THE WORLD ISN’T WHAT IT SEEMS. HERE’S HOW SCIENCE HAS EXPOSED THE FALLACIES AND MISCONCEIVED IDEAS OF EARTH AND THE HEAVENS THROUGHOUT HISTORY
BY MARCUS CHOWN
Our view of reality is severely limited. The reason for this is simple: we evolved on an African plain three million years ago. And so we have the senses necessary to survive on an African plain: eyes that can see far enough to spot a predator approaching, ears sensitive enough to hear a rustling in the long grass… Those senses have revealed only an infinitesimal fraction of the world and provided us with a certain ‘common sense’. But, at every level, we’re deceived by our ape-like intuition. Most of nature is deeply hidden from us and the world isn’t what it seems. So many things that seem obviously true are not. And here are just a few…
1EARTH IS FLAT
Apart from the lumps and bumps of mountains, Earth certainly seems flat. But there are several clues that not only is it curved, but in fact it’s a large ball. For one thing, receding ships drop below the horizon before dwindling to a dot. Also, during an eclipse of the Moon, when Earth passes between the Moon and the Sun, the shadow of Earth on the Moon is clearly curved.
Even stronger evidence that Earth is round came from the first circumnavigation of the world in a ship sailed by the Portuguese navigator Ferdinand Magellan. Though he was killed in the Philippines, the voyage was completed by the Basque navigator Juan Sebastián del Cano in 1521. But, of course, the easiest way to see that Earth is a sphere is from space. And there’s no doubt that what the Apollo 8 astronauts photographed rising above the grey desolation of the Moon half a century ago was a sphere.
Measuring the size of Earth is a bit more difficult. But on a sphere, the mutual distances between four cities are different from what they would be on a flat surface (in fact, the American physicist Steven Weinberg, in his 1972 book, Gravitation and Cosmology, used JRR Tolkien’s distances to deduce that Middle Earth isn’t flat!). By this means, it’s possible to determine Earth’s magnitude from airline mileage tables and confirm that it’s a sphere.
The first estimate of the size of Earth, however, was made around 240 BC by Eratosthenes, chief librarian at the Museum of Alexandria. He knew that at midday on Midsummer’s Day, a vertical pillar at Syrene (modern-day Aswan) cast no shadow because the Sun was directly overhead, whereas one in Alexandria cast a shadow because the Sun w
