In his article, he mentioned a lot of good things about some generalities, such as the difference between physics and mathematics. However, his objection to Schwarzschild’s work, upon which the article was based, was not a valid objection, but rather a misunderstanding on his part of Schwarz’s step and a misplaced application of the rule of dimensional analysis. Schwarzschild noted that the determainant of the metric In the case of ordinary polar coordinates, is not constant and do not equal one. Then he noted that if instead of these coordinates other coordinates were used whose determinant is equal to one everywhere, this would greatly simplify the problem because it would eliminate some of the complex terms in the formation of the Ricci tensor included in the equation, and here Schwarz was guided by a clever trick. It is to change the normal polar coordinates to another polar coordinates as well so that the metric general form does not change, but it is different from them in detais . In this way, he depends on the general meaning of polar coordinates, which are all coordinates based on a point of origin from which axes radiate in all directions. They do not necessarily have to be the ordinary radii, but rather any function of them. Likewise, each axis is separated from its neighboring axes by a value that depends on the angle between them and not necessarily the angle itself, but any function in it, and this is what confused the author of the article, and perhaps because Schwarzschild used symbols for the new axis system similar to the symbols of Cartesian coordinates, he thought that the new coordinates are Cartesian coordinates, and this is apparent when he applied the theory of dimensional analysis to them. He assigned to them all dimensions of length, although even if there were found a difference in dimensions between the original coordinates and the new coordinates then this is not a problem at all because the equation of converting from one coordinate to another is not a physical relationship between two quantities, but rather a difference in the way we want to calculate the distance. For example, if we assume that we are investigating a problem with the usual Cartesian orthogonal coordinates, then a person wants use another coordinates that are the same as these coordinates but replaces the x-axis with another axis equal to cubic x, he can use them without any problem and apply the same laws of physics on the quantities written according to thiese coordinates and we should not then say that this disagree with the theory of dimensional analysis. Schwarz wanted to use coordinates that simplify the calculations, then return the result he arrived at and translate it into the normal polar coordinates with which he started the problem. Regarding this point, Schwarzfeld's step is sound and contains intelligence and creativity that can be credited to him. This does not negate the fact that in his subsequent steps he committed something that required correction and revision, when he assumed in advance that the location of the singularity in the solution he was requesting would be at the origin point. It is now known that if he calculated it in the correct way, it would be at a different point the point which is known today as the Schwarz radius, which depends on the mass, on which the theory of black holes is based , but this is not the subject of this comment.
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