We are surrounded by mystery. This may sound like an anti-science statement but, actually, it's precisely the opposite. We just need to be careful about how we define mystery or the mysterious. Take Albert Einstein, for example:
"The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. He who does not know it and can no longer wonder, is as good as dead, a snuffed-out candle."
To Einstein, the mysterious could be equated with the unknown.
As I explore in my new book The Island of Knowledge: The Limits of Science and The Search for Meaning, just out, the mysterious need not have anything to do with the supernatural. It is what is beyond the known.
The essential question, then, is whether what is unknown, or part of it, is unknowable, beyond our grasp. This question has enormous relevance for science and for society, as it sets the essential limits to knowledge: Are there questions about the world and about ourselves that are unanswerable? What are they?
To answer, we need to examine how science operates. In this space, we can only scratch the surface.
Science can be seen as a process that amplifies our perception of reality. Our five senses are like antennae collecting different aspects of the physical world around us: we see, we hear, we touch, we smell, we taste. The brain is an amazingly complex entity, capable of integrating the stimuli from outside and generating what we call our everyday sense of reality.
On the other hand, we know that our perception of the world is quite limited: what we see or hear, for example, is a small fraction of what's actually "out there." It follows that our construction of reality, based as it is on our five senses, is incomplete. The world is much more than what we perceive of it.
This is where science makes a triumphal entrance, with its tools of exploration. They are our reality amplifiers, allowing us to see and measure farther and with more detail, extending our grasp into realms foreign to our senses. We thus gather information from worlds billions of light year away, see bacteria and molecules, visualize brain activity, study elementary particles in a constant dance of creation and destruction, probe cosmic phenomena that took place near the beginning of time itself.
We see all this; but we don't see all. We can't.
Every tool of exploration has a range and a set precision. With a good pair of binoculars, we can see almost as well as Galileo with his telescope of 1610. We see craters and mountains on the moon, the four largest moons of Jupiter, etc. But we don't see galaxies. For that, we need bigger telescopes. And even those have their limits. We will always see more of nature, but never enough.
We will never see everything there is to see.
There is a persistent veil around our perception of reality, the mystery that surrounds us. This mystery, as Einstein remarked, has tremendous seductive power and has inspired some of the greatest works of art, science and literature. Fortunately, it won't go away.
Apart from technological limitations to how much we can see of reality, nature itself offers barriers to knowledge: the speed of light implies that we live literally within a bubble of information, our "cosmic horizon," with size equal to the distance light has travelled since the Big Bang. The universe most probably continues beyond the horizon; but we can't get information from "out there." The uncertainty principle at the heart of quantum mechanics, that so undid Einstein, is not going away either: there is a fundamental unknowability deep at the heart of matter. Even math and computer science have fundamental incompleteness problems. And understanding consciousness ...
But we can get back to these another day. For now, let's stay with the metaphor of the Island of Knowledge: the more it grows, the more grow the shores of our ignorance, the boundaries between the known and the unknown.