Falling flat

In response to Rachel Brazil’s feature article “Fighting flat-Earth theory” (July 2020), in which she explores why the “shocking” notion that the Earth is not a sphere is increasingly taking hold and how the physics community should best respond.

Two issues need to be handled carefully in challenging flat-Earth theories. First, the language used needs to be accurate. Don’t refer to a “round” or “circular” Earth, refer to a spherical Earth. Another example from the article is the mention of “chem-trails”, which immediately implicitly recognizes the conspiracy theory claim. Use the correct term, con-trails or, even better, condensation trails.

Second, be very sure you understand the evidence for a spherical Earth. A Foucault pendulum is not evidence for a spherical Earth, it is evidence of a rotating Earth that might indeed be a flat disc. As the article goes on to point out, however, this isn’t about science. Even if a flat-Earther were taken up into space and shown a spherical Earth, I’d be confident many would claim a sophisticated hoax.

Although flat-Earth theory is nonsense, it is a symptom of the Internet and something we have to live with in our technological age. Education is vital, but anti-education, which is what this theory represents, has no guaranteed antidote.

My personal best proof against flat-Earth theory came on a business trip I made 30 years ago to Cape Town, South Africa, and my evidence relates to the differences in the night sky. Returning from an evening dinner, I was confronted with a bright sky full of stars none of which I could recognize since I was in the southern hemisphere, where none of the regular constellations I would observe from the UK can be seen. Desperately looking for something I could recognizably pinpoint I found the constellation Orion. But it looked odd. It was upside down. I said to a colleague “Look – there is an upside-down Orion.” “No,” they replied, “here it’s the right way up!”

Another simple test to confront flat-Earthers is that if you are in the northern hemisphere, you can estimate your latitude by pointing at the Northern Star. The angle your arm subtends above the horizontal is your latitude. Easy. I don’t think it’s possible for a flat-Earther to confound that one. It just would not work with any flat-Earth model.

I was intrigued to see a mention in Brazil’s article to the part played by Samuel Shenton, from Dover, in the formation of the International Flat Earth Research Society in 1956. In 1958 I was a young astronomer at the Royal Greenwich Observatory, which was receiving many requests for someone to talk about the International Geophysical Year. I was deputed to go to Dover and give a talk to the local science society.

Answering questions at my talk, I was at first concerned that a questioner seemed to know more about artificial satellites than I did, before it eventually dawned on me that he was arguing that the Earth was flat. I had no difficulty demolishing his theories after that! Later, my host told me that the questioner was a well-known flat-Earther: he must have been Samuel Shenton.

I once walked into a shop in Sydney airport and the vendor was selling sundials with numbers going anticlockwise. Apparently, he sold a lot of these to us folk from the northern hemisphere. I pointed out they would not work north of the Tropic of Cancer because the Sun goes clockwise. He was surprised by this fact, morally challenged, though probably kept selling the sundials. But here is an easy thing to help explain to the flat-Earth advocates that only a spherical Earth would need Down Under sundials with anticlockwise numbers.

This very interesting article reminded me of a letter written by my grandfather during the First World War while serving as a sergeant dispenser in the 102nd Field Ambulance. Although written more than 100 years ago it is clear that many of the issues explored in Brazil’s article were as relevant and challenging then as they are today. On 11 March 1916, aged 19, during a time of heavy casualties and severe weather, he wrote from the front line in northern France to his father in Norfolk about a “most peculiar” schoolmaster from Yorkshire he had encountered:

“He does not think that the world is round, or as the books call it an oblate spheroid, but…to be a flat ellipse and he has most excellent points for his arguments in which he upsets, at any rate to his own satisfaction, all the old proofs of the Earth’s rotundity…I have challenged him to a public debate on the subject but though I am certain of the soundness and safety of my premises I am not sure of being able to prove the falsity of his. This man believes in the absolute and unreserved literal acceptation of the Bible in that he considers the biblical version of the creation of the world to be absolutely true. He works everything out from an astronomical, astrological or numerical aspect and has by the way placed a very strong value on biblical numbers or on the Greek numerical value of letters.”

The biblical references support Brazil’s historical reference to “those who wished to return to biblical literalism” – especially as the letter was addressed to his Baptist minister father. Indeed, it was appropriate for Brazil to quote the concern that flat-Earthers will start to “push their ideas into the US education system”.

Under the circumstances and despite the lack of resources available to him, I was impressed by the number of “proofs” cited in his letter – I seem to recall that he was a keen member of Thetford Grammar School’s astronomical society. He was a member of a debating society while on active service. Later in life he was editor of The Pharmaceutical Journal and the Journal Mondial de Pharmacie.

It was great fun, for me at least, to read Brazil’s article. Insofar as I took the article seriously, I must say that I missed one aspect in particular: how do we distinguish the serious deniers from the jokers? I am sure I myself would be able to feign opinions that are not mine, but that serve to trouble or even torment our profession. Is there any case known where a joker has admitted that they were, of course, pulling our legs?

Seen parked on a dark street one night in Camden Town, in the 1970s, was a van painted with the message: “Flat Earth Society. Expedition to the Edge”. I never saw them again.