This is very weird, even for me. It seems that it is scientifically possible for two people to experience reality in completely different ways. But what separates the two is not reality itself, but what one knows about it. Knowing is the key here (and the point of this post). What this means is that the mind (the organ that generates knowing) has a relationship with what can be known that is not at all intuitive. The reality is, only the reality you know exists. And this has been proven by a new experiment that verified an old thought experiment know as “Wigner’s Friend.”
It is basically this: The Nobel Prize–winning physicist Eugene Wigner imagined, in the early 1960s, a quantum-event experiment conducted in a friend's lab, but he, Wigner, does not know the results of this test. But the experimenter, his friend, does. Winger speculated that what's in the head of the experimenter will not be the same as what's in his own head. The experimenter has a result that says the elementary particle is doing this and that. But from Wigner's position of understanding, that elementary particle is still in a state of fuzziness—meaning, that according to Wigner's position of knowing, the characteristics of the particle have not been resolved or determined. It is still everywhere and nowhere. This condition of indeterminateness is called superposition (or, the quantum field of potential). It spooked Einstein. It should spook you. But it's a fact of life, and there is no way around it. The universe is ghostly.
Basically, before an elementary particle like an electron appears somewhere, it's pure potential. And when you measure it, it pops into, and very briefly participates in, what we recognize as ordinary reality. That is weird enough. But now scientists led by Massimiliano Proietti at Heriot-Watt University in Edinburgh validated the Wigner’s Friend thought experiment. It does speak to an aspect of the reality we can understand. A mind that does not know where an elementary particle is (in this case, a single photon), has a completely different experience of it than one who does.
Seriously, stop and think about that.
And, sorry, but it only gets weirder. If Wigner’s Friend happens to call him and say he has done the experiment on the single photon's behavior, when it popped into conventional reality out of quantum fuzziness, and knows the result, as long as he does not say this result, as long as Wigner does not know the behavior of that specific photon, they are still experiencing two different realities. For Wigner's friend, the reality is the photon doing such and such. But for Wigner, it is still in the condition of potential (or what the French philosopher Gilles Deleuze called the virtual). And this is where language, of all things, enters the bizarre picture and makes it more bizarre. If Wigner's friend tells him what that photon is doing, their realities merge and become one in an instant. Just saying it, makes it so.
The article about this experiment is called "A quantum experiment suggests there’s no such thing as objective reality." This, I think, is misleading or unhelpful. The fact that a-temporal quantum states, when isolated or investigated, reveal unexpected properties of reality does not mean unconventional ones should be dismissed or considered invalid. There is such a thing as an objective reality, and there is, we are discovering, such thing as its non-existence. Or, to put it another way, there is a world that is out there, but, apparently, it is made possible by it not being out there but by a process of co-creation that involves no distinction between the subjective and objective. In a sense, we can only see the world we know.
This curious conclusion has much in common with a brilliant idea presented by Carlo Rovelli is his little book, The Order of Time. He speculates that the universe as we see it is not the whole universe but one of its many parts (or subsets). This includes the Big Bang, and its evolution and key features, such as entropy, the root of time. (Entropy means moving from a state of order to one of disorder because the latter, obviously—for example, a messy room—is more stable than the former—a clean room). But for Rovelli, the configuration of the universe we call the "all in all," is more about how we see it and not the whole of it. The implications of this line of thinking are revolutionary. It means we may see a Big Bang (issuing from a state of low entropy) because one of the many configurations, or subsets, of the universe happens to involve knowability. We can know it because it can be known. And so the knower and the known are one and the same.
It is with respect to the dramatic blurring produced by our interactions with the world, caused by the small set of macroscopic variables in terms of which we describe the world, that the entropy of the universe was low. This, which is a fact, opens up the possibility that it wasn’t the universe that was in a very particular configuration in the past. Perhaps instead it is us, and our interactions with the universe, that are particular. We are the ones who determine a particular macroscopic description. The initial low entropy of the universe, and hence the arrow of time, may be more down to us than to the universe itself. This is the basic idea.
And when Rovelli means we, he means not just humans but entities (or societies, to use the language of Alfred North Whitehead) that participate in a subset of the universe that is initiated by a memory of its initial and self-driving conditions. The birth of the universe includes the condition to remember this birth. Is there a connection between this grand (or macro) picture and that of quantum physics? I bring this up because there has been so much work done by great mathematicians to unify the formulas that explain the ordinary world with that which explains the maddening quantum realm. Is it possible that what links the two, at least from philosophical position, is knowability? Meaning, it's not so much a question of ontology (being) as epistemology (knowing). The first emerging from the second.