Let's say we want to build a model of the sun and Earth alone. Earth has a radius of about 6,371 kilometers (3,959 miles), but let's represent this with a marble 1 centimeter in diameter.

Neil deGrasse Tyson explained why the Earth is not flat in his latest episode of StarTalk. He's pictured here, November 13, 2018, during SiriusXM Presents: "The Science Of Soccer.