2019 SI Standard: Back to Classical Physics

Newton, forgive me! (Einstein)

The first step from classical to modern physics was taken by Einstein in 1905 in his Special Theory of Relativity SR replacing classical Galilean invariance satisfied by Newton's equations, by Lorentz invariance satisfied by Maxwell's wave equations for propagation of light. 

Einstein argued that laws of physics must be Lorentz invariant, which required a reformulation of Newton's mechanics into a new relativistic mechanics taking without gravitation the form of SR. 

In SR length and time were supposed to be measured with meter sticks and mechanical clocks, which by Lorentz invariance were subject to new strange effects of space contraction and time dilation.  

In 2019 (preceded in 1983) a new SI Standard was introduced with the length scale along any given $x$-coordinate axis measured in terms of travel time of light with a preset speed of light of 299792458 meter/second,  and time measured by a standard caesium atomic clock. This means that any given $x$-axis acts like an aether for propagation of light at given fixed speed. 

Consider a similar $x^\prime$-coordinate axis sliding on top of the $x$-axis with constant velocity $w$ as inertial motion with shared time $t$, like a different aether with shared time "carried along" with the sliding $x^\prime$-axis. Assuming that the origins of the axes coincide for $t=0$, the spatial coordinates will then following the 2019 SI Standard be connected by

• $x^\prime = x-wt$ 

which is a Galilean transformation. We can alternatively view the meter scale to be set by a meter-stick which does not change under inertial motion as if the meter stick is carried along by any given spatial axis without change of size. We are thus led to a many-aether theory, which in particular explains the null result of the Michelson-Morley experiment showing non-existence of a single unique aether. 

A basic feature is a connection established through resonance between emitter and absorber of light carried by an aether/coordinate system tied to the absorber, as explored in Computational Black Body Radiation.    

The 2019 SI Standard is in full agreement with Galilean invariant Newtonian mechanics. This means that after an interlude of 114 years Newtonian mechanics is back again, thus replacing relativistic mechanics with its strange space contraction and time dilation and Lorentz invariance. 

Light propagation is in the 2019 SI Standard carried by different aethers as different $x$-axes with basic question:

• To what extent is propagation of light Galilean invariant?  (Q) 

This question is addressed in Many-Minds Relativity as an observer version of a many-aethers theory.

Recall that the step from classical to modern physics was motivated by an argument claiming that Newtonian physics required an "absolute space" as a preferred Euclidean coordinate system, which however could not be identified. But Newtonian physics is Galilean invariant and so works equally well in all inertial systems and so does not need any absolute space. On the other hand, an absolute time rate can be set by a caesium clock unaffected by inertial motion. The rush to modernity thus was not founded on real physics.  

Summary: The 2019 SI Standard with the same preset speed of light in every inertial system effectively brings back classical Galilean invariance into physics, leaving Lorentz invariance/SR as a curiosity without physical meaning along with the original conception of Lorentz. This removes the main obstacle to a unified theory of mechanics and electromagnetics by letting real experimental physics/SI Standard take the lead before Einstein's ad hoc theory based on "thought experiments".