Introductory notes
A black hole is an infinitely dense region that contains the mass of
millions or billions of Suns and from which no light can escape
Probably each elliptical galaxy, the largest in the cosmos, contains a
supermassive black hole when about 3.5 billion years old - these are called
high-energy quasars
The biggest black hole discovered as of 2009 weighs 18 billion suns and
is about the size of an entire galaxy
The event horizon is the sphere around a black hole within which nothing
can escape because all light and info is pulled in and because nothing can
go quicker than the speed of light, the event horizon can also be seen as
the edge of the universe. The universe looks like a kind of Swiss cheese.
'The properties of time and space are reversed'
Celestial bodies can orbit around a black hole as long as they are
outside the event horizon. The mass is still there.
The heaviest black hole observed in 2008 was 3 billion x sun mass, which
is about the mass of an ordinary galaxy = supermassive black holes
An ordinary black hole has about the mass of 10 suns
Light cannot escape a black hole because it loses energy trying to
escape, just like light that moves away from a heavy object loses energy
because it red-shifts to lower frequencies of life.
It isn't clear where the super-massive black holes at the centers of
galaxies came from. They have a mass of billions of suns. It may be that at
the beginning of the cosmos there existed super-massive stars whose collapse
caused the super-massive black holes.
Black holes don't have a surface but neutron stars do. This means that
all gas that approaches a black hole gets sucked in and doesn't radiate
light while neutron stars emit light when this happens.
External links
News articles
- Newest at top
- A Supermassive Black Hole Was Ejected Out Of Its Home Galaxy "One of the most fascinating – and potentially terrifying – things about this discovery is that it implies that there may be supermassive black holes moving through the universe outside of galaxies. And we currently have no way of knowing that they’re there." - Forbes - June 5, 2012
- New Model May Show How Black Holes Become Supermassive "Almost every galaxy has an enormously massive black hole in its centre. Our own galaxy, the Milky Way, has one about four million times heavier than the sun. But some galaxies have black holes a thousand times heavier still. We know they grew very quickly after the Big Bang. These hugely massive black holes were already full-grown when the universe was very young, less than a tenth of its present age." - Forbes - March 26, 2012
- The Smallest Known Black Hole Has 20 Million Mile Per Hour Winds - Forbes - Febr. 22, 2012