How We Know the Earth Is Round And The Flat-Earth Rocket Man Is Wrong

A photo taken by Expedition 46 flight engineer Tim Peake of the European Space Agency (ESA) aboard the International Space Station shows Italy, the Alps and the Mediterranean on January 25, 2016. Reuters

The flat-Earth believer "Mad" Mike Hughes postponed his plans to launch himself in a homemade rocket thousands of feet in the air—but there is plenty of evidence that already reveals the Earth is indeed round, not flat.

Humans figured out that the Earth was round thousands of years ago—and without all the fancy space technology we have today to take photos of the Earth from above. Hughes, along with another notable flat-Earther, rapper B.o.B., are wrong—and there's plenty of evidence why.

As early as 500 B.C., the ancient Greek philosopher Pythagoras proposed the concept of a spherical Earth but without much concrete physical evidence, according to the American Physical Society. A few hundred years later, Aristotle noted several arguments showing that the Earth was round—including ones that people with doubts could see for themselves.

Ships sailing out to sea would disappear hull first, appearing as if they were sinking into the ocean on the horizon. A second reasoning was that different constellations are visible at different latitudes, which shows that the sky seen from Earth appears as a dome above us. Finally, in a lunar eclipse, the Earth casts a round shadow on the moon—as millions of people witnessed this summer during the solar eclipse.

The state of Texas is captured by one of the NASA Expedition 36 crew members aboard the International Space Station, some 240 miles above Earth, using a 50 millimeter lens in this image released on June 27, 2013. Reuters

Aristotle also proposed that planets were spheres moving in a circular motion around Earth, according to the Ancient History Encyclopedia. He got the first part right—planets, including Earth, are round, and they do move in a circular motion. But Earth is not the center of the universe or even just this galaxy. Earth and the other planets revolve around the sun.

He may have gotten that point wrong, but Aristotle still managed to figure out the Earth was round long before humans could travel to space. Now we know about giant radio galaxies, an ancient spiral galaxy born 11 billion years ago and that this black hole bursts a geyser of plasma every decade or so.

Early photographs of Earth weren't taken until the 20th century, in case the ancient Greeks' proof of a spherical Earth weren't enough. On August 23, 1966, the Lunar Orbiter 1 took the first photograph of the Earth from the moon. The image reveals half of the Earth (the other half masked with the night) from a distance of 236,000 miles, according to National Geographic. Two years later, Apollo 8 astronauts took the first color photo of Earth from the moon, called "Earthrise." Another early photograph, from December 7, 1972, is the first to show the Earth in full view—dubbed the "Blue Marble."