Imagine the mental gymnastics necessary to believe something so fundamentally absurd.
The Book of Nothing is stuffed with wonderful stories. Barrow begins with conceptions of nothingness from around the world and throughout history. Rooted in the paradox-rich soil of philosophy and religion, the concept of nothing has blossomed into many strange ideas, and apparently Barrow is familiar with all of them. Naturally he explores the invention of zero; the evolution of words to express this mathematical (and philosophical) concept; and the religious, especially Christian, opposition to the idea. He also clearly explains the nature and persistence of vacuums; zero-point energy and other conundrums of physics; and many of the logical contradictions that turn out not to be contradictions at all
Testing demonstrates that there is a non-zero probability that fluctuations - which come from no Physical source - cause physical effects. ie. Casimir Effect
Or - you can say that "nothingness" that is outside time and space - is Physical. Either way, there exists a "physical" paradox in the minds of men, yet nature performs perfectly and originated just fine.