Plato’s cave is two-thousand year-old story that describes the human situation as like prisoners in a cave chained so their backs face the entrance through which sunlight streams (Figure 3.27). The cave is dark so to see others, they look at their shadows cast on the cave wall, which over time they assume are real and act accordingly.
Socrates told this story to Plato to illustrate that the perceived world is like a shadow puppet-show, based on light from the Good that acts like our sun. The analogy has flaws, as the puppets making the shadows are assumed to be matter, but the concept that seen objects are caused by what can’t be seen fits the proposal that the physical world is a virtual reality based on quantum theory.
Quantum theory can then update Socrates vision in scientific terms, so the cave is physicalism, its walls are our space, the chains that bind came from evolution, and the shadows are observations caused by physical events. Now there is no need for contrived puppets, as our shadows collide when we do, and if the prisoners had a dog, it would be as shadow-driven as they are. Socrates cave is then an allegory of what quantum theory describes today.
Modern physics sees itself standing in the sunlight of science before the dark cave of quantum theory but Socrates would say the reverse, that science still sits in the cave of physicalism, calling the shadows it sees there real, and denying talk of the quantum sunlight or that our space is just a surface.
Why then don’t we turn from the shadows to see their cause? As Socrates explained, this is difficult because turning from shadows to sunlight is blinding and painful, so we return to the shadows we know. Hence when Einstein tried, the quantum sunlight blinded him, so he looked back at the shadows to find hidden variables. Bohr tried too, but the impenetrable Copenhagen suit he wore for protection blocked out the quantum sunlight entirely, so he decided it was unreal.
Physics then decided the quantum world was dangerous even to imagine, so it quarantined it behind walls of equations that only initiates could read, to form a quantum club, whose first rule is that there is no quantum world. They use the quantum light to predict our shadow future without looking at it, and advise others to do the same. The validation of Socrates intuition, that a hidden light creates what we observe like shadows on a wall, is then denied by those who turned their back on it, who declare that they use what doesn’t exist. Yet among those who guard quantum theory from what they call idle speculation, the bravest still turn, to try to envision it.
For example, Wheeler compared quantum reality to a great smoky dragon (Wheeler, 1983), a fearsome beast that is both powerful and mythical, so if it does exist, the world we see is just its smoke (Figure 3.28). In this view, which Socrates would approve, quantum reality isn’t the shadow of physical reality, but the real world whose shadows are the physical world we see.
Table 3.3 compares quantum realism and physical realism for light, but if our universe began as light, how did matter arise? The next chapter addresses this question.