10 May
2016
10 May
'16
12:39 p.m.
My father is a civil engineer. When I was a little
kid, he was in the US Air Force. We would frequently
go to the runway snack bar, get ice cream and watch
the B-52s do "touch-and-go" landing practice. The
plane's wings would "flap". It raised the hair on
the back of my neck. My dad explained that, if they
didn't flex, the wings would break off. After a
while, I understood, intellectually. It still "gave
me the willies". Later I had a similar experience
when I was with him in a tall building and realized
that it was "waving in the wind". Same thing, if it
didn't flex, it would fall.
That reminds me of the following joke :
There is an airline passenger. During some particularly
turbulent conditions he looks out the window and sees
the plane's wings flexing. He looks very worried.
The flight attendant comes over to him and tries to
comfort him by saying
'Our pilots are fully trained to fly in conditions like
this. It's only turbulence, it's quite normal'
He replies
'You don't undertand. I work for Boeing. I am one
of the men who designed this aircraft. The wings
are not supposed to flex like that.'
The other is
that, as I said before, any ground
connection has impedance (it's the inductance that
is troublesome normally) so that points (say IC pins)
that are shown as grounded may actually have a
voltage difference between them.
If I think about it too much, this gives me the
willies, the same way.