Ockham Society (Friday - Week 4, HT19)

Ockham Society

From the perspective of Quantum Field Theory, the fact of fluctuations in the vacuum can be seen as an account for Leibniz' famous enquire ''Why is there something rather than nothing?''.

Nothingness is commonly associated with the void, where no thing exists. In classical field theory, the vacuum -- defined as free space devoid of any material being -- indeed is empty: the property of emptiness is persistent in the classical vacuum. In quantum field theory, the vacuum is introduced as the ground state of the (abstract) Fock space, an algebraic construction composed of all possible quantum states of particle configurations: as its ground state, the quantum vacuum is a state with zero particles and least possible energy.

There are two features of this quantum vacuum which, in contrast to the classical vacuum, make it a rich structure of non-trivial behaviour: 1. The non-vanishing zero-point-energy, composed of energy contributions from all possible modes. 2. The everlasting vacuum fluctuations about the average value of zero particles, which consist of nonterminating creation of virtual particle-antiparticle pairs, followed by their annihilation back to the void.

We will explore the origin and physical significance of these, and argue that they suggest the view that nothingness cannot be a persistent state.

Ockham Society Convenor: Sean Costello | Ockham Society Webpage