Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Physical mythology



Ludwik wrote:

Chuck Britton wrote:

A fairly common misconception is that 'most' of the charge will
collect on the more sharply curved surface, (needle tip). A closer
analysis will indeed show that the charge DENSITY is quite large on
the highly curved surface, but the small area involved does NOT lead
to a preponderance of charge being on the tip. .....

If this misconception is common, as it was in my case, then it is fair
to ask about its origin. We can certainly not blame Aristotle for it. Neither
it comes to us with everyday language. Why is it so common?

I can't illuminate the origin of this particular myth, but it is now
common because it was common a generation ago. Myths are false ideas
that propagate well.

In the middle of the eighteenth century there was a great debate over
the relative merits of lightning rods tipped with balls and with sharp
points. Ben Franklin, arguably the second greatest American physicist
of all time, believed points were more effective, and other American
colonial scientists took his part. The Royal Society, on the other
hand, actually *voted* and took a position that ball-tipped rods were
superior. (The idea of establishing matters of fact democratically is
older than you thought, perhaps?) The matter of defending one of these
positions or the other became a touchstone of patriotism; it was the
end of scientific objectivism on that topic.*

Now you may be saying to yourself "Why is he telling us this story?
What does it have to do with mythology?" Well, tell me, which kind of
lightning rod do you think is superior? What informed your opinion on
this topic, and at what age did you first learn the correct answer?
The inquiring mind wants to know.

Leigh

* This piece of history is treated at some length in "The Flight of
Thunderbolts" by B. J. F. Schonland.