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Perception of an object costs
Precise the Object’s loss –
Perception in itself a Gain.  .  .  .  .  . 
The Object Absolute is naught.

Emily Dickinson, poem 1071 (1866)

I apologize for the sporadic nature of my postings. My mind is constantly brimming with thoughts, but I am often distracted by events in the world, as all of us are, and I sometimes do not have the liberation of spirit needed to write down my thoughts.  Nevertheless .  .  . 

I recently met astronomer Pascal Oesch, an assistant professor at the University of Geneva. Professor Oesch and his colleagues share the distinction of having discovered the most distant known object, a small galaxy called GNz-11. That galaxy is so far away that its light had to travel for 13 billion years to get from there to here.  I asked Professor Oesch if this faint blob on his computer screen feels like part of nature, part of the same world of Keats and Goethe and Emerson, where “vines that round the thatch-eves run; to bend with apples the moss’d cottage-trees”?  Oesch answered that he looks at such distant smudges every day. Sure, they’re part of the universe, he said. But consider the abstraction (thought I). A few exhausted photons of light from GNz-11 dropped on a photoelectric detector aboard a satellite orbiting the earth, produced a tiny electrical current that was translated into 0s and 1s, which were beamed to earth in a radio wave. That information was then processed in data centers in New Mexico and Maryland and eventually landed on Professor Oesch’s computer screen in Geneva.

Is GNz-11 real? What about the subatomic particles that materialize and vanish in nanoseconds within the seven thousand ton detector at the CERN atom smasher? Are they real? And what is “reality” anyway?

Here’s my tentative definition of reality: That which exists independently of our human perceptions. Of course, right off the bat, this definition is hypothetical, because everything we know and experience of the world necessarily comes through our senses and our brains. We cannot escape our brains when we perceive the world. So, it is somewhat a leap of faith to believe that there’s something out there when we’re not looking.

Some philosophers, notably the Irish thinker George Berkeley (1685-1753), have argued that there’s nothing out there beyond the human mind. It’s all in our heads. When we run our hands along the rough bark of a tree and feel it, perhaps the tree is not really there, says Berkeley. “Tree” is just a name we give to an apparition that strikes our senses in a certain way. When we smell the spicy aroma of blue cheese, perhaps the cheese exists only in our minds, he says. And it’s very hard to prove Berkeley wrong. External reality could be an elaborate illusion.

However, I would argue that Berkeley is almost certainly wrong. And it is the triumph of science that makes him almost certainly wrong. Throughout the centuries, and especially in the last few, science has been impressively successful by first assuming that there exists an objective reality independently of our perceptions, and then making accurate predictions about what will happen when we drop a rock or strike a match in a gas called oxygen or attack the pneumonia bacterium with the fungus called penicillin. It would take an avalanche of lucky coincidences for all those successful predictions to be mere juxtapositions of scenes in the imagination.

Just as importantly, if the external world were all a mental fantasy, then scientists would rarely be surprised by the world. But we scientists are constantly surprised. In 1880, when American physicist Albert Michelson attempted to measure the motion of the Earth through the ether – an invisible and gossamer substance assumed to fill all of space and to be responsible for transmitting light in the same way that air transmits sound – he got null results. That is, he could not determine any motion of the Earth through the ether, even as our planet orbited the Sun. It was as if the ether did not exist. But surely light, like sound, could not travel through a vacuum. There had to be some material medium transmitting the waves of light. Michelson was so convinced of the necessity of the ether that he thought he must have made a mistake. He repeated his experiment over and over. Finally, in 1905, Einstein proclaimed that the ether didn’t exist. And in 1907 Michelson received the Nobel for his failure to find it.

Even granted that an external reality exists, outside of our minds, there is the question: Can we know that reality? I think not. In his book Physics and Philosophy: The Revolution in Modern Science, the great quantum physicist Werner Heisenberg wrote that “What we observe is not nature itself but nature exposed to our method of questioning.”

