"Third Thoughts: The Universe We Still Don't Know" by Steven Weinberg is a trade paperback book published by Harvard University Press in 2019. The book offers a collection of essays exploring various topics in the fields of science, philosophy, epistemology, and astrophysics. Weinberg delves into the mysteries of the universe, discussing concepts related to atomic and molecular physics, as well as the history of science. With a thought-provoking style and engaging content, this book is a must-read for those interested in expanding their knowledge of the unknown realms of the cosmos.