Reality’s New Clothes
The prisoners stared intently at the dark, two-dimensional forms playing out a drama for them to observe.
Here, chained to a wall since birth and unable to go and explore the world, these prisoners observed the dance of shadows on the wall, created by the flicker of a flame burning behind them. The fire was designed to keep them warm, but it also provided just enough light for these shadows to perform little stories.
This shadow world was the only reality these prisoners had ever known, and they naturally came to believe that the way they perceived the world was complete and correct. Generation after generation added to the idea that the shadow world was all there was—reality.
One day, a prisoner escaped from his chains and stumbled outside. Gradually, his eyes adjusted and he was able to see the shadow world for what it was. He understood that the real world was out there, outside of the cave, and that shadows were just a clumsy approximation for reality.
When he returned to the cave to tell everyone that their world was a mere illusion, the prisoner was ostracized for the rest of his life, never living down how crazy and silly his claims sounded to everyone else.
This is Plato's Allegory of the Cave.
Around 400 BCE, Plato put this concept out there into the world, that we have a very limited perception of reality. It took 23 centuries for physical science to prove how right this view was.
During the Victorian era, leading up to the early 20th century, there was a very high confidence in the ability of physics to perceive the world as it was. The public was impressed with the ability to predict things and improve lives during much of the 19th century, as scientific concepts were applied to the emerging tech of the day.
There was a view that everything in physics could be predicted, as long as you had all of the data you needed to perform the necessary calculations. The universe was orderly.
The party didn’t last very long: in the early 20th century, the field of quantum mechanics emerged, shattering the classical view of a predictable and deterministic universe. This new branch of physics revealed a reality that operates on principles completely foreign to our everyday experiences.
In the quantum realm, particles can exist in a state of superposition, being in multiple places or states at once, until they are observed. Entanglement links particles across vast distances, with the state of one instantly influencing the other, defying the conventional understanding of space and time. You can’t really look at a particle to observe it, or the particle will move.
Just as the freed prisoner in Plato's allegory discovered a reality far beyond the shadows on the cave wall, quantum physicists uncovered a level of reality that is not just hidden from our direct perception, but fundamentally different from anything we experience in our daily lives.
It turned out that we weren’t seeing the world as it was at all. Instead, we were seeing the dance of shadows on the wall—our perception of the very tiny world.
The next reality revolution happened almost simultaneously with quantum mechanics. Prior to Einstein, there were some assumptions we had made about the way the universe works that were… well, flat-out wrong.
First, there’s no such thing as universal time. If you say two things happened at the same time, someone else will say that one thing happened before the other, and still a third observer will say that the other thing happened first. I explained this a bit in this piece:
Weirder still, time isn’t universal, and it’s actually the same thing as space. Rather, there’s a thing called spacetime that comprises both space and time. This means that if an object speeds up enough, it’ll take up less space.
To say the least, Einstein’s Special Theory of Relativity completely upended Newtonian physics when it was introduced in 1905. Time can dilate—stretch or contract, depending on the relative speed of movement.
As if this wasn’t enough, Einstein’s General Theory of Relativity replaced Newton’s theory of gravity. Instead of a mysterious force acting at a distance, gravity was the warping of spacetime around massive objects. If you can imagine placing a heavy ball on a trampoline, then dropping a couple of marbles on the trampoline, you have a pretty good idea of how gravity brings other objects toward it.
Looking back on the revelations of the 20th century, I can’t help but wonder what sorts of shadow world we’re observing today. Einstein left one cave and came back to tell us about the wonders of the actual world outside, but it took decades for the rest of the world to accept this new explanation.
Will quantum computing help us figure some of these truths out? What about the virtual world—does that have the same potential to imprison us, like participants in The Matrix? What other shadow worlds are we watching?
Are we on the verge of stepping into a new light, revealing dimensions of reality that today, we can scarcely imagine?
This actually reminded me of H.G. Wells's "The Country of the Blind" story, where a climber ends up lost in a valley populated by a tribe of blind people who refuse to believe him when he tries to tell them about the concept of sight.¨
I would not at all be surprised if we keep revealing new layers of reality. I'd go as far as to say it'd be a tiny bit arrogant to assume we've reached the final stage of understanding the world. The best we can hope for is to keep getting incrementally closer to it over time.
The American novelist Howard Fast once wrote a story that very closely resembles the Allegory of the Cave, but it was set in a movie theatre. He was clearly trying to make some kind of point....