HarperCollins

Cracking open my iPhone 6 Plus—Apple’s version of the big-screen “phablet”—reveals not just a marvel of globally sourced miniaturization but also a high-tech road map that touches just about everywhere.

Along with the processor and graphics chipset and the rechargeable battery (the most massive internal part), there is a long list of individually sourced components: two cameras, a video recorder, a digital compass, a satellite-navigation system, a barometer, a fingerprint scanner, a high-resolution color display, an LED flashlight, touch sensors, a stereo system, a motion sensor/game controller, encryption circuits, an array of radio transmitters that connect via WiFi, Bluetooth and near-field communication bands, and, last and also least, the guts of a cellular telephone.

At least two dozen primary suppliers on three continents and two islands (Japan and Taiwan) provide these parts.

The transportation complexity is magnified further because many components do not move in a simple path from supplier to final assembly. Some go on a hopscotching world tour from one country to the next and back again as one piece is joined to another to create an assembly, which is then moved elsewhere in the world for another part to be inserted or attached.

The phone’s innards are put together much as a cook assembles ingredients for a dish that becomes, in turn, a component of another chef’s course, which is then incorporated by someone else into a larger meal. Ingredients move back and forth from high-tech equivalents of refrigerator, cutting board, stove, and plate.

The fingerprint sensor embedded in the iPhone’s home button—Apple’s Touch ID system, which allows a fingerprint scan to replace a typed password—is a good example of this sort of Top Chef supply itinerary.

The home button journey begins in Hunan province, China, at a company called Lens Technology, Ltd., in the city of Changsha, where superhard transparent artificial sapphire crystal is fashioned into the button cover. This is the part of the button an iPhone user physically touches, made of the same synthetic sapphire used in high-end watches, avionics displays, and missile systems because of its near–diamond-like hardness, durability, and scratch resistance.

The sapphire cover is then bonded to a metal trim ring brought 550 miles from the LY Technology factory in Jiangsu province, and then shipped 1,000 miles to the Dutch-owned NXP Semiconductors assembly and testing plant in Kaohsiung, Taiwan. There the sapphire-metal ring combo is married to a driver chip imported from a Shanghai factory (another 600 miles) and a Touch ID sensor chip from an NXP silicon wafer fabrication plant in Europe, which tacks 5,000 more miles onto the itinerary.

Next, a button switch imported from a Panasonic subsidiary is brought in 1,500 miles from Japan, along with the springlike plastic component called a “stiffener” from a Shanghai factory (another 600-plus miles) owned by the American company Molex. These pieces are combined at another Taiwanese manufacturer, Mektec, which adds in its own part, called the flex circuit.

Mektec then ships this assembly 1,500 miles back to Japan, where a plant run by technology giant Sharp laser-welds all the pieces into a sealed and functional Touch ID module. The completed assembly ships about 1,300 miles to the Foxconn plant in Zhengzhou, China, a virtual high-tech city of 128,439 factory workers where the iPhone’s final assembly takes place (and where allegations about bad working conditions—some accurate, others fabricated—sparked a media sensation in 2012).

This is the partial origin story of a collection of parts commonly known as the phone’s home button, with about 12,000 miles required to get it to the place where the iPhone is assembled.

The finished iPhones are shipped to customers and retail locations in the US and around the world to stores, cell phone service providers, and other outlets using virtually every transportation method known to man. Most of the US-bound phones move by air freight through Hong Kong and Alaska, where UPS and Federal Express have major hubs. (The curvature of the earth makes Alaska a direct and ideal transshipment and fueling stop for air cargo moving from Asia to the US.)

This is the partial origin story of a collection of parts commonly known as the phone’s home button, with about 12,000 miles required to get it to the place where the iPhone is assembled. All that is for one button, perhaps the least sexy part of a smartphone. And this triptych is just a partial accounting, because it does not include the movement of raw materials for individual components, nor their packaging, nor the movement of energy, water, and workers at the various factories, all of which could easily double or triple the mileage on that little button below the phone’s touch screen.

Similarly epic journeys are attached to other parts of the iPhone: a barometric sensor and accelerometer from Germany; the Corning “Gorilla Glass” from Kentucky; the five different power amplifiers from California, Massachusetts, Colorado, North Carolina, and Pennsylvania manufacturers; the motion processors from Silicon Valley; the near field communication controller chip from the Netherlands; and many other components from Japan, Taiwan, Korea, and China. The production of the Apple-branded A8 processor semiconductor chip is split between the world’s largest contract chip fabricator, TSMC in Taiwan, and Samsung’s immense new chip plant in Austin, Texas—a $9 billion investment by the South Korean technology company to make computer chips in the US. Samsung is offshoring to America.

Those parts, along with the Touch ID components, combine for that 160,000-mile commute embedded in the iPhone—two-thirds of the distance to the moon. And even that is still only part of the story. The movement of these components does not include the mining, processing, and shipping of the rare earth elements that are so vital to so much of our twenty-first-century technology, or the movement of the vast quantities of energy and water needed to obtain them.

In the end, the iPhone has a transportation footprint at least as great as a 240,000-mile trip to the moon, and most or all of the way back.

These materials, most with unpronounceable names that sound like minor Greek gods, are difficult to mine and pricey to extract from raw ore. Once refined, they can be worth many times their weight in gold. In recent years, China has dominated this rare earth market that the US once led, though suppliers in California and Australia have been reclaiming market share of late. These “rare” materials—which are actually quite plentiful in the earth’s crust, but rarely in sufficient concentrations to make mining practical—have almost magical magnetic, phosphorescent, and catalytic properties even in minute quantities.

They are essential ingredients in everything from giant wind turbines and electric cars, to miniature electric motors, semiconductors, and rechargeable batteries of all stripes: phone-size, Tesla-size, and utility-scale–size. The iPhone contains a chorus of eight rare earth elements: neodymium, praseodymium, dysprosium, terbium, gadolinium, europium, lanthanum, and yttrium. These are not household names, but they are everywhere in the modern household, unseen yet invaluable. These elements can be found in a smartphone’s color screen, various parts of the phone circuitry, the speakers, and the mechanism that causes a phone to vibrate when it receives a message or call.

Then there are the better-known precious metals inside each iPhone—a couple bucks’ worth of gold, silver, platinum, and copper—and the anodized aluminum enclosures. Together, the mining, refining, and transport of these materials—and all the chemical agents and systems needed to produce them—could easily double that 160,000-mile footprint on the iPhone (and any other high-tech product), as the precious metals, aluminum, and rare earths must be shipped from the sources to refineries and processors and then to the individual component makers around the world.

In the end, the iPhone has a transportation footprint at least as great as a 240,000-mile trip to the moon, and most or all of the way back. The wonder of this is compounded by the fact that this transportation intensity is a strategy to increase efficiency and lower cost.

From Door to Door: The Magnificent, Maddening, Mysterious World of Transportation by Edward Humes. Copyright © 2016 by Edward Humes. Reprinted courtesy of Harper, an imprint of HarperCollins Publishers.