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Book by David Michalets

Review of Einstein's 1920 Book on Relativity  (from Translation)

An (original) line precedes original content from the source.

A (remark) line precedes my remark from my review of the preceding original content.

My remark applies to only this section of the original.

Section XXI of 35



WE have already stated several times that  classical mechanics starts out from the  following law: Material particles sufficiently far removed from other material particles continue to move uniformly in a straight line or continue in a state of rest. We have also repeatedly emphasised that this fundamental law can only be valid for bodies of reference K which possess certain unique states of motion, and which are in uniform translational motion relative to each other. Relative to other reference-bodies K the law is not valid. Both in classical mechanics and in the special theory of relativity we therefore differentiate between reference-bodies K relative to which the recognised "laws of nature"
can be said to hold, and reference-bodies K relative to which these laws do not hold.
But no person whose mode of thought is logical can rest satisfied with this condition of things.
He asks: "How does it come that certain reference-bodies (or their states of motion) are given priority over other reference-bodies (or their states of motion)? What is the reason for this preference? In order to show clearly what I mean
by this question, I shall make use of a comparison.
I am standing in front of a gas range. Standing alongside of each other on the range are two pans so much alike that one may be mistaken for the other. Both are half full of water. I notice that steam is being emitted continuously from the one pan, but not from the other. I am surprised at this, even if I have never seen either a gas range or a pan before. But if I now notice a luminous something of bluish colour under the first pan but not under the other, I cease to be astonished, even if I have never before seen a gas flame. For I can only say that this bluish something will cause the emission of the steam, or at least possibly it may do so. If, however, I notice the bluish something in neither case, and if I observe that the one continuously emits steam whilst the other does not, then I shall remain astonished and dissatisfied until I have discovered some
circumstance to which I can attribute the different behaviour of the two pans.
Analogously, I seek in vain for a real something in classical mechanics (or in the special theory of relativity) to which I can attribute the different behaviour of bodies considered with respect to ewton saw this objection and attempted to invalidate it, but without success. But E. Mach recognised it most clearly of all, and because of this objection he claimed that mechanics must be placed on a new basis. It can only be got rid of by means of a physics which is conformable to the general principle of relativity, since the equations of such a theory hold for every body of reference, whatever may be its state of motion.
1 The objection is of importance more especially when the state of motion of the reference-body is of such a nature that it does not require any external agency for its maintenance, e.g. in the case when the reference-body is rotating uniformly.


Einstein reveals a lack of understanding of physics.

The term reference-bodies is meaningless.

Every object in the universe is affected by the external forces acting on it.

Only an observer has a frame of reference, nothing else in the universe has it, or would use it.

An observer requires a coordinate system and a reference point in physical space to anchor its dimensions to measure objects in space, so the reference point will be somewhat near.

It is just erong to pick my current location on Earth's surface as my reference point when seeking to measure positions of distant galaxies. There is no coordinate system that could cover that scope.

The use of reference-body makes this section and relativity irrelevant to a universe driven by the external fundamental forces of gravity and electromagnetism. These fundamental forces act instantaneously, but diminish by inverse-square of distance. Literally everything is affected by everything else, but the effect reduces by distance.

Go to Table of Contents, to read a specific section.

last change 05/07/2022