Accretion disks

what exactly is an accretion disk?i have read over 15 definitions and
still dont know what it means.

"Sam Wormley" wrote in message
news:aizph.346787$1i1.126881@attbi_s72...
Sitav wrote:
what exactly is an accretion disk?i have read over 15 definitions and
still dont know what it means.


This is a pretty good overview
http://en.wikipedia.org/wiki/Accretion_disk

Even though the details of an accretion disks are complex, the
general idea is pretty simple...

Angular Momentum--how much rotation or spin an object or collection
of objects such as a gas has--is conserved in nature. So stuff falling
into or onto a gravitational source (star, white dwarf, neutron star,
black hole... or even water down a drain) spins up forming an accretion
disk (vortex in the case of water down the drain).

Within the accretion disk temperatures tend to rise due to friction
and other complications.

Give it up , he isn't listening to ya Sammy.