Make an “O” shape with your thumb and forefinger and contemplate it. It represents both a number and a concept: zero, nothing. In between your fingers is air, but what about between the air molecules? You say there is a vacuum. Some physicists over the last 40 years, including Stephen Hawking and Leonard Mlodinow, Frank Wilczek, and Laurence Krauss, have gleefully claimed that the vacuum is, in fact, not empty but full of quantum fluctuations. Therefore, they argue, the age-old question: “why is there something instead of nothing?” that has beguiled philosophers since the time of the ancient Greeks has its answer in quantum physics. There is no such thing as nothing and never has been. This is a category error made ambiguous by semantics, however, meaning that they are trying to settle a different question, but worded in the same way. Philosophers have long recognized that the same sequence of words forming a question, depending on where emphasis has been added and how terms are defined, can be many different questions. In this case, the physicists claim …