Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Radius of Gyration

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Re: Radius of Gyration

The question was not what it meant.
The question was on the origin of the term.
It's pointless.
The English language is full examples where it is fruitless trying to explain why something is called what it's called.
For me it was enough to really UNDERSTAND what it meant  in contrast to merely knowing how to define or calculate it.
Yes everyone knows that its calculated by taking the squre root of the result of dividing the Moment of Inertia by the area of the section.

I used to UNDERSTAND radius of gyration as a measure that tells me how far AWAY from the center of gravity of the section the material is distributed or scattered. I would keep reminding myself that the solid circular section would have a small radius of gyration while a tube of the same cross sectional area would have a very large radius of gyration. I could instinctively feel that the more the radius of gyration, the  less the chances of buckling.

Coming to the question of why its called radius of gyration, I suppose there may be no really satisfactory  answer.
I found this an opportune moment to dig out some amusing stuff from my collection and present it here. Some of you may have read this before but I hope you will enjoy reading this again.
I don't remember where I got it from or who wrote it orginally.
But it was fun to read then, fun to read again now and even greater fun to share it with all of you.
Bangalore, India
Let's face it -- English is a crazy language. There is no egg in
eggplant nor ham in hamburger; neither apple nor pine in
English muffins weren't invented in England or French fries in
France. Sweetmeats are candies while sweetbreads, which aren't
sweet, are meat.
We take English for granted. But if we explore its paradoxes, we
find that quicksand can work slowly, boxing rings are square and
a guinea pig is neither from Guinea nor is it a pig.
And why is it that writers write but fingers don't fing, grocers
don't grocer and hammers don't ham? If the plural of tooth is
teeth, why isn't the plural of booth beeth? One goose, 2 geese.
So one moose, 2 meese? One index, 2 indices?
Doesn't it seem crazy that you can make amends but not one
amend, that you comb through annals of history but not a single
If you have a bunch of odds and ends and get rid of all but one
of them, what do you call it?
If teachers taught, why didn't preacher praught? If a vegetarian
eats vegetables, what does a humanitarian eat? If you wrote a
letter, perhaps you bote your tongue?
In what language do people recite at a play and play at a
recital? Ship by truck and send cargo by ship? Have noses that
run and feet that smell? Park on driveways and drive on
How can a slim chance and a fat chance be the same, while a wise
man and wise guy are opposites? How can overlook and oversee be
opposites, while quite a lot and quite a few are alike?
How can the weather be hot as hell one day and cold as hell
Have you noticed that we talk about certain things only when
they are absent?
Have you ever seen a horseful carriage or a strapful gown? Met a
sung hero or experienced requited love? Have you ever run into
someone who was combobulated, gruntled, ruly or peccable? And
where are all those people who ARE spring chickens or who would
ACTUALLY hurt a fly?
You have to marvel at the unique lunacy of a language in which
your house can burn up as it burns down, in which you fill in a
form by filling it out and in which an alarm clock goes off by
going on.
English was invented by people, not computers, and it reflects
the creativity of the human race (which, of course, isn't a race
at all).
That is why, when the stars are out, they are visible,
but when the lights are out, they are invisible.
And why, when I wind up my watch, I start it, but when I wind up
this essay, I end it.