- #1
Ken G
Gold Member
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We know that 4-vectors are invariants, in the sense that they have the same meaning in all reference frames/coordinate systems. We know they transform by the Lorentz transformation in SR, and have an invariant Minkowski norm (let's not bring in GR at this point unless it becomes necessary). It seems to me that any time we wish to measure or determine experimentally a given 4-vector, we must do it by determining its components in some reference frame/coordinate system (I'm not trying to parse the differences between a reference frame and a coordinate system unless it becomes necessary to do so). So my question is, is it ever possible to measure or determine experimentally a 4-vector, without first choosing a reference frame/coordinate system?