Almost everybody knows that the answer to the most important question in the universe is 42. The joke works mainly because of the sheer hubris it would take for anyone to claim they even know what the most important question in the universe is. But is that really so? In my practical experience, it isn’t. More and more, it seems to me that there is one question around which almost everything that matters revolves. And, astonishingly, it is not whether God exists. So what is it? It can be phrased in many ways, but let’s put it like this:
Is it true, or does it only look that way?
Every one of us has asked this question in many different contexts, but it also reveals something fundamental about how this world has been designed — even though it didn’t have to be. Perhaps the most familiar illustration of this is the Duck Test:
If it looks like a duck, swims like a duck, and quacks like a duck, then it’s probably a duck. But we can’t prove it.
Such a situation can only arise in what we call reality — the real world we live in. It doesn’t arise when you create a virtual world, whether as a mathematician in your head or, to make it easier to imagine, as a software developer on your computer. When something that looks like a duck appears on your screen, you can always inspect the code and data to see whether it really is a duck — whether the programmer actually modeled such a concept — or whether it’s just a set of shapes someone drew in a graphics program to create the appearance of a duck.
I’m not contradicting myself here. Yes, there still seems to be a question of whether it only looks like a duck or actually is one, but that question resides in reality, not in the virtual world. In the virtual world, it simply isn’t a duck; it’s just a set of generic shapes that make up an image drawn in a computer program. In reality, the person who drew it may have intended to draw a duck, but there’s no sure way to find out — even if we ask, he might lie.
This holds even for more complex problems. Say you have created a more abstract virtual world where the goal is to pack as many two-dimensional objects from a given set as possible into a given two-dimensional container. Then one day you find what looks like the ideal arrangement. You can prove mathematically whether it really is optimal, at least in principle, given enough time and computing power.
Or, for lovers of Gödel’s theorem who are also familiar with Turing’s halting problem, consider this: if someone brings you a perfect code analyzer — something that supposedly tells you whether any piece of code will finish or hang forever in an infinite loop — you know, thanks to Turing’s proof, that it’s a fake.
I’m not venturing into higher mathematics here. I’m simply saying that when you create a world yourself — through mathematical formalism, code, or perhaps a board game — you never run into this dichotomy. You never have to waver between what is really true and what only seems to be true.
Some will object that many mathematical questions are, in practice, unsolvable, because even billions of years and gigawatts of computing power wouldn’t be enough to tell what only looks like an ideal solution from what actually is one. Others will point out that mathematicians have proven some questions can never be answered. To them I say: look closely at what was proven. It is that no single method can answer all such questions at once, and that question itself has been answered. It is "no." Each particular question still has its answer. A given program either stops or runs forever, and nothing about it is uncertain. What keeps us from the answer is that we must find it with finite means. We have finite time, so we cannot wait for a process that never ends, and finite memory, so we cannot hold what grows without bound. Even our proofs are finite, so they cannot reach every fact. Reality is what makes these questions unanswerable, even when they concern virtual worlds with no physical existence, such as the worlds of numbers and programs we have created entirely in our heads. Free of those constraints, we could follow any process to its end and know the answer to every question about it. The worlds we invent keep no secrets of their own; their limits are the limits of reality we explore them with.
We cannot create a world that imposes limits on what we can know; the best we can do is borrow this feature from reality. In the same way, we cannot produce true randomness; we always have to borrow it from reality. In fact, the problem of true randomness follows directly from the point above. If we managed to produce something that appeared truly random, all it would take is a look at the mechanism to see how it was constructed — and therefore that it isn’t random at all. In my book, I argue that this is the strongest evidence against the idea, proposed by some philosophers, that we might be living in a computer simulation. We are not. Nor would borrowing randomness from some outer reality save the idea, because beyond being unable to generate true randomness, we cannot create anything about which one couldn’t tell whether it truly is so or only seems to be. How could anyone create a simulation without being able to produce these two basic ingredients? And if someone were able to produce them, how different from us they would have to be! So different that we can’t even imagine it, just as nobody can imagine how to build even a simple generator of true randomness.
This shows that there are things we encounter everywhere in everyday life that we cannot replicate. We cannot even imagine what replicating them would require, or what such a replica would look like. Even freed from a physical body, we would not become God-like. We would be more like angels, which offers a faint glimpse of why there may be room in the order of beings for something higher than humans but lower than God.
And yet the question at the heart of this article arises in the most ordinary, everyday situations. It’s a question that deeply preoccupies every small child:
Mommy, do you love me?
All it takes is two conscious beings for one of them to wonder whether something is truly what it appears to be. And there is no way to tell for certain. There may be mothers who hate their children from the moment they are born, still hate them on their deathbed, and appear loving all along. Proof simply isn’t possible.
Similarly, it takes two conscious beings to bring the question into a virtual world, and they bring it with them from reality. Think of a computer game, a social network, or the film The Matrix, which depicts exactly such a virtual world, one whose essential ingredients are borrowed from reality. This, by the way, makes the simulation hypothesis even less probable: a simulation that has to borrow its essential ingredients from reality would be about the least impressive engineering workaround imaginable, especially when much simpler ways exist to achieve the same effect. Humans can build shared virtual worlds without any technology at all. Marxism, for instance, needs only a slim booklet to boot a shared illusory world into existence. And to an engineer like me, social engineering is engineering too.
“Mommy, do you love me?” may be one of the most profound questions of the kind we’re examining, but it is a time-bound one. What point is there in asking it when most of us will never be able to tell appearance from truth, and death will seal the two together forever? The questions humanity asks tend to be more open-ended, and their answers less certain. They call for a leap of faith, or more precisely, they make room for faith to exist.
The following question, for instance, may have more potential to tear the world apart than nuclear weapons:
Is the other person conscious too, or does it only seem that way?
We cannot afford to lose faith in the right answer to this question. Related questions include:
Are animals unable to tell right from wrong, or does it only seem that way?
Do good and evil really exist, or are they just an illusion?
And for anyone willing to weigh the evidence, there are further questions of equal seriousness:
Is Jesus the Son of God, or does it only seem that way?
Is the world an elegant piece of engineering, or does it only look like one?
Do we own this planet, or does it only seem that way?
Having weighed all the evidence I have, I’m in no doubt about how each of these matters appears.
But is it true, or does it only look that way?
That, to me, is the most important question in the universe.