YOU would have thought that, after more than half a century of living on a planet, I would have got the hang of some of its basic characteristics.

But among the things I have learned in the last week is: as near as dammit, the earth is flat.

Who told me and why do I believe them? I’m glad you asked.

I must start by saying it was not the Flat Earth Society, although I did check out their website and was shocked to find it starts by saying “This is not a joke”. Yes, they actually believe the world is flat, and even have some ‘scientific’ theories that ‘prove’ it.

They reckon we live on a disc that has the North Pole at the centre and a wall of ice all around the edge. So there is no such thing as the South Pole – news that must have made Scott and Amundsen feel like a right pair of charlies.

Then there are those who believe the earth is flat because it says so in the Bible.

Isaiah does, indeed, talk about people sitting on “the circle of the earth”, suggesting a disc. But most people who quote the Bible at you conveniently ignore its contradictions – one of them being that Revelations talks about four angels standing on the four corners of the earth”.

Therefore the world is not round but square, rectangular or even diamond-shaped.

I am going to discount both these sources after I stumbled on a beautiful piece of writing called The Relativity of Wrong by Isaac Asimov. You should Google it.

Asimov is best known as a science fiction writer, but as a professor of biochemistry he was also an eminent scientist.

He obviously didn’t believe the earth was actually flat, but explained that those who say so are surprisingly close to being right.

After all, the curvature of the earth is only eight inches in every mile, or 0.0126 per cent, so if you say it’s flat, your error is tiny according to everyday standards of accuracy.

You are also wrong if you think it is spherical. All rotating bodies in space get squashed by centrifugal force, therefore the diameter of the earth is 43km more at the equator than it is from pole to pole. So saying it is a sphere is wrong by 0.34 per cent – and therefore much more wrong than saying it is flat.

Technically, we live on an oblate spheroid, only that isn’t quite true, either, because the distance from the South Pole to the centre of the earth is a few metres more than from the centre to the North Pole. Basically, the world is very slightly ‘pear-shaped’.

Why should this bother us? Well, this column often bemoans the many disadvantages of getting older, but we like to think that one of the consolations is: older means wiser.

The point of Asimov’s story is not really about the earth being flat, but rather how there is rarely any black or white when it comes to being right or wrong.

When I listen to the opinions of some people who are even older than I am, I often find their supposed wisdom is actually based on things people believed long ago, usually in the last century – and just because an argument is old, it doesn’t mean it’s right.

There is no fool like an old fool, and the trick to not being one is realising how little you know, not how much. Besides, as all married men know, if you want to find out if you’re right or wrong, don’t worry. Your wife will soon tell you.