In GR, it is not always possible to synchronize clocks. Clocks can be synchronized along any open curve, but synchronization can be achieved throughout a finite region only if the region is coordinatized with one time-like coordinate, x0, and three space-like ones, xa, such that all components of the metric tensor of the form g0a vanish (see, for example, Lev Landau & Evgenii Lifshitz, 1975, p. 237). Jammer (p. 274) quotes Landau and Lifshitz on this, and then interprets them as saying that ‘‘only a space-time with a static metric admits standard synchronization.’’ The metric just described need not, in fact, be static. It would be static only if, additionally, all of its components were independent of x0 (as Jammer in fact noted on p. 272). Jammer’s formulation also seems to suggest that synchronization is possible only in certain space-times. However, as Landau and Lifshitz (1975, p. 237) also point out, a synchronous coordinate system can be introduced in every space-time.