Two stars represents on Goodreads "it was okay" and I think that's about right. Yet that feels too low, because I did get through this book, and that usually represents at least a three to me--that I liked it--unless I find an ultimate WTF moment. If I was tempted to mark it lower, I think it's that I found this book so uneven. I'm not sure exactly what kind of background in mathematics would be ideal to enjoy this book. I made it to differential calculus in college, and it didn't break me, but it's been a long time since then and at this point I doubt I could solve an equation beyond simple algebra. There were parts of this book where I felt absolutely lost, particularly Chapter Six "Infinity's Twin" on projective geometry, set theory and transfinite numbers, yet so much else, even in later chapters, felt too elementary for anyone with at least a high school education--or at least too familiar. And really, I think he was pushing it in trying to embrace the science of everything through the lens of the concept of zero. At the same time there were tidbits throughout I did find interesting--sometimes fascinating--such as the "Casimir effect" of Quantum mechanics that some speculate could be used to power starships. The thing is those familiar areas? I think Stephen Hawking and Carl Sagan explain and describe them better--and those things not familiar are I think due more to the fact this was published in 2000--so it has more recent findings included than Sagan's Cosmos (1980) or Hawking's A Brief History of Time (1988). So as a science book it didn't impress me--and I just don't find this in the running for a great history book either--where it felt superficial. It was cool to learn Arabic Numerals should actually be known as Indian--because that's where the Muslims got them from--and that the Indians got zero from the Babylonians who were using it in 500 BC--but I felt the history part of zero in the book could be encapsulated in a few pages, so much so the title is almost a misnomer. Neither as science or history did this rock my world.