We sometimes hear people speaking about “gaps” in our scientific knowledge. People often speak as if there were merely a few cracks or gaps in our scientific knowledge, and that in the not-too-distant future those gaps will be filled in (perhaps rather like some construction worker filling in a few cracks in a wall, or like a photo restorer filling in a few cracks in an old photo).
Is it correct to speak in such a way? No, it isn't. But the reason is not that our scientific knowledge is perfect. The reason is that our scientific knowledge is so fragmentary and so tiny that it is misleading to use the term gaps or cracks to refer to what we don't know. What we should be saying is that what we do know is tiny, and what we do not know is vast.
Consider the current state of our knowledge. We know about the surface of our planet and a few other planets. But we live in a vast universe of billions of galaxies, many of which have billions of stars. So we know nothing about 99.99999999999999% of the planets of the universe.
We also know basically nothing about most of the matter and energy in the universe. Scientists say that 96% of the matter and energy is dark matter and dark energy, which we know basically nothing about. We also have no idea what caused the origin of the universe billions of years ago. There are many mysteries regarding how we got from the supposedly infinite density of the Big Bang to the orderly state the universe is in now.
Considering only ourselves and our planet, we know almost nothing about mysteries such as the origin of life and how our brains work. There is much evidence of some great psychic reality that we are almost completely ignorant about. Unraveling how the mind works seems a thousand year project that we have barely started.
Given such realities, is it accurate to say that there are “gaps” or “cracks” in our knowledge? No, because such a term implies that we have learned a good fraction of what there is to know. If someone asked you how much you know about quantum chromodynamics, it would be most misleading for you to say that there are gaps in your knowledge of quantum chromodynamics (as that would imply you know a large fraction of that topic). You should instead say that you know nothing or virtually nothing about such a topic.
Rather than speaking of gaps in our scientific knowledge, it is more truthful to say that our knowledge of nature is fragmentary, and that we have acquired only a few pieces in the vast jigsaw puzzle of nature. In the great million-year project of unlocking the universe's secrets, we are fledglings and newbies.
Those who sell a story of scientific triumphalism often speak as if scientists are like college juniors or seniors with not terribly much left to master in the curriculum. But instead they (and the rest of us) are all like kids who have merely finished the first few weeks of kindergarten.
Imagine a little child who makes a trip to the seashore. After he observes a few seagulls and fills up a bucket with shells, pebbles, and starfish, he may congratulate himself on his splendid progress in understanding nature. But ahead of him lies the vast and mysterious ocean, the mysteries of which he has barely begun to unravel. That little child is like humanity, which has so far accumulated only a few scattered fragments of nature's deep and mysterious truths, too vast in number to be enumerated.
But it is easy to over-estimate how much we know, as the following little story illustrates.
On a distant planet there was a king who was curious about biology, and who wanted to know all about beings such as himself. So he told his chief scientist, “Find out all about the biology of creatures such as you and me.”
The chief scientist was a bright young person with lots of energy, so he trekked around the planet, for 10 years, making an exhaustive study of body shapes, skin color, hair color, and external differences in form. He then returned to the king, and triumphantly reported that he had found out almost everything there was to know about creatures such as himself and the king.
“No, you have barely skimmed the surface,” said the king. “For you forgot to investigate what is inside creatures such as you and me.”
So the chief scientist spent 20 years doing dissection of corpses, to learn about internal anatomy. He then announced triumphantly to the king that he had learned practically everything there was to know about creatures such as himself and the king.
“No, you have barely skimmed the surface,” said the king. “For you forgot to investigate what is inside creatures such as you and me, on a microscopic level.”
So the chief scientist spent 30 years doing microscopic studies. He then announced triumphantly to the king that he had learned practically everything there was to know about creatures such as himself and the king.
But then the king asked him to explain the origin of life, to explain the mystery of development, to explain the mystery of where and how body plans are stored, to explain the origin of astounding biological complexity, and to explain the mystery of consciousness. The chief scientist could not explain these things in a satisfactory way. It seemed that understanding life required some deeper level of understanding that the chief scientist would never be able to reach in his lifetime. It also seemed that there are many layers to the riddle of life, and that understanding the next layer is always twice as hard as understanding the previous layer. Sadly the king once again told the scientist: “You have barely skimmed the surface.”
Our scientists are often like this chief scientist, often tending to triumphantly declare their mastery of a topic when they have barely skimmed the surface of some subject with oceanic depths.