Misconception which led to the material frame-indifference controversy

The confusion over the nature of the useful restriction on the allowable forms of constitutive relations (material frame-indifference, or objectivity) is due to the vague language of its formulation. In the final analysis, the confusion arises because the concept of general covariance of physical laws is applied in the inappropriate setting of the three-dimensional space instead of the four-dimensional space-time.