Re: Negative Gravity

From: Sarah Lawrence (
Date: Wed Feb 09 2000 - 06:43:21 MST

At 9:11 pm -0800 on 26/1/00,

OK, so I'm a little behind. How do you all keep up with this
(wonderful) list?

phil osborn wrote:

>Scientific American just ran a little piece relating the fact that the mass
>of the Earth is less than the sum of its parts - by the amount of the
>gravitational binding energy - i.e., the potential energy lost as the parts
>came together to form it, which they put in the trillions of tons magnitude.
>It occurred to me to consider how this might play re a black hole. If the
>gravitational binding energy were actually larger than the relativistic
>mass, as is almost certainly so anywhere below the event horizon, else light
>or high energy particles could escape and the event horizon wouldn't be,
>then each additional item of mass coming in would actually reduce the total
>mass of the black hole. But this appears to make the black hole itself
>So, my physics degree some thirty-one years old and largely unused, will
>someone tell me what is wrong with my scenario, please. ;>

Yes. Energy *is* conserved. It sounds as though you have not quite
taken that into account.

   Sarah | The Fabric of Reality list -- epistemology,
Lawrence | quantum theory, evolution, and computation
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