropy from experimental evidence of round-trip isotropy as given by the Michelson-Morley experimental null result. The problem is that in SRT, Einstein assumed that nature will always be able to prevent us from synchronizing any given single frame's clocks (based solely on past failures).

This seemingly innocuous statement of SRT has far-reaching ramifications. It tells us that, contrary to popular belief, none of the following have anything to do with SRT itself: (a) Einstein's definition of "synchronization"; (b) the relativistic transformation equations; (c) the "aether"; (d) the null results of the "aether-drift" experiments; (e) Maxwell's equations. Also, and most importantly, it tells us that SRT has yet to be tested, despite the claims that that it has been tested many times and has passed all tests with flying colors! As we have seen, SRT pertains only to two comoving (i.e., same-frame) clocks and the assumed impossibility of synchronizing them. This renders Ole Roemer's one-way experiment irrelevant because it involved clocks in different frames. In short, if we can synchronize clocks, light's one-way speed will vary with frame velocity, thereby disproving SRT. (See "Appendix" for a mathematical version of the above proof that Einstein's clocks are asynchronous.)


Part III -- Simple Method For Determining Distant Simultaneity

All working parts of my clock-starting apparatus lie on the same axis thereby avoiding any perpendicularity problems. Intrinsic clock slowing is allowed because all that is required is a steady clock rhythm, slowed or not. Intrinsic length contraction is allowed because the clock-starting entities are attached only after any contractions/expansions have occurred.

The apparatus consists of a two conveyor belts which will transport the clock-starting entities at equal speeds relative to the clocks. Note that this does not mean "equal speeds as measured by two asynchronous Einsteinian clocks," nor does it mean "equal 'absolute' speeds." We can best understand this by contrasting my clock-starting signals with Einstein's: He uses light signals whose speeds relative to a clock vary with the clock's speed, so his signals do not move at equal speeds relative to the clocks, and will not synchronize them. This was shown by our table example above, and it was also shown by Einstein's train/lightning flashes example where observers have different speeds relative to the approaching light rays (and therefore see the rays arrive differently). As we know, this is all due to light's frame-independent nature, which causes each frame to have a different speed relative to a given light ray (or, to be precise, with respect to the ray's frame-independent emission point).

The two practically touching (edge-to-edge) conveyor belts are friction driven along smooth tables by two shafts whose faces practically touch. One shaft's rotation rate is monitored by a single clock at the top of the shaft's (circular) face. The other shaft, oppositely rotating, is kept in sync with the first by the use of timing marks. After the belts have been in motion for a while, it is possible that one belt may have (intrinsically) contracted more than the other; however, as mentioned above, this can be ignored because any and all points on either belt must travel at the same speed as the belt, and it turns out that our clock-starting entities are nothing more than points on the belts.

As we stated earlier, all working parts lie in a single axis: the monitor clock, the timing marks on the drive shaft's (touching) faces, the edges of the two conveyor belts, and the two clocks which are to be started by the clock-starting entities, shall be simply the two "halves" of a single point placed on the line (the belt's touching edges) at the origin after the belts have been moving for a while.

To guard against possible belt slippage, we can place a sentry clock beside each belt to monitor the passage of equally-spaced marks placed on each belt. It matters not that these marks may be more closely spaced on one belt than on the other; all that matters is that they are equally spaced for the belt upon which they are located.

Unlike Einstein's light signals where frame movement relative to the signals prevents the clocks from starting simultaneously, there is no known reason why the clocks will not be synchronized by our belt-transported clock-starting marks. All that is needed are constant and equal belt speeds relative to the clocks, and this is guaranteed by the fact that the timing marks (on the shafts' perimeters) travel equal distances in equal times (per the same clock) with the coincident shaft faces being equal distances.

Diagram of the test apparatus:

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As I mentioned at the start, a pair of same-frame synchronous clocks would disprove SRT because the light's one-way speed for such clocks would vary directly with frame velocity, and SRT predicts that no optical experiment's results can be used to distinguish frames. And as the previously referenced article2 implied, no one has yet properly measured light's one-way speed. Therefore, Einstein's special relativity theory has yet to be tested let alone proved.




1. Peter Ohrstrom, Conventionality in Distant Simultaneity, Foundations of Phys. Vol. 10, No. 3/4, pp. 333-43 (1978)

2. D. G. Torr and P. Kolen, Misconceptions in Recent Papers on Special Relativity and Absolute Space Theories, Foundations of Phys. Vol. 12, No. 3, pp. 265-84 (1982)



Mathematical proof of the asynchronicity of Einstein's clocks

(Intrinsic length contraction ignored for simplicity)

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