Moment of Inertia, Issue #2 | Two Sides of the Same Coin

Moment of inertia is a place where I'll be giving more of my commentary, in a longer form, on select topics I cover in my newsletter Magnitude and Direction. The goal is to give you 10 to 15 minutes of interesting reading on a topic while you're still in bed - your moment when the inertia of being cozy in bed keeps you there, even though you're awake and getting ready for the weekend morning. I hope you enjoy hearing what I have to say about the topics I cover in M&D and encourage you to participate in the discussion as well.

It occurred to me early yesterday afternoon that I didn't see Moment of Inertia in my own inbox and that it was likely none of you had either. It turns out there was a technical glitch getting the edition out yesterday morning, but hopefully you all appreciate hearing my thoughts as much on Sunday as you do on Saturday.


Two Sides of the Same Coin

In the latest edition of Magnitude and Direction I briefly discussed the publication of the results of NASA's year long study on astronauts Mark and Scott Kelly. Mark stayed here on Earth and Scott went up to the International Space Station for just under 365 days. Scott and Mark being twins, this provided a unique opportunity to study the effects of long-term space habitation on the human body, not only on a physiological level (which we've been able to study to some capacity for quite some time) but also on a cognitive and genetic level.

The results of this study were published just about a week ago in the journal Science and not long after, were read, analyzed, and summarized by journalists and other science writers from all over the world. Suffice it to say, I haven't read all of the articles that have since been published regarding the study, but two that did make their way into my email inbox were from the New York Times and the MIT Technology Review. At first glance, however, you could be forgiven for thinking these two articles were written about two different studies, because the headlines couldn't be more different. From the New York Times: "The results were disturbing" but from MIT: "The findings: They’re promising for space travellers" and " promise for humankind’s space-based future" So how do two publications writing about the same story reach totally different conclusions (at least in their headline summaries?)

To get to the bottom of this discrepancy, I decided to dig a little deeper into both articles (as well as the original Science publication) myself.

For starters, you don't need to read very far past the headline or opening paragraph in either article to see that the published results aren't a clear cut "go/no-go". On the plus side, many aspects of Scott's physiology didn't change more than what would have occurred had he only stayed on the ISS for half as long - so your body doesn't just continue to change/adapt/deteriorate forever in space; there's some lower bound. Additionally, and unexpectedly, Scott's telomeres - think of them as caps that protect your chromosomes during the cell division process - got longer. Due to the increased radiation exposure in space, scientists had initially hypothesized that telomeres would get shorter more quickly than they do here on earth.

As a brief aside, post embryonic stage, our telomeres get shorter throughout out life, pretty much every time our cells divide. So telomere length scales inversely with age. Roughly (and I can't emphasize that enough) speaking, if your telomeres are getting longer then you're getting younger. Read the linked telomere article for some more detailed information about how these little molecules work.

Some of the less encouraging results of the study include what seems to be permanently elevated levels of some genetic mutations, which could be indicative of elevated cancer risk down the line, as well as a period of decreased cognitive capabilities following return from microgravity. With the onus for this study being potential future trips to Mars, which could take years to complete, it's also worth mentioning that radiation exposure would be still more elevated, further increasing genetic mutation risks.

All in all, though, the data from the study looks fairly promising. It seems that we can sustain astronaut health for the duration of a long-haul space flight. So how, then, do two different publications writing about the same data comes to such different conclusions?

The primary source of the discrepancies might be the scientific community itself. When a paper gets published, hundreds, if not thousands of scientists working in related fields will read through it, assess the reported data, and then come to their own conclusions. These conclusions are rarely, if ever, in complete harmony across the board, and different scientists will focus on different pieces of the data. Part of this has to do with each scientists' area(s) of expertise, but part of it also has to do with their own idea of what a positive study conclusion should look like. There's always some implicit bias that gets brought to the table when analyzing data - no observer is truly objective.

As a result, different parts of the data will be weighted differently in the minds of each scientist, summing up to what are, in this case, vastly different conclusions. As the Times reported, Dr. Eric Topol, the Director of the Scripps Institute concluded "...why would anybody want to go to Mars or be in space? ... Because this is really scary.” Quoted in the Tech Review, however, Cornell professor Chris Mason said that the results were "predominantly very good news for spaceflight and those interested in joining the ranks of astronauts.”

So depending on what experts each publication talks to for commentary, vastly different interpretations can come across. Like any other story, however, journalists try to talk to many people to get a range of perspectives, and this did happen for both the Times and Tech Review articles. At the end of the day, though, there has to be some overarching message and the publication must, to some extent, pick sides.

This, perhaps, is the biggest issue around science journalism. Findings from a research study are rarely black-and-white. The data is nuanced, comes with numerous caveats, and is open for interpretation (as was evident from the quotes above). Indeed, the only conclusion that's almost guaranteed in any research paper is that more studies need to be performed in order to get a better handle on the data.

This isn't only true of science, though. The vast majority of the news stories we interact with every day exist in gray areas and contain behind-the-scenes nuances that can't fit in a headline, or even the daily news briefing we get on our phones and read on the train on the way to work. There have been countless other articles written about this phenomenon, so I won't discuss it in depth here, but I would encourage all of us to take some time - no more than 5 minutes is all you'll need, typically - to dig just a tiny bit deeper. A coin might have two sides, but there's only one piece of currency.