There are internet discussion forums for just about any hobby, astronomy included. Cloudy Nights is one I turn to. It’s a place where astronomy enthusiasts from around the world ask questions, offer wisdom, and tell their stories about observing the night sky, amateur telescope making, and astrophotography. And in those fuzzy areas where facts give way to opinions, get into vigorous debates.
You might imagine amateur astronomers to be mild-mannered, even-tempered types. But just try claiming, without bench test data, that your expensive, modern 11-element eyepiece has higher contrast and less light scatter than a beloved classic three-element design. You’d better be ready to watch the sparks fly.
Among the many subforums I’ve wandered into, there is one on the subject of outreach. That’s another name for setting up one’s telescope for passersby to look through and acting as an unofficial ambassador for astronomy and science. I do it in my neighborhood in New York City and every summer during our visits with family in Wellfleet. The outreach discussions usually revolve around how to help first-timers look through the eyepiece, how to gently discourage children (and sometimes adults) from touching the lens, and how to talk about astronomy in a clear and engaging way.
There’s another topic outreach enthusiasts talk about: awkward, bizarre, and sometimes hostile encounters with flat-earthers.
Flat-earthers are people who believe that Earth is a flat disk, and that governments and scientists conspire to cover up this secret truth. Yes, really.
It’s just one example of a fringe idea that has found new life in the age of social media. You’ll find a similar toxic mix of conspiracy theory, junk science, and disregard for expertise with anti-vaxxers and climate change deniers.
Some flat-earthers seem to view the presence of a telescope in a public place as a personal attack on their beliefs. I’ve read accounts on Cloudy Nights of flat-earthers shouting at a bewildered astronomer that the view of Saturn through the eyepiece is just an image stuck to the end of the telescope. They’ve ridiculed the people waiting in line to observe, mocked NASA (there’s a high overlap with Moon landing conspiracy theorists), and scoffed at millennia of observation and evidence. “Do your own research!” they say.
I reflected on flat-earthers while walking my dogs before sunrise a few weeks ago. A lovely crescent Moon rose in the east. Because of clouds and my work schedule, I hadn’t seen or noted the moon’s phase in weeks. Yet that morning, from its orientation and position I knew at a glance where things stood. The Moon was waning and nearing the end of its 29-day orbit around Earth. It would soon vanish for a day or two: new Moon. Then, I knew, as its orbit continued, it would reappear, again as a slim crescent, but now waxing instead of waning, and in the west at sunset, rather than in the east at dawn.
What a strange phenomenon. The lunar cycle can be difficult to explain with words and hard to understand by hearing or reading a description of it. Yet a child can grasp the essentials when you demonstrate the dynamics with a light source and two spheres. There are, of course, also various flat-earther attempts to explain lunar phases. They range from nonsensical to convoluted, contradictory, and magical.
It’s a common myth that people of the ancient and medieval worlds believed the Earth was flat. Most were too busy trying to survive to give the matter much thought. But those who had the luxury to ponder big questions realized that Earth is a sphere. They did so by making observations, performing some calculations, and asking themselves what would explain what they saw. They could then test that explanation, or hypothesis, by using it to make other predictions. If the predictions were accurate, then maybe they were on to something. If not, they had to reconsider the original hypothesis. We now call this the scientific method.
Consider the irony in dismissing science while thriving under the shield of its benefits. Anti-vaxxers need not fear smallpox: we have MRI scanners to find cancer early enough to save their lives, airplanes to take them around the spherical Earth, and computers that power the internet, which they use to such absurd purpose. Often, those who dismiss science abuse the very people who brought them these gifts or who work to keep knowledge alive: scientists, doctors, teachers, and even enthusiastic amateurs who enjoy sharing the beauty of the night sky with strangers.
I’ve been lucky; I have yet to encounter any flat-earthers during my own outreach. But it’s only a matter of time. What to say to such a person? I rehearse how to just smile, decline to engage, and politely ask them to step aside so someone else can look through the telescope. Clear skies!