Despite us living in an era of PowerPoint, smartboards and digital projection, the traditional blackboard still retains an aura and usefulness for physicists that more advanced technologies can’t match. Scientists are among the last holdouts in their love of blackboards and chalk. Many fields of science and investigation have been replaced with whiteboards or slide show presentations, but physicists like to do a back-of-the-envelope calculation before delving deeper into a computation, and blackboards are a great tool for that.