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measurements. For instance, it would be difficult for Einstein to put a clock there! In the above, Einstein has shown also that physical coordinates need not cover the entire space-time as in special relativity. In 1916 earlier Einstein seemed to believe that any Gaussian system would be a valid space-time coordinate system. To argue for a belief of the moment, that is, unrestricted covariance, he wrote [8], "That this requirement of general covariance, which takes away from space and time the last remnant of physical objectivity, is a natural one, will be seen from the following reflexion. All our space-time verifications invariably amount to a determination of space-time coincidences. If, for example, events consisted merely in the motion of material points, then ultimately nothing would be observable but the meetings of two or more of these points. Moreover, the results of our measuring are nothing but verifications of such meetings of the material points of our measuring instruments with other material points, coincidences between the hands of a clock and points on the clock dial, and observed point-events happening at the same place at the same time. The introduction of a system of reference serves no other purpose than to facilitate the description of the totality of such coincidences." However, this argument seems to be incompatible with his equivalence principle and his earlier statement [15], “So he will be obliged to define time in such a way that the rate of a clock depends upon where the clock may be.” Moreover, while all verifications indeed amount to a determination of space-time coincidences, in order to predict such coincidences theoretically, one must able to relate events of different locations in a definite manner. Thus, a coordinate system must be related to objective physical measurements. In fact, as early as 1918, unrestricted general covariance was questioned [24]. As Eddington [2] pointed out, "space is not a lot of points close together; it is a lot of distances interlocked." Understandably, Einstein [1] in his lecture of 1921 dropped the above argument and emphasized his equivalence principle first, and remar ked, “As in special theory of relativity, we have to discriminate between time-like and space-like line elements in the four-dimensional continuum; owing to the change of sign introduced, time-like line elements have a real, space-like line elements an imaginary ds. The time-like ds can be measured directly by a suitably chosen clock.” Thus, a space-coordinate and the time-coordinates in physics are not exchangeable as Hawking [25] claimed since they have distinct characteristics and physical meanings. Einstein also praised Eddington’s book of 1923 to be the finest presentation of the subject ever written [26]. However, the damage to general relativity has already been done, and a prevailing conceptual error3) is the belief of validity of any Gaussian system as a space-time coordinate system in physics. Consequently, Einstein’s equivalence principle is misunderstood and is often incorrectly replaced by the condition for the mathematical existence of a local Minkowski space. In short, general covariance has no meaning beyond the fact that a tensor calculation must be in terms of Riemannian geometry. Kretschmann [27] pointed out in 1917 that the postulate of general covariance does not make any assertions about the physical content of the physical laws, but only about their mathematical formulatio