Life in the nano world Learning to coexist with the very, very small
Fresh bulletins regularly bring news of startling developments in this era’s most surprising and perhaps most poetic form of science, nanotechnology, the study of the unthinkably small.
Science has this habit of renewing our vision of existence. Under the pressure of expanding scholarship we find ourselves re-learning what we once thought we knew about the dimensions of existence. As it turns out, the galaxies reach much farther into the distance than anyone guessed a few years ago. Moreover, life of some kind has existed on Earth much longer than we imagined, about four billion years and counting. And in recent decades chemists and biologists have been slowly altering our sense of the most commonplace objects, the cells and molecules that fill our lives.
An invisible revolution has been under way. Great historic events are enacted in spaces smaller in diameter than the lead in a pencil. The news comes down to three facts: The universe has grown much larger, the past proves to be much longer and the biggest engineering project ever built or imagined by humanity, the Internet, depends on an endless collection of switches, each of them much smaller that we can visualize.
We are looking at the smallest objects in the world with new eyes and a refreshed imagination. The baroque microscopic palace that we call the cell has been placed under observation as never before, revealing countless mysteries. George M. Whitesides, an eminent chemist at Harvard, summarizes the paradox of cells in a few words: They are the smallest living things, they are the stuff from which organisms are built and, while “they are as simple as anything in biology, they are as complicated as anything we know.”
New forms of Lilliputian existence reveal themselves to scientists through instruments designed by genius-level engineers. On atomic-force microscopes, biolo- gists climb down, metaphorically, into secret worlds, like the pioneer spelunkers who invaded the depths beneath Lascaux in France 70 years ago and came up with pictures of Palaeolithic paintings 17,000 years old, messages from pre-history the world has talked about ever since.
The unexplored empire of nanotechnology teems with beautiful and uncommon images, billions of them, as if following John Keats’s belief that “poetry should surpass by a fine excess.” The new science of extreme miniaturization deals with everything from the creatures living their entire lives on our eyelashes to viruses trying to break into our bodies.
A nanometre, a billionth of a metre, is hard to envision, and it doesn’t much help when we learn that, since a human hair is about 100,000 nanometres in width, we can think of a nanometre as a hundred-thousandth of a hair. Even so, the nanometre and its linguistic cousins have invaded the language, occasionally finding a place in the hyperbole of politics. A
New Republic writer described a simpleminded U.S. governor as a man with an attention span measured in nanoseconds. Futurists have suggested the possibility of creating swarms of nanobots that will fly through the air, eating pollutants. They have mentioned medical nanobots of the future, equipped to cruise our blood streams, attacking pathogens.
Whitesides acknowledges that since atoms and molecules make up all of physical reality, everything we can touch, taste, see and feel, “It’s a little unnerving that we have never actually seen one.” To coax us a few nanometres closer to understanding this subject, Whitesides and a talented photographer, Felice C. Frankel, have created No Small Matter: Science on the Nanoscale (Harvard University Press), a book that’s elegant in appearance, elegant in its images of the nanoworld and elegant in prose.
One of those wonderful writers that science produces every now and then, Whitesides has written 60 short, deft essays on nanoscale subjects; he writes with a warming eagerness, clearly anxious to have us share his own excitement. Frankel has either developed her own photographic equivalents of his essays or found images from elsewhere to do the job.
Typically, they show us what nanotechnology reveals about Venus’s Flower Basket, a famous deep-sea sponge in the form of a cage.
A nanometre, a billionth of a metre, is hard to envision
Its intricacy grows steadily more surprising as scientists uncover its anatomy. Under the unassisted human eye it’s already interesting. Consider it under high-power magnification and it becomes infinitely more impressive. It routinely traps two small shrimp, one male and one female, which spend their lives inside its cage, as guests and prisoners. The shrimp breed and their offspring go off to find their own Venus Flower Basket. The cage protects the shrimp; the sponge and the shrimp help to feed one another. “Each element of the cage is composed of smaller elements, and at each scale of size there are astonishing and unexpected details of design, construction and interweaving of elements.”
The sponge builds itself, to demanding standards of construction, with silicic acid from seawater that it converts into silica. An article in Science in 2005 described the process
There are practical applications for these discoveries
under the heading “Structural Hierarchy from the Nanoscale to the Macroscale.”
“This design,” Whiteside tells us, “is as elegant, as anything engineers can conceive, and its fabrication — particularly since the sponge has nothing even faintly resembling a brain, and no raw materials to work with other than seawater — is beyond the best that engineers can do.” Non-scientists will be forgiven if they respond as an editor of The New Yorker once did when an apparently miraculous form of printing was explained to him. “There is no way this could happen,” he said.
There are, as usual, practical applications for many of these discoveries, beyond the Internet and related products. A PBS reporter last month described nanotechnology as a key to America’s economic future. He said, “Maintaining America’s position in the world’s economic networks, it turns out, depends more and more on smaller and smaller.”
I’m as enthusiastic about economic progress as anyone, but I prefer at the moment to think about Horton the Elephant. In 1954 that prophetic genius, Theodor Seuss Geisel, a.k.a. Dr. Seuss, provided his young readers with an advance taste of the nanoworld in his classic fable, Horton Hears a Who! It’s about a civilization that exists on a speck of dust so small that it’s barely visible. It resembles nothing Horton has experienced, but when he sees proof of its existence he rejoices in its uniqueness and embraces it with joy.