I've got a "theory" about these nut cases. They are often intelligent, or even very intelligent, people in technical matters. In technical matters, such as engineering or mechanics, they can see for themselves the direct consequences of adopting a false or misleading idea. And it matters to them to get such matters right, if that's their line of work, or if that's a deeply felt interest of theirs. But once they depart from whatever technical area is their deeply felt interest, or on which their livelihood depends, they are out of their water. For some reason, they don't apply the same rules of evidence to UFOs, etc that they do to fixing an automobile.
In other words, they are realists when it comes to something on which their self-interests hang, but cranks on other things.
I don't think that explains all the cranks I know, but it sure describes some of them.
In other words, they are realists when it comes to something on which their self-interests hang, but cranks on other things.
I don't think that explains all the cranks I know, but it sure describes some of them.