How We Got to Now: Six Innovations That Made the Modern World

by Steven Johnson

original families that emigrated from Turkey.) It

Potassium oxide and manganese burn then use ashes to mix with glass to create clean glass Invented by Barovier

Most materials absorb the energy of light. On a subatomic level, electrons orbiting the atoms that made up the material effectively “swallow” the energy of the incoming photon of light, causing those electrons to gain energy. But electrons can gain or lose energy only in discrete steps, known as “quanta.” But the size of the steps varies from material to material. Silicon dioxide happens to have very large steps, which means that the energy from a single photon of light is not sufficient to bump up the electrons to the higher level of energy. Instead, the light passes through the material.

Most materials absorb the energy of light. On a subatomic level, electrons orbiting the atoms that made up the material effectively “swallow” the energy of the incoming photon of light, causing those electrons to gain energy. But electrons can gain or lose energy only in discrete steps, known as “quanta.” But the size of the steps varies from material to material. Silicon dioxide happens to have very large steps, which means that the energy from a single photon of light is not sufficient to bump up the electrons to the higher level of energy. Instead, the light passes through the material. (Most ultraviolet

Gutenberg’s invention of the printing press in the 1440s. You

another, less celebrated effect: it made a massive number of people aware for the first time that they were farsighted.

cheap and portable, which triggered a rise in literacy, which exposed a flaw in the visual acuity of a sizable part of the population, which then created a new market for the manufacture of spectacles.

Thanks to the printing press, the Continent was suddenly populated by people who were experts at manipulating light through slightly convex pieces of glass.

In 1590

experimented with lining up two lenses,

But his most influential discovery

these pores, or cells, were not very deep,

Hooke gave a name to one of life’s fundamental building blocks—the cell—leading the way to a revolution in science and medicine.

Before long the microscope would reveal the invisible colonies of bacteria and viruses that both sustain and threaten human life, which in turn...

The microscope took nearly three generations to produce

depended on the unique ability of glass to transmit and manipulate light.

Yet glass would turn out to have another bizarre physical property,

In 1887,

Boys wanted to create a very fine shard of glass to measure the effects of delicate physical forces on objects.

To create his thin string of glass, Boys built a special crossbow in his laboratory, and created lightweight arrows (or bolts) for it. To one bolt he attached the end of a glass rod with sealing wax. Then he heated glass until it

it would be just as transparent as looking through a normal windowpane.

the concentrated, orderly light of lasers, and the hyper-clear glass fibers—came to be known as fiber optics.

What we rarely do is recognize the way glass supports this entire network: we take pictures through glass lenses, store and manipulate them on circuit boards made of fiberglass, transmit them around the world via glass cables, and enjoy them on screens made of glass. It’s silicon dioxide all the way down the chain.

Back in Murano, the glassmakers had figured

glass mirrors were allowing us to see ourselves for the first time.

McFarlane has an artful way of describing this kind of causal relationship. The mirror doesn’t “force” the Renaissance to happen; it “allows” it to happen. The elaborate reproductive strategy of the pollinators

didn’t force the hummingbird to evolve its spectacular aerodynamics; it created the conditions that allowed the hummingbird to take advantage of flower’s free sugars by evolving such a distinctive trait.

The question is: Why did it take so long? Why were the extraordinary properties of this substance effectively ignored

technology: the furnace. One

reason that evolution didn’t find much use for silicon dioxide is that most of the really interesting things about the substance don’t appear until you get over 1,000 degrees Fahrenheit. Liquid

water and carbon do wonderfully inventive things at the earth’s atmospheric temperature, but it’s hard to see the promise of...

buffer of air that kept the summer heat away from the ice; his sawdust packaging on the ships ensured that there were countless pockets of air between the wood shavings to keep the ice insulated. Modern insulators such as Styrofoam

Humans had been experimenting with the technology of heat for at least a hundred thousand years,

But the opposite end of the thermal spectrum was much more challenging.

1659, the English scientist Robert Boyle had placed a bird in a jar and sucked out the air with a vacuum pump. The bird died, as Boyle suspected it might, but curiously enough, it also froze. If a vacuum was so different from normal air that it could extinguish life,

And it suggested that changing the volume or pressure of gases could change their temperature.

heat and energy are converted, inventing a whole science of thermodynamics.

Gorrie’s machine worked. No longer dependent on ice shipped from a thousand miles away, Gorrie reduced his

One of those simultaneous inventors was the French engineer Ferdinand Carré, who independently designed a refrigeration machine that followed the same basic principles as Gorrie’s.

These new devices used

ammonia as a refrigerant and could churn out four hundred pounds of ice per hour.

He formed a company called General Seafood using these new production techniques. Birdseye found that just about anything he froze with this method—fruit, meat, vegetables—would be remarkably fresh after thawing.

The first “apparatus for treating air” had been

Willis Carrier in 1902.

late 1940s, after almost fifty years of experimentation, that air-conditioning finally made its way to the home front, with the first in-window portable units appearing on the market.

By 1964, the historic flow of people from South to North that had characterized the post–Civil War era had been reversed. The Sun Belt expanded with new immigrants from colder states, who could put up with the tropical humidity or blazing desert climates thanks to domestic air-conditioning.

The migration to the Sun Belt changed the political map of America.

Once a Democratic stronghold, the South was besieged by a massive influx of retirees who were more conservative in their political outlook.

our ability to manipulate tiny molecules of air and moisture helped transform the geography of American politics. But the rise of the Sun Belt in the United

It’s no accident that the world’s largest cities—London, Paris, New York, Tokyo—were almost exclusively in temperate climates until the second half of the twentieth century.

phoneme uttered by a human voice. And humans would learn to “read” those squiggles the way they had learned to read the squiggles of shorthand. In a sense, Scott wasn’t trying to invent an audio-recording device at all. He was trying to invent the ultimate transcription service—only you had to learn a whole new language in order to read the transcript.