The Human Age (22 page)

Read The Human Age Online

Authors: Diane Ackerman

Tags: #Science, #General

AN (UN)NATURAL
FUTURE OF THE SENSES

W
hat about us? Are
we
natural anymore? How can we be, when we’ve morphed into superheroes? Our ancestors adapted to nature according to the limits of their senses. But over the eons, by extending our senses through clever inventions—language, writing, books, tools, telescopes, telephones, eyeglasses, cars, planes, rocket ships—we’ve changed how we engage the world and also how we think of ourselves. We just assume now that human beings can move across the skies at 500 mph. Or spot a hawk across a valley. Or do colossal calculations at speed. Or watch events unfolding halfway around the world. Or safely repair someone’s heart. Or wage war. Our attitude about our own nature, what sort of creatures we are, now includes the novelties we’ve pinned to our senses.

All these add-ons are a perfectly ordinary part of daily life. The use of tools and technology has become an innate part of our being, as we extend ourselves deeper and deeper into our environment. In the past decades a fundamental change has evolved in the idea of the universe we inhabit, and also what a human being is and may
become. We don’t worry if we can’t see a splinter in a child’s finger. We automatically don glasses and become an animal with keener eyesight. That may save the child from infection, but it also revises what a human being is. How will that continue changing in our lifetime?

Already, we’re masters of the invisible. Just as we accept that the universe is mainly invisible dark matter and dark energy, we accept the reality of protozoans and viruses even though we can’t see them without a microscope, or perhaps as stationary oddities in the pages of a textbook—which few people are tempted to do. We believe in television and radio waves, gnomelike quarks, GPS, microwaves, the World Wide Web, gosling photons, a mantilla of nerve endings in the brain, the voiceless hissing of background fizz from the Big Bang, planets orbiting many stars in the night sky—some hospitable to life. Then there’s all the panting eyes, throbbing jellies, iridescent bladders, and glowing mouths haunting the remote sunless abysses of the deep sea.

Our mental cosmos teems with a thicker texture of invisibles than ever before. Living with invisible forces used to mean spirits, ghosts, gods, angels, and ancestors. Our view of nature now supplies different familiar ghosts, including all the wispy tangles, tinctures, and driblets of a working body being revealed to us as never before through technology and nanotechnology. We take for granted the vast invisible worlds surrounding and inside of us. It’s a sort of high-tech shamanism (the belief that spirits inhabit all things, living or nonliving). Some entities may hide in the holly bush at the front door; others float light-years away.

We can forge so many invisibles in our mind’s eye because enough of our kind have witnessed them firsthand, through microscopes, telescopes, or computers, and smeared that knowledge far and wide. As a result, the air gyrates with invisibles I can hear but not see, and yet take for granted like distant relatives whose photos I’ve framed.

In autumn, a season of night fiddlers, I know summer is fraying away because the air brims with their eerie music, although I
don’t see the hidden musicians—katydids and crickets playing their marimbas, as they lift their wings high and rub a sharp edge of one wing over a ridge of pegs on the other. It’s not easy to spot cellophane-winged aerobats among late summer’s wild chicory, Queen Anne’s lace, and clover-scented milkweed—kingdom of the giant, much showier monarch butterfly.

Nonetheless, I can picture them all combing strands of song from their wings, picture them in microscopic hair-perfect detail. Katydids are rasping a tattletale:
Katy did! Katy did! Katy did!!
Cicadas, buckling and unbuckling their stomach muscles, are yielding the sound of someone sharpening scissors. Fall field crickets, the thermometer hounds, are adding high-pitched tinkling chirps to the jazz. Carolina crickets are furnishing a buzzing trill. Grasshoppers sound like they’re shuffling decks of cards. Snowy tree crickets are lending an evenly spaced chirping melody to the ensemble. It’s the ultimate jug band, using body parts as instruments.

I don’t see any of their courtship, since they’re small and hidden in the darkness. But I’ve learned enough from scientist-seers and their technology to trust that the males do all the serenading, horny for females, each of whom waits in the dark loins of the night, listening with ears in rather odd places—on the abdomen or the knees. She homes in on a winged dude, lured by his siren song. Then the happy male croons a different courtship tune. But they haven’t much time for dalliance before the first heart-stopping frost. According to folklore’s timetable—and I still believe in folklore—frost creeps in ninety days past the katydids’ first song. In my insect-loud yard, I heard the first katydid call about a week early this year, round about the middle of July, and sure enough frost fell in mid-October.

