Hi, I have just joined this forum. My main interest is in the question of human rationality. Are humans rational? What do we mean by ‘rational’? Why do some people believe things that the majority of other people regard as not rational? My background is logic and philosophy, as well as the history of science and the question of scientific methodology. I am the co-author of this book
https://www.amazon.co.uk/Duns-Scotus-Time-Existence-Interpretation/dp/0813226031 on medieval logic and philosophy.
I am also fascinated by fringe and unorthodox theories, such as the phantom time hypothesis
https://en.wikipedia.org/wiki/Phantom_time_hypothesis and things like that.
My question is whether it is rational or not to believe in the Flat Earth hypothesis. Some thoughts. (i) the fact that great majority of people disagree with you, including the scientific establishment, is not enough to prove irrationality. Irrationality is the persistency of maintaining a belief which is inconsistent with what is self-evident. (ii) For the same reason, it is not necessarily irrational to ignore pictures taken from space, authoritative statements from the scientific establishment etc. The pictures could be fake, the authorities could be misleading us. ‘Argument from authority’ is one of the forms of fallacy. ‘Authorities say that p’ does not imply ‘p’. (iii) But it is irrational to maintain what is logically inconsistent. If p logically implies q, it is inconsistent and irrational to accept p but deny q.
I never questioned RE before. I was shown a globe at primary school. This does not prove RE, of course. I was also familiar with the usual stories about ships disappearing below the horizon, and I knew that the ancient Greeks had established RE by a simple experiment by Eratosthenes, a Greek astronomer who had heard that in Syene the Sun was directly overhead at the summer solstice whereas in Alexandria it still cast a shadow. Aristotle also observed that there are stars seen in Egypt and Cyprus which are not seen in the northerly regions.
When I looked more recently I was interested to find so many simple demonstrations of RE. I won’t go through these here, but as a traveller I am interested in flight times. Flight times in the Southern Hemisphere are seemingly inconsistent with any kind of flat projection. For example, if I print out a flat projection, I measure the map-distance from London to Cape town as 6cm, Miami to Cape town as 10 cm. But the ratio between these is different from the flight times. You can repeat this for many other destinations: the result is always inconsistent with a flat projection, but consistent with the standard RE model.
There are other simple experiments. I was fascinated to learn from another site (mythbusters) that simply by standing up you can reveal a lot more of objects apparently below the horizon when sitting down. I don’t understand the geometry of this, but it is compelling.
Sorry for such a long OP. In summary, I am interested whether FEers are rational or not, and I would like to understand their take on the apparently simple demonstrations of the RE model (as opposed to demonstrations based on the authority of the scientific establishment, the government, experts etc).