The denial of sciÂence sufÂfusÂes AmerÂiÂcan sociÂety, and no matÂter what the data says, some conÂserÂvÂaÂtive forces refuse efforts to curÂtail, or even study, cliÂmate change. AstroÂphysiÂcist Katie Mack calls this retrenchÂment a form of “data nihilism,” writÂing in an exasÂperÂatÂed tweet, “What is sciÂence? How can a thing be known? Is anyÂthing even real???” Indeed, what can we expect next from what Isaac AsiÂmov called the UnitÂed States’ anti-intelÂlecÂtuÂal “cult of ignoÂrance”? A flat earth lobÂby?
Welp… at least a couÂple celebriÂty figÂures have come out as flat-earthÂers, perÂhaps the vanÂguard of an anti-round earth moveÂment. Notably, [DalÂlas MavÂerÂicks] guard Kyrie IrvÂing made the claim on a podÂcast, insistÂing, Chris Matyszczyk writes, that “we were being lied to about such basic things by the globÂal elites.” Is this a joke? I hope so. Neil DeGrasse Tyson—who hostÂed the recent CosÂmos remake to try and disÂpel such sciÂenÂtifÂic ignorance—replied all the same, notÂing that IrvÂing should “stay away from jobs that require… underÂstandÂing of the natÂurÂal world.” The weird affair has played out like a sideshow next to the mainÂstage politÂiÂcal cirÂcus, an unsetÂtling reminder of Carl Sagan’s preÂdicÂtion in his last book, The Demon HauntÂed World, that AmerÂiÂcans would soon find their “critÂiÂcal facÂulÂties in decline, unable to disÂtinÂguish between what feels good and what’s true.”
Sagan devotÂed much of his life to counÂterÂing anti-sciÂence trends with warmth and enthuÂsiÂasm, parkÂing himÂself “repeatÂedÂly, arguably comÂpulÂsiveÂly, in front of TV camÂeras,” writes Joel AchenÂbach at SmithÂsonÂian. We most rememÂber him for his origÂiÂnal 1980 CosÂmos minisÂeries, his most pubÂlic role as a “gateÂkeepÂer of sciÂenÂtifÂic credÂiÂbilÂiÂty,” as AchenÂbach calls him. I think Sagan may have chafed at the descripÂtion. He wantÂed to open the gates and let the pubÂlic into sciÂenÂtifÂic inquiry. He charÂiÂtaÂbly lisÂtened to unsciÂenÂtifÂic theÂoÂries, and patientÂly took the time to explain their flaws.
In the very first episode of CosÂmos, Sagan addressed the flat-earthÂers, indiÂrectÂly, by explainÂing how EratosÂthenes (276–194 BC), a Libyan-Greek scholÂar and chief librarÂiÂan at the Library of AlexanÂdria, disÂcovÂered over 2000 years ago that the earth is a sphere. GivÂen the geoÂgÂraÂphÂer, mathÂeÂmatiÂcian, poet, hisÂtoÂriÂan, and astronomer’s incredÂiÂble list of accomplishments—a sysÂtem of latÂiÂtude and lonÂgiÂtude, a map of the world, a sysÂtem for findÂing prime numbers—this may not even rank as his highÂest achieveÂment.
In the CosÂmos clip above, Sagan explains EratosÂthenes’ sciÂenÂtifÂic method: he made obserÂvaÂtions of how shadÂows change length givÂen the posiÂtion of the sun in the sky. EstiÂmatÂing the disÂtance between the cities of Syene and AlexanÂdria, he was then able to mathÂeÂmatÂiÂcalÂly calÂcuÂlate the cirÂcumÂferÂence of the earth, as CynÂthia Stokes Brown explains at Khan AcadÂeÂmy. Although “sevÂerÂal sources of error crept into EratosÂthenes’ calÂcuÂlaÂtions and our interÂpreÂtaÂtion of them,” he nonetheÂless sucÂceedÂed almost perÂfectÂly. His estiÂmaÂtion: 250,000 staÂdia, or 25,000 miles. The actuÂal cirÂcumÂferÂence: 24,860 miles (40.008 kiloÂmeÂters).
No, of course the Earth isn’t flat. But Sagan’s lesÂson on how one sciÂenÂtist from antiqÂuiÂty came to know that isn’t an exerÂcise in debunkÂing. It’s a jourÂney into the moveÂment of the solar sysÂtem, into ancient sciÂenÂtifÂic hisÂtoÂry, and most imporÂtantÂly, perÂhaps, into the sciÂenÂtifÂic method, which does not rely on hearsay from “globÂal elites” or shadÂowy figÂures, but on the tools of obserÂvaÂtion, inferÂence, reaÂsonÂing, and math. ProÂfesÂsionÂal sciÂenÂtists are not withÂout their biasÂes and conÂflicts of interÂest, but the most funÂdaÂmenÂtal intelÂlecÂtuÂal tools they use are availÂable to everyÂone on Earth.
Note: An earÂliÂer verÂsion of this post appeared on our site in 2017. This verÂsion has been lightÂly editÂed and updatÂed.
RelatÂed ConÂtent:
Carl Sagan PreÂdicts the Decline of AmerÂiÂca: Unable to Know “What’s True,” We Will Slide, “WithÂout NoticÂing, Back into SuperÂstiÂtion & DarkÂness” (1995)
Hear Carl Sagan ArtÂfulÂly Refute a CreÂationÂist on a Talk Radio Show: “The DarÂwinÂian ConÂcept of EvoÂluÂtion is ProÂfoundÂly VerÂiÂfied”
Carl Sagan Presents His “Baloney DetecÂtion Kit”: 8 Tools for SkepÂtiÂcal ThinkÂing
Josh Jones is a writer and musiÂcian based in Durham, NC. FolÂlow him at @jdmagness