Cosmos: A Spacetime Odyssey, Episode 7, “The Clean Room”
There may be some fields of science that have absolutely no political implications, but they’re few and far between. Scientists stand on the front lines of humanity’s advancing knowledge, and as such, they’re often the first people to glimpse a looming danger, one that can only be avoided by making changes in society. And when that happens, they’re inevitably faced with a choice between disinterested investigation and political advocacy.
In principle, science is morally neutral. It increases our power to alter the world in accordance with our desires, whatever those desires are. But even though the scientific method, strictly speaking, doesn’t provide moral guidance, time and again we do see scientists choosing to step across that is-ought gap and speak out about what their work means for the rest of us, often at great professional risk.
In one of my Atlas Shrugged posts, I’ve written about the use of lead as an additive in gasoline and paint, and how it was eventually recognized to be toxic and phased out. But until now, I didn’t know the names of the human beings who took part in that drama.
This week’s hero was Clair Patterson, an unassuming geologist who was tasked with determining the age of the Earth by measuring the products of the uranium-lead decay chain in zircons and meteorite fragments. With the obsessive attention to detail that’s the mark of a great scientist, he built one of the world’s first ultra-clean rooms to eliminate every possible source of lead contamination from the environment. The effort paid off, allowing him to show that our world and its solar system are 4.55 billion years old.
But the question of where all that lead contamination was coming from sent him off on a new course of investigation. Driven purely by curiosity, he set out to sample deep ocean waters and Antarctic ice cores, ultimately proving that levels of lead in the environment had spiked since the introduction of leaded gasoline. This put him in conflict with the fossil-fuel industry and their mercenary spokesman, Robert Kehoe, who maintained that lead levels were at a natural equilibrium and harmless (despite the fact that they knew full well how toxic their additive, tetraethyl lead, was to the workers who handled it).
Even on purely scientific grounds, I thought this one hit a home run. The sight of Neil deGrasse Tyson waving his hands and lifting the layers of the Grand Canyon into the air might be the most spectacular visual effect this series has given us. The visit to Arizona’s Meteor Crater was another excellent visual, and a good way to explain how radiometric dating works and why meteorites are good candidates for dating: because they, unlike the Earth, contain primordial solar-system material that hasn’t been recycled by erosion and plate tectonics. (I would’ve liked to see a mention of the fact that different radioactive isotopes have different decay chains and can be used to cross-check each other, but you can’t have everything.)
I appreciated the sly knock at Ussher’s biblical chronology of creation (speaking of the rock record as “the real book”), as well as pointing out how the church scheduled Christmas to compete with the popular festival of Saturnalia, the latest in a long line of winter solstice holidays. But one thing I hadn’t known is that even the Romans were aware that lead was toxic, even while continuing to use it for their plumbing. Just as with the 20th-century fossil fuel industry, the people who suffered the worst poisoning were the laborers who were considered disposable by the elites in charge. It’s a reminder that, in some ways, human nature has changed hardly at all.
Other posts in this series: