Henrietta Leavitt: The Woman Who Measured the Universe

In the wake of the Women’s March on Washington,  International Women’s Day seems to be enjoying a bit of a resurgence this year.

If you read my writing, you’ll know that I’m not a fan of gross statistics that describe large groups of people as if they were homogeneous. As such, you might imagine that I wouldn’t see much point in a holiday that purports to celebrate over half of humanity.

Typically, you’d be right. But a couple days ago, while reading on Fivethirtyeight, I learned about Henrietta Leavitt–an astronomer in all but title who, in 1912, discovered how to use variable stars to measure distances in space. Her story struck a chord with me, and I thought it might be cool to write a little bit about it.

Leavitt discovered that there was a relationship between the brightness of a variable star and its period of pulsation. The length of that period can be used to find the star’s intrinsic brightness, or how bright the star would be at a common distance. From there, she was able to compare the star’s intrinsic brightness to its measured brightness and calculate its distance.

Before her, scientists were able to measure about 100 light years out into space. Leavitt’s discovery helped pushed that boundary to 10 million light years.

Leavitt was, for a long time, largely uncredited for her contribution to our knowledge of the universe. Her boss, Edward Pickering, published her work under his own name–a pattern familiar to women of the era–and referred to her only as the person who “prepared” it. Leavitt has since been credited for her work and posthumously biographied multiple times.

Anyway, I thought she–and by extension, the too-often anonymous female contributors of the past–deserved a shout out. Part of the joy of meticulous work is getting to show off a finished product that makes people say, “You did what? Why?” It’s a shame Leavitt didn’t get to enjoy that in her lifetime. But better late than never, I suppose.

Happy International Women’s Day.

Science Has a Reproducibility Crisis

If your Facebook feed is anything like mine, you may have recently heard about how Bill Nye–the Science Guy himself–“slammed” Tucker Carlson on the latter’s evening show on Fox. THIS. (If you live somewhere else you may have been treated to an equally smug reaction from people claiming that Carlson “won.”)

However you feel about it, the timing, coupled with Nye’s reliance on scientific consensus as a proxy for objective correctness, is somewhat serendipitous. Mounting evidence that the results of scientific studies are often not replicable has caused Nature, a prolific scientific journal, to very publicly tighten its standards for submissions as of its latest issue.

In May of 2016, a survey by Nature revealed that over two thirds of researchers surveyed had tried and failed to reproduce the results of another scientist’s study. Over half of them had been unable to reproduce their own results. Fifty two percent of researchers polled said there was a “significant crisis” of reproducibility.

This is a big deal. The ability to replicate the results of studies is crucial to both scientific integrity and progress. Clinical researchers, for example, depend on reliable results from prior trials to form the building blocks of new drug advancements. In the field of cancer biology, merely 10% of results from published literature were found to be reproducible. Meanwhile, the credibility of scientific literature is understandably compromised by dubious, often sensational findings.

The root of the problem, according to Dame Ottoline Leyser, director of the Sainsbury Laboratory at the University of Cambridge, stems from today’s scientific culture. As quoted in BBC, she cites “a culture that promotes impact over substance, flashy findings over the dull, confirmatory work that most of science is about.”

Others blame a pressure to publish. There has also been, in recent years, doubt cast on the integrity of the peer review process, especially with regard to climate science.

Whatever the culprit, plans to combat issues of reproducibility are emerging. Nature has developed a checklist to serve as guidelines for authors submitting writing to the publication. Efforts shouldn’t end there, the journal argues. Reform at all levels of the scientific process could go a long way:

Renewed attention to reporting and transparency is a small step. Much bigger underlying issues contribute to the problem, and are beyond the reach of journals alone. Too few biologists receive adequate training in statistics and other quantitative aspects of their subject. Mentoring of young scientists on matters of rigour and transparency is inconsistent at best. In academia, the ever increasing pressures to publish and chase funds provide little incentive to pursue studies and publish results that contradict or confirm previous papers. Those who document the validity or irreproducibility of a published piece of work seldom get a welcome from journals and funders, even as money and effort are wasted on false assumptions.

Tackling these issues is a long-term endeavour that will require the commitment of funders, institutions, researchers and publishers. It is encouraging that NIH institutes have led community discussions on this topic and are considering their own recommendations. We urge others to take note of these and of our initiatives, and do whatever they can to improve research reproducibility.

