Free A Deadly Wandering: A Tale of Tragedy and Redemption in the Age of Attention by Matt Richtel Page B

human’s reaction time was immeasurably fast—infinite, as some scientists put it. A person felt a prick and instantly recoiled, or saw a snake and leapt, or heard the sound of thundering hooves and stepped back off the street.
    What could prove otherwise? Try a “galvanometer.” It was an early device used to detect and measure the magnitude of an electric current. Such gadgets were also employed to measure speed; how fast was a current traveling? The devices took various forms, but basically they used twisted metal coils to detect an electrical signal. When a galvanometer detected a signal, it created a magnetic field. The magnetic force, in turn, would cause a little pointer to move, allowing a researcher to measure when a current first appeared, and when it dissipated. Early researchers used them in the field of ballistics to, say, measure the pace and trajectory of a bullet.
    Hermann von Helmholtz used one to measure the reaction time of a frog.
    Helmholtz was an associate professor at the Prussian University of Königsberg and one of the leading scientists of his day. He used an electric current to stimulate an amphibian’s calf, then employed the galvanometer to measure how long it took the electrical current to run along the sciatic nerve. What he found changed the way scientists viewed the human brain. He discovered that what had looked instantaneous from the outside, was, in fact, anything but, and not even close to light speed. It took time for the current to travel to the brain.
    He tried it on a human being and discovered the same thing. Roughly, he estimated that “neural conduction time” was around one hundred meters per second. It took twenty milliseconds for information to get from brain to calf. (By comparison, light travels at about 300,000 kilometers per second.)
    Helmholtz’s use of the galvanometer symbolized not just how scientists were measuring human capacity, but why. The researchers realized that the machines people were building—those mechanized tools of productivity, war, and science—were so powerful that they were moving faster than people could keep up. This was a defining moment. Scientists were putting new technology to work to understand the capacities and limits of the human brain at the very moment that technology was putting those limits into sharp relief.
    “It was not obvious that people were slow to respond until the 1850s. The increasing use of machines began to make this obvious,” says Michael I. Posner, a professor emeritus of neuroscience at the University of Oregon, who is one of the modern pioneers of attention science and a student of its history. The relatively slow reaction time of humans “wasn’t clear until the pressure on people started to rise.”
    Through the nineteenth century, technology quickly evolved. In 1837, across the ocean, Samuel Morse unveiled his first telegraph device, and five years later “Morse convinced Congress to provide $30,000 in support of his plan to ‘wire’ the United States,” according to a history compiled by the Massachusetts Institute of Technology. It notes that in May of 1844, Morse gave a public demonstration, sending a message from Washington to a train depot in Baltimore. The message read: What hath God wrought?
    There were twenty-three thousand miles of telegraph wire in operation by 1854, MIT reported (Western Union was founded in 1851). In 1866, a cable link connected the United States and Europe. Thanks to machines, data was moving much faster than humans could ever transport it.
    In Europe, another innovator, Charles Babbage, born the son of a banker in 1791, was developing an early calculating machine at the time that Morse was refining and evangelizing the telegraph. Babbage designed schematics for a programmable computer, something that could process mathematical equations in place of the human mind. He was celebrated at the time for these marvelous concepts—and then much later as one of the computer’s