Alongside this buzzing-chirping-tinkling-fiddling in the night, and choreographed to it, there’s the raw sexcapade drama. And, although I don’t ogle thousands of bugs
in flagrante
all over the woods, and tens of thousands, maybe millions, yodeling their lust downtown, up in the forest leaf-parlors, and along sinewy country roads, I was a college student once; I get it.

All of this happens unseen, which is a haunting thought, but even without laying our eyes on the crickets, grasshoppers, cicadas, and katydids, we hear them shrilling in this season and trust that they’re the tiny living gargoyles scientists claim. We believe the katydids exist in their scratchy little corner of the invisible—an act of faith that suits us just fine. Most don’t wish to search in the dark buzz of night for the multieyed and antenna-ed.

Anyway, these days, we know we can verify the existence of creatures we can’t see easily enough in books, films, or bug Facetime on the Internet. The ancients believed the gods were angry when storms crackled and boomed. We check the Weather Channel’s radarscope.

Our ancient understanding of nature (faith, lore, hearsay, story) has a new level, one changing almost every day, proxy
sine nomina
from technology-equipped scientists and other researchers, the designated witnesses who behold, listen, and chronicle as the likes of insect love parties on. We agree en masse to believe these professionally designated seers.

Or we become citizen-seers ourselves. A smartphone will do. Walking on a trail in New Forest, in southern England, I stopped in a sunlit clearing when I heard the distinctive rasp of Buddhist monks creating a sand mandala by rubbing brass scrapers down ribbed brass funnels to release single brightly colored grains. A quick spin around: trees, pastures, a perching woodland warbler falling into flight, shadows dancing along the trail. No monks. I smiled at the sleight of ear. Weeks before, at Keystone College in Pennsylvania, I had watched, enchanted, as Tibetan monks sand-dribbled a mandala, producing what sounded like the trills and quiverings of invisible cicadas.

Pulling my iPhone out of my pocket, I opened the Cicada Hunt app, a brainchild of entomologists at the University of Southampton. Over a thousand people sent in reports this past summer. On the iPhone, a green card appeared with a white cicada icon sitting on black velvet at its center. When I held it up and tapped the cicada icon, a white outer ring fanned open around it and the cicada glowed
orange. For eighteen seconds, the app tested the soundscape for the exact frequency of rare New Forest cicadas. No luck. Only a scant few New Forest cicadas have been detected by the thousands of citizen scientists in England since 2000, but that’s enough to offer proof of their whereabouts and need for protection. Though I knew it was a long shot, I found the app doesn’t register the calls of my homely New York variety of cicada.

The Buddhist mandala-makers may live in a cosmos dancing with colorful deities, just as they always have. But now they and the Dalai Lama (a science aficionado) are also aware, from mindful moment to moment, of an invisible dimension that includes neurons, quarks, Higgs bosons, MRIs, condensation nuclei, white dwarfs, DNA, and a googolplex of others.

Elsewhere on Earth, over 5.2 million Internet-connected computers, citizen scientists are helping SETI (Search for Extraterrestrial Intelligence) monitor radio telescope data through the SETI@home project, hoping to catch a message from alien life forms in some distant star system. SETI’s senior astronomer, Seth Shostak, believes that the first calling card from aliens may well be detected on home computers, not by official scientists at radio telescopes arrayed in India, Australia, Puerto Rico, or Chile.

More than ever, our technology allows us to peer into worlds far beyond our outmoded senses, into a realm where cells loom large as lakes, pores are chasms, the body is just another kind of ecosystem, and the idea of cartography no longer applies only to landforms. We’ve mapped galaxies and genomes. We keep projecting ourselves into landscapes we’re not equipped to cross in the flesh. Computers have shed light on biological processes invisible to humankind until very recently. In 1990, I wrote about our sensory grasp of the world in
A Natural History of the Senses
. Only twenty years later, the basic experience is the same, but its scope has been vastly amplified. For example, our proprioception, the sense of where we are in space, now spins far beyond the physical body. We can spy on ourselves in sly, public, or cloak-and-dagger ways, from lavish perspectives, inside
and out. By satellite, a drone’s eye, via Skype, on security cameras, through electron microscopes. Some of us are even relaxed about, or excited by, the promise of connecting our brains to the world outside of the body. In such sweeping sensory adventures, our cameo of who and what we are shifts, and also how we may decide to know ourselves in the future.

