Published in the British Journal of Theoretical Physics.
Principle of Relativity.
Most people understand that if two ships are far from land, it is impossible to tell which is moving simply by observing one from the other.
Able Seaman Lemming runs along sloop. w = 0-v
Sloop moves under Able Seaman Lemming. 0 = w+v
Similarly we know a plane is moving through air, then air provides a third reference frame, but anybody that has ever flown and looked down at the ground sees the ground moving beneath them. In the immense void of space the same rule applies. We cannot tell if the other ship is moving or we are moving, all we can say is that there is relative motion between us and the other ship. In this animation this principle is demonstrated, and the source of light is a star.
In the frame of the star the ship moves
In the frame of the ship the star moves
In the frame of the light the star moves
The relativistic ship.
The aether frame for a moving star
The moving star image above would apply if there were any aether (or air or other medium), but none has been detected. The moving ship image is impossible, it would imply the ship caused the light from the star to change by ship's own motion and is therefore a violation of physics and the Principle of Relativity. I have not made the ship or star exceed the speed of light, but unfortunately the light is not moving in the inertial universal frame of the aether.
It is known that Maxwell's electrodynamics--as usually understood at the present time--when applied to moving bodies, leads to asymmetries which do not appear to be inherent in the phenomena. Take, for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable phenomenon here depends only on the relative motion of the conductor and the magnet, whereas the customary view draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion. For if the magnet is in motion and the conductor at rest, there arises in the neighbourhood of the magnet an electric field with a certain definite energy, producing a current at the places where parts of the conductor are situated. But if the magnet is stationary and the conductor in motion, no electric field arises in the neighbourhood of the magnet. In the conductor, however, we find an electromotive force, to which in itself there is no corresponding energy, but which gives rise--assuming equality of relative motion in the two cases discussed--to electric currents of the same path and intensity as those produced by the electric forces in the former case.
Examples of this sort, together with the unsuccessful attempts to discover any motion of the earth relatively to the ``light medium,'' suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest. They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good. We will raise this conjecture (the purport of which will hereafter be called the ``Principle of Relativity'') to the status of a postulate, and also introduce another postulate, which is "only"
apparently clearly irreconcilable with the former, namely, that light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body.
THERE is hardly a simpler law in physics than that according to which light is propagated in empty space. Every child at school knows, or believes he knows, that this propagation takes place in straight lines with a velocity c = 300,000 km./sec (relative to the source).
At all events we know with great exactness that this velocity is the same for all colours, because if this were not the case, the minimum of emission would not be observed simultaneously for different colours during the eclipse of a fixed star by its dark neighbour.
By means of similar considerations based on observations of double stars, the Dutch astronomer De Sitter was also able to show that the velocity of propagation of light cannot depend on the velocity of motion of the body emitting the light.
Which has since been proven untrue.
The assumption that this velocity of propagation is dependent on the direction “in space” is in itself improbable
In short, let us assume that the simple law of the constancy of the velocity of light c (in vacuum) is justifiably believed by the child at school. Who would imagine that this simple law has plunged the conscientiously thoughtful physicist into the greatest intellectual difficulties? Let us consider how these difficulties arise.
(They arise out of failure to understand the Principle of Relativity)
Of course we must refer the process of the propagation of light (and indeed every other process) to a rigid reference-body (co-ordinate system). As such a system let us again choose our embankment.
No! Let us choose the train.
We shall imagine the air above it to have been removed. If a ray of light be sent along the
embankment train, we see from the above that the tip of the ray will be transmitted with the velocity c relative to the embankment train. Now let us suppose that our railway carriage embankment is again travelling along the railway lines train with the velocity v, and that its direction is the same as that of the ray of light, but its velocity of course much less. Let us inquire about the velocity of propagation of the ray of light relative to the carriage embankment. It is obvious that we can here apply the consideration of the previous section, since the ray of light plays the part of the man walking along relatively to the carriage trackside. The velocity W of the man relative to the embankment carriages is here replaced by the velocity of light relative to the embankment train. w is the required velocity of light with respect to the embankment carriage, and we have w = c - v.
The velocity of propagation of a ray of light relative to the
carriage embankment thus comes out smaller than c, unless its direction is reversed, in which case w = v+c which Einstein is careful not to mention.
But this result comes into conflict with the principle of relativity set forth in Section V.
And that is a bald-faced lie!
For, like every other general law of nature, the law of the transmission of light in vacuo must, according to the principle of relativity, be the same for the railway carriage as reference-body as when the rails are the body of reference.
And that is a bald-faced lie repeated!
Every child in school knows what the principle of relativity is, has done since Copernicus, and w = c - v is compatible with it.
But, from our above consideration, this would appear to be impossible. If every ray of light is propagated relative to the
embankment train with the velocity c, then for this reason it would appear that another law of propagation of light must necessarily hold with respect to the carriage embankment —a result contradictory to the principle of relativity, "the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good" and the equations of mechanics are w = c - v.
In view of this dilemma (What dilemma? w = c-v, Einstein said so!) there appears to be nothing else for it than to abandon either the principle of relativity or the simple law of the propagation of light in vacuo (which Einstein said were only apparently irreconcilable).
So let's abandon the simpleton's simple-minded so-called "law" and retain the law of the principle of relativity.
Those of you who have carefully followed the preceding discussion are almost sure to expect that we should retain the principle of relativity, which appeals so convincingly to the intellect because it is so natural and simple.
The law of the propagation of light in vacuo would then have to be replaced by a more complicated law conformable to the principle of relativity.
Tough beans, Einstein. The more complicated law conformable to the principle of relativity is w = c-v.
The development of theoretical physics shows, however, that we cannot pursue this course. The epoch-making theoretical investigations of H. A. Lorentz on the electrodynamical and optical phenomena connected with moving bodies show that experience in this domain leads conclusively to a theory of electromagnetic phenomena, of which the law of the constancy of the velocity of light in vacuo is a necessary consequence,
because Lorentz believed in aether and Einstein said that was superfluous.
Prominent theoretical physicists (Who, Einstein and Lorentz, the prominent egotistical idiots?) were therefore more inclined to reject the principle of relativity, in spite of the fact that no empirical data had been found which were contradictory to this principle.
But real physicists retained the PoR, notably A A Michelson and G. Sagnac, you whining lying toady, charlatan, philanderer and all round confidence trickster, Einstein.
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