Subspace Physics Today was a periodical published in the 24th century.
Lieutenant Commander Data, while in command of the USS Sutherland, read the articles "Weiss Ratio in Tachyon Propagation" (Vol. 217, No. 33) and "Ruiz Displacement in Tachyon Propagation" (Vol. 217, No. 37) from this periodical on a viewscreen while searching for clues on how to detect cloaked Romulan warbirds during the Klingon Civil War in 2368. (TNG: "Redemption II")