We're now more than halfway through this second incarnation of Cosmos and the show continues to surprise. Episode seven, "The Clean Room," could have easily been another historical tale of our millennia-long journey to understand the age of the Earth; instead, it became a twentieth-century tale of one man's scientific advocacy. Let's take a look at how well that worked.
Science as a collaborative effort: I'm not sure how illuminating the animation of Patterson's sample coming apart inside of the mass spectrometer was, but the voice-over of him thanking all the scientists on whose work his was based was beautiful. A great reminder that in the twentieth century no one's work truly stands alone. We all rely on the efforts of those that came before us.
Unintentional discoveries: Some of the most amazing stories in science spring from researchers' always-lonely struggle to understand and eliminate the factors which are disrupting their experiments. From the discovery of penicillin to the identification of the cosmic microwave background, some of our most profound and important breakthroughs have come because a few scientists were observant when perhaps they didn't need to be.
Battling the lead industry: Patterson's decades-long battle against the lead industry must have been demoralizing and we all owe him and those he worked with an enormous debt of gratitude. Like the doctors who endorsed smoking during the same time period, lead lobbyists and their hired scientists sure come off as being true villains. Thank goodness the arc of progress seems to be against them. A glimmer of hope in our current battle against climate-change deniers, I suppose.
The uranium to lead animation: It was a quick and simple visualization, but I thought the pillar of uranium turning into one of lead as a clock ticked forward really drove home how atomic dating is done. Ratios of elements or chemical isotopes form the foundation for dating everything both here on Earth and out in the Universe, so it was nice to hear a bit about how that works.
I didn't like...
Leaving out William Thompson: This is the first time, I think, that I've quibbled with an omission in Cosmos' stellar historical sections. However, William Thompson's (better known as Lord Kelvin) efforts to calculate the age of the Earth from basic scientific principles is an illustrative one. Working in the late 1800s, Thompson (correctly) assumed that the Earth began as a molten ball of rock and computed that it would take between 20 and 400 million years for the planet to cool to its present temperature. His reasoning was excellent, yet he was off by more than a factor of ten. Why? Radioactive decay and the heat it releases had yet to be discovered. The moral of the story is, even great scientific work can be tripped up by things yet to be uncovered. I can see how this might not have fit cleanly into the narrative the writers were trying to tell, but I believe it's important to recognize and acknowledge that science isn't infallible. It doesn't have to be perfect for it to work - we just have to be willing to change our minds.
I think "The Clean Room" was one of my favorite episodes thus far. Perhaps no story they've told has as much everyday relevance and accessibility. After all, we all pass by those "unleaded gasoline" signs every time we fill up the car. Like "no smoking" signs in airplane bathrooms, I often wonder if these reminders are really necessary in 2014. Hopefully labels of "zero emission" will seem as quaint in the not-too-distant future.