Ever since Democritus proposed the idea of the atom over two millennia ago, many have sought to understand reality by splitting it into discrete bits. In modern physics, this approach is called “quantisation” and has become the winning paradigm that divides previously seen smooth and continuous phenomena into bits. It extends from physical things to quantities like light, electric charge even space and time. Nobel Prizes have been awarded for quantising the electromagnetic and weak fields. However, all our efforts to do the same for gravity have failed. Critics argue that the very project of quantisation is a mistake. Roger Penrose, for example, argues that instead of quantising gravity we should change our understanding of quantum mechanics.
Should we give up on the idea that all of reality can be described in terms of discrete quantities? Is the desire to quantise gravity based on a reductionist prejudice that reality must be divisible into bits? Or can we indeed quantise all physical things and interactions no matter at what scale?
