Freeman Dyson on Brian Greene

“The Fabric of the Cosmos covers a wider field than The Elegant Universe and paints it with a broader brush. There is not much overlap between the two books. ...Neither is a prerequisite for reading the other. The new book is easier, and should preferably be read first. Readers who get stuck halfway through The Elegant Universe may find the new book more digestible.”

“Greene takes it for granted, and here the great majority of physicists agree with him, that the division of physics into separate theories for large and small objects is unacceptable. ...Greene believes that there is an urgent need to find a theory of quantum gravity that applies to large and small objects alike. ...As a conservative, I do not agree that a division of physics into separate theories for large and small is unacceptable. ...The essence of any theory of quantum gravity is that there exists a particle called the graviton... I looked at various possible ways of detecting gravitons and did not find a single one that worked. Because of the extreme weakness of the gravitational interaction, any putative detector of gravitons has to be extremely massive. If the detector has normal density, most of it is too far from the source of gravitons to be effective, and if it is compressed to a high density around the source it collapses into a black hole. There seems to be a conspiracy of nature to prevent the detector from working.”