Knocking on Heaven’s Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World is the second non-fiction book by Lisa Randall.

The title is explained in the text: "Scientists knock on heaven's door in an attempt to cross the threshold separating the known from the unknown.

As the subtitle indicates, she wishes to take up larger questions about the nature of scientific thinking, including its relation to religion and its reliance on probability.

At the same time, she wishes to bring her audience up to date regarding the status of her theory within the larger ambit of particle physics and cosmology as the Large Hadron Collider (LHC) begins its work, a monumental collaboration involving the whole world.

The good part about its wider ambition emerges in Randall’s clarification of the exact purport and scope of scientific work.