2014 Celebrating their 10 th Anniversary Trinity Hall

2014 - Celebrating their 10 th Anniversary Trinity Hall, Guildford, Wednesday Feb 26 Written in the Stars How to live happily in a deterministic universe

Dismissing the wrongheaded arguments: • Not only is our fate is determined, but it is literally determined by the stars and planets • Our fate and all that happens in the Universe is known to a higher power, so what we think to be free choices we make are just the will of God • Our fate is in our own hands because we are more than just mechanical machines subject to the laws of physics

Some definitions Determinism – what philosophers refer to as causal determinism: the idea that events in the past cause events in the future. So, given precise initial conditions we can in principle know the future completely Randomness – individual events cannot be determined precisely in advance as they do not depend on past events, actions or conditions. Often also called ‘indeterminacy’. Predictability – If a process is determinisitic then we should, in principle be able to predict or calculate what will happen next.

There are four options available when it comes to the sort of universe we live in: 1. Determinism is true so all our actions are predictable and we have no free will, just the illusion that we are making free choices; 2. Determinism is true but we can still have free will; 3. Determinism is false; there is built-in randomness to the Universe allowing us the room to have free will; 4. Determinism is false, but we still don’t have free will since events happen randomly that we have no more control over than we would if they were predetermined.

Einstein’s Block Universe Here and now Sp e c a PAST Time FUTURE But does this mean our future is already decided? Is it ‘pre-determined’? pre-determined’

1920 s – Quantum Mechanics

Even Nature has not decided what she will do next. This suggests our future is not predetermined. Have we been given back our free will? will

So, how do we cope with this mystery? ?

Pierre-Simon Laplace (1749 -1827) Henri Poincaré (1854 -1912)

Edward Lorenz (MIT meteorologist) Coined “Butterfly Effect” in 1960 s

A personal, physicist’s view: Despite indeterminacy on the quantum level, this is just statistical on the macroscopic scale and we do live in a deterministic universe. But, we can never in practice know the initial conditions of a process to predict with accuracy how it will evolve in the future. This gives us the illusion of free will.

It doesn’t matter that we live in a deterministic universe. That (fixed) future is never knowable to us, imbedded as we are within space-time. It is that very unpredictability that gives us an open future. The choices we make are, to us, real choices You might prefer to say that the future is preordained and that our free will is just an illusion, but the point is, our actions still determine which of the infinite number of possible futures is the one that gets played out.

Am I then a compatibilist (that free will and determinism can exist alongside each other) ? Strictly speaking, no. I prefer to redefine the term free will. So, does free will exist? FAPP*, yes it does. Even if it is illusory. _______________ * - For All Practical Purposes

Life Molecular biology Organic chemistry Quantum physics

Living organisms are the only macroscopic objects whose dynamics is controlled by a single molecule. It is possible that mutations in DNA might rely on quantum randomness.