Parallel Transport - a metaphor for how people change their minds

 


How do we change our minds?  We like to think we're reasonable people - that we listen to the argument and if it is good enough we change our minds!  According to Carl Sagan that barely ever happens outside of science:

"In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion."

-- Carl Sagan, 1987 CSICOP keynote address


So what about the rest of the world?  People do change their minds, so how do they go about it?  It occurred to me that a good metaphor for the mechanism is a concept from general relativity.  The concept is Parallel Transport and the animation above illustrates the point (source here).  On a curved surface if you start off pointing one way and then go on a long journey around a closed path, when you get back to where you started you find you are now pointing the other way!  There was no moment at which you changed the direction you were facing, and the change of orientation isn't noticeable over a short journey.  On some surfaces the journey needed to change direction by 180 degrees is so large we forget that we started off looking at the world the other way.

 

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