Re: No Hair

[roger haar <haar@soliton.physics.arizona.edu>]

Hi,

	I think that fundamentally, most of the characteristics of 
whatever is inside the black hole are hidden from the outside observer
except for mass, charge, and angular momentum.

	From Misner, Thorne and Wheeler's book, "Gravitation" Freeman 1970,
p 876, first paragraph:

	The following theorems come close to proving that the external 
	gravitational and electromagnetic fields of a stationary black
	hole (a black hole that has settled down into its "final" state) 
	are determined uniquely by the hole's mass M, charge Q and 
	angular momentum S -- i.e., the black hole can have no "hair" (no 
	other independant characteristics). 


	I suspect that in the last 25 years lots of work has been done 
on this topic, so something made have been added to the list of what
characteristics that define a black hole.  I know the entropy of a 
black hole is a hot topic.  I also recall something that implied that the 
hair analogy had split into "short hair" and "long hair" (I think there 
was a Physical Review Letter titled " A Black Hole Has No Short Hair" 
about 4 years ago).

Thanks
Roger Haar
U of AZ

*********************************************************************
On Tue, 22 Jul 1997, Jim Green wrote:

> What does the list suppose Hawking means when he says that a "black hole has
> no hair"?
>
>
> Jim Green
> JMGreen@sisna.com
>