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Los Alamos National Laboratory

Contact:
James Rickman, [email]elvis@lanl.gov[/email], (505) 665-9203

02-035

Los Alamos researcher says 'black holes' aren't holes at all

LOS ALAMOS, N.M., April 21, 2002 -- Researchers from the U.S. Department
of Energy's Los Alamos National Laboratory and the University of South
Carolina have provided a hypothesis that "black holes" in space are not
holes at all, but instead are more akin to bubbles.

Researcher Emil Mottola of Los Alamos' Theoretical Division today
presented a new explanation for black holes at the American Physical
Society annual meeting in Albuquerque, N.M. Pawel Mazur of the
University of South Carolina is Mottola's co-author. The researchers'
explanation redefines black holes not as "holes" in space where matter
and light inexplicably disappear into another dimension, but rather as
spherical voids surrounded by an extremely durable form of matter never
before experienced on Earth. Mazur and Mottola call the extraordinary
objects Gravastars.

The Gravastar explanation for black holes helps provide answers to some
of the daunting questions raised by traditional black-hole descriptions.
Based on earlier-held astrophysical explanations, black holes form in
space when stars reach the end of their lives and collapse in on
themselves. According to black hole theory, the matter from these dying
stars occupies a tiny amount of space -- a mere pinpoint -- and creates
a mind-boggling gravitational field so powerful that nothing can escape,
not even light.

Mottola and Pawel suggest that while some degree of collapsing does
take place in a dying star, the collapse proceeds only to a certain
point. At that point, the intense gravity of the dying star transforms
the star's matter into an entirely new phase. Mottolla describes this
phase as similar to a Bose-Einstein condensate, a phase of matter
recently observed in a laboratory setting and the subject of
scientific excitement in the past few years.

On Earth, a Bose-Einstein condensate forms when matter is plunged to
very low temperatures approaching Absolute Zero, the theoretical
temperature at which all atomic motion -- the motion of electrons,
protons and all other subatomic particles within an individual
atom -- is believed to cease. When matter is cooled sufficiently to
become a Bose-Einstein condensate, the atoms that make up the matter
enter a strange new phase. The atoms all reach the same energy state,
or quantum state, and they coalesce into a blob of material called a
"super atom." The properties of Bose-Einstein condensates are the
subject of intense study and many physicists are working to
understand them.

Mottola and Mazur believe that dying stars collapse to the "Event
Horizon" -- in essence the point of no return for objects entering
the gravitational field of a black hole. At this point, the matter
in the dying star transforms to a new state of matter that forms a
Gravastar. According to the two researchers, the dying star's matter
creates an ultra-thin, ultra-cold, ultra-dark shell of material that
is virtually indestructible. The new form of gravitational energy in
the interior is akin to a Bose-Einstien condensate, although it
appears on the inside to be a bubble of vacuum, hence the term Gra
(vitational) Va (cuum) Star, or Gravastar.

"Since this new form of matter is very durable, but somewhat flexible,
like a bubble, anything that became trapped by its intense gravity
and smashed into it would be obliterated and then assimilated into
the shell of the Gravastar," Mottola said. "However, any matter in
the vicinity that fell onto the surface could be re-emitted as another
form of energy, which would make Gravastars potentially much more
powerful emitters of radiation than black holes, which simply swallow
the material."

The space trapped inside the Gravastar's shell is a similarly uncanny
conceptually. The interior of the Gravastar would be totally warped
space-time (the traditional three dimensions plus time). According
to the researchers, this interior space would exert an outward force
on the shell, adding to its durability.

Although unconventional, Mottola and Mazur's Gravastar explanation
for black holes does solve at least one serious quandary created by
black hole theory. Under a black-hole scenario, the amount of entropy
created in a black hole would become nearly infinite. Physicists have
struggled for years to account for the huge entropy of black holes,
and largely have failed. Unlike their black hole counterparts,
Gravastars would have a very low entropy.

Mottola and Mazur continue to refine their theory and are working on
a concept behind rotating Gravastars. They even suggest that the
universe we now know and live in may be the interior of a Gravastar.

"These are fascinating concepts to think about," Mottola said. "I
look forward to exploring this hypothesis further."

Los Alamos National Laboratory is operated by the University of
California for the U.S. Department of Energy.

[i]Mottola and Mazur continue to refine their theory and are working on
a concept behind rotating Gravastars. They even suggest that the
universe we now know and live in may be the interior of a Gravastar.[/i]

Would this not indicate that there must be other Gravastars (universes)? Would this not also indicate that outside each Gravastar, including our own, is matter, and not the unknown void in which the universe is thought to be expanding? If the "shell" of the Gravastar is expanding outwards, would it not eventually lose its cohesion and collapse? What of the 'flat' universe model?

Why haven't other Gravastars (universes) already collided with ours? Are they that far apart from one another that collisions never occur? Or is it such that the Big Bang was a collision between two or more Gravastars?

So many questions.