flat
ed in 1956 by Samuel Shenton, The Flat Earth Society promotes the idea that Earth is not a spherical body orbiting the Sun, but is in fact a flat disc, at the centre of the Solar System; and it's impossible to fall off the edge because Antarctica is actually a wall of ice encircling the Earth. Followers believe that satellite pictures are fake, and the truth is being guarded from the public by NASA.
A model of a Flat Earth depicting Antarctica as an ice wall surrounding a disc-shaped Earth. Imageby Trekky0623 / CC BYThe Earth was proved to be round over 2000 years ago by the Ancient Greeks when they compared the shadow of a stick in one city with that of another stick in a city 500 miles north. When the Sun was directly overhead in the first city, the stick cast no shadow, whilst at the same time, a shadow was cast by the second stick. On a Flat Earth the shadows would be identical because the sticks would be at the same angle to the Sun. The difference in shadows is because Earth is curved, and so the sticks are at different angles to the Sun. Using the difference in angles, the Ancient Greeks calculated the Earth's circumference (to within 10 per cent!).
Some 'evidence' given to support the flat Earth theory involves airliner flight paths such as Johannesburg to Perth. 'Flat Earthers' point out that the flight always stops off in Dubai, and never goes directly. To them, this makes "no sense on a ball", but if the path is mapped on a flat Earth, it is "completely understandable". In reality, there is just so little demand for Johannesburg to Perth flights that airlines fly to a more popular destination, then passengers get on a different flight to their destination – the plane is not 'stopping off' – they are two completely separate flights. And if a plane were to fly to the edge of the flat Earth, it would simply teleport to the other side of the planet (of course), just like when Pac-man reaches the edge of the screen.
Another fact that supports a round Earth is that gravity acts downwards, wherever you are, which is only possible on a sphere. A flat Earth's centre of gravity would be the centre point, the North Pole, so everything nearer the edges would be pulled sideways towards the middle. Evidently, this hasn't happened, disproving their theory once again.
And Earth would have no reason to be flat. The other planets in our Solar System are round – a fact that's been acknowledged even by Flat Earthers. But their legitimate-as-always explanation is that Earth "is not a planet". They say we're at the centre of the solar system, with the Sun orbiting Earth. The other planets are simply "lights in the sky", an homage to their ancient definition: planētēs, or 'wandering stars'.
You can prove, for yourself, that Earth is indeed round. Take a pair of binoculars to a harbour or port and watch a ship sail off to sea. On a flat Earth the ship would become increasingly smaller and eventually disappear. But on a round Earth, you'll notice the ship 'sink' over the horizon as it sails over Earth's curved surface — the same as watching a car go over a hill.
Our planet is empirically round. Not everybody has been to space and seen the beautiful blue marble Earth for themselves, but almost 600 people have. Combining what they've seen with imagery from orbiting satellites, and observations that can be made from the ground, is it not obvious that we live on a ball?
