#### nomadreid

Gold Member

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^{2}= (cdt)

^{2}- dx

^{2}- dy

^{2}-dz

^{2}or dx

^{2}+ dy

^{2}+ dz

^{2}- (cdt)

^{2}, depending on the convention of your choice, and ds

^{2}is called the spacetime interval between the corresponding events, the square being used to avoid nasty ambiguities and irritating imaginary numbers. Fine. But if one wants to refer to ds, is there any standard term for it besides the clumsy "the square root of the spacetime interval" or "that which when squared gives the spacetime interval"?

Thanks.