All we know of nature is what our measuring instruments tell us. For example, if we connect a voltmeter to a morass of wires, resistors, and batteries, the needle points to a particular number, telling us the voltage between two points of that electrical circuit. And that number is all we know. We can hypothesize about what the electrons might be doing as they flow through the wires, or whether “electrons” actually exist, but all we know is where the needle points.

I would argue that the ultimate aim of science is to predict where that needle will point. One can view all of our theories in science, replete with their equations and diagrams and assumptions, as simply tools for predicting where the needle will point. Questions about the “true nature” or underlying “reality” of the electrons and wires lie in the domain of philosophy, not science.

To be sure, we have built some pretty fancy instruments, which have gone far beyond our meager sense perceptions and enormously extended what we know of the physical world. We have created devices that can detect X-rays and radio waves, invisible to the human eye. We have built piezoelectric nanofiber acoustic devices that can hear an ant’s footsteps across a quiet room. Still, we know only where the needle points.

So, there’s a hierarchy of levels of experience. First is “reality,” which we can never know (but can philosophize about). Then there is the superhuman perception of the world as revealed by the instruments we build and measurements we make with those instruments. At the bottom of the hierarchy, but most immediate and vital to us feeling creatures, is our human perception. That human perception is a world of its own. As Milton wrote in Paradise Lost, “The mind is its own place, and in itself can make a Heaven of Hell, a Hell of Heaven.”

I’d like to dwell a bit longer at the bottom of the pyramid, our human perceptions. Our perceptions of the world – what we take in with our own eyes, ears, nose, hands, and brain – from a scientific view are notoriously unreliable. In courtrooms, witnesses who saw exactly the same event sometimes give markedly different accounts of that event. Onions smell delightful to some people and sickening to others. A sixty degree day feels cool in August and balmy in December.

And then there is memory, which forms a large part of our self identity. Neurobiologists tell us that memory isn’t the replay of a video camera, but instead a pastiche of neuronal fragments gathered from here and there, wandering smells, oddly cut visual scraps, translucent experiences laid on top of one another. Moments, scenes, moments that never occurred in the external world materialize in our minds. Others that may have been captured by cameras dissolve in a sea of ambiguity. It’s all in the electrical currents and flow of particular molecules. Neurobiologists tell us that connections between the billions of neurons in a human brain change over time. If so, the universe shifts and shifts and shifts in our minds.

Marcel Proust, the artist of memory, described the situation in his novel Swann’s Way:

I put down the cup and examine my own mind. It alone can discover the truth. But how? What an abyss of uncertainty, whenever the mind feels overtaken by itself; when it, the seeker, is at the same time the dark region through which it must go seeking and where all its equipment will avail it nothing. Seek? More than that: create. It is face to face with something which does not yet exist, which it alone can make actual, which it alone can bring into the light of day.

And I begin again to ask myself what it could have been, this unremembered state which brought with it no logical proof, but the indisputable evidence, of its felicity, its reality, and in whose presence other states of consciousness melted and vanished . . . .

How will I end this brief essay on reality and perception? Elsewhere, I have calculated that the fraction of all matter in the universe in living form is one billionth of one billionth, likened to one grain of sand on the Gobi desert. Each of us is an exceedingly rare arrangement of atoms and molecules that can feel, sense, think. We living beings are the only mechanism by which the universe can observe itself. Whatever unknowable thing is reality, and despite the limitations of our sensory perceptions and the Proustian unreliability of memory, we sentient beings are here, now, to gaze upon and record this dazzling spectacle of a cosmos we find ourselves in.

Notes

“vines that round the thatch-eves run . . . ” from “To Autumn” (1819) by John Keats

“What we observe is not nature itself .  .  .  ” Physics and Philosophy: The Revolution in Modern Science (1958) by Werner Heisenberg  (New York: Harper Perennial, 2007) p. 32

“The mind is its own place .  .  .   Paradise Lost (1667) by John Milton, Book I, lines 254-255

“I put down the cup and examine my own mind .  .  .  ” In Search of Lost Time, Vol. 1 Swann’s Way, (1912) by Marcel Proust, trans. C.K. Scott Moncrieff and Terence Kilmartin (New York: Modern Library, 1992), pg 61.