Dark Energy Stars

[Nethius]

I came across an article regarding black holes, and how they don't exist. And that they are actually Dark Energy Stars.

http://www.nature.com/news/2005/0503...0328-8_pf.html

How well accepted is Dark Energy?

Quoting one paragraph...

This strange behaviour, he says, is the signature of a 'quantum phase transition' of space-time. Chapline argues that a star doesn't simply collapse to form a black hole; instead, the space-time inside it becomes filled with dark energy and this has some intriguing gravitational effects.

I'm confused to how exactly they would propose this actually happening?

Anyone have any insight on this?



edit - couple spelling mistakes

[Eta C]

Well, first off, I would caution you, and anyone else, from coming to conclusions about the validity of any scientific theory based on a popular article, even one from a journal like Nature. I can't begin to count the number of times general relativity, big bang cosmology, and other theories have been pronounced "dead" in such releases. Yet the theories are still here. Rumors of their death have been "greatly exaggerated" to paraphrase Twain.

Second, this is one physicist's interpretation. It is highly speculative and has yet to be fully developed or tested against observation. It represents an attempt to explain the existence of black holes through dark energy rather than as a gravitational effect. I might add that dark energy itself is rather speculative. The theories that describe it are in their infancy and there are many competing concepts. The whole idea of dark energy might be abandoned (personally, I don't think so, but it is a possibility) and Chapline's idea would go out with it.

Finally, this article contains two of my pet peeves. First, it uses a sensationalistic headline "Black holes do not exist" as if this were a done deal and all research into black holes and GR has ceased. This is far from the truth. A bettter headline would be "Physicist proposes theory in which black holes may be a manifestation of dark energy." More accurate, but less punchy.

Second, we have the obligatory "Einstein didn't belive in black holes" line that would seem to indicate that black holes should be regarded as suspect. This would only be true if everything Einstein believed about his theories is still relevant. While we should honor him for developing an extremely robust and elegant theory, Einstein's opinions about what his theory meant and what he considered valid are largely meaningless today. There's been a lot of work on GR and cosmology over the 60 years since Einstein died and while what he thought about should be considered, it is by no means the final word. After all, science isn't a religion and we don't have to take every utterance of Einstein as infallible, inerrant gospel. We certainly don't treat the musings of Maxwell, Bohr, Schroedinger, or even Pauli ( 8) ) in this way. Why should Einstein be any different.

[Cougar]

Chapline's claim that black holes don't exist and they're really "dark energy stars" is accepted by very few - perhaps only him.

Dark energy as some unknown "force" permeating space (and causing the expansion to accelerate) is fairly broadly accepted due to the confirming observations of distant type Ia supernova by two major investigative groups.

[Nethius]

Thanks for the replies!

Yea I'm basically taking this article with a grain of salt. I'm just interested in any theories out there, and trying to better understand this one.

Any more input greatly welcome!

[publiusr]

I'll keep an open mind. I do believe in black Holes-- (though Archibald Wheeler still thinks there is a bit of material left--a sand grain monobock as it were).

But there could be black suns out there too perhaps.

[Gullible Jones]

Don't believe in anything...

[genebujold]

First of all, one quote from the site is wrong: "The theory suggests that a sufficiently massive star, when it dies, will collapse under its own gravity to a single point."

Not true. We know that even black holes have an upward density limit, essentially all space between all subatomic particles (quite a lot) removed. Something like a teaspoon of black hole would weigh as much as the Earth. But not a point.

Secondly, the event horizon is simply the point where the gravitation pull exceeds the escape velocity of light, and the black hole doesn't become "black" until the event horizon exists at all points surrounding the black hole at a distance greater than the distance to the surface of the compressed matter.

Third, we know that an event horizon will fluctuate, allowing some radiation to escape. Hawking's theories provided the initial push in this direction, and the math was confirmed elsewhere. Thus, if a black hole of any size doesn't have enough matter to feed it, it will continue to radiate and eventually cease to be a black hole.

[Andreas]

First of all, one quote from the site is wrong: "The theory suggests that a sufficiently massive star, when it dies, will collapse under its own gravity to a single point."

Not true. We know that even black holes have an upward density limit, essentially all space between all subatomic particles (quite a lot) removed. Something like a teaspoon of black hole would weigh as much as the Earth. But not a point.

I don't think that "we know" that. By which theory are you reasoning? In GR a singularity arises from the density becoming infinite. If you use the standard model and remove all space between particles it still results in a zero dimensional point because all elementary particles are zero dimensional points. I'm not saying that that would be valid reasoning in any case, as keeping the particles in one point isn't possible.

The problem with keeping the particles intact and having a density limit, as I see it, is that it requires particles to travel faster than light. The particles can only travel towards the center otherwise and would not be able to keep an equilibrium with some sort of counter-collapse force.

Thing is, without a theory of quantum gravity we have no valid description of the essence of a black hole. Given that we don't have a working theory of that kind yet, and that the theories being worked on (like string theory) have rather more exotic possibilities for black holes than "remove all space between particles" - we really don't "know" what you claim.

[Gullible Jones]

First of all, one quote from the site is wrong: "The theory suggests that a sufficiently massive star, when it dies, will collapse under its own gravity to a single point."

Not true. We know that even black holes have an upward density limit, essentially all space between all subatomic particles (quite a lot) removed. Something like a teaspoon of black hole would weigh as much as the Earth. But not a point.

No... A ring, because you'll have a lot of trouble finding a black hole that doesn't spin. That aside, I think you're confusing black holes with neutron stars.

[genebujold]

Thanks for the clarifications!

[publiusr]

Don't believe in anything...

I believe in math--I see where you're going though.