Re: Star chime could reveal small black holes



On Sep 14, 8:29 am, bert <herbertglazie...@xxxxxxx> wrote:
On Sep 12, 5:06 pm, Sam Wormley <sworml...@xxxxxxxxx> wrote:









Star chime could reveal small black holes
   http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.107.111101

"In theory, black holes come in all sizes, not just the star- and
galaxy-scale objects that astronomers have already seen. In particular,
smaller “primordial” black holes might have formed from density
fluctuations in the first seconds after the big bang. In addition to
providing a window into the universe in its earliest moments, these
remnants could be the cold dark matter that makes up about a quarter of
its present mass.

"Previous observations rule out abundant black holes smaller than 10^-16
or larger than 10^-7 times the mass of the sun, but intermediate sizes
could still account for cold dark matter. In Physical Review Letters,
Michael Kesden at New York University and Shravan Hanasoge at Princeton
University, New Jersey, propose that these medium-sized black holes
could be detected when they pass through a star. Although the black hole
will hardly be affected, it will leave lingering acoustic vibrations in
the star, analogous to the ringing of a bell".

See:http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.107.111101

If you cut a black hole in three pieces would you have 3 black
holes,or 3 neutron stars?   TreBert

It's impossible to cut a singularity -- a zero-dimensional object --
into pieces.

If somehow it were possible to do that, it would be impossible to
separate the pieces into three separate black holes. If it were
possible, then the original was not a black hole.

A black hole can never turn back into a neutron star. It can,
however, explode.
.