Within this 1963 text, Professor Watson writes as a physicist seeking to understand how it is that physics goes on at an ever increasing pace to reveal new structure in the world, matching the achievements in chemistry, biology and applied science, but exposing us to philosophical confusion about our pictures of microphysical phenomena and how we speak of them. Watson's basic quest was for an intuitive grasp of atomic existence. He discusses atomicity in relation to the physics of his day, showing how to disengage our thinking from habits associated with continuity, in order to put our philosophical difficulties behind us. Nearly half a century after the work's original publication, this paperback edition of Understanding Physics Today will provide readers with fresh opportunities to engage with this historically valuable text.