In this blog post we're going to fly from quantum mechanics to Darwin to theatre as quickly as possible, using only links and the single engine plane of my mind, so hold on. Ready?
One of essential differences between classical and quantum physics is probability. At the incredibly small Planck level, particles are neither here nor there, but a probability wave of both, a superposition of states. When observed, this wavefunction collapses into the familiar one location/state of classical physics (perhaps you've heard of our hapless feline friend, Schrodinger's cat). But the probability wave is real, and the physics that surround it incredibly accurate and exceedingly strange, giving rise to quantum entanglement and theories of parallel worlds.
The process of wavefunction collapse, and the obscuring of the bizarre quantum world, happens through a process called decoherence, which I talked about in theatre terms here. The actual process of decoherence remains uncertain. But in this process lies the answer of how our observable classical here-not-there cause-and-effect lovely world emerges from the quantum weirdness.
Physicist Wojciech Zurek came up with a theory based in an unlikely source: Darwin's theory of evolution. The probability wave of the quantum world insists that a particle is both here and there until it is observed; Zurek believes that observation is a kind of selection, whereby the particles that interact with the probability wave select the location/state that is most useful to them, aka, the fittest; and then deliver the information of that state into the world; and though other particles may interact with the wave in a different location, they are overwhelmed by the process of selection that says this particle is most fit here, not there.
Two beautiful things about this idea: the first is that the probabilistic nature of the quantum world does not collapse, as if the superposition of states was some foreign magical universe; but rather we only see the fittest version, based on a process of selection below the Planck level. The second is that if correct, the framework that underpins all of life's astonishing diversity is theoretically connected to the way the universe moves from possibility into being.
Pretty enough, but what on earth does this have to do with theatre?
Recent posts have wrestled with my fear that Presence, the essential difference of theatre to other narrative communal arts, isn't an essential enough difference to make up for its shortcomings. But here, with quantum Darwinism as a model, we have a possible conceptual framework for why the live audience/actor experience matters.
In theatre, the actor is the probability wave, and the audience is the force that pressures each evolving moment into the fittest choice. No matter what a rehearsal process has been, a play will inevitably move towards what an audience wants; as many a despairing director returning to a long run discovers. An actor makes a choice, and if enough audience members connect viscerally with that choice, a current runs from house to stage and changes the way that actor plays; they hold longer for a laugh, or go further with a big choice, emboldened by that current of yes.
In this feedback loop, an audience is shaping the performance in a way that is fundamentally Darwinian; choices that fall flat, arcs that don't work, will quickly find extinction as the play evolves under the selective pressures of the audience. In The Empty Space, Peter Brook bemoans a production that played with beautiful detail in one country, only to becomes coarse and simplistic in another; but really, the production was doing exactly what a play should do - evolve to meet the present moment.
When we say a great actor has Presence, what do we mean? What do we mean when we say In The Moment?
I think we mean that a great actor's performance is like that probability wave of quantum mechanics: it is both here and there, a superposition of possible states; until, acted upon by the pressures of the audience's perception, that possibility crystalizes into a choice; and if that actor is very good, we keenly feel the the current of that feedback running through each moment we make together.
So in this way, theatre is more than the observation of a human moment; it is the practice of shaping it. In this framework, the audience is participatory in more than just passive terms; they are the essential pressure which gives the play life.
And in this way, theatre is linked not only to the evolution of life; but to each present moment crystalizing out of quantum possibility into the only world we know.
A play is possibility, then the pressure of perception making the present, then the past.