TV Review: Cosmos, Episode 7

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).

This was the most explicitly political episode of Cosmos yet, and good for them. Carl Sagan’s original series never hesitated to make science a tool for good, advocating against anti-intellectualism, global warming and the threat of nuclear war, and I’m happy to see the remake following in his footsteps. It makes the point that vested interests have always tried to distort science for self-serving ends, a lesson that resonates now more strongly than ever. And it’s an amazing true story as well, that the successful quest for the age of the earth also led to the discovery that we were pumping a poison into our air and water.

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:

TV Review: Cosmos, Episode 13
You Got Your Ideology in My Atheism!
Anti-Vaccination Fever Rages On
Repost: The Age of Wonder
About Adam Lee

Adam Lee is an atheist writer and speaker living in New York City. His new novel, City of Light, is available in paperback and e-book. Read his full bio, or follow him on Twitter.

  • Gideon

    When I heard the rock layers compared to a book, it reminded me of a common concept from my religious background. Whenever someone was voicing their support for scientific discovery, they’d refer to it as reading The Book Of Nature. They didn’t discourage me from learning scientific knowledge, because they said The Book Of Nature was one more method to understand the work of God. One of their slogans was “all truth is God’s truth.”

    Of course, later I found out that this harmonious partnership stopped working very well centuries ago. I suppose it’s still possible now to reconcile The Book Of Nature with other sacred texts, but the necessary contortions are hardly persuasive…

  • Doomedd

    I couldn’t help but notices the similarities between lead gasoline and global warming. The same arguments are the same. If anything is different today, contrarians have friendly governments (quite embarrassing to be a Canadian) and the problem is more abstract. Guess we have some arguments that directly address the free market angle..

    I found the drop of lead quite impressive. It just show that the industry, and market, were not wrong, they were spectacularly wrong and weren’t bothered by it.

  • GubbaBumpkin

    Did you notice how some of the “Big Oil” representatives were smoking? Smoking was much more common back then, but I’m sure the point of including it in this animation was to remind viewers of how Big Tobacco would use the same strategies later in the century.

  • Ani J. Sharmin

    This episode gave me nightmares about lead poisoning. I suppose that’s a sign of its effectiveness in getting its message across. When the episode first started, I was a little curious/confused about what direction they were going to go in, but I think they did a generally good job. I would have liked a little more about the investigation into the age of the Earth (again, they probably couldn’t go into more detail as a result of limiting the series to 13 episodes) but I liked how they tied it in with the discovery of the dangers of lead. It was really fascinating and a topic whose history I didn’t know as much about.

    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.

    Definitely cool. And it made me think of the X-Men.

  • anna

    Im not very good at science so correct me if Im wrong here- Clair Patterson measured the amount of lead in meteorites that were as old as the earth. Since the lead had started out as uranium, the amount of time it took the uranium to decay into that much lead is the age of the earth. Then later he saw there was more lead on the surface than in the deep water of the oceans, so saw that it must be coming from above and sinking down. Right? How did he figure out the rate it was sinking down? Thanks.

  • GCT

    I think the salient point there was that he was finding more lead in shallow water than in deeper water, 3 to 10 times higher concentrations. When compared with other metals that are similar, this trend didn’t hold (barium, for instance). This indicated that lead was being deposited into the water supply from some other means. So, it’s not about the rate that it’s sinking down, but more about the levels measured being imbalanced and not in line with similar metals. Does that help?

  • GubbaBumpkin

    The lead was not sinking down. Ice in ice caps grows layer by layer as more snow falls each year and gets compressed by layers above. The same with mud in lake bottom sediments, new layers are added (roughly) once a year, or whenever there is a flood. So the layers on top are newer. This is the Law of Superposition. When things get stacked up like that, the newer stuff is on the top. Using this principle, geologists had concluded, even before the time of Darwin’s book, that the earth was much older than Bishop Usher’s timeline.

    This same reasoning is used in the ice core samples used to measure carbon dioxide levels in some of the climate change data.

    So, the rate of deposition is not exactly uniform. There may be years of drought or years with heavy flooding. It would be nice if there was a way to absolutely date some layers, and then you could tell that layers above those were older, and layers above were newer. This happened after the discovery of radioactivity. The uranium-lead dating method used by Patterson is only one method, there are a number of other methods, including the potassium-argon and argon-argon methods. These can be used on volcanic residues.

  • GubbaBumpkin

    A couple other notes:

    Occasionally geological formations are found in which relatively small pieces have been overturned. In these cases, there is clear evidence that the pieces have been re-oriented, and within the pieces the layering still holds. Creationists generally don’t admit to this.

    There are multiple isotopes of lead which result from different radioactive decay chains, and which can be used to

    cross-check some dating results.

  • GubbaBumpkin

    Reading your comment more closely, you are asking about the rate of mixing of shallow and deep water. I don’t know, and the program certainly didn’t go into detail. My impression is that Patterson derived a qualitative answer from the water issue, then to get more quantitative turned to other methods like ice cores and lake bottom sediments.

  • Adam Lee

    Very astute! That connection didn’t occur to me.

  • Adam Lee

    Yes, it was very X-Men-esque. :) Something else the episode alluded to, I read this week, was that he also lobbied against the use of lead solder for cans of food (!). That explains the scene in the supermarket.

  • Adam Lee

    Yes, that’s basically an accurate summary.

    I’m not sure exactly how the rate of turnover in ocean water is calculated. I’d imagine it involves measuring how slowly particles of lead diffuse through water, then extrapolating from that number to how long it would take for lead from an initial point source to become evenly distributed in a body of water the size of the ocean.

  • I was there

    The problem with the Cosmos story is that lead was removed from gasoline primarily because it poisoned the elements used in catalytic converters which were being introduced to clean up smog-producing automotive exhaust components. The fact that tetraethyl lead could also have negative effects on humans was only a very secondary reason for banning it.

  • cipher

    Adam, you’re forgetting that Jesus magically changed the rate of decay, as well as the speed of light. That’s how we know the universe is only a few miles across as well as only 6,000 years of age.

  • GubbaBumpkin

    You should do an umbrella introduction to this series of reviews, linking to each and providing a brief summary of the subject of each episode. I think I missed at least one episode and am trying to figure out which one it was.

  • Adam Lee

    Wish granted! I’d been meaning to set up a table of contents, this was the prodding I needed.

  • Randy Owens

    Coincidentally, while re-watching the original Cosmos recently, one of the things that jumped out at me was the scenes of people smoking in JPL during the Voyager flybys. A far cry from how it is today, certainly.

  • Randy Owens

    Perhaps you should add to that a link to Cosmos Upsets the Courtiers”?