Early in the book, Weinberg explores the origins and implications of the Hubble constant, that the red shift of galaxies is proportional to their distance, and how this is evidence for the expansion of the Universe.

[3] After giving the reader a basis of understanding of astrophysics and particle physics, in chapter 5, Weinberg lays out the makeup of the Universe after its origin in a series of frozen frames.

In the introduction, Weinberg explains his views on writing about physics for the nonspecialist: “When a lawyer writes for the public, he assumes that they do not know Law French or the Rule Against Perpetuities, but he does not think the worse of them for that, and he does not condescend to them… I picture the reader as a smart old attorney, who does not speak my language, but who expects nonetheless to hear some convincing arguments before he makes up his mind.”[4] The book contains a glossary and a "mathematical supplement" for readers who want to understand the mathematics behind the physics.

"[5] In The New Yorker, Jeremy Bernstein wrote that "Weinberg builds such a convincing case...that one comes away from his book feeling not only that the idea of an original cosmic explosion is not crazy but that any other theory is scientifically irrational.

After Weinberg's passing, Scientific American mentioned his "most famous (or perhaps infamous) statement can be found on the second-to-last page of his first popular book, The First Three Minutes": "The more the universe seems comprehensible, the more it also seems pointless.