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From: kevin@ecsvax.UUCP
Newsgroups: net.physics
Subject: Re: Hourglass Thought Experiment
Message-ID: <1334@ecsvax.UUCP>
Date: Mon, 3-Oct-83 20:51:38 EDT
Article-I.D.: ecsvax.1334
Posted: Mon Oct  3 20:51:38 1983
Date-Received: Fri, 7-Oct-83 02:06:34 EDT
Lines: 21




The following Thought Experiment was proposed by Keith Lofstrom (tekcad.62):

>  A weight scale with "infinite sensitivity", no memory, and no platform
>  deflection.
>  An hourglass with "infinitesimal" sand inside.
>
>  Set the hourglass on the scale with the sand in the upper chamber.
>  What does the scale read as a function of time?  How will the changing
>  behavior of the stream of sand change the apparent weight?

As for the first question, the weight will increase with as a function of
time.  The increase is justified by the fact that objects at higher altitudes
weight less then objects a low elevations.  The change may be small but then
the scale is "infinitely sensitive."

The second part of the question I think was answered by Lew Mammel, Jr.
(ihuxr.679).  In his article he stated, that the falling mass would
exert a small force on the bottom of the Hourglass.