Comment on “Contact Mechanics for Randomly Rough Surfaces: On the Validity of the Method of Reduction of Dimensionality” by Bo Persson in Tribology Letters

In a recent paper, Persson (Tribol Lett, 2015 . doi: 10.1007/s11249-015-0498-1 ) has criticized the validity of the method of dimensionality reduction in contact mechanics. Attempts to determine the scope and validity of particular theories clearly are an important and necessary part of science. However, we believe that much of the criticism by Persson is misleading in both scope and particulars, and take this opportunity to present the other side of the argument. We hope that our comment can help the reader to avoid misunderstandings and to arrive at a more balanced view of the method in question.