Two learned people from Lakewood reached out to me recently. They said that they greatly appreciated my writings on rabbinic astronomy, in which I demonstrated that Chazal (for the most part) subscribed to the Babylonian cosmology in which the world is flat. However, they differed with my conclusions in one regard. Whereas I concluded that Chazal were wrong, they said that Chazal were right!

These were not the first Flat Earthers that I’ve encountered. True, while the belief in a flat earth held out in some circles into the nineteenth century, it had totally disappeared by the twentieth century. And yet the wonderful book on the history of this concept and its extinction, Flat Earth: The History of an Infamous Idea, is now out of date, because in the past few years this belief has made a revival. (See this post in which I discuss the approach of the 19th century Flat Earthers.)

While the Lakewooders were relating it to Chazal’s position, that was not the source of their belief. (In fact, they told me that they have a lot of problems with various people telling them that they are going against the mesorah to believe in a flat earth!) Instead, they told me, they had started by becoming skeptical of medical science, and then proceeded to Earth science. I’ve seen other people take this path, and unfortunately this sort of conspiratorial thinking sometimes ends up with those who believe that the Rothschilds are controlling it all. Along with the total nonsensicality of it, this motivated me to give a shot at dissuading them.

They were surprised that I didn’t use any of the arguments that they were expecting. I didn’t speak about ships on horizons or photos from NASA or anything like that. I mentioned the absurdity of the believing that all the world’s governments along with endless scientists and pilots are involved in a coordinated conspiracy, but in terms of the actual scientific arguments, I used one that they had never even encountered: flight times.

It takes an average of five hours to fly between Los Angeles and New York, which are 2400 miles apart. And it takes twice as long, ten hours, to fly between Johannesburg and Perth. This makes perfect sense with a spherical earth, on which they are twice as far apart as LA and NY, at 5000 miles. But it disproves the flat earth model, according to which (as you can see in the picture below) Johannesburg and Perth are 9000 miles apart! According to that model, it should take nearly twenty hours to fly between them, not ten.

My interlocuters first argued that it’s very suspicious that there are so few transoceanic flights over the Southern hemisphere - most of them go via Dubai or some such place. I responded that there are both safety and economic reasons why this is the case, and that in any case nonstop transoceanic flights definitely do exist!

Then they attempted to argue that the only way to determine exact distances based on flight time is by having access to aircraft speed, wind speed, aircraft model, exact flight direction, and many other variables. I pointed out that this is completely true for determining exact distances, but we don’t need exact distances.

They then argued that with a good tail wind, planes can go much faster. I responded that it’s true that in the most extreme cases, you can fly from LA to NY in four hours - about 80% of the usual time it takes. But it's never less than that, and the average is a little over five hours. Meanwhile, the average flight time between Johannesburg and Perth is 10 hours, even though the distance according to the flat earth model is nearly double that with the spherical earth.

When it comes to the flight from Johannesburg to Sydney, there’s another argument to add. According to the Flat Earth model, instead of flying over the southern Indian Ocean, the plane is going over Asia! How is it that nobody notices? Are all the passengers part of the conspiracy too?

I am not going to delude myself into thinking that rational arguments can necessarily convince people who are determined to subscribe to a particular belief. But I haven’t heard a response back from my Lakewood friends, so perhaps there’s hope!