This is the 50th Anniversary issue of Physical Review Letters. Readers will note only a few differences between it and the 2,400 or more issues that preceded it over the past half century. The cover image is not a figure from a Letter, but is instead a portrait of founding Editor Samuel Goudsmit. The issue contains an interesting Essay by APS Editor-in-Chief Emeritus Ben Bederson. It is a brief biography of Goudsmit, focused on his life prior to becoming an APS editor. Beyond that readers will find, as always, an excellent collection of Letters that address current research in all areas of physics. These blend seamlessly with the roughly 75,000 Letters that have graced PRL’s 300,000 or so pages over the past 50 years.
As we look ahead to the second half of PRL’s first century, we thank the authors of the 75,000 Letters that appeared in the first half, many of which have had significant impact on the progress of physics. We also thank the referees of all submissions, published and not published. Their assistance in making that distinction was, and continues to be, crucial. Finally, we thank the readers of PRL. The goal of any journal is to convey information, which makes a public of readers essential for any publication.