Re: So long, farewell, auf Wiedersehen, adieu

On 10 Sep 2008 08:12:54 GMT, jpd <read_the_sig@xxxxxxxxxxxxxxxxxxxxxx>
wrote:
On Tue, 09 Sep 2008 21:09:23 -0700,
Steve VanDevender <stevev@xxxxxxxxxxxxxxxxxxxxxxx> wrote:

[snippety!]
* _if_ they don't evaporate, they'd have event horizons smaller than
nucleons, making it rather difficult for them to suck in more than
about one subatomic particle at a time, so the time needed to accrete
enough mas to become a problem would be pretty large (i.e. millions to
billions of years)

Perhaps a slightly larger blackhole would be more suitable for the
following. I can't help but wonder how the concept popularly portrayed as
an inconceivably dense gobbler of everything named blackhole has a limit
on its uptake. How does that work and what would happen if one'd manage to
stuff mass several times its uptake capacity down its event horizon?

Take the earth and replace it with a black hole the mass of the earth.
Apart from being 1.48*10^-27 metres in diameter instead of 1.3*10^4 m
(around the event horizon), nothing much would change off earth. That
black hole would still orbit the sun, the moon would still orbit it. The
only thing that changes is that it gets a lot harder for the gods to score
a direct hit in their asteroid pool game.

Yes, any interplanetary matter getting within the radius of what used to
be the planet is gonna be affected, but it might not even be affected
enough to drop all the way into the hole. It would still grow, it would
just take until the moon dropped for it to gain any significant mass. And
the moon would probably have less tidal effects to worry about, due to the
lack of moving oceans under it, thus staying up longer.

A similar thing -- even without Hawking radiation -- applies to a black
hole massing a proton or two. It is *so* small that it can pass straight
through a plate of lead without even noticing anything other than a mild
haze in the utter vacuum -- if that.

Jasper
.

Relevant Pages

  • Re: Getting out of this world?
    ... Something that's consistent with the real world. ... it's not something the Earth "possesses". ... other mass, ... in all matter around it isn't a very dangerous 'black hole'. ...
    (rec.arts.sf.science)
  • Re: In what space is the Moon orbiting the Earth?
    ... Everybody knows that the Earth and the Moon are orbiting each ... which the equations of Newtonian mechanics hold good. ... And the coordinate system tied to the center of mass between the moon ...
    (sci.physics.relativity)
  • Re: Gravity of Newton, relativity, and falling space
    ... >> the Moon will also fall at the same speed. ... >> feather would not orbit the Earth as the Moon does. ... >> Let M be the mass of the Earth ... >> This is the acceleration of the object you measure on Earth. ...
    (sci.physics.relativity)
  • Re: Conservation of angular momentum
    ... :> The axis spinangularmomentumof the Moon alone is conserved. ... :> Much as the Moon keeps one face toward the Earth, ... Ok, but remember that velocity ... :> has a sign, mass does not. ...
    (sci.physics)
  • Re: Angular momentum considerations
    ... for the earth. ... I pointed out that if we assummed the Earh's mass grew ... R is the raidus of the lunar orbit and V is the ... velocity of the moon in its orbit. ...
    (sci.geo.geology)