Black Holes No More -- Introducing the Gravastar

Mark Eymer observes: "From the Space.com article: 'Emil Mottola of the Los Alamos National Laboratory and Pawel Mazur of the University of South Carolina suggest that instead of a star collapsing into a pinpoint of space with virtually infinite gravity, its matter is transformed into a spherical void surrounded by "an extremely durable form of matter never before experienced on Earth."' While these objects may abound in the universe, they also say that our entire universe may reside within a giant gravastar." This new theory attempts to fill holes in the currently accepted concept of the "black hole".

Comments

So the real question is....

[Alan]

So what's on the outside of this giant gravstar we're in? :)

Re:It's turtles all the way down!

[pr0t0]

Memory fading, but I'll be close...

The title comes from the retelling of a story in Carl Sagan's Broca's Brain where a 17th century philosopher/physicist (which one I can't remember) is giving a lecture on how the Earth moves in the Solar System, floating in space. A woman stands and claims the theory is ridiculous. She states everyone knows that the Earth rests on the back of a giant turtle. To which the scientist asks, "Well then, what is the turtle resting on?"

Her reply? "Very clever young man, but it's turtles all the way down!"

It's a great book.

Sig: I'm sorry but your opinion seems to be wrong.

Re:ah....

[Fishstick]

...and each gravastar holds an entire universe which holds a finite number of gravastars each containing yet another universe and so on...

kind of like the russian dolls metaphor, eh?

Question: why would we assume that there is ever an outermost gravistar that holds the universe and then ... nothing? Wouldn't it be easier on the limited human intellect to just assume that the gravistar->universe->gravistar-> encapsulation is infinite in each direction?

Reminds me of Farnsworth's "universe in a box" experiment where each universe held a number of boxes each leading to a parallel universe in which Farnsworth had created a number of boxes which each holding a parallel universe ....

"Good news, everyone..."

Ow, my brain has just been subjected to a paralyzing blow -- think I'll take the rest of the day off and drink vodka tonics until the throbbing goes away. ;-)

if we're in a gravastar...

[fudgefactor7]

...then how do they explain that our universe seems to be accellerating in its expansion? Unless all the matter and gravitational forces are centered on the "shell" of the bubble...which seems to defy all current theories. Should not the bubble collapse inward upon itself as each section of the shell pulls on opposing sections?

The gravastar seems more weird than a generally accepted black hole.

The "other side of" the same gravistar.

[Ungrounded Lightning]

So what's on the outside of this giant gravstar we're in? :)

The "other side" of the same gravistar.

It's like "what's beyond the north pole" on a sphere.

On the surface of a sphere there is no "beyond the edge". Inside a kliensphere there is no "beyond the rim", because there is no rim.

Imagine the space in the universe is the 2-D surface of the water hanging from a dripping faucet. You're on the new-forming drip. Then the drip comes lose. The surface you're on closes into the surface of the drop. In 2-D there IS no beyond - you need an extra dimension for that.

Now consider a dripping faucet in 4-space, where the "surface" of the 4-D drop is the 3-D space of our universe.