Everything around us is made from 'stuff' from planets to books to our own bodies Whatever it is we call it matter or material substance It is solid; it has mass But what is matter exactly? We are taught in school that matter is not continuous but discrete As a few of the philosophers of ancient Greece once speculated nearly two & a half thousand years ago matter comes in 'lumps' & science has relentlessly peeled away successive layers of matter to reveal its ultimate constituents Surely we can't keep doing this indefinitely We imagine that we should eventually run up against some kind of ultimately fundamental indivisible type of stuff the building blocks from which everything in the Universe is made The English physicist Paul Dirac called this 'the dream of philosophers' But science has discovered that the foundations of our Universe are not as solid or as certain & dependable as we might have once imagined They are instead built from ghosts & phantoms of a peculiar quantum kind & at some point on this exciting journey of scientific discovery we lost our grip on the reassuringly familiar concept of mass How did this happen? How did the answers to our questions become so complicated & so difficult to comprehend? In Mass Jim Baggott explains how we come to find ourselves here confronted by a very different understanding of the nature of matter the origin of mass & its implications for our understanding of the material world Ranging from the Greek philosophers Leucippus & Democritus & their theories of atoms & void to the development of quantum field theory & the discovery of a Higgs boson-like particle he explores our changing understanding of the nature of matter & the fundamental related concept of mass