The weak nuclear force, despite its name, is ten billion billion billion times stronger than gravity, and the strong nuclear force is more powerful still-vastly so, in fact-but their influence extends to only the tiniest distances. The grip of the strong force reaches out only to about 1/100,000 of the diameter of an atom. That’s why the nuclei of atoms are so compacted and dense and why elements with big, crowded nuclei tend to be so unstable: the strong force just can’t hold on to all the protons.
The upshot of all this is that physics ended up with two bodies of laws-one for the world of the very small, one for the universe at large-leading quite separate lives. Einstein disliked that, too. He devoted the rest of his life to searching for a way to tie up these loose ends by finding a grand unified theory, and always failed. From time to time he thought he had it, but it always unraveled on him in the end. As time passed he became increasingly marginalized and even a little pitied. Almost without exception, wrote Snow, “his colleagues thought, and still think, that he wasted the second half of his life.”
Elsewhere, however, real progress was being made. By the mid-1940s scientists had reached a point where they understood the atom at an extremely profound level-as they all too effectively demonstrated in August 1945 by exploding a pair of atomic bombs over Japan.
By this point physicists could be excused for thinking that they had just about conquered the atom. In fact, everything in particle physics was about to get a whole lot more complicated. But before we take up that slightly exhausting story, we must bring another straw of our history up to date by considering an important and salutary tale of avarice, deceit, bad science, several needless deaths, and the final determination of the age of the Earth.
10 GETTING THE LEAD OUT
IN THE LATE 1940s, a graduate student at the University of Chicago named Clair Patterson (who was, first name notwithstanding, an Iowa farm boy by origin) was using a new method of lead isotope measurement to try to get a definitive age for the Earth at last. Unfortunately all his samples came up contaminated-usually wildly so. Most contained something like two hundred times the levels of lead that would normally be expected to occur. Many years would pass before Patterson realized that the reason for this lay with a regrettable Ohio inventor named Thomas Midgley, Jr.
Midgley was an engineer by training, and the world would no doubt have been a safer place if he had stayed so. Instead, he developed an interest in the industrial applications of chemistry. In 1921, while working for the General Motors Research Corporation in Dayton, Ohio, he investigated a compound called tetraethyl lead (also known, confusingly, as lead tetraethyl), and discovered that it significantly reduced the juddering condition known as engine knock.
Even though lead was widely known to be dangerous, by the early years of the twentieth century it could be found in all manner of consumer products. Food came in cans sealed with lead solder. Water was often stored in lead-lined tanks. It was sprayed onto fruit as a pesticide in the form of lead arsenate. It even came as part of the packaging of toothpaste tubes. Hardly a product existed that didn’t bring a little lead into consumers’ lives. However, nothing gave it a greater and more lasting intimacy than its addition to gasoline.
Lead is a neurotoxin. Get too much of it and you can irreparably damage the brain and central nervous system. Among the many symptoms associated with overexposure are blindness, insomnia, kidney failure, hearing loss, cancer, palsies, and convulsions. In its most acute form it produces abrupt and terrifying hallucinations, disturbing to victims and onlookers alike, which generally then give way to coma and death. You really don’t want to get too much lead into your system.
On the other hand, lead was easy to extract and work, and almost embarrassingly profitable to produce industrially-and tetraethyl lead did indubitably stop engines from knocking. So in 1923 three of America’s largest corporations, General Motors, Du Pont, and Standard Oil of New Jersey, formed a joint enterprise called the Ethyl Gasoline Corporation (later shortened to simply Ethyl Corporation) with a view to making as much tetraethyl lead as the world was willing to buy, and that proved to be a very great deal. They called their additive “ethyl” because it sounded friendlier and less toxic than “lead” and introduced it for public consumption (in more ways than most people realized) on February 1, 1923.
Almost at once production workers began to exhibit the staggered gait and confused faculties that mark the recently poisoned. Also almost at once, the Ethyl Corporation embarked on a policy of calm but unyielding denial that would serve it well for decades. As Sharon Bertsch McGrayne notes in her absorbing history of industrial chemistry, Prometheans in the Lab, when employees at one plant developed irreversible delusions, a spokesman blandly informed reporters: “These men probably went insane because they worked too hard.” Altogether at least fifteen workers died in the early days of production of leaded gasoline, and untold numbers of others became ill, often violently so; the exact numbers are unknown because the company nearly always managed to hush up news of embarrassing leakages, spills, and poisonings. At times, however, suppressing the news became impossible, most notably in 1924 when in a matter of days five production workers died and thirty-five more were turned into permanent staggering wrecks at a single ill-ventilated facility.
As rumors circulated about the dangers of the new product, ethyl’s ebullient inventor, Thomas Midgley, decided to hold a demonstration for reporters to allay their concerns. As he chatted away about the company’s commitment to safety, he poured tetraethyl lead over his hands, then held a beaker of it to his nose for sixty seconds, claiming all the while that he could repeat the procedure daily without harm. In fact, Midgley knew only too well the perils of lead poisoning: he had himself been made seriously ill from overexposure a few months earlier and now, except when reassuring journalists, never went near the stuff if he could help it.
Buoyed by the success of leaded gasoline, Midgley now turned to another technological problem of the age. Refrigerators in the 1920s were often appallingly risky because they used dangerous gases that sometimes leaked. One leak from a refrigerator at a hospital in Cleveland, Ohio, in 1929 killed more than a hundred people. Midgley set out to create a gas that was stable, nonflammable, noncorrosive, and safe to breathe. With an instinct for the regrettable that was almost uncanny, he invented chlorofluorocarbons, or CFCs.
Seldom has an industrial product been more swiftly or unfortunately embraced. CFCs went into production in the early 1930s and found a thousand applications in everything from car air conditioners to deodorant sprays before it was noticed, half a century later, that they were devouring the ozone in the stratosphere. As you will be aware, this was not a good thing.
Ozone is a form of oxygen in which each molecule bears three atoms of oxygen instead of two. It is a bit of a chemical oddity in that at ground level it is a pollutant, while way up in the stratosphere it is beneficial, since it soaks up dangerous ultraviolet radiation. Beneficial ozone is not terribly abundant, however. If it were distributed evenly throughout the stratosphere, it would form a layer just one eighth of an inch or so thick. That is why it is so easily disturbed, and why such disturbances don’t take long to become critical.
Chlorofluorocarbons are also not very abundant-they constitute only about one part per billion of the atmosphere as a whole-but they are extravagantly destructive. One pound of CFCs can capture and annihilate seventy thousand pounds of atmospheric ozone. CFCs also hang around for a long time-about a century on average-wreaking havoc all the while. They are also great heat sponges. A single CFC molecule is about ten thousand times more efficient at exacerbating greenhouse effects than a molecule of carbon dioxide-and carbon dioxide is of course no slouch itself as a greenhouse gas. In short, chlorofluorocarbons may ultimately prove to be just about the worst invention of the twentieth century.