Re: Black Holes and tidal forces

[Jack Uretsky <jlu@HEP.ANL.GOV>]

I don't understand the context of the question.  Where did you find anyone
doing "Newton's laws of gravitation" ?

The issue, as I understood it, was how do you give your cocktail party
companion a feel for the meaning of "gradient" without actually using the
term?

On Tue, 27 Nov 2001, Kossom wrote:

> To a first approximation, is it legitmate to just do Newton's Law of
> Universal Gravitation for two points with a change in r of about two meters?
>
> I have often found that just playing with some numbers, especially on a
> spreadsheet can help students get a feel for the algebraic expression. I
> have done a related exercise measuring the difference in centripetal force
> between two points on a proposed space station to argue that space stations
> need to be pretty big not to have a steep centripetal force gradient.
>
> Marc "Zeke" Kossover
> (who still translates "grad" to graduate student even after many years in
> physics.)
>
> -----Original Message-----
> From: Jack Uretsky
> To: PHYS-L@lists.nau.edu
> Sent: 11/27/01 6:29 PM
> Subject: Re: Black Holes and tidal forces
>
>         1.  Yes, of course.  So don't use the word "gradient" in polite
> company.
>         2. Say something like: "gravity is pulling a lot harder on your
> feet (if you're falling feet first) than it is on your head, so pretty
> soon you get like stretched way out of shape."

--
"But as much as I love and respect you, I will beat you and I will kill
you, because that is what I must do.  Tonight it is only you and me, fish.
It is your strength against my intelligence.  It is a veritable potpourri
of metaphor, every nuance of which is fraught with meaning."
                     Greg Nagan from "The Old Man and the Sea" in
                     <The 5-MINUTE ILIAD and Other Classics>