Flat Earth

Fairly recently there occurred the death of a brilliant author called Terry Pratchett. His stories of the ‘Discworld’ were loaded with great humour that demanded rereading lest some may have been missed.

This ‘Discworld’ was a place of magic; a disc that was supported on the backs of elephants that were, in turn, standing on the back of a giant turtle that swam endlessly through space.

Light spread slowly across the surface of the ‘Discworld’; the unseen University had a librarian that had been turned, by force of great magic, into an Orang Utan whose sole contribution to conversation was invariably to utter ‘Ook… Ook’.

I’m not sure that Orang Utans actually say, ‘Ook… Ook,’ but Mr. Pratchett said so and thus you yearn to believe.

Does ‘Death’, who rides a white horse, really speak in upper case letters? Who knows. Terry Pratchett knew and explained it to us so convincingly that we fell in with his ideas and revelled in the activities of all his heroes.

But there are those who have taken it all a little too seriously.

There is a collection of people who, I am told, believe that the Earth is flat. Some, even, who say that it is concave – or convex, one or the other.

My son told me that there is a video on ‘youtube’ that purports to show that the World is not spherical. They carry out experiments to prove their case. The video is around one and a half hours long and that makes it around one and a half hours of completely wasted life. At my age I do not wish to spend that long indulging in nonsense as I have few hours remaining to me on this Earth – regardless of its shape.

The video left me cold near the start where they explained that one of their experiments would take place across the Straits of Gibraltar in the South of France…

Yes. Precisely. I could not have said it better myself, Jacques.

Perhaps a little perspective on this ‘spherical’ versus ‘flat’ Earth situation.

Irrespective of whatever experiments you wish to carry out with lasers, telescopes and GPS signals that measure the distance between the base of two buildings and the tops of those same buildings there is just one tiny little detail that you may wish to consider:

Gravity.

Every object that has mass also has gravity.

It is a fact. Floating toys in the bath will gravitate towards the side of the bath because both the toy and the bath possess their own gravity. It is an incredibly small force but it exists.

Because of gravity a ball will not only fall towards the Earth but Earth will also tend to move towards the ball. Observe that I said ‘tend to move’ because the attraction is there but the Earth is so massive and the ball so pathetically small in comparison that the movement of the Earth towards the ball will be immeasurably small.

Gravity exists. Without it we should all float away into space.

Furthermore, gravity acts towards the centre of the mass that is producing it. That part is extremely important.

You will have noticed, from photographs, that asteroids are often irregularly shaped lumps of rock or iron. This is because they have very little gravity. Yes, some of them are pretty hefty but, still, their gravity is low.

The moon only has around one sixth of the gravity of Earth and yet it is, on the scale of things, big. You would not wish to pop it into the boot of your car and drive off with it.

Asteroids have insufficient mass to produce a gravitic force that is strong enough to agglomerate the materials from which it is constructed into a sphere. The Earth definitely does have enough gravity to do that.

Even Mercury can do it – tiny though that little planet is.

Let me put this idea of the effect of gravity into another light for you.

Since gravity pulls towards the centre of the mass then water will be pulled towards the centre of that object, too. Water is fluid so it will run towards the strongest gravitational pull. Air, too, will be at the greatest pressure towards the centre of the gravitational pull.

If the Earth is flat then the gravitational pull will be felt the strongest at the centre of the disc. For this reason all the water – and the air, no doubt, will be piled up in the centre of the disc making life there for terrestrial creatures us!) untenable.

Walk to the edge? You will not fall off. As you approach the edge you will be walking at a greater angle, leaning forward, because gravity is acting towards… OK. You are ahead of me.

On reaching the edge you will not ‘fall off’ because you will be able to walk around the, dry, rim to the other side.

It would be interesting to know what the sun is doing in all this!

As a footnote: the ‘Flat Earth Society’ has, according to its own brochures, ‘Branches all over the Globe’. I’ll let you stop and think about that.

Ook… Ook.