  The primary aim, in teaching physics, is that the student should gain an
understanding of the principles of physics and how to apply them to different
problems. A secondary aim is to allow the students to appreciate the scientific
approach and significance of it in the evolution of science and society. One
approach for the second aim has been to include 'historical material' in
physics textbooks. The quantity of the historical material included is quite
diverse, from textbooks with a very strong historical approach to others
without any historical material. The quality of the material included is also
diverse. In this article we focus on the development of the historical
material, i.e. a certain historical development, in a specific textbook (Sears
& Zemansky's University Physics) over a number of editions. The aim is to see
when and how the historical material is included and how well it describes the
actual history. Will the physics adapt to history or vice-verse. The event of
interest is the introduction of the Blackbody radiation formula or Planck's
radiation formula. This is well known out of an historical perspective, but
also a case where a quasi-historical is quite common in textbooks.
