Archive for August, 2011

Monism and Quantum Gravity

12/08/2011

How does Monism compare with Quantum Gravity theories?

The most general scientific theories of the universe are theories of Quantum Gravity. Theories of Quantum Gravity are attempts to unify General Relativity with Quantum Mechanics in a single mathematical formalism (where General Relativity is the theory describing gravity and Quantum Mechanics the theory describing the behaviour of sub-atomic particles). There is not a complete theory of Quantum Gravity yet, and there are several approaches to it. The two main approaches are String Theory and Loop Quantum Gravity.

So, how does Monism compare with String Theory and Loop Quantum Gravity?

String Theory has many compatibilities with monism. The theory is based in the idea that there are no point particles in the world. Particles have an extension, and what are now considered to be fundamental particles are constituted by more fundamental extended elements called string. According to Sting Theory, the properties of particles are given by the different modes of vibration of strings. From a monist point of view, the modes of vibration described by String Theory gives an insight into two fundamental aspects of Space: one is the geometric nature of Space and the other its dynamic nature. Although in a monist universe Space is more fundamental than strings, the description of the behaviour of strings can be thought as a model for the behaviour of Space.
Loop Quantum Gravity get even closer to a description of a monist universe. The theory introduces two important concepts. First, it sustains that space, at Planck scales, is not continuous but it has a discrete structure. And second, the theory satisfies a condition that many consider fundamental for a unification theory: background independence. That is, it can describe events without the need of a reference space or fields in space, but through space itself. In other words, events can be thought as processes that don’t occur in space, but they are defined by space itself. From a monist point of view, Loop Quantum Gravity not only reflects the geometric and dynamic nature of Space, but it also reflects the most fundamental aspect of Spatial Monism: elements are not objects in Space but they are constituted by Space itself. Background independence is not only a useful mathematical construction, but it is a reflection of the nature of the universe: a constituted by Space.

Monism and theories of Quantum Gravity are compatible. Quantum Gravity theories describe different aspects of monism. And the more the theories advance towards background independece, the closer they get to a monist description of the universe.