Re: Naive User Stories

"Tristan Miller" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Greetings.
>
> In article <[EMAIL PROTECTED]> on rec.humor.funny.reruns, Bluegrass
> For Breakfast wrote:
> > A Computer Operator says as she is lifting an RP06 disk pack from the
> > drive:  "Gee, how much does one of these weigh?"
> >
> > Me:  "It depends on how much data is on the disk....
> >
> > The operator believed it.
>
> This joke is funny because writing data to a magnetic disk obviously won't
> result in any macroscopically observable changes in the disk's weight.
> But, as someone quite ignorant of electromagnetics, I wonder whether it
> might not be true that the weight of the disk would fluctuate on a (very)
> minute level.  The earth presumably has some sort of magnetic charge, and
> so does the computer disk.  By altering the charge on the disk via data
> writing operations, is it not possible that the nature of the interaction
> of the magnetic fields of the disk and the earth will be very slightly
> changed so that they are either more strongly attracted or repelled?  And
> assuming one had an extremely precise spring scale, would it not be
> possible to measure the intensity of this change?  If so, what might be an
> upper bound on the difference in weight between a "empty" (say, all bits
0)
> and "full" (all bits 1) MS-DOS-formatted 1.44MB 3.5" floppy disk?
>
none.  there is no magnetic charge (at least that has been detected to date)
so for every north pole on the disk there is an equal and opposite south
one.  this results in no net field to interact with the earth's field.