The Natural Sciences

From Edward O. Wilson’s “Consilience: The Unity of Knowledge”, chapter 4, pp.45-48

“….Without the instruments and accumulated knowledge of the natural sciences – physics, chemistry and biology – humans are trapped in a cognitive prison. They are like intelligent fish born in a deep, shadowed pool. Wondering and restless, longing to reach out, they think about the world outside. They invent ingenious speculations and myths about the origin of the confining waters, of the sun and the sky and the stars above, and the meaning of their own existence. But they are wrong, always wrong, because the world is too remote from ordinary experience to be merely imagined……

With instrumental science humanity has escaped confinement and prodigiously extended its grasp of physical reality. Once we were nearly blind, now we can see – literally. Visible light, we have learned, is not the sole illuminating energy of the universe, as pre-scientific common sense decreed. It is instead an infinitesimal sliver of electromagnetic radiation, comprising wavelengths of 400 to 700 nanometers (billionths of a meter), within a spectrum that ranges from gamma waves trillions of times shorter to radio waves trillions of times longer. Radiation over this span, in wildly varying amounts, continually rain down on our bodies. But without instruments we were oblivious to its existence. Because the human retina is rigged to report only 400 to 700 nanometers, the unaided brain concludes that only visible light exists.

Many kinds of animals know better. They live in a different visual world, oblivious to part of the human visible spectrum, sensitive to some wavelengths outside it. Below 400 nanometers, butterflies find flowers and pinpoint pollen and nectar sources by the pattern of ultraviolet rays reflected off the petals. Where we see a plain yellow or white blossom, they see spots and concentric circles in light and dark. The patterns have evolved in plants to guide insect pollinators to the anthers and nectar pools.

With the aid of appropriate instruments we can now see the world with butterfly eyes.

Scientists have entered the visual world of animals and beyond because they understand the electromagnetic spectrum. They can translate any wavelength into visible light and audible sound and generate most of the spectrum from diverse energy sources. By manipulating selected segments of the electromagnetic spectrum they peer downward to the trajectories of sub-atomic particles and outward to star birth in distant galaxies whose incoming light dates back to near the beginning of the universe. They (more accurately we, since scientific knowledge is universally available) can visualize matter across thirty seven orders of magnitude. The largest galactic cluster is larger than the smallest known particle by a factor of one with about thirty-seven zeroes following it.

I mean no disrespect when I say that pre-scientific people, regardless of their innate genius, could never guess the physical reality beyond the tiny sphere attainable by unaided common sense……and notwithstanding the emotional satisfaction it gives, mysticism, the strongest pre-scientific probe into the unknown, has yielded zero. No shaman’s spell or fast upon a sacred mountain can summon the electromagnetic spectrum. Prophets of the great religions were kept unaware of its existence, not because of a secretive god but because they lacked the hard-won knowledge of physics………

All our other senses have been expanded by science. Once we were deaf; now we can hear everything. The human auditory range is 20 to 20,000 Hz, or cycles of air compression per second. Above that range, flying bats broadcast ultrasonic pulses into the night air and listen to echoes to locate moths and other insects on the wing. Many of their potential prey listen with ears tuned to the same frequencies as the bats……..

We have even uncovered basic senses entirely outside the human repertory. Where humans detect electricity only indirectly by a tingling of skin or flash of light, the electric fishes of Africa or South America, a medley of freshwater eels, catfish, and elephant-nosed fishes, live in a galvanic world. They generate charged fields around their bodies with trunk muscle tissue that has been modified by evolution into organic batteries……They also communicate with one another by means of coded electrical bursts. Zoologists, using generators and detectors, can join the conversation. They are able to talk as through a fish’s skin.

From these and countless other examples can be drawn an informal rule of biological evolution important to the understanding of the human condition: if an organic sensor can be imagined that picks up any signal from the environment, there exists a species somewhere that possesses it. The bountiful powers of life expressed in such diversity raise a question about the incapacity of the unaided human senses. Why can’t our species, the supposed summum bonum of Creation, do as much as all the animals combined, and more? Why were we brought into the world physically handicapped?

Evolutionary biology offers a simple answer. Natural selection……prepares organisms only for necessities…..It follows that each species lives in its own sensory world.…….Natural selection, in short, does not anticipate future needs. But this principle, while explaining so much so well, presents a difficulty. If the principle is universally true, how did natural selection prepare the mind for civilization before civilization existed? That is the great mystery of human evolution: how to account for calculus and Mozart.