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Video abstract for the article 'Fully covariant radiation force on a polarizable particle' by Gregor Pieplow and Carsten Henkel (Gregor Pieplow and Carsten Henkel 2013 New J. Phys. 15 023027). Read the full article in New Journal of Physics http://iopscience.iop.org/1367-2630/15/2/023027/article. GENERAL SCIENTIFIC SUMMARY Introduction and background. To find an expression from basic principles that describes friction phenomena is a difficult undertaking, because there are many different processes that transform kinetic energy into heat. Consider for example a brick sliding over a tilted ramp. Although simple, if one wants to formulate a microscopic theory, one has to include roughness, contamination, airflow (fluid dynamics), etc. In brief, it is very easy to rush down a slide, but it is in no way simple. Main results. In our paper we study a body sliding at constant speed through the vacuum above a surface. Special relativity is a very natural building block to understanding constant motion so we chose it as a cornerstone. It describes the transformation from one system to another in order to implement the fundamental credo: the laws of physics have the same appearance in all inertial frames. We have chosen a so-called covariant formulation in terms of vectors that live in the four-dimensional space--time because it facilitates transformations between frames. A natural playground for an elementary force in a relativistic treatment is electromagnetism. We derived a formulation of previous treatments of the force on the body due to exchange of photons (electromagnetic quanta). Wider implications. Our formalism also recovers the special case of an atom moving in free space through the blackbody radiation field, a setting that goes back to Einstein's work on the quantum theory of radiation. Altogether, this is an interesting and compelling angle on the deceptively simple problem of electromagnetic friction that has been, nevertheless, the subject of controversial discussions lately.