In “The Matrix”, the main character, Neo (which means “new”), learns that his entire reality to date has been the result of a sophisticated computer generated simulation, and that he, and everyone else, has lived his life in a pod, and used as a human battery.
This is not so far from the situation we all face, but without knowing it. We think we live in the real world, but we don’t, we live in a personal sim.
Our brains do not perceive the real world. What they receive is a set of electrical impulses, generated by sensory organs – the eyes, ears, nose, skin and tongue, representing sight, sound, smell, touch and taste. The brain creates a model of what it thinks the real world is like based on those impulses.
There is no way to prove that the brain’s working sim is the same as anyone else’s. In the old saw, how can we prove that what I see as yellow, you do not see as blue? There is not way to tell that is not the case, and it really doesn’t matter as long as your brain model is internally consistent and coherent. When I eat a cheeseburger, how can you tell that my experience of eating a cheeseburger is the same as yours?
Worse, there is no way to prove that your internal model aligns with external reality. Or even that there is an external reality. Thoughts have varied over the years on this subject. Ancient Greeks like Artistotle believed in a world that was more real than our own, they saw the heavens as the source of all pure reality, while the Earth was a pale and corrupt representation of the heavenly pureness. This is similar to the idea that there is a more real world out there, represented internally by a simulation.
Modern thinkers such as Descarte (1596–1650) attempted to prove the existence of the world and of God starting from the deduced fact of their own existence (“Cogito, Ergo Sum” – “I think, therefore I am”). Actually, he wrote in French “Je pense donc je suis", and only later in Latin. He started by eliminating all things in the universe that he could not prove, and ended with only the fact that he was observing something, and thinking about it, so he must exist. But he could not convincingly prove that anything else exists!
What this means for us is that there is no way to say with confidence that we understand the Universe, or even that there is a Universe. All we can say is that we own a consistent and coherent model that might represent the way things are. In fact, I suspect that there is no reality as such. I think that the only real thing is mathematics – the world is a set of mathematical principles encoded in what we perceive as matter and energy, but in fact all we can determine is how they interact with the brain, and with the consciousness encoded in the brain.
This takes away a lot of the issues related to quantum mechanics – the idea that the Universe is somehow interacting with me, the observer. Everything is an interaction. The Moon literally doesn’t exist when I’m not looking at it – it is a set of mathematical equations that resolve when I resolve them – the act of creation for me. The unobserved tree that falls in a forest literally doesn’t make a sound – because it doesn’t have an independent reality.
When Schrondinger’s cat is neither alive nor dead in the experiment I discussed earlier, it is neither alive nor dead because until I observe it, it doesn’t exist (for me). This is the ultimate in Relativity – not only is time relative to the observer, but so is everything else! The whole of existence is relative.
You can choose your friends, but you can't choose your relativity! Or can you?