Science and Politics: An Abusive Relationship

Decades before Luis Pasteur fostered scientific consensus on germ theory, Ignaz Semmelweis was imploring obstetricians to wash their hands after handling corpses. His work did little to inspire his fellow medical practitioners. On the contrary, he was met with indignation and disbelief at almost every turn. Though aided by his increasingly erratic behavior and political inelegance, there is no doubt that his alienation from the medical community was due in part to his then-heretical proposals.

We’ve come a long way since the Roman Inquisition locked Galileo under house arrest for advancing the theory of heliocentricity. Yet still, skepticism is a trait that can inspire zealous culture warriors to brand others “deniers” or deride them as being “anti-science.”

Of course, there’s nothing more scientific than scrutinizing an accepted norm. The scientific process is dependent on constant refinement by people attempting to prove each other wrong. Indeed, science needs skepticism to sharpen its ham-fisted hypotheses into acute theories.

Our devotion to explaining the universe through rational observation and rigorous testing has catapulted us from a species-wide state of destitution to one of unimaginable wealth. That’s largely due to thousands of years of continued knowledge expansion and the pursuit of logical explanation. If science is the vehicle that brought us this far, then the fuel is undoubtedly…well, doubt.

This unique feature stands in sharp contrast to another primary way humans have explained the world: religion, which asks us to accept without questioning. Doubt may have been bad for Thomas, but Copernicus did wonderful things with it. There are few things as amusing as the rabid atheist who has not so much embraced doubt as become a cynic. Remember that uncertainty, regardless of its target, is the very heart of science.

A cursory glance at the past is all one needs to find examples of misplaced faith in science of the day. As the story of Dr. Semmelweis illustrates, there was a time when nearly all doctors were pretty damn sure that they didn’t need to wash their hands after handling dead bodies. In fact, they were offended by the notion.

More recently, Brian Nosek of the University of Virginia tried to replicate 100 studies appearing in top psychological journals; he and his team were unable to replicate about two thirds of them.

Treating scientific consensus axiomatically is a step in the wrong direction. We need to keep gathering information, and that information has to include research by iconoclasts in order to be well rounded. Remember that many widely held beliefs started out as heresies. Behind each of them was someone willing to come out against conventional wisdom, sometimes at great personal or professional risk.

The greatest minds of humanity used to believe in a static universe, phrenology, and many more things that we might find ridiculous today. So if skepticism is so demonstrably useful and deserved, why do people demonize each other for failure to follow the herd?

It’s politics, stupid.

Like basically anything today, science often finds itself mired in the ostentatious game of political signaling. Opinions and interpretations of scientific research are as much a part of political identity as a bumper sticker or a lawn sign. This is hugely unfortunate because it leads people to adopt dogmatic approaches to a process that should be objective.

Politics ruin science (and pretty much everything else) because everything is reduced to a zero-sum game: an us versus them scenario where concession is likened to defeat. They also reduce diversity of opinion and promote groupthink.

If you think I’m exaggerating, consider this: as people’s scientific literacy increases, their opinions on climate change polarize depending on their political affiliation. But that’s not all. According to the same study, conservatives who are more scientifically literate are also more likely to believe that there is a scientific consensus on global warming. Dan Kahan writes:

Accordingly, as relatively “right-leaning” individuals become progressively more proficient in making sense of scientific information (a facility reflected in their scores on the Ordinary Science Intelligence assessment, which puts a heavy emphasis on critical reasoning skills), they become simultaneously more likely to believe there is “scientific consensus” on human-caused climate change but less likely to “believe” in it themselves! 

While skepticism of climate change science is a markedly right-wing prejudice, those on the left are more likely to display similarly rock-ribbed opinions on fracking, GMO safety, and other areas that conflict with scientific consensus.

Politics are an inevitable part of living in a republic, but scientific debate loses integrity when we let our politics decide how we feel about science instead of the other way around. It’s divisive, but worse: it’s lazy and positively unscientific.

In an increasingly polarized country, we would do well to remember the humanity of our detractors. We also might make a conscious effort to both admit and overcome our biases, even as we argue with conviction.

Perhaps most importantly, we should stop acting like morality and argumentative position are inextricably linked. Doing so makes it that much easier to demonize people with differing opinions (If my opinion is moral and yours is different, it is less moral. Therefore, since you are putting forth an immoral opinion, you are evil)  and makes us far less capable of changing our own.

Leave the crusades in the 15th century.