What we see and think when we look at the night sky has also changed. Two decades ago, the only planets were here in our own solar system. Now we know that the cosmos is littered with them. We know now that the Milky Way, the backbone of night, is twice as large, even heavier, and spinning faster than we previously thought. Also that it has four arms, not two. Our telescopes listen with cupped ears for whispers from the beginning of time, when the whole universe was no larger than a grapefruit, a small solid object, before the light of stars and the destiny of planets. How could something that small give birth to more space than the mind’s eye can fathom?

Although the brain’s star chamber is sealed and invisible in its cave of bone, we’re craning our high-tech senses (MRI, fMRI, PET scan, etc.) to peer in as never before at networks lit like night views of Earth from space. Thanks to digital displays, scalpel-less dissecting of live patients is commonplace, as is cut-free slicing of gray matter into wafer-thin sheets that can be viewed three-dimensionally and rotated as if the conscious, alert, and no doubt mind-wandering occupant had set his actual brain on an anatomy bench for anyone to probe. All sorts of abnormalities and diseases, such as schizophrenia and autism, have bared some of their bones, and we’ve begun exploring the mental haunts of such notorious intangibles as religion, addiction, and compassion. By studying busy neural work sites, increased traffic flow, and where thought-crews guzzle oxygen as they toil, we’re forming insights about everything from lying to love. For the first time, we’re able to see some of the ties that bind us. The verb we use, “scan,” which used to mean a brief skim with the eyes, has evolved into its opposite: a machine’s searching stare. People gamely volunteer to have their heads examined
so that researchers can witness emotional regattas in full sail (or, sometimes, on the rocks).

Nightly news often reports the latest nugget about concussion, depression, rejection, multitasking, empathy, risk-taking, fear, and other states of mind—explained in terms of the neural architecture and wiring of the brain. In 2012, when President Obama proposed a federally funded $100 million brain-mapping project, stressing that “as humans we can identify galaxies light-years away, study particles smaller than an atom, but we still haven’t unlocked the mystery of the three pounds of matter that sits between our ears,” some people balked at the expense, but few believed it wasn’t possible and a worthy goal.

A new field, called interpersonal neurobiology, draws its vigor from one of the great discoveries of our age: the brain is rewiring itself daily, and all relationships change the brain—but especially our most intimate bonds, which foster or fail us, altering the delicate circuits that shape memories, emotions, and that ultimate souvenir, the self. Love is the best school, but the tuition is high, and the homework can be physically painful. As imaging studies by the UCLA neuroscientist Naomi Eisenberger show, the same areas of the brain that register physical pain are active when someone feels brutalized by love. That’s why rejection hurts all over the body, but in no place you can point to. Or rather, you’d need to point to the dorsal anterior cingulate in the brain, the front of a collar wrapped around the corpus callosum, the bundle of nerve fibers zinging messages between the hemispheres, that registers both rejection and physical assault. Whether they speak Armenian or Mandarin, people around the world use the same images of physical pain to describe a broken heart, which they perceive as
crushing
,
crippling
,
a real blow
that
hurts so bad
they
go all to pieces
. It’s not just a metaphor for an emotional punch that’s too shadowy to name. As our technology is beginning to reveal, social pain—rejection, the end of an affair, bereavement—can trigger the same sort of sensations as a stomachache or a broken bone.

But a loving touch is enough to change everything. The neuroscientist James Coan, of the University of Virginia in Charlottesville, conducted experiments in which he gave an electric shock to one ankle of women in happy committed relationships. Tests registered their anxiety before and pain level during the shocks. Then they were shocked again, this time holding their loving partner’s hand. The same level of electricity produced significantly lower pain and even less neural response in the cingulate. In troubled relationships, this protective effect did not occur. If you’re in a healthy relationship, holding your partner’s hand is enough to subdue your blood pressure, ease your response to stress, improve your health, and even soften physical pain. We’re able to dramatically alter one another’s physiology and neural functions—and watch.

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