Gravity

https://barryhisblog.blogspot.com/p/gravity.html Or how we can cling to obviously mistaken ideas because we don't want to admit that we were mistaken, especially to ourselves.

Dad was a pilot in the British Royal Air Force (RAF). He volunteered to fight the Nazis at the beginning of WWII, and the authorities decided that he had the makings of a pilot, so he was sent to Arizona to learn and train. It turned out that he had a natural talent for flying high-performance combat aircraft, but he was not sent back to Europe to fight - and probably die. Instead, he was kept back, with other skilled new pilots, to help train yet more new recruits, the demand for training being so urgent. He was about to be sent to fight in the Far East, when Hiroshima and Nagasaki were, horrifically, nuked, and the war ended.

Like many of my generation and our descendants, we might never have been born.

Reg was my dad's name. He was not well-educated, being born in the 1920s into an ordinary working-class family in Chatham, Kent, UK, but he was an intelligent chap.

He must have had some instruction, when he was being taught to fly, on the principles by which aircraft work - how they get up into the air and how they can remain there. He understood that it was the shape of aircraft wings that increased air pressure under the wings as they moved forwards, as compared with the pressure over, that gave aircraft lift, and lifted them and stopped them falling.

Now as I said, he was not well educated. I had the luck to go to better schools where I learned, among other things, basic physics. They hadn't caught up with Einstein and his understanding of gravity, only about 50 years had passed, but Newton's inverse square law is still a good approximation in ordinary circumstances. The "force" of gravity "felt" between two masses depended on the masses themselves, and the distance between them.

Not for Reg. He had decided that air pressure differentials kept aircraft in the air (which is correct), so when there is less pressure below they fall, and this explains gravity.

Gravity is caused by air pressure. 

Which is incorrect.

Neither Newton nor Einstein would agree with it.

I didn't agree with it either. But could I convince him he was wrong? We had many discussions about this. They were always good-natured, but I did get frustrated that I could never put him straight about this. What about Galileo dropping different weights from the leaning tower of Pisa? (Most historians say this didn't happen. It was a "thought experiment", but he did time different-sized balls rolling down an inclined track because it was easier to time them.) What about a lead ball and a feather dropped inside a vacated bell-jar? 

Nothing convinced him. Gravity made no sense to him except as an effect of air pressure - air pressing down on things.

"What about on the Moon? There is no air. Yet gravity operates." "There must be air on the Moon", was his answer.

Then came Apollo 15. 

He was still not convinced. Nowadays, he might have been an Apollo mission denier, he clung to his conviction so tenaciously.

My point is that people who hold on to weird ideas despite the obvious evidence that they are wrong may do so for no better reason than they do not want to admit to themselves that they were mistaken. Dad had no ideological or religious reasons for his conviction. All our family members were all a-political and a-theistic. He was just badly taught by a sloppy instructor. But the bad lesson stuck, and there was no correcting it.

I often bear this in mind when I am talking to people who believe that Apollo was faked, that evolutionary science is a vast international inter-generational hoax designed just to fool real™ Christians, that the earth is flat, that vaccines contain microchips to subvert your powers of reason, that masks are a method of control (how, and what for)?, that Trump is not one of the nastiest pieces of work ever to walk the planet. The list is seemingly endless. The reason that these ideas are so fixed in peoples' minds can sometimes be simply that they are unprepared to own up to the reality that these ideas are, after all, nuts.